To celebrate Rosetta closing in to less than 10,000 km from its target comet as of today, i'm gonna start a new thread for that.
Because it's started to become interesting. On the weekend the following picture of the comet was leaked (yes, leaked), showing a "contact binary" consisting of two distinct nuclei for the comet:
Someone also took the time to create an animated gif of the comet's rotation:
These images were taken on July 11th, one week after ESA released the first grainy pictures of 67P/C-G's shape.
The leak came through CNES, the French Space Agency, and has apparently since been deleted from there. ESA swiftly reacted to the leaking by doing a lengthy post in the Rosetta blog on why there's limited imagery released officially. Along with that comes the promise for an image package - images newer than July 11th - and a movie being officially released tomorrow, so let's wait for that.
Based on Hubble Space Telescope imagery, the shape of the comet was originally, at Rosetta's launch, estimated to look roughly like this:
... which mostly tells us that Hubble of course can't really discern details of rocks at most a few km wide at multi-AU distances.
Posts by Rosetta's managers yesterday already hinted at an entirely "new" shape being revealed in tomorrow's image package.
The shape will not impact Rosetta's planned orbiting of the comet much, since the orbits are finetuned to high detail to consider outside gravitational influences - in particular of the sun when approaching, passing and leaving perihelion - anyway and do no resemble "standard" orbits around a equilibrated spherical object like Earth or other planets.
The navigator for the lander Philae though apparently thinks the shape might complicate finding landing sites.
Rosetta will come within 100 km of the comet on 6th August, which is treated as the official "arrival date". She completed the 7th of 10 planned burns to slow her relative velocity to 67P/C-G this noon. There will be one more FAT (Far Approach Trajectory) burn next wednesday, then after that two CAT (Close Approach Trajectory) burns. The first CAT will occur on August 3rd (at a distance of probably somewhere around 400-500 km), slightly altering her trajectory - currently a 200-km safety flyby - to a 70-km target flyby distance and lowering her speed to 1 m/s relative. The second CAT burn will be on the "arrival date", and will insert Rosetta into the orbit.
Both Rosetta and Philae are now fully operational and have started running their sensors. Philae is currently in a cool-down phase after running its instruments over a 30-hour phase from Monday to Tuesday.
Because it's started to become interesting. On the weekend the following picture of the comet was leaked (yes, leaked), showing a "contact binary" consisting of two distinct nuclei for the comet:
Someone also took the time to create an animated gif of the comet's rotation:
These images were taken on July 11th, one week after ESA released the first grainy pictures of 67P/C-G's shape.
The leak came through CNES, the French Space Agency, and has apparently since been deleted from there. ESA swiftly reacted to the leaking by doing a lengthy post in the Rosetta blog on why there's limited imagery released officially. Along with that comes the promise for an image package - images newer than July 11th - and a movie being officially released tomorrow, so let's wait for that.
Based on Hubble Space Telescope imagery, the shape of the comet was originally, at Rosetta's launch, estimated to look roughly like this:
... which mostly tells us that Hubble of course can't really discern details of rocks at most a few km wide at multi-AU distances.
Posts by Rosetta's managers yesterday already hinted at an entirely "new" shape being revealed in tomorrow's image package.
The shape will not impact Rosetta's planned orbiting of the comet much, since the orbits are finetuned to high detail to consider outside gravitational influences - in particular of the sun when approaching, passing and leaving perihelion - anyway and do no resemble "standard" orbits around a equilibrated spherical object like Earth or other planets.
The navigator for the lander Philae though apparently thinks the shape might complicate finding landing sites.
Rosetta will come within 100 km of the comet on 6th August, which is treated as the official "arrival date". She completed the 7th of 10 planned burns to slow her relative velocity to 67P/C-G this noon. There will be one more FAT (Far Approach Trajectory) burn next wednesday, then after that two CAT (Close Approach Trajectory) burns. The first CAT will occur on August 3rd (at a distance of probably somewhere around 400-500 km), slightly altering her trajectory - currently a 200-km safety flyby - to a 70-km target flyby distance and lowering her speed to 1 m/s relative. The second CAT burn will be on the "arrival date", and will insert Rosetta into the orbit.
Both Rosetta and Philae are now fully operational and have started running their sensors. Philae is currently in a cool-down phase after running its instruments over a 30-hour phase from Monday to Tuesday.
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