Phobos!
On Easter Sunday, HiRISE took two observations of the Martian satellite Phobos. This is the larger of the red planet’s two satellites. We took two color images at slightly different angles, so we could combine them to make a three-dimensional stereo image.
It was another special sequence that had to be specially designed, commanded, tested and re-tested before it executes on board the spacecraft. Many people from JPL and LMA worked to make this happen, as well as almost everyone on the uplink team here at HiROC. In addition, the date chosen meant that people had to come in and work on a holiday to support it. So we were thrilled when the images arrived Sunday night, and we saw that they are PERFECT! The focus, timing, and pointing were bang-on, and we got a beautiful exposure of the satellite in both images.
I wish I could give you a sneak peak, but we’re still processing the images. The downlink group has to do a lot of work on special images like these. Because they’re not normal Mars images, the normal calibration routines and processing pipelines can’t be used. Much of this work has to be done by hand. We’re also trying to get some additional products together that we don’t usually release; I think you’ll like them! 
So this is really just a teaser. 
We’re planning on releasing the Phobos images next week, so keep an eye on the website! In the meantime, here’s a warmup act: views of Phobos from previous missions, MGS (above right) and Mars Express (left).
March 28th, 2008 at 5:56 pm
That’s just CRUEL!!!! Curse you for dangling that carrot in front of us!!!
Can’t wait to see those pics…
April 2nd, 2008 at 10:59 am
Great stuff,
I suggested this some while back.
What resolution will these images of Phobos be?
I hope we get to see a good, sharp monochromatic image & not just a gory mess that the 3D images tend to be.
Will the same be done with Deimos & have requested that HiRISE be turned towards Saturn on Sunday 18th May 2008, as from Mars, Saturn will be at opposition.
Andrew Brown.
April 9th, 2008 at 12:33 pm
My jaw has hit the floor.
Absolutely incredible, well done to all involved. Please, please attempt Deimos & Jupiter & Saturn at the next oppositions. Phobos & Deimos are just so fabulously interesting, added to the possibilty that they are captured type D asteroids, more common in the outer part of the Asteroid Belt & some of Jupiter’s outermost moons such as Pasiphae, Sinope, Ananke, Carme, etc, the outer retrograde group of Jupiter’s moons, also possibly captured type C & D asteroids.
Once again, thank you so much, I am speechless.
Andrew Brown.
April 9th, 2008 at 8:29 pm
WOW! Absolutely amazing!! Well done to you all. At the recent Phobos and Deimos Conference at NASA Ames, which I was involved with organising, there was much discussion about the possibility of imagery from MRO. Some preliminary results from CRISM were also presented. These results are worth every moment of time that was spent trying to acquire them. Thank you and keep up the great work! These will keep the debates about Phobos origin going and hopefully answer so of it’s riddles too
Cheers,
Michael West
Mars Institute
April 9th, 2008 at 8:57 pm
[...] The spectacular images have been released today here and were alluded to about a week ago on the HiRISE Blog. All I can say is WOW! Hopefully these images will assist in solving some of the riddles associated [...]
April 14th, 2008 at 5:45 am
Hi Michael West.
Great blog you have there. I have been really examining the images, making crops & enlargements of various features. What do you think of Phobos & Deimos origins?
1). Pieces of debris lifted from Mars through large impacts & formed out of that?
2). Formed insitu around Mars?
3). Both are captured type D asteroids, that once were in heliocentric orbit in the outer part of the Asteroid Belt?
Myself, personally, I think No 3.
I hope that HiRISE will repeat these observations when Mars is in a different position in its heliocentric orbit, so the angle of illumination will be different (obviously not when Phobos is at New Phase, as there would be nothing to see & we do not want an accidental pointing of HiRISE at the Sun).
Also I hope that Deimos too, will be observed. Using the same filters as for the Phobos observations would be really useful in comparing the two, like for like & we’ll see how similar or different they are.
The grooves in their east – west direction are very detailed. To me it looks like they are very old, as many of them have craters superimposed, so what ever caused them, appears to have stopped. General idea that they are fractures from the Stickney impact, yet I have seen doubts cast on that idea by ESA scientists, using Mars Express data, stressing that their convergence point do not meet in the centre of Stickney Crater & they may already have been there. Worth mentioning that Main Belt Asteroid 951 Gaspra has grooves also.
Andrew Brown.
April 17th, 2008 at 3:31 pm
Any hints as to what the other ‘Unusual products’ are that you do not usually release are?
Hopefully a Deimos HiRISE observation included?
Or how about Asteroids 1 Ceres, 2 Pallas & 4 Vesta, as Mars passes closer to them than Earth does at opposition, or Comet 17P/ Holmes outburst last Autumn?
Just thinking about what else the HiRISE team may attempt that’s unusual but safe for the HiRISE instrument.
Andrew Brown.
July 5th, 2008 at 12:11 am
Andrew,
I like the discussion on the grooves. They are a curious lot. Not only Gaspra displays grooves, Ida and Eros show evidence too. This supports the idea that Phobos surface features are not unique and that Phobos could be a captured asteroid. Personally I also believe the capture theory for both Phobos and Deimos. I also believe that grooves are structural depressions, possibly giving us a clue to whats beneath the surface. But having said that, I can’t help but observe crater chains in images, some that seem to be parallel to groove structures and even within them. But if Phobos’ grooves were formed by secondary cratering sourced from ejected Martian materal, what then caused the grooves on asteroids, such as Gaspra, Ida and Eros, far away from any influential planet?
November 6th, 2008 at 1:36 pm
I’m wondering if Phobos could have been captured by repeated collisions with a martian ring system. This would explain the uniform nature of the grooves on Phobos, although I’ve not been able to find any references to “capture by ring collision”(for any body). Rings create a larger target for asteroids, so one would thing that such collisions would be more common than with moons and such. Also I’m wondering if collision of an object with Mars could create uniform linear streams of particles(through tidal forces) fast enough to explain the uniformity of the grooves.