HomeOn 10 July 2010, Rosetta will pass by asteroid (21) Lutetia, with closest approach predicted to take place at 15:44 UTC (17:44 CEST).
This will be the spacecraft's second asteroid encounter with an asteroid of the main asteroid belt between Mars and Jupiter.
Rosetta is expected to pass the asteroid with a relative velocity of 15 km/s at a minimum distance of 3160 km (all figures subject to change). The selected flyby strategy allows continuous observation of the asteroid before, during and after closest approach. Most of the scientific instruments on Rosetta will be switched on for investigations. Imaging and spectral observations will be obtained covering ultraviolet to sub-millimetre wavelengths. A number of in situ measurements will be made of the asteroid as well as of its direct environment.
The target, (21) Lutetia, is a large asteroid with an estimated diameter of about 95 km. It has been classified as either C-type or M-type, meaning that remote sensing observations have shown features that hint at characteristics of carbonaceous chondrite (a type of meteorite that contains organic chemicals and water), but also to a metallic surface composition. This contradiction makes (21) Lutetia an extraordinarily interesting object for close inspection from space.
More info to follow in the coming days here in the Rosetta Blog!
This will be the spacecraft's second asteroid encounter with an asteroid of the main asteroid belt between Mars and Jupiter.
Rosetta is expected to pass the asteroid with a relative velocity of 15 km/s at a minimum distance of 3160 km (all figures subject to change). The selected flyby strategy allows continuous observation of the asteroid before, during and after closest approach. Most of the scientific instruments on Rosetta will be switched on for investigations. Imaging and spectral observations will be obtained covering ultraviolet to sub-millimetre wavelengths. A number of in situ measurements will be made of the asteroid as well as of its direct environment.
The target, (21) Lutetia, is a large asteroid with an estimated diameter of about 95 km. It has been classified as either C-type or M-type, meaning that remote sensing observations have shown features that hint at characteristics of carbonaceous chondrite (a type of meteorite that contains organic chemicals and water), but also to a metallic surface composition. This contradiction makes (21) Lutetia an extraordinarily interesting object for close inspection from space.
More info to follow in the coming days here in the Rosetta Blog!
8 comments | "Lutetia flyby 10 July 2010"
15-06-2010 • 19:22:09
What considerations is the minimum distance of about 3200Km based on? Why not, say, 5 times less... or more? Is this the closest possible approach? Thank you!
17-06-2010 • 17:34:42
Franz: Armelle Hubault, an engineer working on the Rosetta Flight Operations Team, gave us this reply: The closest approach (CA) distance for Lutetia was driven by the size of Lutetia itself. At CA, Lutetia will fill the whole tracking window in the NavCam field of view. For Steins, it was a different situation because the asteroid was much smaller. In that case, the CA distance was driven by the maximum rates authorised for the reaction wheels [since the spacecraft has to slew as it passes by to keep the cameras pointed at the target].
We'll publish a few more details on this topic in our next blog post. Cheers - Daniel
15-06-2010 • 17:01:32
Today in http://www.esa.int/esaSC/SEM9VRQVEAG_index_0.html ESA repeatedly states that "no one knows what it looks like" - yet already in May the paper http://arxiv.org/abs/1005.5356 showed resolved images of Lutetia, taken with large telescopes and Adaptive Optics. We not only know - roughly - what the asteroid looks like (namely like a giant Camembert, as the authors put it) but even how it rotates and what its seasons are.
16-06-2010 • 16:05:15
Daniel: We posed this query to several of the ESA scientists working with the mission and the answer is simple: "Although recent high resolution ground-based images have given some idea of the overall shape of Lutetia, we have no idea what it looks like in detail, and Rosetta will tell us that." - DGS
13-06-2010 • 13:57:15
Please can we not wait too long for the images at least. Will it be possible to post them as soon as they are returned. I will not be the only one who are willing to assist with enhancements, etc IF they are needed (I suspect not).
In my opinion I think 21 Lutetia will be more exciting & interesting than the target comet 67P Churyumov-Gerasimenko
13-06-2010 • 13:36:11
I am following this intently. 21 Lutetia by far will be that largest asteroid seen up close, similar in size to the Saturn moon Epimetheus.
Do we know what season 21 Lutetia will be in at encounter? 21 Lutetia has an axial tilt of approx 76 degrees, so hopefully it will be near an equinox. Even if near a solstice, we will still get some fantastic imagery.
Please do not let the same mistake happen as at 2867 Šteins, i.e instrument shutdown due to software errors.
We'll know for sure what type 21 Lutetia is & also if it has any moons. The size of 21 Lutetia (132 KM by 95 KM) may reveal a variety of surface features.
04-06-2010 • 08:43:22
BTW. This ahs been mentuiione don the Dr Phil Plait's very popular Bad Astronomy science blog - see :
http://blogs.discovermagazine.com/badastronomy/2010/06/02/two-upcoming-spacecraft-encounters
04-06-2010 • 08:41:27
Good luck and best wishes for this -hope all goes well and we get some excellent images! :-)