Rosetta has been returning some stunning images of Comet 67P/Churyumov-Gerasimenko that ESA is putting up on the Rosetta Blog.
This one shows 67P/G-C from a distance of 415 km / 258 miles show nice outgassing. We are looking at the southern hemisphere some of which has been in darkness for five and a half years, just becoming visible in May.
Comet 67P/Churyumov-Gerasimenko and its human-made-moon called Rosetta has now passed its closest distance to the Sun in this orbit (perihelion) and is now spending several weeks at peak activity. The activity means the flight operations team must be prepared to react to fast jets of dust and gas erupting from the comet or stray boulders ejected from its surface.
The Philae lander shows us what the surface of Comet 67P/Churyumov–Gerasimenko looks like in this very nice image. I don’t know what I expected to see, but this is surprisingly familiar. I wonder what the surface make up is.
From ESA: This image was taken by Philae’s ROsetta Lander Imaging System, ROLIS 9 m above the Agilkia landing site on the small lobe of Comet 67P/Churyumov–Gerasimenko. The image was acquired at 15:33:58 GMT on 12 November 2014. The image measures 9.7 m across and the image scale is 0.95 cm/pixel. Part of Philae’s landing gear can be seen in the top corners.
This detailed image reveals the granular texture of the comet’s surface down to the cm scale, with fragments of material of diverse shapes and random orientations seen in clusters or alone. The regolith in this region is thought to extend to a depth of 2 m in places, but seems to be free from very fine-grained dust deposits at the resolution of the images.
On 20 September 2014, ESA’s Rosetta spacecraft made an extremely close pass to Comet 67/P Churyumov–Gerasimenko. This image was taken from just 26 km / 16 miles from the surface.
There are 18 pits identified on 67/G-C, each named for the region they are in. Some are active and some are not. This image shows the Seth series of pits, Seth_01 is the one in the center and the easiet to recognize. See this ESA post for more location information. Seth_01 is 220 m / 722 feet across and 185 m / 607 feet deep. We don’t see activity in the image, however the diversity of the terrain was the goal.
I will admit to fiddling with the image to see if I could bring out some activty but I could not. One has to wonder if the same image was taken today if activity would be seen.
ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
These images from the Rosetta orbiter around Comet 67P/Churyumov-Gerasimenko show what appear to be a shiny rock outcrop in the Khepry region (top image) and a lone boulder in the Hatmehit region (bottom image). There have been 120 such areas like these found on the comet.
These particular images were taken last September from about 20 km.
What are the shiny objects? They are thought to be exposed patches of water-ice!
This is a view of Comet 67P/Churyumov-Gerasimenko just before receiving the long awaited signal from Philae on 13 June. Rosetta was just 201 km / 125 miles from the center of the comet at the time. The image has the small lobe to the right and the depression called Hatmehit is visible. Philae is thought to be situated near the top right of the image just outside the rim.
Philae is receiving enough sunlight to attain an acceptable operation temperature and generate electricity. The local “comet day” the power generated rises from about 13 watts at sunrise to a bit more than 24 watts. the power required to turn on the transmitter is 19 watts. I should note the comet has about a 12 hour rotation and the day light cycle is some portion of that and may be more or less than half the time. The time the solar panels receive power is 135 minutes during the daylight cycle.
“While the information we have is very preliminary, it appears that the lander is in as good a condition as we could have hoped,” says Dr Ulamec.
I know, it’s been a while. Rosetta is still orbiting Comet 67P/Churymov-Gerasineko and the spacecraft is doing well.
It has to be, the distance between Rosetta and the comet is 200 km / 124 miles and the pair
are moving at 30.91 km/s / 69,143 mph!
The comet is a little over 310,344,000 km / 192,839,000 miles. The pair should be closing
in on the orbit of Mars, which it will do at a fairly shallow angle.
As the pair gets closer the expected increase in activity in terms of streamers coming off the comet is occurring.
The Rosetta blog shows an enhanced version and a nice description including topographical features of the comet.
A Rosetta NAVCAM image of Comet 67P/Churyumov-Gerasimenko from 81.4 km / 50.6 miles. ESA did a nice job of processing the image in order to bring out some of the outflow. The outflow should become more evident over time and give 67P/G-C the classic comet look.
In the mean time Rosetta is intermittently sending radio signals to the Philae lander to establish contact. So far nothing has been heard from the little lander. Possibly the solar panels have not built up enough power in the systems to function or maybe it is just too cold. The lander remains in hibernation.
Philae needs an internal temperature above -45 C / -49 F and five watts of power to turn on – which is pretty impressive. The lander needs to be able to generate 19 watts in order to send signals to Rosetta.
ESA is choosing when to send signals to Philae so the alignment between it and Rosetta and presumably the sun to have the best chance for success. The first half of April will be the next best opportunity to contact.
If you click the image above you will see a version with some of the craters labeled.