Lutetia: First results of VIRTIS -M data analysis

Details Lutetia: First results of VIRTIS -M data analysis Lutetia: First results of VIRTIS -M data analysis

Dec 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufm.p14b..04c&link_type=abstract

American Geophysical Union, Fall Meeting 2010, abstract #P14B-04

Mathematics

Logic

[6205] Planetary Sciences: Solar System Objects / Asteroids

Scientific paper

VIRTIS aboard Rosetta has successfully returned spatially-resolved 0.4-5.0 µm hyperspectral data of the main belt asteroid 21 Lutetia during the 10th July 2010 flyby. Moreover the first thermal map of the asteroid has been obtained. During the encounter both channels of VIRTIS (M- mapper, H- high resolution) worked nominally. The flyby observation strategy is divided in three phases: 1) Light Curve phase performed during the approach period up to about 1 hour before Closest Approach (CA). During this phase the angular size of the object varies from about 75 µrad up to 2000 µrad. Two full rotations of the target are acquired. The spectral light curve provide us an indication of the degree of the spectral heterogeneity of the entire asteroid’s surface as a function of the rotational phase allowing to correlate any brightness variation to either compositional or morphological variegation of the surface itself; 2) Scanning Imaging phase has been performed in the interval (CA-1800) seconds to (CA-500) seconds. In this phase the relative speed between S/C and asteroid has been low enough to allow VIRTIS-M to operate with its scanning mirror to build up several hyperspectral cubes; 3) Pushbroom Imaging phase includes the closer range period (down to about 3000 km distance) when the S/C speed is too large to allow scanning, consequently the instrument has been operated in pushbroom mode. At the end of this phase VIRTIS observed regions towards the terminator and on the asteroid’s night side. The most important observations were collected during this last phase when the average spatial resolution was about 800 m/pixel and the full asteroid’s disk spanned across about 130 pixels. On VIRTIS-M images several craters and grooves are observed allowing us to map different surface units. Lutetia’s average VIS-IR reflectance spectra is not incompatible with a carbonaceous chondrites composition. In the 0.4-0.5 µm the spectrum appears red, with a spectral knee at about 0.55 µm; from here up to about 2.5 µm it remains flat, not showing any detectable absorption band. From 3.5 µm up to 5 µm we observe a significant thermal emission; the calculated maximum temperature close to the subsolar point is of about 240K. After having removed the thermal emission we cannot firmly confirm the presence of a possible 2.7 µm OH hydration band, even if a weak large band can be identified. Finally, after having carefully removed the thermal emission, we observe several absorption bands in the 4.5-5.0 µm spectral range which are compatible with the presence of solar protons implanted on the surface.

Affiliated with

Also associated with

No associations

Rating

Lutetia: First results of VIRTIS -M data analysis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Lutetia: First results of VIRTIS -M data analysis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lutetia: First results of VIRTIS -M data analysis will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1495086