MESSENGER Nears Mercury
Release Date: January 13, 2008



With just one day until MESSENGER's historic flyby of Mercury, MESSENGER has Mercury clearly in its sights. The Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS), took this image on January 12, 2008, when MESSENGER was about 1.2 million kilometers (750,000 miles) away from Mercury. Mercury has a diameter of about 4880 kilometers (3030 miles), and this image has a resolution of about 31 kilometers/pixel (19 miles/pixel).

Tomorrow, Monday, January 14, 2008, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will pass a mere 200 kilometers (124 miles) above the surface of Mercury and will be the first spacecraft to visit Mercury in nearly a third of a century, since Mariner 10 flew by Mercury in 1974 and 1975. Among the extensive scientific observations planned during the flyby is imaging a large portion of Mercury's surface that was not visible to the Mariner 10 mission. MESSENGER's flyby tomorrow will yield the first spacecraft images ever of these regions of Mercury's surface.

Image acquired on January 12, 2008, 09:06 UTC.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington


Source: JHUAPL - MESSENGER - Gallery

MESSENGER Mission News
January 14, 2008
_http://messenger.jhuapl.edu

Today MESSENGER Flies by Mercury!

Today, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will fly 200 kilometers (124 miles) above Mercury’s surface. As the spacecraft continues to speed toward the planet, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury. The image was taken on January 13, when the spacecraft was about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4,880 kilometers (about 3,030 miles) in diameter, and the smallest feature visible in this image is about 20 kilometers (12 miles) across.

During the historic encounter today, extensive scientific data will be gathered. The MDIS cameras will acquire more than 1,200 images of Mercury, including images of portions of the surface never before viewed by a spacecraft. The Mercury Atmospheric and Surface Composition Spectrometer will observe Mercury's surface as well as its tenuous atmosphere. The Magnetometer will accurately measure Mercury's magnetic field, and the Energetic Particle and Plasma Spectrometer will characterize Mercury's space environment and interactions with the solar wind. The Mercury Laser Altimeter will sense surface topography along a narrow profile. The Gamma-Ray and Neutron Spectrometer and X-Ray Spectrometer will make the first measurements of Mercury’s surface elemental composition.

MESSENGER will begin to transmit the new data to Earth once all of the scientific measurements are completed, about 22 hours after the spacecraft's closest approach to Mercury. These flyby data will shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury. As scientists analyze the data, the MESSENGER spacecraft will continue on its planned journey, which includes two more encounters of Mercury in October 2008 and September 2009, before entering an orbit around Mercury in March 2011.

Additional information and features from this first flyby will be available online at http://messenger.jhuapl.edu/mer_flyby1.html, so check back frequently. Following the flyby, be sure to check for the latest released images and science results!


MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Source: JHUAPL - MESSENGER - Status Report

Countdown to MESSENGER's Closest Approach with Mercury
Release Date: January 14, 2008



Today, January 14, 2008, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will experience its closest approach to Mercury, passing just 200 kilometers (124 miles) above the planet's surface. As the MESSENGER spacecraft continues to speed toward Mercury, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury. The image was taken on January 13, 2008, when the spacecraft was at a distance of about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4880 kilometers (about 3030 miles) in diameter, and this image has a resolution of about 20 kilometers/pixel (12 miles/pixel).

During the historic flyby encounter today, extensive scientific data will be gathered. The MDIS instrument will acquire over 1200 images of Mercury, including images of portions of the surface never before viewed by a spacecraft. The MDIS instrument is just one member of a whole suite of instruments that will be used to study Mercury during the flyby. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) will observe Mercury's surface as well as its tenuous atmosphere. The MESSENGER Magnetometer (MAG) will accurately measure Mercury's magnetic field, and the Energetic Particle and Plasma Spectrometer (EPPS) will characterize Mercury's space environment and interactions with the solar wind. The Mercury Laser Altimeter (MLA) will sense surface topography along a narrow profile. The Gamma-Ray and Neutron Spectrometer (GRNS) and X-Ray Spectrometer (XRS) will make the first measurements of Mercury’s surface elemental composition.

MESSENGER will begin to transmit the new data to Earth once all of the scientific measurements are completed, about 22 hours after the spacecraft's closest approach to Mercury. These flyby data will shed light on fundamental scientific questions related to the formation and evolution of the planet Mercury. As scientists analyze the data, the MESSENGER spacecraft will continue on its planned journey, which includes two more encounters of Mercury in October 2008 and September 2009, before entering an orbit around Mercury in March 2011.

Image acquired on January 13, 2008, 06:34 UTC.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington



Source: JHUAPL - MESSENGER - Gallery

MESSENGER Mission News
January 14, 2008
_http://messenger.jhuapl.edu

MESSENGER Flyby of Mercury

At 2:04 p.m. EST MESSENGER skimmed 200 kilometers (124 miles) above the surface of Mercury in the first of three flybys of the planet. Initial indications from the radio signals indicate the spacecraft is still operating nominally. The first science data return from the flyby was received today, just minutes before the closest approach point with the planet, as planned.

“The engineers and operators at the Deep Space Network (DSN) in Goldstone, Calif., in conjunction with engineers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., pulled off a tremendous feat, acquiring and locking onto the downlink signal from the spacecraft within seconds, providing the necessary Doppler measurements for the Radio Science team” said MESSENGER Mission Systems Engineer Eric Finnegan, of APL.“ The spacecraft is continuing to collect imagery and other scientific measurements from the planet as we now depart Mercury from the illuminated side, documenting for the first time the previously unseen surface of the planet.”

Tomorrow at noon EST, the spacecraft will turn back towards the Earth to start down-linking the on-board stored data. Measurements of this Doppler signal from the spacecraft will allow improve knowledge of Mercury’s gravity field.


Keeping a Rendezvous with Mercury

Between January 9 and 13, 2008, as the MESSENGER probe approached Mercury for its first flyby, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS), acquired a series of images of the planet in support of spacecraft navigation. These images have been put together as frames in a movie. The final frame of the movie has the highest spatial resolution (20 km/pixel, 12 miles/pixel) and was recorded when the spacecraft was at a distance of about 760,000 kilometers (470,000 miles) from Mercury. Mercury is about 4.880 kilometers (about 3,030 miles) in diameter.

As part of MESSENGER's flyby on January 14, MDIS will obtain high-resolution image sequences with the Narrow Angle Camera, and the Wide Angle Camera will collect images in eleven colors. The images will cover portions of the planet never before seen by spacecraft, as well as regions that were photographed by Mariner 10 in 1974 and 1975. The new data for the previously studied areas of Mercury will help scientists to interpret the data for the parts of the planet that MESSENGER will reveal for the first time.

Additional information and features from this first flyby can be viewed online at _http://messenger.jhuapl.edu/mer_flyby1.html. The latest released images and science results from the flyby will be posted as they become available



MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Source: JHUAPL - MESSENGER - Status Report

Can't wait for the downlinks...!

A phenomenal accomplishment....

Phenomenal indeed. Imagine the pictures.... "It's like taking a 2008 Jaguar and comparing it to a six-year-old's toy bike," Stern said of the improvements since Mariner 10.





I just love this stuff.

Yea...it reminds me of the feeling I had watching Huygens land on Titan, and those amazing shots...absolutely awesome stuff, and a testimony to the fabulous people at JPL.

I think, at this moment they're getting the downlinked flyby data and imagery. It'll be a while before it's all processed and released, but that's gonna be something!

MESSENGER Mission News
January 15, 2008
_http://messenger.jhuapl.edu

Mercury Flyby Observations Are on the Way!

At 16:30 UTC (11:30 a.m. EST) today, MESSENGER flight controllers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., received the first telemetry from the spacecraft following the probe’s closest approach to Mercury yesterday. All spacecraft subsystems and instruments are operating normally, and telemetry data indicate that the command sequence during the flyby executed as expected.

The data from the probe – which include 1,213 images – are scheduled to start coming down to the Deep Space Network in Canberra, Australia in a few hours. As soon as the downlink transmission is complete, the MESSENGER Science Team will complete the processing of the first images.

“We are delighted with the successful outcome of the flyby,” said MESSENGER Principal Investigator Sean Solomon of the Carnegie Institution of Washington. “The MESSENGER team is now eagerly awaiting the return of all of the scientific observations made over the past two days. We hope to share, within the next 24 hours, a first look at the side of Mercury never before seen at close range.”

Additional information and features from this first flyby will be available online at
_http://messenger.jhuapl.edu/mer_flyby1.html. Following the flyby, be sure to check for the latest released images and science results!



MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Source: JHUAPL - MESSENGER - Status Report

Keeping a Rendezvous with Mercury
Release Date: January 14, 2008



As the MESSENGER spacecraft approached Mercury for its first flyby, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired a series of images of the planet in support of spacecraft navigation. The nine images shown here were taken from January 9 to 13, 2008, as MESSENGER closed to between 2.7 million kilometers and 760,000 kilometers (1.7 million miles and 470,000 miles) from Mercury. These nine images can also be viewed in sequence, forming this movie.

At the beginning of the image sequence, Mercury was no more than a bright crescent in the blackness of space. As MESSENGER drew closer, surface features began to be resolved. The image from January 13 (bottom right) has the highest spatial resolution of this sequence (20 kilometers/pixel, 12 miles/pixel). In this image, bright markings are visible, and impact craters can be seen near the terminator (the line between Mercury's day side, to the left, and the night side to the right).

During MESSENGER's closest pass by Mercury yesterday, January 14, 2008, extensive scientific observations were executed. Today, the last of these planned observations will be completed, and at noon EST, the spacecraft will begin to transmit the data gathered during the flyby to Earth. This exciting new dataset will be used to address fundamental questions about the origin and evolution of the planet Mercury and our solar system. Currently, the MESSENGER team is anxiously awaiting the arrival of this dataset.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington



Source: JHUAPL - MESSENGER - Gallery

MESSENGER’s First Look at Mercury’s Previously Unseen Side
Release Date: January 15, 2008



When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere missed by Mariner 10. This image was snapped by the Wide Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, about 80 minutes after MESSENGER's closest approach to Mercury (2:04 pm EST), when the spacecraft was at a distance of about 27,000 kilometers (about 17,000 miles). The image shows features as small as 10 kilometers (6 miles) in size. This image was taken through a filter sensitive to light near the red end of the visible spectrum (750 nm), one of a sequence of images taken through each of MDIS’s 11 filters.

Like the previously mapped portion of Mercury, this hemisphere appears heavily cratered. It also reveals some unique and distinctive features. On the upper right is the giant Caloris basin, including its western portions never before seen by spacecraft. Formed by the impact of a large asteroid or comet, Caloris is one of the largest, and perhaps one of the youngest, basins in the Solar System. The new image shows the complete basin interior and reveals that it is brighter than the surrounding regions and may therefore have a different composition. Darker smooth plains completely surround Caloris, and many unusual dark-rimmed craters are observed inside the basin. Several other multi-ringed basins are seen in this image for the first time. Prominent fault scarps (large ridges) lace the newly viewed region.

Other images obtained during the flyby will reveal surface features in color and in much more detail. Collectively, these images and measurements made by other MESSENGER instruments will soon provide a detailed global view of the surface of Mercury, yielding key information for understanding the formation and geologic history of the innermost planet.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Reveals Mercury in New Detail
Release Date: January 16, 2008



As MESSENGER approached Mercury on January 14, 2008, the spacecraft’s Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured this view of the planet’s rugged, cratered landscape illuminated obliquely by the Sun. The large, shadow-filled, double ringed crater to the upper right was glimpsed by Mariner 10 more than three decades ago and named Vivaldi, after the Italian composer. Its outer ring has a diameter of about 200 kilometers (about 125 miles). MESSENGER’s modern camera has revealed detail that was not well seen by Mariner 10, including the broad ancient depression overlapped by the lower-left part of the Vivaldi crater. The MESSENGER science team is in the process of evaluating later images snapped from even closer range showing features on the side of Mercury never seen by Mariner 10. It is already clear that MESSENGER’s superior camera will tell us much that could not be resolved even on the side of Mercury viewed by Mariner’s vidicon camera in the mid-1970s.

This MESSENGER image was taken from a distance of about18,000 kilometers (11,000 miles), about 56 minutes before the spacecraft's closest encounter with Mercury. It shows a region roughly 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Detailed Close-up of Mercury’s Previously Unseen Surface
Release Date: January 16, 2008



Just 21 minutes after MESSENGER’s closest approach to Mercury, the Narrow Angle Camera (NAC) took this picture showing a variety of intriguing surface features, including craters as small as about 300 meters (about 300 yards) across. This is one of a set of 68 NAC images showing landscapes near Mercury’s equator on the side of the planet never before imaged by spacecraft. From such highly detailed close-ups, planetary geologists can study the processes that have shaped Mercury’s surface over the past 4 billion years. One of the highest and longest scarps (cliffs) yet seen on Mercury curves from the top center down across the right side of this image. (The Sun is shining low from the left, so the scarp casts a wide shadow.) Great forces in Mercury’s crust have thrust the terrain occupying the left two-thirds of the picture up and over the terrain to the right. An impact crater has subsequently destroyed a small part of the scarp near the top of the image.

This image was taken from a distance of only 5,800 kilometers (3,600 miles) from surface of the planet and shows a region about 170 kilometers (about 100 miles) across.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury's Cratered Surface
Release Date: January 16, 2008



During its flyby of Mercury, the MESSENGER spacecraft acquired high-resolution images of the planet's surface. This image, taken by the Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS), was obtained on January 14, 2008, about 37 minutes after MESSENGER's closest approach to the planet. The image reveals the surface of Mercury at a resolution of about 360 meters/pixel (about 1180 feet/pixel), and the width of the image is about 370 kilometers (about 230 miles). This image is the 98th in a set of 99 images that were taken in a pattern of 9 rows and 11 columns to enable the creation of a large, high-resolution mosaic of the northeast quarter of the region not seen by Mariner 10. During the encounter with Mercury, the MDIS instrument acquired image sets for seven large mosaics with the NAC.

This image shows a previously unseen crater with distinctive bright rays of ejected material extending radially outward from the crater's center. A chain of craters nearby is also visible. Studying impact craters provides insight into the history and composition of Mercury as well as dynamical processes that occurred throughout our Solar System. The MESSENGER Science Team has begun analyzing these high-resolution images to unravel these fundamental questions.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Reveals Mercury’s Geological History
Release Date: January 17, 2008



Shortly following MESSENGER’s closest approach to Mercury on January 14, 2008, the spacecraft’s Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) instrument acquired this image as part of a mosaic that covers much of the sunlit portion of the hemisphere not viewed by Mariner 10. Images such as this one can be read in terms of a sequence of geological events and provide insight into the relative timing of processes that have acted on Mercury's surface in the past.

The double-ringed crater pictured in the upper right of this image appears to be filled with smooth plains material, perhaps volcanic in nature. This crater was subsequently disrupted by the formation of a prominent scarp (cliff), the surface expression of a major crustal fault system, that runs alongside part of its southern rim and may have led to the uplift seen across a portion of the crater’s floor. A smaller crater in the upper left of the image has also been cut by the scarp, showing that the fault beneath the scarp was active after both of these craters had formed. The MESSENGER team is working to combine inferences about the timing of events gained from this image with similar information from the hundreds of other images acquired by MESSENGER to extend and refine the geological history of Mercury previously defined on the basis only of Mariner 10 images.

This MESSENGER image was taken from a distance of about 18,000 kilometers (11,000 miles) from the surface of Mercury, at 20:03 UTC, about 58 minutes after the closest approach point of the flyby. The region shown is about 500 kilometers (300 miles) across, and craters as small as 1 kilometer (0.6 mile) can be seen in this image.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Views Mercury’s Horizon
Release Date: January 17, 2008



As the MESSENGER spacecraft drew closer to Mercury for its historic first flyby, the spacecraft’s Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired an image mosaic of the sunlit portion of the planet. This image is one of those mosaic frames and was acquired on January 14, 2008, 18:10 UTC, when the spacecraft was about 18,000 kilometers (11,000 miles) from the surface of Mercury, about 55 minutes before MESSENGER’s closest approach to the planet.

The image shows a variety of surface textures, including smooth plains at the center of the image, many impact craters (some with central peaks), and rough material that appears to have been ejected from the large crater to the lower right. This large 200-kilometer-wide (about 120 miles) crater was seen in less detail by Mariner 10 more than three decades ago and was named Sholem Aleichem for the Yiddish writer. In this MESSENGER image, it can be seen that the plains deposits filling the crater’s interior have been deformed by linear ridges. The shadowed area on the right of the image is the day-night boundary, known as the terminator. Altogether, MESSENGER acquired over 1200 images of Mercury, which the science team members are now examining in detail to learn about the history and evolution of the innermost planet.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Looks like Earth's moon....

I can imagine that is exactly what was said back in 1974 when Mercury was first imaged by Mariner 10, which returned images such as this:


There are some major differences, the most noticable of which is the lack of the dark Mare regions which can be found on the moon. These Mare are evident in the picture below, which was taken by the Galileo spacecraft on its way to Jupiter back in July 1992.


A NASA article which discusses the similarities and differences can be found HERE.

On 18 January 2008 ESA and Astrium signed the industrial contract to start the development of ESA´s BepiColombo mission to Mercury. The ceremony took place in Friedrichshafen, Germany.
From the left: ESA´s Director of Science, Prof. David Southwood; the Prime Minister of Baden-Württemberg, Guenther Oettinger; the CEO of Astrium Satellites, Evert Dudok.



Credits: Astrium

18 January 2008
The industrial development of BepiColombo, Europe’s first mission to Mercury, has been officially kicked off. The prime contract, awarded by ESA to Astrium, was signed today during a ceremony that took place in Friedrichshafen, Germany.

BepiColombo, a mission to make the most comprehensive study of Mercury ever, was selected by ESA as one of its cornerstone missions in October 2000. Since then, several industrial studies have been performed and their assessment led to the selection of Astrium as prime contractor in 2006.
BepiColombo is due for launch in August 2013, and will reach Mercury in 2019 after a six-year journey towards the inner Solar System. It is the first dual mission to Mercury, with one European spacecraft and one provided from Japan. The programme is carried out as a joint mission under ESA leadership with the Japanese Aerospace Exploration Agency (JAXA).

This artist’s impression provides a view of the two BepiColombo spacecraft, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO), in their elliptical polar orbits around Mercury.
The MPO will circle the planet along an orbit ranging between 400 and 1500 kilometres above the surface. The MMO orbit ranges between 400 and 12 000 kilometres above the surface. The inclination and the eccentricity of these orbits are optimised for the study of the planet and of its magnetosphere in the very high temperature environment around Mercury.

The MPO will circle the planet along an orbit ranging between 400 and 1500 kilometres distance from the surface. The MMO orbit ranges between 400 and 12000 kilometres from the surface. The inclination and the eccentricity of these orbits are optimised for the study of the planet and of its magnetosphere in the very-high-temperature environment around Mercury.

Credits: ESA - image by C.Carreau

“The two spacecraft will address scientific questions such as the origin and evolution of a planet close to its parent star, the status of the planet’s interior and of its magnetic field, as well as a test of Einstein’s theory of General Relativity,” said Johannes Benkhoff, ESA Project Scientist for BepiColombo.

One spacecraft, ESA’s Mercury Planetary Orbiter (MPO), will carry 11 instruments to study the surface and internal composition of the planet with unprecedented accuracy, using different wavelengths and investigation techniques.

The second spacecraft, JAXA’s Mercury Magnetospheric Orbiter (MMO), will carry five instruments to study the planet’s magnetosphere, that is the region of space around the planet that is dominated by its magnetic field.

On behalf of ESA, Astrium will lead a network of subcontractors to design and build ESA’s MPO spacecraft and the so-called Mercury Transfer Module - that is the module to carry the MPO-MMO composite spacecraft to its destination.

“Astrium will have to address several technical challenges,” added Jan van Casteren, ESA’s BepiColombo Project Manager. “They mostly derive from the difficulty of operating a spacecraft in the harsh environment of a planet so close to the Sun, where the radiation is about ten times more intense than in Earth’s proximity.”

This image provides a close-up on the jets of ionised gas ejected by BepiColombo’s solar-electric propulsion (SEP) system.

In its cruise configuration, BepiColombo consists of: a transfer module, the Mercury Planetary Orbit (MPO), the sun shield and the Mercury Magnetospheric Orbiter (MMO).

The transfer module is provided with both solar-electric propulsion and chemical propulsion units. The former will be used during the cruise to destination; the latter will be used to boost the initial launch orbit out to the Moon for a gravity assist manoeuvre.

Credits: ESA - C. Carreau

An additional difficulty is that reaching Mercury and then entering into orbit requires a large amount of energy to brake against the Sun’s gravity. To achieve this, the cruise and the orbit insertion phases will primarily rely on solar-electric propulsion, complemented by several planetary gravity-assist manoeuvres and conventional (chemical) propulsion.

To achieve the best science, the Mercury Planetary Orbiter will operate facing down the planet with its instruments, something never tried before at Mercury due to the intense heat coming from the surface. It will also feature the highest data rate capacity ever used at Mercury, returning a high-volume of high-quality data to Earth, for the maximum scientific return. All these technical challenges are reflected in the spacecraft design.

Upon arrival at Mercury in 2019, the components of the BepiColombo cruise-configuration spacecraft will separate. The transfer module will be ejected into space and the composite spacecraft, consisting of the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO), will use conventional rocket engines and the so-called 'weak stability boundary capture technique' to enter into polar orbit around the planet. When the MMO orbit is reached, the MPO will separate and lower its altitude to its operational orbit by chemical propulsion. Scientific investigations will go on for at least one Earth year (that is four Mercury orbits around the Sun).

Credits: ESA - AOES Medialab

Astrium is already consolidating the design itself, ready for the preliminary design review to take place in late spring, after which the actual building of the spacecraft will start. In the meantime, the subcontractors are being selected for the procurement of the equipment and units needed to build the spacecraft. This procurement phase will continue throughout 2008.

The cost of BepiColombo to ESA is 665 million Euros, including the launch and the operations up to 2020. The contract to Astrium is for 350.9 million Euros. The cost of the MPO instruments, funded by European institutes, is over 200 million Euros.

“Mercury is the planet closest the Sun, making it hard to get to and so it is a technical challenge by anyone’s measure,” said Prof. David Southwood, ESA’s Director of Science. “However Mercury has also regularly confounded planetary scientists with its exceptional properties and that makes it a grand scientific challenge.”

Note

This artist’s impression shows BepiColombo’s Mercury Planetary Orbiter (MPO) in orbit around Mercury.

The MPO, led by ESA, will study the planet itself and, among several investigations, make complete maps of Mercury in several wavelengths. It will also map the planet's mineralogy and elemental composition and determine whether the planet has a molten core.

The MPO will work in tandem with the Mercury Magnetospheric Orbiter (MMO), led by JAXA, which will study the magnetosphere (the region of space around a planet dominated by its magnetic field).

BepiColombo is the first ever dual-satellite mission to Mercury.

Credits: ESA - AOES Medialab

Astrium’s subcontracting companies include: the Italian branch of Thales Alenia Space Italy, which will be the co-prime contractor for the development of the MPO’s electrical power, thermal control and communications systems and for the integration and test activities; Astrium Ltd (UK), co-prime contractor for the electrical and chemical propulsion system as well as for the complete composite spacecraft structure and Astrium (France), which will develop the on-board software.

BepiColombo will be launched from the European Spaceport in Kourou, French Guiana, on board a Soyuz-Fregat 2-1B rocket provided through Arianespace.


For more information

Jan van Casteren, ESA BepiColombo Project Manager
Email: Jan.van.Casteren @ esa.int

Johannes Benkhoff, ESA BepiColombo Project Scientist
Email: Johannes.benkhoff @ esa.int


Source: ESA - News

An Overview of Mercury as MESSENGER Approached
Release Date: January 18, 2008



As MESSENGER neared Mercury on January 14, 2008, the spacecraft’s Wide Angle Camera on the Mercury Dual Imaging System (MDIS) took images of the planet through each of its 11 filters. This image of the planet’s full crescent was taken using the 7th filter, in light near the far-red end of the visible spectrum (750 nm). The image shows portions of Mercury previously seen by Mariner 10, but when Mariner 10 flew by the planet at each of its encounters the Sun was nearly overhead. For this MESSENGER flyby, in contrast, the Sun is shining obliquely on regions near the day/night boundary (called the terminator) on the right-hand side of the crescent, revealing the surface topography in sharp relief. This image illustrates how MESSENGER, during its future flybys and subsequent orbital mission, will teach us much about the portion of Mercury already imaged by Mariner 10, and not just because of its superior camera and close proximity to the planet. The solar lighting geometry makes an enormous difference.

This picture provides a global context for the MDIS Narrow Angle Camera (NAC) images taken while MESSENGER was inbound. For example, the NAC image of the crater Vivaldi, released earlier this week, would fit as a small patch on the terminator just above the center of the crescent. The already released image that includes the crater Sholem Aleichem shows a part of Mercury near the top of the crescent. More NAC images of the incoming crescent will be released in the future.

This image was taken about 80 minutes before closest approach from a distance of about 27,000 kilometers (17,000 miles) and shows features as small as 10 kilometers (6 miles).


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury's Complex Cratering History
Release Date: January 18, 2008



On January 14, 2008, the MESSENGER spacecraft observed about half of the hemisphere not seen by Mariner 10. These images, mosaicked together by the MESSENGER team, were taken by the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS) instrument, about 20 minutes after MESSENGER's closest approach to Mercury (2:04 pm EST), when the spacecraft was at a distance of about 5,000 kilometers (about 3,100 miles). The image shows features as small as 400 meters (0.25 miles) in size and is about 370 kilometers (230 miles) across.

The image shows part of a large, fresh crater with secondary crater chains located near Mercury’s equator on the side of the planet newly imaged by MESSENGER. Large, flat-floored craters often have terraced rims from post-impact collapse of their newly formed walls. The hundreds of secondary impactors that are excavated from the planet’s surface by the incoming object create long, linear crater chains radial to the main crater. These chains, in addition to the rest of the ejecta blanket, create the complicated, hilly terrain surrounding the primary crater. By counting craters on the ejecta blanket that have formed since the impact event, the age of the crater can be estimated. This count can then be compared with a similar count for the crater floor to determine whether any material has partially filled the crater since its formation. With their large size and production of abundant secondary craters, these flat-floored craters both illuminate and confound the study of the geological history of Mercury.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Mission News
January 16, 2008
_http://messenger.jhuapl.edu

MESSENGER’s Mercury Flyby Science Data Now Safely on Earth

A day after its successful flyby of Mercury, the MESSENGER spacecraft turned toward Earth on Tuesday and began downloading the 500 megabytes of data that had been stored on the solid-state recorder during the encounter. All of those data, including 1,213 images from the Mercury Dual Imaging System (MDIS) cameras, have now been received by the Science Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. Preliminary analysis of these data by the MESSENGER Science Team has confirmed that all seven MESSENGER instruments are healthy and operated as planned during the flyby.

As MESSENGER flew by the planet, it missed its targeted aim point by only 8.25 kilometers (5.12 miles), affording the critical gravity assist needed to continue on a course to become – in 2011 – the first spacecraft ever to orbit Mercury. During this first encounter, the payload successfully conducted a carefully orchestrated sequence of observations designed to take full advantage of the geometry of the flyby trajectory and to optimize the science return from each instrument.

In addition to images of the previously unseen portion of the planet’s surface, measurements were made that will contribute to the characterization of all aspects of Mercury and its environment, from its metallic core to the far reaches of its magnetosphere. “We have one excited Science Team,” says MESSENGER Project Manager, Peter D. Bedini, of APL, “and their enthusiasm is contagious.”

The analysis of these data is just beginning, but there are already indications that new discoveries are at hand.



MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA.

Source: JHUAPL - MESSENGER - Status Report

There is nothing in venus unless you want to start mining it to see what we get...

All I can say to this is ????

Venus is a highly complex planet with a highly complex atmosphere. To dismiss it in such a way is to fail to understand what we can learn from such a world. Venus should be similar to Earth and yet has undergone a runaway greenhouse effect resulting in surface temperatures hot enough to melt tin and lead. The clouds are not water but sulphuric acid. There may also be huge active volcanos. There is so much to learn there that will help us understand the processes that occur on our own planet.

As for mining Venus that may be problematic, what with the atmospheric pressure being 90 times that of Earth's, the temperature being hotter than the inside of an oven and the sulphuric acid rain.

MESSENGER’s First Image after Closest Approach
Release Date: January 19, 2008



Just nine minutes after the MESSENGER spacecraft passed 200 kilometers (124 miles) above the surface of Mercury, its closest distance to the planet during the January 14, 2008, flyby, the Wide Angle Camera (WAC) on the Mercury Dual Imaging System (MDIS) snapped this image. The WAC is equipped with 11 different narrow-band filters, and this image was taken in filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm). This view, also imaged through the remaining 10 WAC filters, is from the first set of images taken following MESSENGER's closest approach with Mercury.

The image shows Mercury's surface as seen from a low viewing angle, looking over the surface and off the limb of the planet on the right side of the image. The cratered terrain in the image is on the side of Mercury unseen by spacecraft prior to this MESSENGER flyby. This scene was imaged at multiple viewing angles as MESSENGER sped away from Mercury, and these multiple views of the same surface features from different perspectives and in different colors will be used to help understand the properties of Mercury's surface.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

First Results from the Mercury Laser Altimeter
Release Date: January 19, 2008



On January 14, 2008, MESSENGER's Mercury Laser Altimeter (MLA) became the first instrument to measure the distance between a spacecraft and the surface of Mercury. MLA operates by first firing a brief laser pulse at the surface. It then measures the time for the pulse to reach the surface and return to the spacecraft, thereby providing a precise distance.

This figure shows the distance, or range, from the MESSENGER spacecraft to the surface of Mercury as measured by MLA during the flyby of Mercury. The instrument acquired the surface at a slant range of about 600 kilometers (about 370 miles) and tracked the surface through closest approach near 200 kilometers (about 125 miles) and out to a distance of about 1500 kilometers (about 930 miles). During the Mercury encounter, the instrument met or exceeded all performance specifications. The MESSENGER team is continuing to process the MLA data, and the final results should enable distances to be measured to better than a meter, allowing the profiles of craters and other features to be measured.

The vertical exaggeration in the figure is about 5:1. The MLA was designed and built at the NASA Goddard Space Flight Center.


Credit: NASA/Goddard Space Flight Center/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Views an Intriguing Crater
Release Date: January 20, 2008



MESSENGER's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired this view of Mercury’s surface illuminated obliquely from the right by the Sun. The unnamed crater (52 kilometers, or 31 miles, in diameter) in the center of the image displays a telephone-shaped collapse feature on its floor. Such a collapse feature, not seen on the floors of other craters in this image, could reflect past volcanic activity at and just below the surface of this particular crater. MESSENGER team members are examining closely the more than 1200 images returned from this flyby for other surface features that can provide clues to the geological history of the innermost planet.

The crater is located in the southern hemisphere of Mercury, on the side that was not viewed by Mariner 10 during any of its three flybys (1974-1975). This scene was imaged while MESSENGER was departing from Mercury from a distance of about 19,300 kilometers (12,000 miles), about 1 hour after the spacecraft's closest encounter with Mercury. The image is of a region approximately 236 kilometers (147 miles) across, and craters as small as 1.6 kilometers (1 mile) can be seen.


Mission Elapsed Time (MET) of image: 108828208


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Ridges and Cliffs on Mercury's Surface
Release Date: January 20, 2008



A complex history of geological evolution is recorded in this frame from the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS) instrument, taken during MESSENGER’s close flyby of Mercury on January 14, 2008. Part of an old, large crater occupies most of the lower left portion of the frame. An arrangement of ridges and cliffs in the shape of a "Y" crosses the crater’s floor. The shadows defining the ridges are cast on the floor of the crater by the Sun shining from the right, indicating a descending stair-step of plains. The main, right-hand branch of the "Y" crosses the crater floor, the crater rim, and continues off the top edge of the picture; it appears to be a classic “lobate scarp” (irregularly shaped cliff) common in all areas of Mercury imaged so far. These lobate scarps were formed during a period when Mercury’s crust was contracting as the planet cooled. In contrast, the branch of the Y to the left ends at the crater rim and is restricted to the floor of the crater. Both it and the lighter-colored ridge that extends downward from it resemble “wrinkle ridges” that are common on the large volcanic plains, or "maria," on the Moon. The MESSENGER science team is studying what features like these reveal about the interior cooling history of Mercury.

Ghostly remnants of a few craters are seen on the right side of this image, possibly indicating that once-pristine, bowl-shaped craters (like those on the large crater’s floor) have been subsequently flooded by volcanism or some other plains-forming process.

This image was taken 18 minutes after close approach, when MESSENGER was about 5,000 kilometers (about 3,000 miles) away from Mercury. The image is about 200 kilometers (about 125 miles) across, and features as small as about 400 meters (about 400 yards) can be resolved.


Mission Elapsed Time (MET) of image: 108825904


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Looking Toward the South Pole of Mercury
Release Date: January 21, 2008



One week ago, on January 14, 2008, the MESSENGER spacecraft passed 200 kilometers (124 miles) above the surface of Mercury and snapped the first pictures of a side of Mercury not previously seen by spacecraft. This image shows that previously unseen side, with a view looking toward Mercury's south pole. The southern limb of the planet can be seen in the bottom right of the image. The bottom left of the image shows the transition from the sunlit, day side of Mercury to the dark, night side of the planet, a transition line known as the terminator. In the region near the terminator, the sun shines on the surface at a low angle, causing the rims of craters and other elevated surface features to cast long shadows, accentuating height differences in the image.

This image is just one in a planned sequence of 42 images acquired by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). From these 42 images, the MESSENGER team is creating a high-resolution mosaic image of this previously unseen portion of Mercury. In total during the flyby, MDIS took more than 1200 images, which are being combined to create multiple mosaics with different resolutions and of different portions of the planet. The creation of high-resolution mosaic images will enable a global view of Mercury's surface and will be used to understand the geologic processes that made Mercury the planet we see today.

This image was acquired about 98 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 33,000 kilometers (21,000 miles).

Mission Elapsed Time (MET) of image: 108830711


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury - in Color!
Release Date: January 22, 2008



One week ago, the MESSENGER spacecraft transmitted to Earth the first high-resolution image of Mercury by a spacecraft in over 30 years, since the three Mercury flybys of Mariner 10 in 1974 and 1975. MESSENGER's Wide Angle Camera (WAC), part of the Mercury Dual Imaging System (MDIS), is equipped with 11 narrow-band color filters, in contrast to the two visible-light filters and one ultraviolet filter that were on Mariner 10's vidicon camera. By combining images taken through different filters in the visible and infrared, the MESSENGER data allow Mercury to be seen in a variety of high-resolution color views not previously possible. MESSENGER’s eyes can see far beyond the color range of the human eye, and the colors seen in the accompanying image are somewhat different from what a human would see.

The color image was generated by combining three separate images taken through WAC filters sensitive to light in different wavelengths; filters that transmit light with wavelengths of 1000, 700, and 430 nanometers (infrared, far red, and violet, respectively) were placed in the red, green, and blue channels, respectively, to create this image. The human eye is sensitive across only the wavelength range 400 to 700 nanometers. Creating a false-color image in this way accentuates color differences on Mercury's surface that cannot be seen in the single-filter, black-and-white image released last week.

This visible-infrared image shows an incoming view of Mercury, about 80 minutes before MESSENGER's closest pass of the planet on January 14, 2008, from a distance of about 27,000 kilometers (17,000 miles).

Image sequences acquired through the 11 different MDIS filters are being used to distinguish subtle color variations indicative of different rock types. By analyzing color differences across all 11 filters, the MESSENGER team is investigating the variety of mineral and rock types present on Mercury’s surface. Such information will be key to addressing fundamental questions about how Mercury formed and evolved.

Mercury has a diameter of about 4880 kilometers (3030 miles), and the smallest feature visible in this color image is about 10 kilometers (6 miles) in size.

Mission Elapsed Times (MET) of images: 108820022, 108820037, 108820057


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

First MESSENGER Spectrum of Mercury
Release Date: January 22, 2008



During its flyby of Mercury, the MESSENGER spacecraft acquired the first high-resolution spectra of the planet’s surface in ultraviolet, visible, and near-infrared light. The image on the left shows a portion of the ground-track along which the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument accumulated over 650 observations of the surface. The depicted area is about 300 kilometers (190 miles) across. The white track covers about 60 of the MASCS “footprints” or spectral snapshots. The red area highlights about 20 footprints averaged to make the example spectrum on the right, showing the relative amount of sunlight reflected from the surface at wavelengths from the ultraviolet to the visible (rainbow) to the infrared. The observations were taken on January 14, 2008, beginning as the spectrometer’s field of view crossed into the day-lit side of the planet at a distance of about 1,900 kilometers (about 1,200 miles), and continuing until the field of view left the planet at a distance of about 8,500 kilometers (about 5,300 miles) from Mercury. Mercury is about 4880 kilometers (about 3030 miles) in diameter, and the footprints shown here are about 1 by 5 kilometers (0.6 by 3.4 miles).

The Mercury spectrum shows the degree to which different wavelengths of sunlight are absorbed or reflected by its surface materials. Dips in the spectrum indicate where sunlight shining on the surface is partially absorbed. The absorption bands’ sizes and colors are diagnostic of the minerals in surface rocks. While Mercury has been observed telescopically from Earth for centuries, and Mariner 10 took images in one ultraviolet and two color filters when it flew by in 1974 and 1975, MESSENGER is the first mission to observe the surface with enough spatial and spectral resolution to determine Mercury’s surface composition.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Laboratory for Atmospheric and Space Physics, University of Colorado

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Dances by Matisse
Release Date: January 23, 2008



As the MESSENGER spacecraft approached Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) snapped this image of the crater Matisse. Named for the French artist Henri Matisse, Matisse crater was imaged during the Mariner 10 mission and is about 210 kilometers (130 miles) in diameter. Matisse crater is in the southern hemisphere and can be seen near the terminator of the planet (the line between the sunlit, day side and the dark, night side) in both the color and single-filter, black-and-white images released previously that show an overview of the entire incoming side of Mercury.

On Mercury, craters are named for people, now deceased, who have made contributions to the humanities, such as artists, musicians, painters, and authors. The International Astronomical Union (IAU) oversees the official process of naming new craters and other new features discovered on bodies throughout the solar system. Scientists studying and mapping unnamed features can suggest names for consideration by the IAU. The 1213 images taken by MESSENGER during its first flyby encounter with Mercury cover a large region of Mercury's surface previously unseen by spacecraft, revealing many new craters and other features that will need to be named.

Mission Elapsed Time (MET) of image: 108821375


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Counting Mercury's Craters
Release Date: January 24, 2008



On January 14, 2008, MESSENGER flew by Mercury and snapped images of a large portion of the surface that had not been previously seen by spacecraft. Ever since the first images were received back on Earth one day later, January 15, MESSENGER team members have been closely examining and studying this "new" terrain with great interest and excitement.

One of many investigations underway includes identifying and measuring the impact craters on these previously unseen regions. The density of craters on the surface of a planet can be used to indicate the relative age of different places on the surface; the more craters the surface has accumulated, the older the surface. By counting craters on different areas of Mercury's surface, a relative geologic history of the planet can be constructed, indicating which surfaces formed first and which formed later. However, this process is also time consuming; Mercury has a lot of craters! This image shows just a portion (276 kilometers, or 172 miles, wide) of one frame taken with the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS). In this image alone, 763 craters have been identified and measured (shown in green) along with 189 hills (shown in yellow). Altogether, 491 frames were taken by the NAC to create high-resolution mosaics of Mercury's surface.

Of course, simply counting the craters is not enough. Each crater has to be measured and classified to fully interpret the differences in crater density. Many small craters form as "secondaries," as clumps of material ejected from a "primary" crater re-impact the surface in the regions surrounding the primary. In order to learn about the history of asteroid and comet impacts on Mercury, scientists have to distinguish between the primary and secondary craters. Once many more craters are measured, MESSENGER researchers will have new insights into the geological history of Mercury.

Image Mission Elapsed Time (MET): 108826672


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER's Different Views
Release Date: January 25, 2008



During MESSENGER's flyby of Mercury on January 14, 2008, part of the planned sequence of observations included taking images of the same portion of Mercury's surface from five different viewing angles. The first view from this sequence was taken just after MESSENGER made its closest approach to Mercury, from a low viewing angle; an image of the first view was released on January 19. The image released here, acquired with the Wide Angle Camera (WAC) on the Mercury Dual Imaging System (MDIS), was snapped 13 minutes after MESSENGER's closest approach with Mercury. The lower two-thirds of this image shows much of the same terrain seen in the first view, but from a much higher viewing angle, as the spacecraft began to pass nearly overhead. At the time of this image, MESSENGER was at a distance of about 3000 kilometers (about 2000 miles) from Mercury.

A comparison of the images taken at different viewing angles provides important information about the properties of the materials that make up Mercury's surface. In addition, each view was taken through all 11 of the WAC's narrow-band color filters. The image shown here is from filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm). The MESSENGER team is working to compare these images taken from different perspectives and in different colors to understand surface properties on Mercury. In addition, knowledge of the variation of image properties with viewing angle in this region will permit a more confident comparison of images of other portions of the surface taken at different illumination and viewing angles.

This image is about 1000 kilometers (about 600 miles) across.

Image Mission Elapsed Time (MET): 108825632


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER Looks to the North
Release Date: January 26, 2008



As MESSENGER sped by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this shot looking toward Mercury's north pole. The surface shown in this image is from the side of Mercury not previously seen by spacecraft. The top right of this image shows the limb of the planet, which transitions into the terminator (the line between the sunlit, day side and the dark, night side) on the top left of the image. Near the terminator, the Sun illuminates surface features at a low angle, casting long shadows and causing height differences of the surface to appear more prominent in this region.

It is interesting to compare MESSENGER's view to the north with the image looking toward the south pole, released on January 21. Comparing these two images, it can be seen that the terrain near the south pole is more heavily cratered while some of the region near the north pole shows less cratered, smooth plains material, consistent with the general observations of the poles made by Mariner 10. MESSENGER acquired over 1200 images of Mercury's surface during its flyby, and the MESSENGER team is busy examining all of those images in detail, to understand the geologic history of the planet as a whole, from pole to pole.

This image was acquired about 94 minutes after MESSENGER's closest approach to Mercury, when the spacecraft was at a distance of about 32,000 kilometers (20,000 miles).

Mission Elapsed Time (MET) of image: 108830513


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury's Long Cliffs
Release Date: January 27, 2008



As the MESSENGER team continues to study the high-resolution images taken during the Mercury flyby encounter on January 14, 2008, scarps (cliffs) that extend for long distances are discovered. This frame, taken by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS), shows a region of Mercury's surface previously unseen by spacecraft and a large scarp crossing vertically through the scene, on the far right of the image. This scarp is the northern continuation of the one seen in the NAC image released on January 16. The width of this image is about 200 kilometers (about 125 miles), showing that these scarps can be hundreds of kilometers long on Mercury.

The presence of many long and high scarps, as discovered from pictures from the Mariner 10 mission in 1974 and 1975, suggests a history for Mercury that is unlike that of any of the other planets in the solar system. These giant scarps are believed to have formed when Mercury’s interior cooled and the entire planet shrank slightly as a result. However, Mariner 10 was able to view less than half the planet, so the global extent of these scarps has been unknown. MESSENGER images, like this one, are providing the first high-resolution looks at many areas on Mercury's surface, and science team members are busy mapping these newly discovered scarps to see whether they are common everywhere on the planet.

Mission Elapsed Time (MET) of image: 108826206


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

A Closer Look at the Previously Unseen Side
Release Date: January 28, 2008



Two weeks ago, on January 14, 2008, MESSENGER became the first spacecraft to see the side of Mercury shown in this image. The first image transmitted back to Earth following the flyby of Mercury, and then released to the web within hours, shows the historic first look at the previously unseen side. This image, taken by the Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS), shows a closer view of much of that territory.

Just above and to the left of center of this image is a small crater with a pronounced set of bright rays extending across Mercury's surface away from the crater. Bright rays are commonly made in a crater-forming explosion when an asteroid strikes the surface of an airless body like the Moon or Mercury. But rays fade with time as tiny meteoroids and particles from the solar wind strike the surface and darken the rays. The prominence of these rays implies that the small crater at the center of the ray pattern formed comparatively recently.

This image is one in a planned set of 99. Nine different views of Mercury were snapped in this set to create a mosaic pattern with images in 3 rows and 3 columns. The WAC is equipped with 11 narrow-band color filters, and each of the 9 different views was acquired through all 11 filters. This image was taken in filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm), and shows features as small as about 6 kilometers (4 miles) in size. The MESSENGER team is studying this previously unseen side of Mercury in detail to map and identify new geologic features and to construct the planet’s geological history.

Mission Elapsed Time (MET) of image: 108827618


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

MESSENGER's Departing Shots
Release Date: January 29, 2008



After MESSENGER completed its successful flyby of Mercury, the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS), took images of the receding planet. Beginning on January 14, 2008, about 100 minutes after MESSENGER's closest pass by the surface of Mercury, until January 15, 2008, about 19 hours later, the NAC acquired one image every four minutes. In all, 288 images were snapped during this sequence; shown here are just 12 of those departing shots. The top left image was taken when MESSENGER was about 34,000 kilometers (21,000 miles) from Mercury, and the bottom right image was snapped from a distance of about 400,000 kilometers (250,000 miles).

This large set of departing NAC images has been assembled into a movie, which will be shown tomorrow during a NASA press conference at 1 pm EST. Tune in tomorrow, via the web or NASA TV, to watch the NASA press conference, see this movie, and hear about the major discoveries made by MESSENGER from its historic flyby of Mercury!


Mission Elapsed Times (MET) of images: 108830924, 108836684, 108842444, 108848204, 108853964, 108859724, 108865484, 108871244, 108877004, 108882764, 108888524, 108894284.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

First Laser Altimetry for Mercury
Release Date: January 30, 2008



At top center is the first laser altimeter profile of Mercury’s topography, taken by MESSENGER’s Mercury Laser Altimeter (MLA) instrument during the spacecraft’s flyby of Mercury on January 14, 2008. At bottom center is the MLA ground projected onto a mosaic of radar images obtained by Harmon and others at the Arecibo Observatory in Puerto Rico.

The interval during which MESSENGER was sufficiently close to the planet to be within measurement range of the MLA was when the spacecraft was on the night side, so there are no corresponding images of this region acquired by MESSENGER during this flyby; this region was also unseen by Mariner 10. The length of the profile is about 3200 km (about 2000 miles), and the dynamic range in elevation across the profile is about 5 km (about 3 miles). The profile sampled numerous craters and basins. The vertical exaggeration in the figure is 105:1.

At top left is a photograph of the MLA flight unit.


Credit: NASA/Goddard Space Flight Center/Cornell University/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury’s Magnetic Field
Release Date: January 30, 2008



This plot shows the measured magnitude of the magnetic field of Mercury as MESSENGER executed its first flyby of that planet. MESSENGER’s Magnetometer (MAG) provided definitive identification of all boundaries of the Mercury magnetosphere system, consistent with the observations made with the Fast Imaging Plasma Spectrometer (FIPS) on the Energetic Particle and Plasma Spectrometer (EPPS) instrument, and revealed a much more quiescent system than was seen during the first Mariner 10 flyby. This state of the system was also consistent with the absence of energetic particles as documented by the Energetic Particle Spectrometer (EPS) portion of MESSENGER’s EPPS instrument. Mercury lacks radiations belts similar to the Van Allen belts at the Earth discovered by James Van Allen with a simple particle experiment on Explorer I launched 50 years ago.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury’s Sodium Tail
Release Date: January 30, 2008



This plot shows the intensity of emission of light associated with sodium atoms in the vicinity of Mercury. The observations were made with the Ultraviolet and Visible Spectrometer (UVVS) section of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). The intensity (up to 40 kiloRayleighs) indicates the relative abundance of material, in this case sodium atoms, along the observational line of sight back to the spacecraft. While sodium from Mercury has been observed with Earth-based telescopes, this is the highest-spatial-resolution image ever made. The geometry and observing circumstances have to be disentangled to infer the true spatial distribution, but the observations do confirm a north-south asymmetry that has previously been observed in ground-based sodium images.

The sodium emission is at 589 nm (in the visible part of the spectrum and the same wavelength, or color, as in sodium lamps and street lights on Earth). Because sodium atoms have intense emission, they are easy to detect, and this makes sodium a good tracer for other volatile elements in Mercury’s exosphere.


Credit: NASA/University of Colorado/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

“The Spider” – Radial Troughs within Caloris
Release Date: January 30, 2008



The Narrow Angle Camera of the Mercury Dual Imaging System (MDIS) on the MESSENGER spacecraft obtained high-resolution images of the floor of the Caloris basin on January 14, 2008. Near the center of the basin, an area unseen by Mariner 10, this remarkable feature – nicknamed “the spider” by the science team – was revealed. A set of troughs radiates outward in a geometry unlike anything seen by Mariner 10. The radial troughs are interpreted to be the result of extension (breaking apart) of the floor materials that filled the Caloris basin after its formation. Other troughs near the center form a polygonal pattern. This type of polygonal pattern of troughs is also seen along the interior margin of the Caloris basin. An impact crater about 40 km (~25 miles) in diameter appears to be centered on “the spider.” The straight-line segments of the crater walls may have been influenced by preexisting extensional troughs, but some of the troughs may have formed at the time that the crater was excavated.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury Shows Its True Colors
Release Date: January 30, 2008



MESSENGER's Wide Angle Camera (WAC), part of the Mercury Dual Imaging System (MDIS), is equipped with 11 narrow-band color filters. As the spacecraft receded from Mercury after making its closest approach on January 14, 2008, the WAC recorded a 3x3 mosaic covering part of the planet not previously seen by spacecraft. The color image shown here was generated by combining the mosaics taken through the WAC filters that transmit light at wavelengths of 1000 nanometers (infrared), 700 nanometers (far red), and 430 nanometers (violet). These three images were placed in the red, green, and blue channels, respectively, to create the visualization presented here. The human eye is sensitive only across the wavelength range from about 400 to 700 nanometers. Creating a false-color image in this way accentuates color differences on Mercury's surface that cannot be seen in black-and-white (single-color) images.

Color differences on Mercury are subtle, but they reveal important information about the nature of the planet's surface material. A number of bright spots with a bluish tinge are visible in this image. These are relatively recent impact craters. Some of the bright craters have bright streaks (called "rays" by planetary scientists) emanating from them. Bright features such as these are caused by the presence of freshly crushed rock material that was excavated and deposited during the highly energetic collision of a meteoroid with Mercury to form an impact crater. The large circular light-colored area in the upper right of the image is the interior of the Caloris basin. Mariner 10 viewed only the eastern (right) portion of this enormous impact basin, under lighting conditions that emphasized shadows and elevation differences rather than brightness and color differences. MESSENGER has revealed that Caloris is filled with smooth plains that are brighter than the surrounding terrain, hinting at a compositional contrast between these geologic units. The interior of Caloris also harbors several unusual dark-rimmed craters, which are visible in this image. The MESSENGER science team is working with the 11-color images in order to gain a better understanding of what minerals are present in these rocks of Mercury's crust.

The diameter of Mercury is about 4880 kilometers (3030 miles). The image spatial resolution is about 2.5 kilometers per pixel (1.6 miles/pixel). The WAC departure mosaic sequence was executed by the spacecraft from approximately 19:45 to 19:56 UTC on January 14, 2008, when the spacecraft was moving from a distance of roughly 12,800 to 16,700 km (7954 to 10377 miles) from the surface of Mercury.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Mercury’s Internal Magnetic Field
Release Date: January 31, 2008



This depiction of a simulated Mercury magnetosphere shows representations of the distortions of the planetary magnetic field lines (blue) by the solar wind. Mariner 10 data showed the first evidence for a magnetic field at Mercury, an unexpected result. The equatorial pass of MESSENGER during quiet solar conditions provided better data than were available from Mariner 10.

MESSENGER saw an internal magnetic field that is well described by the field from a dipole nearly aligned with the planet’s spin axis (dipole tilt ~ 10°). This geometry is similar to that observed by Mariner 10 during its first flyby. The field strength is weaker by about one third than that detected by Mariner 10 during its third (and last) flyby, owing primarily to the difference in trajectories (Mariner 10 flow directly over the magnetic pole where the field strength is greatest). When corrected for our best estimate for the external field, the MESSENGER observations and the two Mariner 10 passes are consistent with very similar solutions for the mean planetary magnetic dipole. The dipolar field is consistent with an active electrical dynamo in which the magnetic field is produced by electrical currents flowing in an outer core of molten metal. The observations do not yet allow us to identify whether a small secular variation may have occurred, determine higher order structure in the field, or assess whether crustal magnetic signatures may be present at other longitudes. A combination of the next two flybys and the orbital phase of MESSENGER’s mission will be required to sort out all of these possible effects.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Topographic Close-up
Release Date: January 31, 2008



A close-up of the Mercury Laser Altimeter (MLA) profile of Mercury acquired during MESSENGER’s first Mercury flyby on January 14, 2008. Comparison with an Arecibo radar image mosaic (bottom) provided by Harmon and co-workers shows that the two largest depressions are adjacent impact craters. The craters have rim-to-rim diameters of 107 km (left) and 122 km (right). The root mean square roughness of the floor the larger crater is ~35 m. The vertical exaggeration in the figure is 35:1.


Credit: NASA/Goddard Space Flight Center/Cornell University/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

Seeking Information on Mercury’s Mineralogy
Release Date: January 31, 2008



The top plot shows the ground track of observations made by the Visible and Infrared Spectrograph (VIRS) component of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). The ground track is projected onto a MESSENGER image of the portion of the planet seen in high-resolution by MESSENGER for the first time.

The bottom plot shows the relative spectral reflectance as a function of wavelength at the two locations indicated on the previous graphic. The visible and infrared portions of the spectra are shown for the two nearby areas, one including ejected material from a bright, relatively young crater and the other from surrounding plains. The two spectra have been shifted vertically to match at 850 nm (in the near-infrared). Differences between the two spectra, most notable in the infrared, are indicative of differences in the mineral abundances in these two regions.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Source: JHUAPL - MESSENGER - Gallery

The Great Caloris Basin on Mercury
Release Date: January 31, 2008



This image shows details of the Caloris basin, one of the largest impact basins in the solar system. Caloris was discovered in 1974 from the Mariner 10 images, but when Mariner 10 flew by Mercury, only the eastern half of the basin was in daylight. During its first flyby of Mercury, on January 14, 2008, the MESSENGER spacecraft was able to snap the first high-resolution images of the western half of the basin. This image is a compilation of pictures from the Mariner 10 mission (right portion of the image) and images from MESSENGER's Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (left portion of the image).

When Mariner 10 imaged the Caloris basin, the lighting conditions were very different from those experienced by MESSENGER, as is evidenced by the visible seam created when images from both missions are mosaicked together. Despite the different lighting conditions, the MESSENGER images show that the Caloris basin is even larger than previously believed. On the basis of images from Mariner 10, the rim of the Caloris structure was estimated at about 1300 km (about 800 miles) in diameter, shown as a yellow dotted line in this image. MESSENGER's images, which allow the entire Caloris basin to be seen at high-resolution for the first time, indicate that the basin rim, shown as a blue dotted line in the image, is actually closer to 1550 kilometers (about 960 miles) in diameter. Understanding the formation of this giant basin will provide insight into the early history of major impacts in the inner Solar System, with implications not just for Mercury, but for all the planets, including Earth.


Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/Brown University

Source: JHUAPL - MESSENGER - Gallery