Rosetta’s first sighting of its target was taken on
21 March by the OSIRIS Narrow Angle Camera.
The comet is indicated by the small circle next
to the bright globular star cluster M107.
The image was taken from a distance
of about 5 million kilometres to the comet.
Credit: ESA/Rosetta/MPS for OSIRIS Team
Rosetta’s OSIRIS narrow angle camera
captured this image of the comet on 7 August
from a distance of 104 km.
Credit: ESA/Rosetta/MPS for OSIRIS Team
In preparation for the November
12 landing of the companion Philae
spacecraft, Rosetta is taking up an
orbit only 19 miles above the surface
of the comet. The final landing site
was chosen as the primary landing
site because the majority of terrain
within a square kilometre area has
slopes of less than 30º relative to the
local vertical and because there
are relatively few large boulders.
Because the gravity of the
10-billion-ton nucleus is so weak,
Philae will actually approach the
surface at about 2 miles per hour
and “dock” with the surface, just like
NASA’s Space Shuttle used to dock
with the International Space Station.
To avoid bouncing off, Philae will
immediately launch two harpoons
into the icy surface to anchor itself.
The comet reaches its closest
point to the Sun, called perihelion,
on Aug. 13, 2015, and the Rosetta
mission ends in December 2015, so
we will at last be able to see how the
comet nucleus outgasses to form a
tail. Because perihelion is 30-percent
farther from the Sun than Earth’s
orbit, the comet will not heat up very
much, so the flow of vaporized water
and other volatiles from the surface
will be pretty weak. The comet’s
Five candidate sites (from an initial selection of 10 possible sites) were identified for landing of the Philae probe. The approximate locations of the five regions are marked
on these OSIRIS narrow-angle camera images taken on 16 August from a distance of about 100 km. Credit: ESA/Rosetta/MPS for OSIRIS Team
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