Comments on: A Different Side of Mercury

By: Collimator

Collimator — Wed, 08 Oct 2008 12:37:57 +0000

Once the ejecta is blown out in a straight radial pattern the ballistic return imprint on the surface must account for the spin of the planet during the time of travel of this debris. I suspect a slightly spiral pattern along the north south meridian and a linear compression effect along the east west orientation. As to the lack of apparent crater for a ray maybe it belongs to a feature behind the visible limb.

By: alandee

alandee — Tue, 07 Oct 2008 23:08:27 +0000

Wicked images ..
@Bill, I'm hearing you, but, being as close to the sun, and having a very thin atmosphere, maybe the ejecta gets buffeted about as it settles back down. Just throwing it out there with no basis other than guesswork, I can only imagine that solar winds would do quite a good job of moving something bright and reflective .. ?

By: Astrofiend

Astrofiend — Tue, 07 Oct 2008 23:05:34 +0000

"# joe Says:
October 7th, 2008 at 8:09 am

"Why isn't Mercury volcanic? Venus, earth, mars are."

Mercury has had extensive volcanism acting in the distant past, particularly around the Caloris Basin. The planet has cooled far too much for there to be any significant volcanism these days.

By: turkka

turkka — Tue, 07 Oct 2008 19:27:56 +0000

cool images. although the first one reminds me of a watermelon :p

By: Bill

Bill — Tue, 07 Oct 2008 17:36:08 +0000

Does it bother anyone that the "ejecta" rays are not usually straight, are not always associated with craters and do not in many cases lead to a crater, and display a fractal pattern close to craters? Impact ejecta would have to follow a ballistic trajectory emanating from the point of impact, and could only leave a straight (as projected onto a sphere, thus a geodesic) ground track. The odd morphologies I mention are highly evident in the photo, and can be seen on the moon too. For instance, between the two prominent ray craters is at least one ray that appears to be disassociated from any origin.

By: DestroyAllHumans

DestroyAllHumans — Tue, 07 Oct 2008 16:32:30 +0000

So Mercury has its own Tycho now.

Now people will say even more that the planet is just like the Moon.

I kinda miss the old Mariner 10 images, not entirely sure why. Maybe having only them to look at for 35 years is part of the reason.

Before Mariner 10 arrived in 1974, there were people who speculated that Mercury would be a totally flat and dull surface, having been completely melted from being so close to the Sun. Guess not.

By: LLDIAZ

LLDIAZ — Tue, 07 Oct 2008 15:14:02 +0000

I though that by being closest to the sun Mercury would be different I don't know how different but it looks just like the moon.

By: joe

joe — Tue, 07 Oct 2008 15:09:34 +0000

Why isn't Mercury volcanic? Venus, earth, mars are.

By: Silver Thread

Silver Thread — Tue, 07 Oct 2008 14:49:44 +0000

That would have made a tricky "Where in the Universe". Incredible images to be sure