Category Archives: Comets

Sleep Well Little Philae

Decline in battery power aboard Philae. Credit: ESA via Twitter
Decline in battery power aboard Philae. Credit: ESA via Twitter

The Philae lander is now in an “idle mode” in which most of the systems on board are shut down, including communications.

Before going to sleep, Philae was able to send all of the science data collected so far and completed its main mission in the 57 hours on the comet surface.

Stephan Ulamec, Lander Manager said “This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered.”

Contact with Philae was lost at 00:36 UT (20:36 EST for the US), according to Rosetta Blog this was about the time of a scheduled loss of signal anyway as Rosetta which was acting as a repeater orbited out of sight of Philae.

Rosetta mission control did try to rotate the lander as was reported and with that effort there was a possibility of communications at 10:00 UTC (05:00 EST) this morning (15 Nov) so Rosetta was listening but no signal came.

As Comet 67P/Churyumov-Gerasimenko gets closer to the Sun there is a possibility enough sunlight will eventually revive the batteries enough to get Philae back on-line. Still I have to wonder if the deep discharge state of the batteries will preclude that given the time and cold environment – time will tell.

A Stunning Look at Philae

Philae is right at home. Credits: ESA/Rosetta/Philae/CIVA
Philae is right at home. Credits: ESA/Rosetta/Philae/CIVA

WOW! This is just simply amazing.

This is a two image mosaic of Philae on the surface of the Comet 67P/Churyumov-Gerasimenko. Click the image and just marvel at the view of both Philae and the surface features.

You can get an even larger version at Rosetta blog’s Welcome to a Comet!

Philae is pretty close to a cliff that will shadow the solar panels for much of a day and this will limit how much Philae will be able to do at least in the short term. I’m pretty sure ESA is studying how to squeeze the most out of what they have you can be sure of that.
ESA is live streaming the media briefings, you can find out when by going to Rosetta Blog or you can check the Live Stream page.

Don’t forget about Twitter, I am on the run a lot the past couple days and it has been great for keeping up you can get all the images and briefings there too.

What a Day!

 ROLIS descent image of Comet 67P/C-G. Credits: ESA/Rosetta/Philae/ROLIS/DLR

ROLIS descent image of Comet 67P/C-G. Credits: ESA/Rosetta/Philae/ROLIS/DLR

As the Philae lander approached comet 67P/G-C it used the ROLIS instrument to take this image at 14:38:41 UT from just 3 km / 1.9 miles above the surface.

The ROLIS instrument looks downward during descent and gets close up views after landing so texture and microsturcture of surface materials.

Yes, that is part of the lander you see in the upper right.

ROLIS (ROsetta Lander Imaging System) is a descent and close-up camera on the Philae Lander. It has been developed by the DLR Institute of Planetary Research, Berlin.

I had to include the image below, I think it’s just excellent. We are looking at the Philae lander shortly after being released from the mother ship (Rosetta) after a 10 year trip together on this totally amazing mission.

Good luck Philae. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Good luck Philae. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

No word yet on what is going on with the harpoons (anchors), but ESA did mention “Maybe today we didn’t just land once…we even landed twice!”

There will be plenty more images here, but check out the Rosetta Blog.

ESA Rosetta Mission on Twitter

Congratulations ESA !

I bet the smiles are abundant and they should be. :mrgreen:

Good Luck Philae!

GOOD LUCK!  I can hardly believe the day has finally come – it’s been a long time!

Update:  Landing confirmed.  Harpoons did not fire, investigation in progress.  The one way radio travel time is a bit over 28 minutes – each way.

ESA is reporting all is well with Philae is in good shape despite the harpoons.

If you see no video above it is because ESA isn’t broadcasting at the time.

Check out the Rosetta Blog and for last second updates.


Two Days Away

Rosetta's NAVCAM image just 31.8 km from the centre of Comet 67P/Churyumov-Gerasimenko on 4 November 2014 ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Rosetta’s NAVCAM image just 31.8 km from the centre of Comet 67P/Churyumov-Gerasimenko on 4 November 2014 ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

An image  on 04 November shows some activity in the way of the jets emanating from the central region of comet 67P/Churyumov-Gerasimenko.

For the past couple of weeks I’ve developed quite an interest in what the cometary “soil” is like and how it got to be the way it is.  Happily we could get more clues just watching the Philae lander land on Wednesday. If the composition is very fine we could see quite a cloud kicked up relative to how much is at the landing site of course.

If you would like the four individual panels making up this image you can get them at Comet Watch


Making History

Just three days away.

This is Friday’s press conference with Rosetta mission experts hosted by Emily Baldwin, ESA space science editor / Rosetta Blog

The video is in distinct segments of about 15 minutes and questions at the end.

Introduction and mission plans fellowed by Science at 15 minutes, Landing at 30 minutes and Summary at 45 followed by questions.

Video link

About the Mars Comet

A teleconference discussing some of the science findings from the C/2013 A1 Siding Spring (aka: the Mars Comet) fly by of the planet Mars.

A bit technical here and there but very well explained and totally worth seeing.

BTW, it takes a few minutes to get going.

The participants were:

  • Jim Green, director, Planetary Science Division, NASA Headquarters, Washington
  • Nick Schneider, instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph, University of Colorado, Boulder
  • Mehdi Benna, instrument scientist for MAVEN’s Neutral Gas and Ion Mass Spectrometer, NASA Goddard Space Flight Center, Greenbelt, Maryland
  • Don Gurnett, co-investigator on the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument on Mars Express, University of Iowa, Iowa City
  • Alan Delamere, co-investigator for MRO’s HiRISE instrument, Delamere Support Services, Boulder, Colorado


Rosetta’s Comet


Wow, what a great view of a comet you can get from just 30 km (18.6 miles).

Click the image above for a larger version and enjoy the detail.

Caption via NASA:

This image of comet 67P/Churyumov-Gerasimenko was obtained on October 30, 2014 by the OSIRIS scientific imaging system on the Rosetta spacecraft. The right half is obscured by darkness. The image was taken from a distance of approximately 18.6 miles (30 kilometers).
Image Credit: ESA/Rosetta/MPS for OSIRIS Team

Mars and Comet Siding Spring

A Hubble look at Mars and comet Siding Spring. Image Credit: NASA/ESA/PSI/JHU/APL, STScI/AURA
A Hubble look at Mars and comet Siding Spring. Image Credit: NASA/ESA/PSI/JHU/APL, STScI/AURA

Have a look at this Hubble image of Mars AND comet Siding Spring in the same field of view during the close pass on 19 October. The comet came as close as 140,000 km / 87,000 miles – only a third of our Earth to Moon distance. I am trying to imagine what that would be like.

This from Hubblesite:

This composite of NASA Hubble Space Telescope images captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet, which happened at 2:28 p.m. EDT October 19, 2014. The comet passed by Mars at approximately 87,000 miles (about one-third of the distance between Earth and the Moon). At that time, the comet and Mars were approximately 149 million miles from Earth.


The comet image shown here is a composite of Hubble exposures taken between Oct. 18, 8:06 a.m. EDT to Oct. 19, 11:17 p.m. EDT. Hubble took a separate photograph of Mars at 10:37 p.m. EDT on Oct. 18.

The Mars and comet images have been added together to create a single picture to illustrate the angular separation, or distance, between the comet and Mars at closest approach. The separation is approximately 1.5 arc minutes, or one-twentieth of the angular diameter of the full Moon. The background starfield in this composite image is synthesized from ground-based telescope data provided by the Palomar Digital Sky Survey, which has been reprocessed to approximate Hubble’s resolution. The solid icy comet nucleus is too small to be resolved in the Hubble picture. The comet’s bright coma, a diffuse cloud of dust enshrouding the nucleus, and a dusty tail, are clearly visible.


This is a composite image because a single exposure of the stellar background, comet Siding Spring, and Mars would be problematic. Mars is actually 10,000 times brighter than the comet, and so could not be properly exposed to show detail in the Red Planet. The comet and Mars were also moving with respect to each other and so could not be imaged simultaneously in one exposure without one of the objects being motion blurred. Hubble had to be programmed to track on the comet and Mars separately in two different observations.


The images were taken with Hubble’s Wide Field Camera 3.