Rosetta space mission - Philae probe due to land on comet on 12th Nov 2014
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2hats
Dust.
Over the next two weeks some spectacular images from yesterday's close fly-by should slowly be released (it is low data rate 'season' as the probe and comet are on the far side of the Sun, seen from the Earth, so the Sun will interfere with the data return - this will last around a month).
2hats
Dust.
The high resolution images from OSIRIS are being released. The one below (from 6km above the surface) covers 228x228m at a resolution of 11cm. The (blurred, extended, due to increasing proximity to the Sun) shadow of Rosetta itself on the surface can even been seen (lower edge):
Detailed image here.
Location:
The geometry of this and other images acquired around the same time will facilitate understanding of the various sizes of the pieces of material of which the surface is composed.
(Note the brightening effect around Rosetta's penumbral shadow which is down to the lighting geometry leading to 'shadow hiding' and a consequent bright region at the observer's antisolar point: Heiligenschein - seen with the lunar regolith and not uncommon on Earth either.)
Detailed image here.
Location:
The geometry of this and other images acquired around the same time will facilitate understanding of the various sizes of the pieces of material of which the surface is composed.
(Note the brightening effect around Rosetta's penumbral shadow which is down to the lighting geometry leading to 'shadow hiding' and a consequent bright region at the observer's antisolar point: Heiligenschein - seen with the lunar regolith and not uncommon on Earth either.)
Impossible Girl
Time traveller and Companion
I've followed this intensely and the pics are amazing, thanks for posting them. Just hope Philae will wake up soon to get more of these !
That's so sweet 
2hats
Dust.
First in a series of attempts to contact Philae will occur tomorrow from 0100UTC and then periodically till 20th March. Philae may still be 'asleep' or may already be awake (ie it has recharged sufficiently and the local thermal situation is suitable). If the latter, and it has sufficient additional power to communicate, then it should send back a health check to the orbiter. Most likely it is still slumbering but the chances of making contact should improve as time passes (lighting angles for recharge improve).
(Edited to correct the contact window timing).
(Edited to correct the contact window timing).
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Impossible Girl
Time traveller and Companion
*opens popcorn box and shares it around*
2hats
Dust.
During the most recent close flyby of the nucleus (14km above the surface in recent days) Rosetta experienced some pointing problems and communication with the spacecraft was temporarily lost.
This is due to the increasing surface activity on the comet as it approaches the Sun - increasing surface debris ejected in to the near-nucleus environment is confusing the star trackers and leading to pointing errors (and consequent loss of signal). When this happens the spacecraft drops in to a safe mode and mission controllers are subsequently able to recover it (this happened twice over the weekend). Safe mode also involves powering down instruments (so inevitably this impacts the collection of various science data).
Most likely mission planners will revise future trajectories in order to to maintain as near continuous operation as possible towards and through perihelion.
Fine details here.
This is due to the increasing surface activity on the comet as it approaches the Sun - increasing surface debris ejected in to the near-nucleus environment is confusing the star trackers and leading to pointing errors (and consequent loss of signal). When this happens the spacecraft drops in to a safe mode and mission controllers are subsequently able to recover it (this happened twice over the weekend). Safe mode also involves powering down instruments (so inevitably this impacts the collection of various science data).
Most likely mission planners will revise future trajectories in order to to maintain as near continuous operation as possible towards and through perihelion.
Fine details here.
2hats
Dust.
Rosetta is now 'orbiting' along a set of revised pyramid trajectories some 100km from the cometary nucleus. It will start listening out again for Philae from tomorrow, continuously through till at least June in order to (hopefully) catch the lander waking up. If the orbiter proves to be stable, with no communications problems, then mission managers may start to lower the orbit in May (if there are issues arising from increased comet activity they will probably edge a little further away from the nucleus).
2hats
Dust.
For the first time a jet has been 'seen' to burst in to action. These two frames were taken around 2 minutes apart:
Interestingly this is a jet erupting on the 'dark side' of the nucleus. Either it sprung from a region that was only just coming in to sunlight, or perhaps more likely, is the result of heat propagating through the nucleus from (already) sunlit regions which melted ice in the interior causing it to outgas.
Interestingly this is a jet erupting on the 'dark side' of the nucleus. Either it sprung from a region that was only just coming in to sunlight, or perhaps more likely, is the result of heat propagating through the nucleus from (already) sunlit regions which melted ice in the interior causing it to outgas.
2hats
Dust.
NAVCAM images are being released. A clutch from September-November last year with a lot of close-ups such as this from 19 October (distance 7.9km, resolution 77 cm/pixel, hi-res version here):
More covering November-December are being released next month.
Only 76 days to go to perihelion.
More covering November-December are being released next month.
Only 76 days to go to perihelion.
2hats
Dust.
More night time dust jets - these active after local sunset, as seen by the OSIRIS camera on 25 April:
Quite probably thermal energy is being stored/transported in the sub-surface resulting in 'night time' activity - up until mid March activity had only be seen on the sunward facing sides of the nucleus. Note that the image has been processed to bring out the jets (resulting in the lit surface being overexposed).
Quite probably thermal energy is being stored/transported in the sub-surface resulting in 'night time' activity - up until mid March activity had only be seen on the sunward facing sides of the nucleus. Note that the image has been processed to bring out the jets (resulting in the lit surface being overexposed).
Steel Icarus
ersatz maven
Some stunning images here 2hats, thanks for posting
2hats
Dust.
Modelling suggests (or did last time I checked) that the jets are simply too tenuous to drive Philae off the surface. However, one could imagine that if the surface the lander is in contact with were to evaporate then Philae could conceivably end up in close proximity to the surface and then either eventually come to rest in contact with it (weak gravitational attraction) or, if impinged upon by sufficient jet activity, driven away from the surface into the near-nucleus environment. Of course, Philae would appear to be in a quite heavily shadowed area, (probably) a slightly less active area and thus at lower risk of this than if it had landed somewhere well lit.
TheHoodedClaw
acknowledging ur soup leg
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