Philae is down.

[BazBear]

With the news regarding the problem of charging the batteries, people are asking why weren't RTGs used... why weren't they? I would guess ESA had a good reason, but I don't know enough about the subject to comment.

In the ESA's case, it might well be mainly a political issue.

Even if that wasn't the case, the worldwide stock of ²³⁸Pu used for RTGs is very low. The US hasn't made any since the late 80s, and while the Russians were selling it for some time, they're apparently not producing it anymore either.

The DoE and NASA had a deal to split the costs for resuming production, but Congress hasn't appropriated all the funding they need to do so.

[AstroBrant]

It's certainly not what I would have expected. The jagged appearance seems to indicate that it is much younger than the moon.
I think it's cool that we can see some haze of the ejecta from the surface.

[AstroBrant]

By the way, have you seen this?

Wow! That is a very cool production for a space mission.

[AstroBrant]

I couldn't resist...

http://planet.infowars.com/science/awe-proven-to-be-a-liar

Nice work, Bryan. I'm glad someone is keeping tabs on him and holding him accountable for the garbage he pulls. I was going to say "keeping him honest," but of course, no one can do that.

[Bryanpoprobson]

Nice work, Bryan. I'm glad someone is keeping tabs on him and holding him accountable for the garbage he pulls. I was going to say "keeping him honest," but of course, no one can do that.

I just knew what he was about to do and took the screen shots.

[raven]

It's certainly not what I would have expected. The jagged appearance seems to indicate that it is much younger than the moon.
I think it's cool that we can see some haze of the ejecta from the surface.

Well, each pass around the sun would resurface it to a degree, yes?

[Bryanpoprobson]

I think that the surface is a lot more like rock, than what I would have expected. All these years of envisaging a what a "dirty snowball" looks like, did not ready me for this!

[cjameshuff]

Don't know what I was expecting, but not what I'm seeing...is that snow in one of those images?, or am I suffering from a case of pareidolia?

Probably dust.

I think that the surface is a lot more like rock, than what I would have expected. All these years of envisaging a what a "dirty snowball" looks like, did not ready me for this!

Comets have been imaged before...they're some of the blackest objects in the solar system, covered with gunk left behind by ice that has sublimated away. Less of a snowball with some specks of dirt in it, and more of one covered in blackened frozen mud, dust, and bits of rock.

The surface under Philae is apparently an unexpectedly hard and solid crust of largely water ice. I guess they expected a smoother transition from surface dust to icy granular material, perhaps not expecting the crust to form at the temperatures and pressures involved.

With the news regarding the problem of charging the batteries, people are asking why weren't RTGs used... why weren't they? I would guess ESA had a good reason, but I don't know enough about the subject to comment.

Apart from the politics, they didn't and still don't have RTGs developed for use, and it was to be a short duration high-risk mission that would have wasted most of an RTG's potential.