I really love these Deimos observations with HiRISE, another formal request of mine to the HiRISE team carried out & am NOT disappointed. Superb.

The more I see Phobos & Deimos like this, the more I think that they are captured primitive asteroids. I suspect now that their type D status is confirmed, now that we have detailed HiRISE observations along side the CRISM observations a while back.

What is obvious is that Deimos using the same filters is not as ‘red’ as Phobos. To me that is a fundamental difference. Regolith composition slightly different? Different texture (certainly shown in the Viking 2 imagery)????

Now to convince if possible ESA to send Mars Express close by Deimos, over the anti Mars side & compare with these HiRISE observations.

These are the best Deimos observations since the Viking 2 orbiter in October 1977. That is nearly 32.5 years ago!!!!!!!

Are Phobos & Deimos indeed captured asteroids, possibly originating in the outer part of the Asteroid Belt?

Are they indeed similar to some of Jupiter’s members of the outermost retrograde group of small moons such as Pasiphae, Ananke or Sinope?

If so, do they share a common origin?

Andrew Brown 3488.