RSSAll Entries Tagged With: "Lutetia"

Comet mission on course

The European Space Agency’s (ESA) Rosetta spacecraft made a successful fly-by of asteroid Lutetia on July 10-11, but its real target is comet Churyumov-Gerasimenko. It will rendezvous with the comet in 2014, mapping it and studying it. It will then accompany the comet for months, from near the orbit of Jupiter down to its closest approach to the Sun.

In November 2014, Rosetta will deploy a mini-spacecraft called Philae to land on the comet’s nucleus.

This video was made just before Rosetta’s fly-by of Lutetia.

Adapted from information issued by Euronews / ESA.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

Zooming in on an asteroid

Approaching asteroid Lutetia

A sequence of images taken by the Rosetta spacecraft as it closed in on the asteroid Lutetia on July 10, 2010.

Europe’s comet-bound spacecraft Rosetta flew past the asteroid Lutetia on July 10, 2010, sending back tremendous images of the 130km-long rocky world.

The European Space Agency has put together this sequence of images (above) to show us what the view was like as Rosetta approached Lutetia. The rotation of the asteroid can be discerned, as can the craters pock-marking its surface.

Rosetta’s closest approach came at a distance of 3,162 kilometres.

Rosetta is on course for a rendezvous with its ultimate target, the comet Churyumov-Gerasimenko, which it will reach in 2014.

For more Rosetta images of Lutetia, see our earlier story, Asteroid fly-by success!

Adapted from information issued by OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA.

Get SpaceInfo.com.au daily updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates. Or follow us on Twitter, @spaceinfo_oz

Asteroid fly-by success!

Asteroid Lutetia

An amazing image of asteroid Lutetia taken at the moment of closest approach during the fly-by successfully accomplished by the Rosetta spacecraft.

  • Fly-by of asteroid of Lutetia accomplished
  • Rosetta spacecraft worked flawlessly
  • Now on target for Comet Churyumov-Gerasimenko

Asteroid Lutetia has been revealed as a battered world of many craters.

The European Space Agency’s (ESA) Rosetta mission has returned the first close-up images of the asteroid, showing that it is most probably a primitive survivor from the violent birth of the Solar System.

Asteroid Lutetia

At a distance of 36,000km, the OSIRIS Narrow Angle Camera (NAC) took this image of Lutetia, catching the planet Saturn in the background.

The fly-by has been a spectacular success with Rosetta performing faultlessly. Closest approach took place at 2:10am Sunday, Sydney time, (16:10 UTC Saturday), at a distance of 3,162 km.

The images show that Lutetia is heavily cratered, having suffered many impacts during its 4.5 billion years of existence. As Rosetta drew close, a giant bowl-shaped depression stretching across much of the asteroid rotated into view.

The images confirm that Lutetia is an elongated body, with its longest side around 130km.

The images come from the OSIRIS instrument, which combines a wide angle and a narrow angle camera. At closest approach, details down to a scale of 60 metres can be seen over the entire surface of Lutetia.

“I think this is a very old object. Tonight we have seen a remnant of the Solar System’s creation,” says Holger Sierks, OSIRIS principal investigator, Max Planck Institute for Solar System Research, Lindau.

Rosetta raced past the asteroid at 15 km/s, completing the fly-by in just one minute. But the cameras and other instruments had been working for hours and in some cases days beforehand, and will continue afterwards. Shortly after closest approach, Rosetta began transmitting data to Earth for processing.

Asteroid Lutetia

A sequence of images taken as Rosetta approached Lutetia. The first image was taken about 9.5 hours before closest approach, 510000 km from the asteroid; the last one about 1.5 hours before closest approach, 8,100 km from the asteroid. The resolution changes from 9.6 km/pixel to 1.5 km/pixel.

Asteroid Lutetia

The final sequence of images of Lutetia before Rosetta's closest approach.

Ready for its next target

Lutetia has been a mystery for many years. Ground-based telescopes have shown that the asteroid presents confusing characteristics.

In some respects it resembles a C-type asteroid, a primitive body left over from the formation of the Solar System. In others, it looks like an M-type asteroid. These have been associated with iron meteorites, are usually reddish in colour and thought to be fragments of the cores of much larger objects.

Rosetta operated a full suite of instruments at the encounter, looking for evidence of a thin atmosphere, magnetic effects, and surface chemical composition as well as the asteroid’s density.

Asteroid Lutetia

Farewell Lutetia — Rosetta looked back for a final glimpse as it zoomed past.

They also attempted to catch any dust grains that may have been floating in space near the asteroid for on-board analysis. The results from these instruments will come in time.

The fly-by marks the attainment of one of Rosetta’s main objectives. The spacecraft will now continue to its primary target, Comet Churyumov-Gerasimenko. It will rendezvous with the comet in 2014, mapping it and studying it. It will then accompany the comet for months, from near the orbit of Jupiter down to its closest approach to the Sun.

In November 2014, Rosetta will deploy a mini-spacecraft called Philae to land on the comet nucleus.

Adapted from information issued by ESA 2010 MPS for OSIRIS Team  / MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA.

Get daily SpaceInfo.com.au updates by RSS or email! Click the RSS Feed link at the top right-hand corner of this page, and then save the RSS Feed page to your bookmarks. Or, enter your email address (privacy assured) and we’ll send you daily updates.

Rosetta’s blind date with Lutetia

Artist’s impression of Rosetta about to rendezvous with Comet 67P/Churyumov-Gerasimenko in 2014.

Artist’s impression of Rosetta's rendezvous with Comet 67P/Churyumov-Gerasimenko in 2014.

  • Rosetta probe on its way to a comet
  • Will fly past an asteroid on July 10
  • Comet rendezvous due in 2014

ESA’s comet-chaser spacecraft Rosetta is heading for a blind date with asteroid Lutetia. Rosetta does not yet know what Lutetia looks like up-close, but beautiful or otherwise, the two will meet on July10.

Like many first dates, Rosetta will meet Lutetia on a Saturday night, flying to within 3,200 km of the space rock. Rosetta started taking navigational sightings of Lutetia at the end of May so that ground controllers can determine any course corrections required to achieve their intended flyby distance.

The close pass will enable around two hours of good imaging. The spacecraft will instantly begin beaming the data back to Earth and the first pictures will be released later that evening.

Rosetta flew by asteroid Steins in 2008, and other space missions have encountered a handful of asteroids. Each asteroid has proven to be an individual and Lutetia is expected to continue the trend.

An animation of asteroid (2867) Steins

An animation of asteroid (2867) Steins, which was visited by Rosetta in September 2008.

The mystery of Lutetia

Although recent high-resolution ground-based images have given some idea of the overall shape of Lutetia, astronomers no idea what it looks like in detail. Rosetta will tell us that.

Orbiting in the main belt of asteroids between Mars and Jupiter, initially it was thought that Lutetia is around 95 km in diameter but only mildly off-circular. Recent estimates suggest 134 km, with a pronounced elongated shape. Rosetta will tell us for certain and will also investigate the composition of the asteroid, wherein lies another mystery.

By any measure, Lutetia is quite large. Planetary scientists believe that it is a primitive asteroid, left on the shelf for billions of years because no planet consumed it as the Solar System formed. Indeed, most measurements appear to back this picture, making the asteroid out to be a ‘C-type’, which contains primitive compounds of carbon.

However, some measurements suggest that Lutetia is an ‘M-type’, which could mean there are metals in its surface. “If Lutetia is a metallic asteroid then we have found a real winner,” says Rita Schulz, ESA Rosetta Project Scientist.

That’s because although metallic asteroids do exist, they are thought to be fragments of the metallic core of larger asteroids that have since been shattered into pieces. If Lutetia is made of metal or even contains large amounts of metal, Dr Schulz says that the traditional asteroid classification scheme will need rethinking. “C-class asteroids should not have metals on their surfaces,” she says.

A busy fly-by

Asteroid science stands to gain once this observational conundrum is resolved because Rosetta’s data will provide a valuable collection of ‘ground truths’ that can be used to resolve conflicting ground-based observations not just for Lutetia but for other asteroids as well.

For 36 hours around the moment of closest approach, Rosetta will be in almost continuous contact with the ground. The only breaks will come as Earth rotates and engineers have to switch from one tracking station to another.

Artist’s impression of Rosetta as it flies by asteroid Steins

Rosetta encountered asteroid Steins in 2008. Next stop is asteroid Lutetia on July 10, 2010.

Good contact is essential because the uncertainties in the asteroid’s position and shape may demand last minute fine-tuning to keep it centred in Rosetta’s instruments during the flyby. “The skeleton of the operation is in place, and we have the ability to update our plans at any time,” says Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager.

Stay in touch with the flyby as it happens by visiting the Rosetta blog.

Mission to a comet

Rosetta’s 11-year expedition began in March 2004, with an Ariane 5 launch from Kourou in French Guiana, and the spacecraft was then sent towards the outer Solar System. The long journey includes three gravity assists at Earth (2004, 2007, 2009), one at Mars (2007), and two asteroid encounters: (2867) Steins (2008) and (21) Lutetia (2010).

After the third Earth-gravity assist and a large deep-space manoeuvre, the spacecraft will go into hibernation (July 2011 – January 2014). During this period, Rosetta will record its maximum distances from the Sun (about 800 million kilometres) and Earth (about 1 thousand million kilometres).

The spacecraft will be reactivated prior to the comet-rendezvous manoeuvre, during which the thrusters will fire for several hours to slow the relative drift rate between the spacecraft and comet to about 25 m/s.

Built by EADS Astrium, the Rosetta probe consists of a 3,065-kg spacecraft (1,578-kg dry mass) designed to enter orbit around the comet’s nucleus in August 2014 after a series of gravity assist manoeuvres to gain enough orbital energy, with three swing-bys at Earth (March 2005, November 2007 and November 2009) and one at Mars (February 2007).

The spacecraft carries 11 science instruments to probe the comet’s nucleus and map its surface in fine detail. It will also land a package of instruments (the Philae Lander) to study some of the most primitive, unprocessed material in the Solar System.

The mission will provide clues to the physical and chemical processes at work during the formation of planets, beginning 4.6 billion years ago.

Adapted from information issued by ESA / C.Carreau / AOES Medialab / J. Huart.