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2006 Transit of Mercury

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2006 Transit of Mercury


October 20, 2006: Mark your calendar: On Wednesday, Nov 8th, the planet Mercury will pass directly in front the Sun. The transit begins at 2:12 pm EST (11:12 am PST) and lasts for almost five hours. Good views can be had from the Americas, Hawaii, Australia and all along the Pacific Rim: visibility map.

What will it look like? A picture is worth a thousand words:

user posted image
Image credit: Larry Koehn. Click to view the Sun's full disk.

During the transit, Mercury's tiny disk—jet black and perfectly round—will glide slowly across the face of the Sun. Only a speck of the Sun's surface is actually covered, so the Sun remains as dangerous as ever to look at. But with a proper filter and a little imagination, the Transit of Mercury can be a marvelous experience.

There are many ways to safely observe the Sun, e.g., through eclipse glasses or by means of a pinhole projector. In this case, nothing beats a telescope equipped with a sun-safe H-alpha filter. H-alpha filters are narrowly tuned to the red glow of solar hydrogen. They reveal the Sun as a boiling inferno, cross-crossed by dark magnetic filaments and peppered with sunspots. Warning: The sight of Mercury navigating this starscape could be mind blowing.

Teachers, call your local astronomy club and ask if they have such a solar telescope. Amateur astronomers love to show off the heavens, and someone will probably volunteer to bring their 'scope to your classroom for the transit. (You can also view the transit online at the SOHO web site--no telescope required.)

user posted image
Above: Mercury, photographed by
Mariner 10. [More]


Here's something to think about while watching the transit: Mercury is fantastically mysterious. More than half of the planet is unknown to us. When Mariner 10 flew by in the mid-70s, it managed to photograph only 45% of Mercury's cratered surface. What lies on the other side? More craters? Or something totally unexpected? You're free to speculate, because the next spacecraft to visit Mercury, NASA's MESSENGER probe, won't enter orbit until 2011.

One of Mercury's greatest secrets is the mystery-material at its poles. Radars on Earth have pinged Mercury and received a strong echo from polar craters. A favorite explanation is ice. While Mercury's daylit surface heats up to 400o C, the temperature in deep, dark polar craters dips below -200o C. If an icy comet landed in one of those craters (or made one of those craters), the comet's ices, vaporized by impact, might re-freeze and stick around. As skeptics like to say, however, "it's just a theory," one of many that MESSENGER will check.

Another puzzle is Mercury's wrinkles. Geologists call them "lobate scarps." Like wrinkles on a raisin, the scarps are thought to be a sign of shrinkage. Mercury may actually be collapsing in on itself as its massive iron core cools and contracts. To check this idea, MESSENGER will map Mercury's magnetic field, which springs from the core. If the core is collapsing, the collapse may leave telltale signs in the planet's magnetism. MESSENGER will also look for lobate scarps on the uncharted side of Mercury to see if this is truly a global phenomenon.

The answers are years away. Meanwhile, we watch and wonder, and Nov. 8th is a good day for that.

Author: Dr. Tony Phillips | Production Editor: Dr. Tony Phillips | Credit: Science@NASA


More Information

2006 Transit of Mercury -- maps and timetables

MESSENGER -- home page

Science Mysteries of Mercury -- compiled by the MESSENGER science team

H-alpha views of the 2003 Transit of Mercury

More maps and images

The Vision for Space Exploration

Source: Science@NASA

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A warning: NEVER look directly at the sun either with the unaided eye or through telescope/binoculars. This can lead to serious and permanent damage to the eyes.

To repeat what the above article says:

Eclipse glasses are safe as long as they are free from damage. Telescopes and binoculars are safe if fitted with special filters over the objective lens.

Never use the dark filters that fit onto telescope eyepieces which are sometimes provided with cheaper telescopes. These can shatter and cause blindness.

The safest way to observe the sun is by projection. Point the binoculars/telescope at the sun WITHOUT LOOKING THROUGH THEM and then focus the image onto a white sheet of cardboard.

Edited by Waspie_Dwarf

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Mercury Transit Foreshadows Future Planet Hunt


IPB Image\
Image above: Time-lapse image of the 2003 Mercury transit as observed by NASA's SOHO spacecraft.

"Cunning Mercury wanted to cross without being seen. It came sooner than anyone had expected! But it could not escape being discovered. I found it and saw it! It happened to nobody before me on 7 November 1631 in the morning." *
- Pierre Gassendi
French philosopher and scientist, 1592-1655


It was a Frenchman, Pierre Gassendi, who first observed the transit of Mercury. But it's thanks to a German astronomer, Johannes Kepler, that Gassendi knew when to look for it.

The next transit of Mercury happens Wednesday afternoon, Nov. 8, 2006. You'll need a telescope with a special filter to view it safely. Astronomy clubs around the country are preparing to share this unusual sight with their communities.
The transit of Mercury takes place when the planet crosses between the sun and the Earth. Mercury is seen as a small black dot moving across the face of the sun. This phenomenon occurs about 13 times during each century.

IPB Image
Image right: Artist's concept of the Kepler
spacecraft, with portrait of Johannes Kepler
(1571-1630)


+ Listen to an audio version of this feature

The transit cannot be seen with the unaided eye, but it can be viewed with a telescope (with the proper filter) or with a homemade optical projector.

Appropriately, NASA has named a forthcoming planet-finding mission after Kepler, who discovered the laws of planetary motion four centuries ago. Kepler is a space telescope designed to determine if terrestrial planets - like the one we live on - are common or rare in the galaxy.

"The Mercury transit, I think, reminds us that we live in a family of planets that orbit our stars," said Jim Fanson, Kepler deputy project manager. "This method of seeing a planet transit, that is, pass between us and the sun and cover part of the sun's disc, this is exactly the method that the Kepler mission is going to use to find planets around other stars."

Scheduled for launch in 2008, Kepler will stare at one portion of the night sky and monitor the brightness of 100,000 stars, watching for planetary transits. Each transit will cause the star to dim slightly in brightness. That's a signal that a planet is passing between Earth and the distant star, just as Mercury will pass between Earth and a very nearby star - the sun - on November 8.

William Borucki of NASA Ames Research Center, principal investigator for Kepler, calls the mission a first step in determining the extent of life in our galaxy.

"Kepler is unique in that it's an exploration mission," Borucki said. "It has the ability to look at these 100,000 stars. If most of these stars have planets, we would find hundreds of planets in the habitable zone. And if we find that, life may be ubiquitous in the galaxy. If we don't, we might be alone."

The habitable zone is the region around a star where it's not too hot, and not too cold, for liquid water to exist on a planet's surface. And scientists believe liquid water is a prerequisite for life as we know it to emerge.

Kepler is only the first step in NASA's long-range quest for new worlds. Other missions that NASA has in the planning stages, like the SIM PlanetQuest and Terrestrial Planet Finder, will be able to detect Earthlike planets around the nearest stars and take "family portraits" where we can see the planets orbiting and measure their atmospheres. "Then, we'll be able to make very profound conclusions or inferences about the habitability of those planets," Fanson said.

The Kepler mission, a NASA Discovery mission, is an Ames Research Center mission that is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate, Washington.

To find out more about NASA's search for new planets, visit the PlanetQuest Web site at http://planetquest.jpl.nasa.gov.

* Quotation courtesy the European Space Agency.
_______________________________________________________


How to view the transit safely
The Mercury transit will take place Nov. 8 from 11:12 a.m. - 4:10 p.m. PST (2:12 p.m. - 7:10 p.m. EST). Portions of event will be visible from the Pacific, the Americas, eastern Asia, Australia, and New Zealand.

NEVER look directly at the sun. The transit cannot be seen with the unaided eye. To view the transit, seek the assistance of an experienced observer with a telescope and the proper filter.



Written by Randal Jackson/PlanetQuest


Source: NASA - Exploring The Universe - New Worlds

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See Mercury’s silhouette with SOHO


IPB Image
This illustration shows Mercury's path across the solar disk as seen from Earth. The
transit starts at 20:12 CET on 8 November and ends at 01:10 CET on 9 November 2006.

ESA/NASA's SOHO will witness the event from 21:09 CET on 8 November until 02:57
CET on 9 November 2006.

Credits: NASA/ESA



8 November 2006
On Wednesday 8 November 2006, Mercury will pass directly between the Sun and the Earth. The innermost planet will be seen not as a bright point in the sky but as a tiny black dot, silhouetted against the brilliant surface of the Sun. Although this spectacle is not visible from Europe, the ESA-NASA solar satellite SOHO will be watching.

Such a crossing is known as a transit. From Earth’s vantage point, only Mercury and Venus transit the Sun, because these are the only planets inside Earth’s orbit. In the case of Venus, the planet is large enough to be seen against the Sun without optical aid, providing that a pair of solar filters is worn to cut down the damaging glare of the Sun.

Mercury, however, is much smaller. At only 1/194 of the Sun's apparent diameter, a small telescope is needed. The telescope must be fitted with a solar filter, otherwise the bright Sun will permanently damage the eyes of anyone who looks through it. Once filtered, an eyepiece that provides a magnification of 50-100 times will give the best view of this event.


This transit is the second of 14 Mercury transits that will take place during the 21st century. The previous Mercury transit was on 7 May 2003 and the next will not happen until 9 May 2016.

However, if you are in Europe, the timing of today's event is wrong. The transit begins at 20:12 CET today - the Sun will have set – and it will last until 01:10 CET tomorrow (9 November 2006). European sky watchers need not despair, however. The ESA-NASA solar watchdog SOHO (SOlar and Heliospheric Observatory) will be in the position favourable to observe the event from 21:09 CET on 8 November until 02:57 CET on 9 November, and will beam those pictures back to Earth, where they can be seen live on the internet.

The images will be visible by following this link. As the event takes place, the images will be compiled into a movie of the transit.

In previous centuries, transits – especially of Venus – were used to measure the absolute distance between the Sun and the Earth. Nowadays, they are mostly observed for enjoyment. However, the scientists and engineers working with SOHO have found a use for them. "These transits provide unique opportunities for characterising the imagers and spectrometers," says Bernhard Fleck, ESA's SOHO Project Scientist. By checking the instruments in this way, the SOHO team can be sure of producing the best science data possible.

Beyond the Solar System, transits of extrasolar planets around other stars are now being observed. The drop in light registered as the distant planet moves in front of the star can tell astronomers the diameter of the planet. In December 2006, CoRoT, the international space telescope with ESA participation, will launch from Kazakhstan. It will search hundreds of thousands of stars for transits. In this way, it is expected to detect hundreds of previously unknown planets.


Source: ESA - News Edited by Waspie_Dwarf

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2006 Transit of Mercury


On Wednesday, Nov 8, the planet Mercury passed directly in front the Sun. What did it look like? A picture is worth a thousand words:

IPB Image

From a vantage point one million miles out in space the Solar and Heliospheric Observatory (SOHO) spacecraft captured images of the planet Mercury passing directly in front the Sun of the transit. Good views could also be seen from Americas, Hawaii, Australia, along the Pacific Rim. The transit began at 2:12 p.m. EST (11:12 a.m. PST) and lasted for almost five hours. During the transit, Mercury's tiny disk--jet black and perfectly round--glided slowly across the face of the Sun. Only a speck of the Sun's surface is actually covered, so the Sun remains as dangerous as ever to look at. But with a proper filter or a spacecraft and a little imagination, the Transit of Mercury is a marvelous experience.

IPB Image
Above: Mercury, photographed by
Mariner 10. [More]


Here's something to think about while watching the transit: Mercury is fantastically mysterious. More than half of the planet is unknown to us. When Mariner 10 flew by in the mid-70s, it managed to photograph only 45% of Mercury's cratered surface. What lies on the other side? More craters? Or something totally unexpected? You're free to speculate, because the next spacecraft to visit Mercury, NASA's MESSENGER probe, won't enter orbit until 2011.

One of Mercury's greatest secrets is the mystery-material at its poles. Radars on Earth have pinged Mercury and received a strong echo from polar craters. A favorite explanation is ice. While Mercury's daylit surface heats up to 400o C, the temperature in deep, dark polar craters dips below -200o C. If an icy comet landed in one of those craters (or made one of those craters), the comet's ices, vaporized by impact, might re-freeze and stick around. As skeptics like to say, however, "it's just a theory," one of many that MESSENGER will check.

Another puzzle is Mercury's wrinkles. Geologists call them "lobate scarps." Like wrinkles on a raisin, the scarps are thought to be a sign of shrinkage. Mercury may actually be collapsing in on itself as its massive iron core cools and contracts. To check this idea, MESSENGER will map Mercury's magnetic field, which springs from the core. If the core is collapsing, the collapse may leave telltale signs in the planet's magnetism. MESSENGER will also look for lobate scarps on the uncharted side of Mercury to see if this is truly a global phenomenon.

The answers are years away. Meanwhile, we watch and wonder, and Nov. 8th is a good day for that.

Author: Dr. Tony Phillips | Production Editor: Dr. Tony Phillips | Credit: Science@NASA


More Information

2006 Transit of Mercury -- maps and timetables

MESSENGER -- home page

Source: Science@NASA

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X-ray Transit of Mercury


Nov. 17, 2006: To appreciate the majesty and power of a typical G-type star, you need only glance at this photo:

IPB Image
Above: Mercury and the Sun, the view through Hinode's X-ray Telescope. The arrow points
to Mercury. [Zoom] [More]


The tiny black speck is Mercury. The star looming in the background is our own sun.

The Japanese Space Agency's new orbiting solar observatory, Hinode (formerly known as Solar B ), took the picture on Nov. 8th just as Mercury was about to begin a rare solar transit. Thousands of people on Earth saw and photographed the event, but Hinode's photo is like no other because it shows the view through an X-ray telescope.

"Hinode's X-ray telescope, the XRT, is the best solar X-ray telescope ever flown," says John Davis, NASA's Hinode project scientist at the Marshall Space Flight Center. "The XRT has arc-second resolution and can take pictures as rapidly as once every second."

X-rays interest solar physicists because they reveal the hottest gases in the sun's atmosphere. The bright flourish just above Mercury, for instance, is a gigantic mass of million-degree plasma trapped in the magnetic field of a sunspot. Viewed through an ordinary white light telescope, that hot mass would be almost completely invisible.

Truly, "these are unique images," says Davis.

When the transit began, that is, when Mercury moved directly in front of the sun's surface, Hinode zoomed in using another of its telescopes, the SOT (Solar Optical Telescope). The images reveal Mercury as no mere speck but a full-fledged planetary disk:

IPB Image
Movies: larger (20 MB) or smaller (1 MB)

Viewing the movie, Davis points out "the motions in the background." The sun's surface boils like water atop a hot stove. Each of the bubbling "granules" is about the size of a terrestrial continent.

Hinode, just launched in September, is still in the shake-down phase of its mission. Ground controllers are testing Hinode's telescopes and other systems and don't expect to begin routine science operations until next month. The transit of Mercury is just a hint of what's to come.

Author: Dr. Tony Phillips | Production Editor: Dr. Tony Phillips | Credit: Science@NASA


Hinode is a joint mission of the Japan Aerospace Exploration Agency (JAXA), the National Astronomical Observatory of Japan (NAOJ), the National Aeronautics and Space Administration (NASA) and the Particle Physics and Astronomy Research Council (PPARC). The Marshall Space Flight Center (MSFC) manages Hinode science operations for NASA and is also supporting science operations in Japan.

More to the story...

Mercury Transit Observed by Hinode -- JAXA press release

First Light for Hinode -- (Science@NASA)

2006 Transit of Mercury -- (Science@NASA)

Hinode home page -- from JAXA

Hinode home page -- from NASA

The Vision for Space Exploration

Source: Science@NASA

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