European probe Rosetta flies by asteroid: ESA (w/ Video)

Jul 11, 2010
An image released by the ESA shows the Lutetia asteroid at closest approach from the Rosetta spacecraft. The European spacecraft Rosetta performed a fly-by of a massive asteroid on Saturday, the European Space Agency said, taking images that could one day help Earth defend itself from destruction.

The European spacecraft Rosetta performed a fly-by of a massive asteroid, the European Space Agency said, taking images that could one day help Earth defend itself from destruction.

Racing through the belt between Mars and Jupiter at 47,800 kph (29,925 mph), the billion-euro (1.25-billion-dollar) probe flew Saturday within 3,200 kms (2,000 miles) of the huge potato-shaped rock, Lutetia.

"The fly-by has been a spectacular success with Rosetta performing fautlessly," ESA said in a statement.

"Just 24 hours ago, Lutetia was a distant stranger. Now, thanks to Rosetta, it has become a close friend," the agency added.

Holger Sierks of Germany's Max Planck Institute, who is in charge of the spacecraft's Osiris (Optical, Spectroscopic and Infrared Remote Imaging System) camera said the more than 400 "phantastic images" showed many craters and details.

"Rosetta opened up a new world which will keep scientists busy for years," he added.

"We have completed the fly-by phase," Rosetta's director of operations Andrea Accomazzo said earlier on the ESA's website from the European Space Operations Centre in Darmstadt, Germany.

The aim of the fly-by of the asteroid, measuring 134 kms (83.75 miles) in diameter, is to measure Lutetia's mass and then calculate its density, knowledge which could one day be a lifesaver, according to ESA scientists.

If a rogue asteroid enters on a collision course with Earth, knowing its density will help the planet's defenders to determine whether they should try to deflect the rock or, instead, blow it up.

This video is not supported by your browser at this time.
Simulation showing view of Lutetia from Rosetta during flyby on 10 July. Credits: ESA/AOES Medialab

As Rosetta is around 500 million kilometres from Earth, the probe's signal and images took 25 minutes to be received.

Once widely dismissed as bland lumps of debris left over from the building of the planets, asteroids have turned out to be intriguingly individual.

They are extremely different in shape and size, from just hundreds of metres (yards) across to behemoths of 100 kms (60 miles) or more, and also vary in mineral flavours.

Most measurements suggest Lutetia is a "C" type of asteroid, meaning that it contains primitive compounds of carbon. But others indicate it could be an "M" type, meaning that it holds metals.

New data proving this could rewrite the theory about asteroid classification.

European probe Rosetta flies by asteroid: ESA (w/ Video)
Zoom in on a possible landslide and boulders at the highest resolution. Credits: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Metallic asteroids are far smaller than Lutetia: they are deemed to be fragments of far larger rocks that, in the bump and grind of the , were smashed apart.

The fly-by comes halfway through the extraordinary voyage of Rosetta, launched in 2004 on a 12-year, 7.1-billion-kilometre (4.4-billion-mile) mission.

One of the biggest gambles in the history of space exploration, the unmanned explorer is designed to meet up in 2014 with Comet 67/P Churyumov-Gerasimenko 675 million kms (422 million miles) from home.

The goal is to unlock the secrets of these lonely wanderers of the cosmos, whose origins date back to the dawn of the Solar System, some 4.5 billion years ago, before planets existed.

To get to its distant meeting point, has had to play planetary billiards for five years, using four "gravitational assists" from Earth and Mars as slingshots to build up speed.

Explore further: Europe postpones launch of first 'space plane'

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User comments : 19

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Parsec
5 / 5 (5) Jul 11, 2010
As Rosetta is around half a million kilometres from Earth, the probe's signal and images took 25 minutes to be received.


At 300,000 km/sec, it is quite unlikely it would take 25 minutes to travel 500,000 km (1/2 million km).
yyz
5 / 5 (1) Jul 11, 2010
Very interesting to see examples of grooved terrain similar to that seen on Phobos. That might point to a common origin. The Rosetta blog has the latest images (including a nice shot with Saturn in the distance): http://webservice.../blog/5/

Parsec, I see that the ESA press release indeed notes:

"....the enormous distance between Rosetta and Earth means it will take 25 minutes for these messages to travel to or from the spacecraft. Thus, when a command is sent, it takes almost an hour before confirmation of receipt of that command sent by the spacecraft arrives back on Earth." (ESA PR thru SpaceRef.com: http://www.spacer...id=31183 ). Possibly the distance is suspect?
Caliban
1.7 / 5 (6) Jul 11, 2010
@yyz,

It appears, suspiciously, to possess a certain bilateral symmetry- at least from this view.

It should be interesting to hear Richard Hoagland's views on this, given what he's said regarding Asteroid Steins and Phobos.
Available hear for the curious:

http://www.enterp...ion.com/

I find his speculations entertaining, at the least. As far as the scientific validity of his claims- that remains an open question.

Can't really speak to the transmission delay, except to say that I found a distance figure of ~454 million km between Earth 'n' Lutetia, roughly 2.7AU. Except to say that I don't believe that radio waves propagate at C.
Deesky
2.1 / 5 (11) Jul 11, 2010
What unit of measure is kms?
antialias
5 / 5 (3) Jul 12, 2010
At 300,000 km/sec, it is quite unlikely it would take 25 minutes to travel 500,000 km (1/2 million km).


I think this is a typo. The line should read:

"As Rosetta is around half a BILLION kilometres from Earth..." (which comes out to roughly 27 minutes of transmission time)

Half a million kilometers would be barely further away than the moon.
Caliban
1 / 5 (1) Jul 12, 2010
@antialias

Bingo!
freemind
not rated yet Jul 12, 2010
http://www.esa.in...D_0.html

"Rosetta's journey takes it out to 5.25 AU (about 790 million kilometres from the Sun). The journey to Comet 67P/Churyumov-Gerasimenko lasts 10 years..."
frajo
5 / 5 (1) Jul 12, 2010
It should be interesting to hear Richard Hoagland's views on this, given what he's said regarding Asteroid Steins and Phobos.
Available hear for the curious:
...
I find his speculations entertaining, at the least. As far as the scientific validity of his claims- that remains an open question.
It's not interesting nor entertaining - it's a nuisance. Posting such a link here is misleading the weak and stealing the time of serious people. And no, the scientific validity of those claims is no way an open question. His claims have one and only one validity: commercial trickery.
Caliban
1 / 5 (3) Jul 12, 2010
It's not interesting nor entertaining - it's a nuisance. Posting such a link here is misleading the weak and stealing the time of serious people. And no, the scientific validity of those claims is no way an open question. His claims have one and only one validity: commercial trickery.


Frajo,
I posted that link after a pretty explicit hint of its dubious nature, and for those here who might have enjoyed a little entertainment.

It's too bad if you felt taken in by Hoagland's speculations, if that is, in fact, the case.

I have to say that I really don't understand why you found it so offensive, but I will certainly bear that in mind in future.
frajo
5 / 5 (1) Jul 12, 2010
Very interesting to see examples of grooved terrain similar to that seen on Phobos. That might point to a common origin.
Or to a common building process at a different place and a different time.
Caliban
1 / 5 (2) Jul 12, 2010
Very interesting to see examples of grooved terrain similar to that seen on Phobos. That might point to a common origin.
Or to a common building process at a different place and a different time.


Do I detect a bit of sarcastic humor?
plasticpower
5 / 5 (2) Jul 12, 2010
Why do these probes never have color cameras? Would love to see this thing in full color.
frajo
5 / 5 (3) Jul 12, 2010
I have to say that I really don't understand why you found it so offensive
I wouldn't call it "offensive". But you can't expect other people not to notice your continuous high rankings of otto1923's campaign to induce his superstitious phantasies of an "Empire" under the disguise of an anti-Christian expedition nor those utterly unscientific hints at "ancient america".
I'm weary of all those wealthy ladies and her companionship of seemingly higher education who take one aside to whisper "is it really true that the stars define our destiny?" just because they've heard one is engaged in astrophysics.

Not religion is the pest of the cultures. Superstition is. Because it is not organized and because you never know who's infected. The religious people at least are open about their beliefs and most try to reconcile their beliefs with science whereas the superstitious people are masquerading and would never admit any inclination to anti-scientific thinking.
GSwift7
1 / 5 (1) Jul 12, 2010
In the close-up view, it looks like there's a central crater. Then there's a chip out of the bottom of it. If you visualize an object entering the picture from the bottom and grazing the lip of that crater and breaking apart, with the bulk impacting the top side of the crater, then it would seem to explain what is seen. It would spray debris to the sides and cause a flow like what you see, collapsing the walls on the bottom and top in varying degrees. I wonder if that is what they will eventually decide happened here.

That would indicate a much softer surface than what I've always imagined on a body like this. That would be very interresting.
yyz
not rated yet Jul 12, 2010
After posting "That might point to a common origin" I had a (thankfully brief) flashback to Hoagland's claims wrt Phobos but I let the double entendre stand. Congrats to Caliban for picking up on it.

More to the (intended) point, grooves seen on several asteroids and Phobos may be indicative of fracturing of the body. This 2001 paper explores the relationship between grooves and the internal 'strength' of Phobos and asteroids Gaspra, Ida and Eros: http://www.terrap...1065.pdf

Curiously, a 2006 paper proposed that grooves on Phobos may result from ejecta from impacts on Mars( http://www.lpi.us...2195.pdf ). While this is unlikely for other reasons, grooves on asteroids do not rule out this scenario for Phobos.

BTW, according to Hoagland's unnamed source at ESA (janitor? receptionist?), ESA was supposed to announce the artificial nature of Phobos "soon".
GSwift7
1 / 5 (1) Jul 12, 2010
ESA was supposed to announce the artificial nature of Phobos "soon".

so, you're saying... wait for it.... drum roll....

"that's no moon, that's a space station!"

yyz
5 / 5 (1) Jul 12, 2010
I just find it interesting that grooves/grooved terrain is fairly common in our very small sample of asteroids (and moons) visited by spacecraft to date. Asteroid Steins and Saturn's moon Phoebe also display groove phenomena, along with Ida, Gaspra, Eros and Phobos. Perhaps more than one mechanism is involved? It does seem that this could be an important clue.
antialias
not rated yet Jul 12, 2010
I'll hazard two hypotheses:

1) Large bodies with significant gravity bend the paths of incoming boulders so that they will more likely collide head-on (forming craters). Bodies with little gravity will not do so (or only minimally) - so you can expect a lot more 'glancing blows' which would lead to grooves.

2) The objects were originally part of another, larger body which expelled them after getting hit or breaking up.
What we see as 'grooves' might be underlying stratification (since temperature differentials during day/night cycles after expulsion will work hardest on areas with inhomogeneous materials - causing higher erosion alongthe material edges). That we don't see the bands of materials may simply be due to dust. This would alos explain why the grooves are often parallel.

Oh well..so much for my off-the-top-off-my-head-theories for the day.
david_42
not rated yet Jul 12, 2010
Am I the only one who is annoyed that the "video" is a simulation? What can I find a real link?