[meteorite-list] Rosetta Delivers Phobos Transit Animation and 'Sees' Mars in Stereo

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 4 Mar 2007 21:53:07 -0800 (PST)
Message-ID: <200703050553.VAA29737_at_zagami.jpl.nasa.gov>

http://www.esa.int/esaCP/SEM9R6N0LYE_index_0.html

Rosetta delivers Phobos transit animation and 'sees' Mars in stereo
European Space Agency
27 February 2007

During Rosetta's recent Mars swingby, the OSIRIS cameras captured a series
of images of Mars and of Phobos transiting Mars' disk. The OSIRIS team have
produced a cool animated sequence and a 3D view of the Red Planet.

The animated sequences (one faster, one slower) show the shadow of Phobos
transiting Mars' disk on 24 February; the images were captured around 22:08
CET [2108 UTC], a few hours prior to Rosetta's successful Mars swingby on 25
February.

The movies were produced by combining a series of separate images taken by
the Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS) on
board Rosetta.

The background of Mars changes slightly from image to image since the
individual images were acquired using different colour filters. Phobos
appears dark because it reflects less sunlight than Mars.

Phobos is the inner moon of Mars; Phobos orbits closer to a major planet
compared to any other moon in our solar system (less than 6000 km above the
surface of Mars), and it is also one of the smallest known moons in the
solar system.

Mars in 3D
 
Although Rosetta's direction relative to Mars was relatively constant during
the approach phase, the surface view of Mars changed due to the rotation of
the planet.

Thus, it was possible to produce a stereoscopic image, or anaglyph, by
processing and combining images acquired by OSIRIS at different times.

The image was produced by combining several views of Mars taken from
slightly different angles. In this case, the anaglyph was generated using
images acquired 6 minutes apart.

To see the 3D effect, use a pair of left-eye red, right-eye blue colour
glasses.

The 3D image clearly shows the spherical shape of Mars. However, due to the
angle between the different views, Martian topography is not visible
stereoscopically.

At closest approach at 03:15 CET on 25 February, Rosetta passed over the
planet's surface at a relative speed of 36 191 km/hr. During the swingby,
the gravitational energy of Mars helped Rosetta change direction, while the
spacecraft was decelerated with respect to the Sun by an estimated 7887
km/hour.

The spacecraft is now on the correct track towards Earth -- its next
destination planet whose gravitational energy Rosetta will exploit in
November this year to gain acceleration and continue on its trek.

Contact for more information:
 
Uwe Keller
OSIRIS Principal Investigator
Max-Planck-Institut f Aeronomie
Email: KELLER _at_ linmpi.mpg.de

Gerhard Schwehm
ESA Rosetta Mission Manager
Email: gerhard.schwehm _at_ esa.int

[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaSC/SEM9R6N0LYE_index_1.html ]
Received on Mon 05 Mar 2007 12:53:07 AM PST