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Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.

Vicomt

By Vicomt
in Science & Spaceflight

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lajoswinkler

lajoswinkler

Posted
Posted

Interactive 3D rendering of the comet.

http://sci.esa.int/comet-viewer/

Enjoy. :)

The pictures of the outburst, unless cropped in gradual manner, show the change in orientation.

Could it be a result from the tremors caused by the outburst?

No, the outburst is infinitesimaly weak compared to the kinetic energy needed to do that. To turn a comet like this would mean to disrupt its shape, too. The comet is rotating and Rosetta is orbiting. That's the cause of the different angles.

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Frida Space

Frida Space

Posted
Posted
Oh...

Somehow I got the idea they were taken by Philae. Ah, well.

Haven't got new images from Philae since Nov 2014. There was a plan to make it send a new CIVA panorama, but there has been no contact since.

Some fine images of 67P/C-G from various Earth observatories (Gemini N & S, VLT, Liverpool...). Also a spectra (red line is average spectra of a sun like star)

earth.png

- - - Updated - - -

Still waiting for the press release...

image.png

12_ag.png

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http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_s_big_day_in_the_Sun

- - - Updated - - -

Approaching_perihelion_Animation_node_full_image_2.gif

- - - Updated - - -

A boulder flying away:

Boulder_flying_by_comet_node_full_image_2.gif

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softweir

softweir

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Thanks for linking that. :)

But OW my eyes! They don't take kindly to viewing stereo pairs. Hint: A lot of people may well see the image too large on their screens, so should to zoom out to get the stereo pair small enough to view.

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Frida Space

Frida Space

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At 1:40 GMT on September 23rd, Rosetta will depart her 450 km orbit for a three week excursion that will bring her on September 30th up to 1500 km from the nucleus, at which point the probe will be flying over -60 degrees of latitude, where it will be morning. It will then perform a return maneouvre and by October 7th it will be back at 500 km from the nucleus, at which point it will start a cautions approach, as we won't have real time data on the nucleus' activity level. The departure burn will consist in a 2.34 m/s maneouvre. The excursion's aim is to study the bow shock.

http://blogs.esa.int/rosetta/2015/09/18/rosettas-far-excursion-to-study-the-coma-at-large/

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RainDreamer

RainDreamer

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The link has some guess from ESA about that (image is theirs too). It is erosion due to sunlight-driven sublimation of the ice on surface, but because of the rapid rate of changes, they are guessing it is also assisted by something else:

A simple possibility is that the surface material is very weak, allowing for more rapid erosion, but it is also possible that the crystallisation of amorphous ice or the destabilisation of so-called ‘clathrates’ (a lattice of one kind of molecule containing other molecules) could liberate energy and thus drive the expansion of the features at faster speeds.
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LordFerret

LordFerret

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Let's bump this thread back up with some recent news...

Rosetta comet likely formed from two separate objects - from Phys.org

an international team says it has solved the riddle' date=' affirming in the science journal Nature that: "comet 67P/Churyumov-Gerasimenko is (made) of two distinct objects".[/quote']

Also, from Astronomy magazine.

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MichaelPoole

MichaelPoole

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Okay, so I saw 2 incorrect bits of info.

1. Ion engines as "pathetic" (despite this probe having chemical ones), sure, their thrust is not enough to propel a skateboard, but regular engines fire for minutes while ion engines fire for years. The specific impulse of ion drives is 10x that of chemical ones and the exhaust velocity is 10x too. If they had the thrust of chemical rockets, you would be getting very close to speed of light. Ever seen this weird spiral trajectory Dawn has: http://www.jpl.nasa.gov/images/blog/20140331/dawn_blog_20140331-full.jpg ? Notice how the majority of it is powered for 3 years? And how these are not flybys, but hopping from one orbit to another? A chemical powered craft can never do this. Seen NASA engineers saying how orbiting Pluto is impossible because it would require too much fuel? Well, actually, it is possible - just not with a chemical engine. The reason why ion engines were never used beyond the asteroid belt is the high power requirements that an RTG cannot meet, only solar energy - or nuclear power. Solar panels are useless at Pluto, so New Horizons could have been an orbiter if it used ion propulsion and a full nuclear reactor. PR is really what prevented this - the Soviets have used full nuclear reactors on satellites decades ago.

2. NASA having a 6 month embargo policy and not releasing images from yesterday. No, just no. It is not justifyable, which is why NASA is not in fact doing it, unlike ESA. NASA has no embargoes and press releases always mean full release of the information too. Remember how New Horizon image of Pluto was on Wikipedia the day it was taken? Read http://www.universetoday.com/84526/were-done-with-embargoes/

And the biggest source of news in our industry, NASA, never uses embargoes. They just announce their news – or announce an upcoming press conference. Some people poorly speculate on what NASA is going to announce, but everyone knows something’s coming, and they all discover what it is at the same moment.
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Frida Space

Frida Space

Posted
Posted (edited)

According to Finnish media, Rosetta established a 10-second link with Philae during which it downloaded 51 data packets, including status reports. It seems possible as long as the quality of the link was pretty good: in two previous contacts, Philae had uplinked only 80 telemetry packets in 20 minutes (very poor quality) and then more than 300 in just 85 seconds (very good link).

Still waiting for ESA/DLR confirmation.

UPDATE: The unconfirmed wake-up of Philae occured at 03:17 am CET (GMT+2) on December 22nd.

Edited by Frida Space
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