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ESA Releases Lutetia Flyby Images

Soulskill posted more than 4 years ago | from the pretty-pictures dept.

Space 48

The European Space Agency has released images from yesterday's close approach of asteroid 21 Lutetia by the Rosetta probe. At its closest, the probe was a mere 3,162 km from the asteroid, passing at 15 km/s and snapping photos sharp enough to make out features as small as 60 meters. "Rosetta operated a full suite of sensors at the encounter, including remote sensing and in-situ measurements. Some of the payload of its Philae lander were also switched on. Together they looked for evidence of a highly tenuous atmosphere, magnetic effects, and studied the surface composition as well as the asteroid’s density. ... The flyby marks the attainment of one of Rosetta's main scientific objectives. The spacecraft will now continue to a 2014 rendezvous with its primary target, comet Churyumov-Gerasimenko. 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 release Philae to land on the comet nucleus." There is also a replay of the media event webcast on the ESA's website.

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Christmas (-1, Offtopic)

Anne_Nonymous (313852) | more than 4 years ago | (#32866216)

It's beginning to feel a lot like Christmas.

Re:Christmas (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#32866302)

How about you feel my ballsack.

Fuck Allah!!! (-1, Troll)

Anonymous Coward | more than 4 years ago | (#32866306)

Islam is nothing more than an excuse to be a murderer and a tyrant. The followers of Islam are a blood thirsty bunch who are either unwitting slaves or ego maniacs who want to keep people repressed.

Fuck Mohammad, Fuck Allah, Fuck Islam!!!

And if you're a Muslim? FUCK YOU!!!

Re:Fuck Allah!!! (-1, Troll)

Anonymous Coward | more than 4 years ago | (#32866324)

And the same goes for all kikes and christians.

Fake!!! (4, Funny)

Anonymous Coward | more than 4 years ago | (#32866330)

When NASA faked the Moon landings they needed an entire film studio. Here all the ESA needed was a potato.

Re:Fake!!! (0)

Anonymous Coward | more than 4 years ago | (#32866780)

I wish every person spitting fake moon landing would ask himself why the Russians would stop dead in their track on the race to land on the moon. The Russians fooled by some supposed cheapo NASA fake ? Some people..

Re:Fake!!! (1, Funny)

Anonymous Coward | more than 4 years ago | (#32867254)

The Russians stopped trying to create their own fake moon landing. No one's actually trying to land.

Re:Fake!!! (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32867784)

Anyone with a brain in their head knows we actually landed on the moon.

Re:Fake!!! (0)

Anonymous Coward | more than 4 years ago | (#32871206)

That's a conspiracy too, your brain is obviously in your pelvis.

Re:Fake!!! (1)

Tablizer (95088) | more than 4 years ago | (#32871618)

When NASA faked the Moon landings they needed an entire film studio. Here all the ESA needed was a potato.

Hasn't your mother told you not to conspiratize on an empty stomach?

cool (1)

dominious (1077089) | more than 4 years ago | (#32866598)

In related news: high-resolution Asteroids 1.2 for linux released.

"Lutetia" (0)

Anonymous Coward | more than 4 years ago | (#32866604)

Damn, I was hoping for some early aerial paintings of ancient Paris.
This is why you shouldn't name things after other things. At least call it "Lutetia II" or "jr." or something.

What they should have called the asteroid.... (0)

Anonymous Coward | more than 4 years ago | (#32866842)

Naw they should have called the asteroid the Rosetta's Stone.

Re:"Lutetia" (1)

Razalhague (1497249) | more than 4 years ago | (#32872152)

At least call it "Lutetia II" or "jr." or something.

They are calling it "21 Lutetia".

Great. (1)

Okian Warrior (537106) | more than 4 years ago | (#32866834)

It's a rock.

Re:Great. (4, Funny)

ColdWetDog (752185) | more than 4 years ago | (#32867156)

It's a rock.

What did you expect? A moon?

Re:Great. (0)

Anonymous Coward | more than 4 years ago | (#32867262)

That's no moon.

Re:Great. (0)

Anonymous Coward | more than 4 years ago | (#32878794)

That's a potato.

Re:Great. (0)

Anonymous Coward | more than 4 years ago | (#32867944)

What did you expect? A moon?

Bread. Apples. Very small rocks.

Re:Great. (1)

steelfood (895457) | more than 4 years ago | (#32878796)

A space station.

About SI units. (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#32866998)

Something that bothers me a bit is that large units of distance are always given in kilometers. Wouldn't it be more "proper" to give it as 3.x megameters (or 3.x million meters)? For some reason you just never see measurements given in these larger units. I can only guess that it is because the kilometer is the easiest large unit of measurement to visualize.

Re:About SI units. (1)

Teun (17872) | more than 4 years ago | (#32868172)

Kilometer is the common measure for distance in most of the world.

Miles is another one.

The next one up is usually astronomical units (Sun-Earth distance) or even light years.

Mega or Giga meters are just like Mega or Giga miles unknown.

Re:About SI units. (0)

Anonymous Coward | more than 4 years ago | (#32869110)

Mega or giga miles don't make sense; that is mixing two measurement systems. Mega or giga meters make perfect sense, but I guess like you say it is just more common to give units in kilometers.

Question for the rocket scientist(s)... (2, Interesting)

wisebabo (638845) | more than 4 years ago | (#32867328)

As an armchair astronomer, I'm as always, extremely impressed by stuff like this. I know the level of precision to pull this off is nothing more than astounding, involving very complex math, deep knowledge of astrophysics and out-of-this-world engineering.

Still I was wondering; why didn't they aim the flyby a little closer, say 100km and not 3500? I believe they had an earlier flyby which did just that at another asteroid so I assume they had the requisite level of precision. I know this might have required them to be off "course" by a few thousand kilometers but in a journey with hundreds of millions to go it would seem to be a detour requiring very little delta-v (and thus very little propellant). Wouldn't the instruments be able to get much better data from a much closer object? Or maybe the position of this asteroid wasn't precisely known, not only giving a (small) risk of collision but making observation via pre-programmed instruments with narrow fields of view impossible. If anyone has a clue, pray tell!

Re:Question for the rocket scientist(s)... (3, Interesting)

Chris Tucker (302549) | more than 4 years ago | (#32868092)

Probably due to the mechanics of the 2014 encounter with the comet.

For every ounce of fuel needed to change trajectory, an ounce of scientific optics and electronics has to be sacrificed.

A lot of good science can be done with a flyby of this nature, as well as allowing for the calibration of some instruments needed for the comet encounter.

Every mission of this nature is one of compromises.

How close can we get to the asteroid?

How much instrument weight can be devoted to asteroid only observations?

Can we use one instrument to serve several mission objectives at the asteroid and the comet, and can this be done without compromising the amount and granularity of the data returned?

And of course: How much money do we have to spend on the vehicle itself and the scientific packages installed in the vehicle?

Can we sacrifice something in order to have a bigger and better sensor package?

If so, what gets sacrificed?

All things considered, this looks like a very good return of data and science from the asteroid flyby.

Re:Question for the rocket scientist(s)... (1)

Tablizer (95088) | more than 4 years ago | (#32871672)

For every ounce of fuel needed to change trajectory, an ounce of scientific optics and electronics has to be sacrificed.

I'm a little skeptical. That far away from the comet the fuel difference is not a lot. They usually make a few minor course corrections anyhow because the exact route is never known until fairly close to the target. In other words, the difference between a closer flyby and a medium-distance flyby of that rock probably has a smaller fuel impact than the typical navigation error size anyhow.

Maybe if they got real close, then the asteroid's gravity may have a significant influence, but I doubt it's an issue between the choice of semi-close versus medium because it's a small asteroid.
   

Re:Question for the rocket scientist(s)... (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32868100)

I'm no rocket scientist, but maybe the closer they get, the less time they have to take pictures: the article says it flew by at 15 km/s.

Re:Question for the rocket scientist(s)... (2, Interesting)

Tablizer (95088) | more than 4 years ago | (#32868180)

why didn't they aim the flyby a little closer, say 100km and not 3500?

For one, at that close the instruments and/or craft must be coordinated to move in a way that keeps the target area in view of cameras and instruments. Features would pass by at a rather quick pace. Handling such adds to the complexity of the craft and mission. It's designed to study comets, not asteroids, and one must keep a distance from a comet because of the dust. (It has a detachable comet lander dedicated to such with dust protection engineering.)

Second, they didn't know the shape of the asteroid very well until they actually got there. If you plan a close flyby and part of the asteroid juts out, El Klunnnng!

Third, some asteroids have their own little moons. The closer you get, the more likely you are to "eat" one.
     

Re:Question for the rocket scientist(s)... (5, Interesting)

Tablizer (95088) | more than 4 years ago | (#32868360)

For one, at that close the instruments and/or craft must be coordinated to move in a way that keeps the target area in view of cameras and instruments. Features would pass by at a rather quick pace. Handling such adds to the complexity of the craft and mission.

This is similar to a key issue with the New Horizons (NH) Pluto/Kuiper-Belt mission. It's moving so fast that it doesn't have a long time at targets. The Voyager crafts had separate, semi-dedicated platforms for each instrument or instrument group. Thus, each could be aimed to work at its optimum pace.

However, that was deemed too expensive for NH, so instead they designed the *whole craft* to move via gyros and pressurized gas to aim each instrument. Many instruments thus have to take turns. It's not the ideal, but it cut costs. If you get too close, then there's no time for each instrument to get a look. You have to pick and choose. Maybe one instrument may get a good look, but the returns are diminishing.

For example, it may be cheaper to have a bigger telescopic lens rather than an independent camera platform and study the target from a medium distance.

Re:Question for the rocket scientist(s)... (0)

Anonymous Coward | more than 4 years ago | (#32868304)

The launch was delayed twice. As a result the mission was already so low on fuel they had to change the mission profile to do a risky low-altitude flyby of Mars for a gravitational slingshot. I imagine with fuel in such short supply they could not afford to spend any more on a side trip before heading off to their real objective.

Re:Question for the rocket scientist(s)... (2, Insightful)

BlindRobin (768267) | more than 4 years ago | (#32869428)

Obviously the persons in charge of the mission didn't evaluate the risk using the same criteria as you and deemed the risk to be greater than the benefit.

Re:Question for the rocket scientist(s)... (0)

Anonymous Coward | more than 4 years ago | (#32870648)

Thanks for a non-answer. You fail.

Re:Question for the rocket scientist(s)... (0)

Anonymous Coward | more than 4 years ago | (#32871124)

Hey! I'm not a rocket scientist!
I'm a brain surgeon.

Rocket science is down the hall in room 322A.

Re:Question for the rocket scientist(s)... (1, Informative)

Anonymous Coward | more than 4 years ago | (#32872400)

I've read the replies to this question, and would like to give my (insider's) input. In simple terms, the flyby distance was determined to be no closer than 3160km because the whole object needed to fit inside the tracking camera's field of view. Otherwise, we would get unpredictable results in the spacecraft attitude at closest approach. Given that the NAVCAMs have a 5deg x 5deg FOV and we could use about 45% of that (for processing speed/exposure time reasons), and the asteroid was estimated to be 130km on its longest axis, add some safety margin, and you get something of the order of the given distance. Incidentally, we were 3160km from the center of the object, so a bit closer to the surface. There was some speculation about the fuel impact a closer flyby would have had. There would have been none, since we would have aimed closer at a very early time already. As it was, we actually had to move out from the asteroid with a correction maneuver.

Re:Question for the rocket scientist(s)... (1)

wisebabo (638845) | more than 4 years ago | (#32872674)

Great! Thank you very much for answering my question! I knew something non-obvious was going on..

Uh, just in case you feel inclined to answer another question; I assume you won't be using the NAVCAMs for the final approach to the comet. What will you do? (Maybe you should just refer me to a good web article).

Thanks again.

Re:Question for the rocket scientist(s)... (0)

Anonymous Coward | more than 4 years ago | (#32873172)

On the contrary, we shall be using the NAVCAMs on our approach to the comet. As soon as it is discernible on NAVCAM images, this data will be used to augment ground-based orbit determination data. (Orbit determination, that is, of both the comet and the spacecraft.)

This way, at least the relative position between comet and spacecraft can be determined very precisely. Using this orbital data, we will design a manoeuvre to put Rosetta into a tight orbit around the comet.

As to whether there are web articles that contain this type of information, I cannot say. I know it from working in the team, as well as the spacecraft user manuals, which are,of course, not publicly available ;-).

Re:Question for the rocket scientist(s)... (1)

wisebabo (638845) | more than 4 years ago | (#32873452)

Wow, great, don't get too close (until you need to)!

Best of luck, will be waiting for the rendezvous!

P.S. It's funny to think of something so sophisticated and one of a kind as a comet orbiter having a user manual. I guess everything has one; I'd like to see one for an aircraft carrier or, for that matter, planet earth. ;)

Re:Question for the rocket scientist(s)... (1)

MaunaLoa (774516) | more than 4 years ago | (#32875400)

I guess it would be suboptimal to discover that Lutetia has a moon when it already fills the windscreen of the probe...

It has Striations! (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32869592)

Just like Phobos and Deimos. We are going to see linear striations (tracks?) everywhere, I bet.

Re:It has Striations! (1)

cusco (717999) | more than 4 years ago | (#32871636)

Was just coming here to post the same thing. I believe there were also striations on Eros and Ida.

Re:It has Striations! (1)

Tablizer (95088) | more than 4 years ago | (#32871692)

Did they ever find the cause?

Re:It has Striations! (0)

Anonymous Coward | more than 4 years ago | (#32872540)

Too close flybys by past civilizations' probes.

Re:It has Striations! (1)

cusco (717999) | more than 4 years ago | (#32883318)

Not that I know of. I would suspect shrinking as the object cooled. A large impact will heat it and cause expansion, and then as it cools contraction could cause wrinkling of the surface layer. Just my guess, I haven't read any better explanations from actual planetologists.

Re:It has Striations! (1)

Tablizer (95088) | more than 4 years ago | (#32895682)

I would expect shrinkage would produce a more irregular pattern, similar to Mercury's surface, which is suspected of having shrank. It's kind of an elephant-skin look.

Strange Shadows (1)

Muad'Dave (255648) | more than 4 years ago | (#32874558)

Can someone explain the seemingly strange shadows on the bottom-right image in this montage [esa.int] ?

The shadows on the craters in the upper part of the image seem to suggest that the source of illumination is toward the middle-left off of the image, but the craters on the bottom of the image seem to be illuminated from the top of the image.

The only thing I can think of is that there's quite a bit more curvature in that image than is apparent.

Ideas?

What Source Striations? (1)

FurtiveGlancer (1274746) | more than 4 years ago | (#32875488)

In the last two photos of TFA, striations are clearly visible. Since the craters appear to be mostly round, I doubt the impacts would carry ejecta linearly along the asteroid. Any ideas?

Re:What Source Striations? (0)

Anonymous Coward | more than 4 years ago | (#32879426)

In the last two photos of TFA, striations are clearly visible. Since the craters appear to be mostly round, I doubt the impacts would carry ejecta linearly along the asteroid. Any ideas?

Depending on the impact angle the ejecta might be able to produce that, or perhaps it's some result of the vibrations caused by impacts with certain characteristics. Perhapsthese people [nasa.gov] should look into it, this type of thing seems right up their alley.

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