Seeing the surface of Venus with VIRTIS on VENUS EXPRESS



 
 Overlay between the globally averaged relative emissivity as observed from the VIRTIS instrument (continuous lines) and the relative emissivity as it would appear according to our simulation (dashed lines).
zum Bild Overlay between the globally averaged relative emissivity as observed from the VIRTIS instrument (continuous lines) and the relative emissivity as it would appear according to our simulation (dashed lines).

The ESA Venus Express probe was launched on November 9, 2005, from the Baikonur Cosmodrome in Kazakhstan and it arrived at Venus on April 2006. The Mission is mainly devoted to study Venusian atmosphere, cloud system and surface volcanic activity. One of the key questions of the Venus Express Mission is trying to answer is that of understanding whether or not Venus has a still active volcanism: our group undertakes this particular task.

 The VIRTIS instrument mounted on the Venus Express probe.
zum Bild The VIRTIS instrument mounted on the Venus Express probe.

The VIRTIS on the ESA mission VenusExpress (VEX) was the first instrument to routinely map the surface of Venus using the near infrared windows from orbit. The instrument is the flight spare of the VIRTIS instrument on the ESA Rosetta comet encounter mission. Originally designed to observe a very cold target far from the Sun, it was adapted to work in the Venus environment. The instruments main purpose on VEX was to study the structure, dynamics and composition of the atmosphere in 3 dimensions. The idea of surface studies were introduced very late in the mission planning and VIRTIS was never specifically adapted for this purpose. Despite some issues VIRTIS was an excellent proof-of-concept and far exceeded our expectations. It provided significant new scientific results and could show for example that Venus had volcanic activity in the very recent geological past.

The ongoing analysis of the VIRTIS data is focusing on the relation between surface emissivity variations, surface weathering and compositional variations. To support this we have set up the Planetary Emissivity Laboratory which allows taking emissivity measurements in the spectral range of the atmospheric windows at sample temperatures of 500°C.


Contact
Dr.rer.nat. Jörn Helbert
German Aerospace Center

Institute of Planetary Research
, Experimental Planetary Physics
Tel: +49 30 67055-319

Fax: +49 30 67055-384

E-Mail: Joern.Helbert@dlr.de
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