Probe set for comet collision
Robin McKie
Sunday July 3, 2005
The Observer
The space probe Deep Impact is 'healthy and ready' for its collision tomorrow with comet Tempel 1 and has already provided images critical to understanding the building blocks of life on Earth, Nasa officials said yesterday.
The spacecraft was still on track to release its coffee-table sized 'impactor' last night. It will smash into the comet at 23,000mph. Although all of the systems appear to be in working order, officials said if the impactor failed to detach from the ship, they had contingency plans to send Deep Impact itself on a collision course.
If all goes well, the crash with the comet - described as 'a jet black, pickle-shaped, icy dirt ball the size of Washington DC' - will be surveyed by the main spacecraft from 310 miles away. It will have 13 minutes to capture images and data before it weathers a blizzard of particles thrown out of the comet's nucleus.
A total of 60 telescopes, in 20 countries, and several orbiting observatories - including the Hubble Space Telescope - will also study the blast which is expected to fire primordial material left over from the formation of the solar system into space. 'These materials have not seen the light of day for 4.6 billion years,' said Jessica Sunshine, a scientist working on the mission. 'That's what we're waiting to see.'
guardian.co.uk
Full Version: Probe set for comet collision
Just under an hour left before impact, those of you with a broadband connection can 'watch' the collision live via the internet;
HERE
Click on the NASA TV link on the left side of the page.
HERE
Click on the NASA TV link on the left side of the page.
July 04, 2005
Nasa probe hits comet
By Times Online and Tim Reid of The Times
Comet Tempel 1 after collision with the impactor probe from the Deep Impact spacecraft (AP/Jet Propulsion Laboratory)
America kicked off its Independence Day celebrations this morning with an intergalactic fireworks display courtesy of Nasa as a spacecraft smashed into an onrushing comet.
The successful strike 83 million miles (134 million kilometers) away from Earth occurred just before 0700 BST, according to mission control at Nasa’s Jet Propulsion Laboratory in Pasadena, which is managing the US$333 million ($275 million) mission.
Scientists at mission control erupted in applause and hugged each other as news of the impact spread. It was a milestone for the American space agency, which hopes the experiment will answer basic questions about the origins of the solar system. The cosmic smash-up did not significantly alter the comet’s orbit around the sun and Nasa said the experiment does not pose any danger to Earth.
A 372kg (820lb) copper bullet, the size of a beer barrel, was dropped yesterday from the spacecraft Deep Impact, which was on collision course with Tempel 1, a lumpy, pickle-shaped comet the size of Manhattan Island that is hurtling through space at 23,000mph.
The high-speed crash, an impact similar to detonating nearly five tonnes of TNT, is the first attempt by the American space agency to glimpse a comet’s core. Scientists believe that comets date from the dawn of the solar system, and getting a first look at their frozen ingredients could provide clues to how the Sun and planets, including Earth, were formed.
They are blobs of ice and dust that orbit the Sun and were formed about four-and-a-half billion years ago, at nearly the same time as the solar system. When a cloud of gas and dust condensed to form the Sun and planets, comets formed from what was left over.
Because they have been frozen, they are largely the same as when they were formed, unlike planets and moons, which have been altered by wind, weather, meteors and volcanoes.
After the impact, as a cloud of ice and dust explodes into space, the mother ship, having staked out a front-row seat 5,000 miles from the collision, began recording the crash and resulting crater with its high-resolution telescope. About 15 minutes later, Deep Impact made its closest fly-by of the comet nucleus, approaching within 310 miles.
The climax of the $333 million (£188 million) mission was also be watched by Nasa’s space-based Hubble, Chandra and Spitzer telescopes. The European Space Agency’s Rosetta spacecraft, on its way to a 2014 rendezvous with a comet, also watched, as did professional astronomers from dozens of observatories in 20 countries.
As the copper probe hurtled towards its target, relying on computers and thrusters to steer itself into the comet’s path, it was expected to beam back pictures of its target in near-real time until moments before its spectacular demise.
Nasa acknowledged the potential problems, not least that the probe could miss. David Spencer, the Deep Impact mission manager, said that the comet is a tiny object in the vastness of space. "It’s a very small target to hit. Plus it’s moving around. It’s not a nice, steady orbit. So it’s a moving target and we have to adjust to hit it."
There was also the chance that the cloud of gas and dust surrounding the comet’s nucleus might damage the spacecraft and probe and prevent data transmissions back to Earth. Deep Impact was launched from Cape Canaveral in Florida on January 12 for its six-month, 268-million-mile voyage. Tempel 1, discovered in 1867, moves around the Sun in an elliptical orbit between Mars and Jupiter every six years or so.
Nasa probe hits comet
By Times Online and Tim Reid of The Times
Comet Tempel 1 after collision with the impactor probe from the Deep Impact spacecraft (AP/Jet Propulsion Laboratory)
America kicked off its Independence Day celebrations this morning with an intergalactic fireworks display courtesy of Nasa as a spacecraft smashed into an onrushing comet.
The successful strike 83 million miles (134 million kilometers) away from Earth occurred just before 0700 BST, according to mission control at Nasa’s Jet Propulsion Laboratory in Pasadena, which is managing the US$333 million ($275 million) mission.
Scientists at mission control erupted in applause and hugged each other as news of the impact spread. It was a milestone for the American space agency, which hopes the experiment will answer basic questions about the origins of the solar system. The cosmic smash-up did not significantly alter the comet’s orbit around the sun and Nasa said the experiment does not pose any danger to Earth.
A 372kg (820lb) copper bullet, the size of a beer barrel, was dropped yesterday from the spacecraft Deep Impact, which was on collision course with Tempel 1, a lumpy, pickle-shaped comet the size of Manhattan Island that is hurtling through space at 23,000mph.
The high-speed crash, an impact similar to detonating nearly five tonnes of TNT, is the first attempt by the American space agency to glimpse a comet’s core. Scientists believe that comets date from the dawn of the solar system, and getting a first look at their frozen ingredients could provide clues to how the Sun and planets, including Earth, were formed.
They are blobs of ice and dust that orbit the Sun and were formed about four-and-a-half billion years ago, at nearly the same time as the solar system. When a cloud of gas and dust condensed to form the Sun and planets, comets formed from what was left over.
Because they have been frozen, they are largely the same as when they were formed, unlike planets and moons, which have been altered by wind, weather, meteors and volcanoes.
After the impact, as a cloud of ice and dust explodes into space, the mother ship, having staked out a front-row seat 5,000 miles from the collision, began recording the crash and resulting crater with its high-resolution telescope. About 15 minutes later, Deep Impact made its closest fly-by of the comet nucleus, approaching within 310 miles.
The climax of the $333 million (£188 million) mission was also be watched by Nasa’s space-based Hubble, Chandra and Spitzer telescopes. The European Space Agency’s Rosetta spacecraft, on its way to a 2014 rendezvous with a comet, also watched, as did professional astronomers from dozens of observatories in 20 countries.
As the copper probe hurtled towards its target, relying on computers and thrusters to steer itself into the comet’s path, it was expected to beam back pictures of its target in near-real time until moments before its spectacular demise.
Nasa acknowledged the potential problems, not least that the probe could miss. David Spencer, the Deep Impact mission manager, said that the comet is a tiny object in the vastness of space. "It’s a very small target to hit. Plus it’s moving around. It’s not a nice, steady orbit. So it’s a moving target and we have to adjust to hit it."
There was also the chance that the cloud of gas and dust surrounding the comet’s nucleus might damage the spacecraft and probe and prevent data transmissions back to Earth. Deep Impact was launched from Cape Canaveral in Florida on January 12 for its six-month, 268-million-mile voyage. Tempel 1, discovered in 1867, moves around the Sun in an elliptical orbit between Mars and Jupiter every six years or so.
That would be a lot of stress over and over adjusting it to hit the target...
$333 million dollars... to take a chunk out of a piece of ice/rock/dust?
Just kidding people... that is awesome! We had better learn something out of this though... or it will be just a mission to take put a whole in a chunk of ice/rock/dust.
$333 million dollars... to take a chunk out of a piece of ice/rock/dust?
Just kidding people... that is awesome! We had better learn something out of this though... or it will be just a mission to take put a whole in a chunk of ice/rock/dust.
^Well it allows us to get a better look at the composition of comets allowing us to determine how hard/easy one would be to destory or change its orbit if it was on a collision course with earth. Plus there are just so many other things it allows us to learn, that is indeed worth the 333 million.
i wish we could see just what nasa's contingency plans are if one of these damn things does decide to crash right into earth.if it's going 35,00 mph,just how the hell
are they gonna divert it?
are they gonna divert it?
Comet crash clues for Europe
By Paul Rincon
BBC News science reporter
As Nasa controllers whooped and cheered in California at news of Deep Impact's success, their efforts were being watched intently by scientists in far-off London.
Through a live link to a news conference in London, UK space scientists were sharing in some of the delight and fascination of Deep Impact's American team.
This was due in part to the enormous amount of information scientists are certain to glean from the collision.
And British researchers have been observing the collision from telescopes around the world, including the Faulkes Telescope and United Kingdom Infra-Red Telescope (UKIRT) in Hawaii, The INT Telescope in Spain and the UK Schmidt telescope in Australia.
But many of the scientists here are also involved in a European mission called Rosetta which aims to orbit and land on a comet for the first time.
Comet chaser
Deep Impact, they told reporters, would give valuable insights into what lies in store for the European spacecraft, which was launched in February 2004 on a 10-year trek to Comet 67P/Churyumov-Gerasimenko.
"Deep Impact is beautiful preparation for Rosetta," said Dr Andrew Coates, of the Mullard Space Science Laboratory (MSSL) at University College London.
Rosetta is not designed to crash into its target. Instead, it will catch up with "CG" in 2014 after flybys of Earth, Mars and the asteroids and a three-year period of deep space hibernation.
"Anything we can do to find out more about cometary surfaces is important," Dr Coates told the BBC News website.
The Rosetta flyby spacecraft drops its lander craft towards the surface of CG. The lander then fires a harpoon to anchor it to the comet's surface.
A soft landing is a particular problem given the extremely weak gravitational force exerted by the comet nucleus. The lander, which weighs 100kg on Earth, will on the comet be as light as a sheet of paper.
If there were a slight recoil, it would bounce back like a rubber ball. To prevent this, the lander's three legs are equipped with special shock-absorbers and are fitted with ice pitons which bore into the ground immediately on touchdown.
Surprise output
"One of the big unknowns [of the Rosetta mission] is the internal structure of the nucleus, how it sticks together and the strength of the material," Dr Gerhard Schwehm, Rosetta's project scientist told the BBC News website.
"These are things we hope to learn now from the science of Deep Impact. They help us pin down our scenario when putting the [Rosetta] lander on the nucleus."
Even if they wanted to, the Rosetta team would not be able to make any big changes to the landing stage of the mission. But knowing more about the surface they are landing on will allow mission scientists to check their models of the touchdown, says Dr Schwehm.
Rosetta's Philae lander will determine the composition of surface and subsurface materials using spectroscopy and sample analysis. It will also take high-resolution photographs, and carries a radar to determine the internal structure of the comet's nucleus.
One of the big surprises about Monday's impact was the unexpectedly large amount of material excavated by the collision between Tempel 1 and Deep Impact's projectile.
It had been thought that the impact would excavate as much material in 15 minutes as the comet usually discharges in a month.
"I would say it's more like a year," commented Professor John Zarnecki, a space scientist at the Open University in Milton Keynes.
Early interpretations
Scientists made some early interpretations. Firstly, Comet Tempel 1's crust is probably weaker than expected.
Professor Zarnecki said it also suggested the material in the comet was probably brittle, a bit like breeze block. Dr Coates likened it to compacted snow.
Dr Schwehm said he thought that a build-up of gases just beneath the surface might have contributed to the large plume.
"When it was triggered by the impactor, they just came out," he said.
But scientists allayed fears that the impact might throw the comet off course, perhaps on a collision course with Earth.
"It was like a mosquito hitting a 747. What we've found is that the mosquito didn't splat on the surface; it's actually gone through the windscreen," explained Professor Iwan Williams of Queen Mary, University of London, and a co-investigator on Rosetta.
Though Tempel 1 poses no current threat to Earth, other cometary bodies have wrought devastation on our planet in the geological past. An asteroid or comet impact is blamed for wiping out the dinosaurs at the end of the Cretaceous Period.
"Sixty-five million years ago, one of these things took out the dinosaurs," said Faulkes Telescope director Paul Roche, before the collision. Now, he said, "we're going to get our own back".
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/4648437.stm
By Paul Rincon
BBC News science reporter
As Nasa controllers whooped and cheered in California at news of Deep Impact's success, their efforts were being watched intently by scientists in far-off London.
Through a live link to a news conference in London, UK space scientists were sharing in some of the delight and fascination of Deep Impact's American team.
This was due in part to the enormous amount of information scientists are certain to glean from the collision.
And British researchers have been observing the collision from telescopes around the world, including the Faulkes Telescope and United Kingdom Infra-Red Telescope (UKIRT) in Hawaii, The INT Telescope in Spain and the UK Schmidt telescope in Australia.
But many of the scientists here are also involved in a European mission called Rosetta which aims to orbit and land on a comet for the first time.
Comet chaser
Deep Impact, they told reporters, would give valuable insights into what lies in store for the European spacecraft, which was launched in February 2004 on a 10-year trek to Comet 67P/Churyumov-Gerasimenko.
"Deep Impact is beautiful preparation for Rosetta," said Dr Andrew Coates, of the Mullard Space Science Laboratory (MSSL) at University College London.
Rosetta is not designed to crash into its target. Instead, it will catch up with "CG" in 2014 after flybys of Earth, Mars and the asteroids and a three-year period of deep space hibernation.
"Anything we can do to find out more about cometary surfaces is important," Dr Coates told the BBC News website.
The Rosetta flyby spacecraft drops its lander craft towards the surface of CG. The lander then fires a harpoon to anchor it to the comet's surface.
A soft landing is a particular problem given the extremely weak gravitational force exerted by the comet nucleus. The lander, which weighs 100kg on Earth, will on the comet be as light as a sheet of paper.
If there were a slight recoil, it would bounce back like a rubber ball. To prevent this, the lander's three legs are equipped with special shock-absorbers and are fitted with ice pitons which bore into the ground immediately on touchdown.
Surprise output
"One of the big unknowns [of the Rosetta mission] is the internal structure of the nucleus, how it sticks together and the strength of the material," Dr Gerhard Schwehm, Rosetta's project scientist told the BBC News website.
"These are things we hope to learn now from the science of Deep Impact. They help us pin down our scenario when putting the [Rosetta] lander on the nucleus."
Even if they wanted to, the Rosetta team would not be able to make any big changes to the landing stage of the mission. But knowing more about the surface they are landing on will allow mission scientists to check their models of the touchdown, says Dr Schwehm.
Rosetta's Philae lander will determine the composition of surface and subsurface materials using spectroscopy and sample analysis. It will also take high-resolution photographs, and carries a radar to determine the internal structure of the comet's nucleus.
One of the big surprises about Monday's impact was the unexpectedly large amount of material excavated by the collision between Tempel 1 and Deep Impact's projectile.
It had been thought that the impact would excavate as much material in 15 minutes as the comet usually discharges in a month.
"I would say it's more like a year," commented Professor John Zarnecki, a space scientist at the Open University in Milton Keynes.
Early interpretations
Scientists made some early interpretations. Firstly, Comet Tempel 1's crust is probably weaker than expected.
Professor Zarnecki said it also suggested the material in the comet was probably brittle, a bit like breeze block. Dr Coates likened it to compacted snow.
Dr Schwehm said he thought that a build-up of gases just beneath the surface might have contributed to the large plume.
"When it was triggered by the impactor, they just came out," he said.
But scientists allayed fears that the impact might throw the comet off course, perhaps on a collision course with Earth.
"It was like a mosquito hitting a 747. What we've found is that the mosquito didn't splat on the surface; it's actually gone through the windscreen," explained Professor Iwan Williams of Queen Mary, University of London, and a co-investigator on Rosetta.
Though Tempel 1 poses no current threat to Earth, other cometary bodies have wrought devastation on our planet in the geological past. An asteroid or comet impact is blamed for wiping out the dinosaurs at the end of the Cretaceous Period.
"Sixty-five million years ago, one of these things took out the dinosaurs," said Faulkes Telescope director Paul Roche, before the collision. Now, he said, "we're going to get our own back".
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/4648437.stm
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