Hole in Mars (APOD 28 Sep 07)

salientNZ · Post by **salientNZ** » Sun Sep 30, 2007 9:55 pm

As soon as I saw this I thought "This is obviously the launch tube for the Martian missiles to earth", since I've just seen Jeff Wayne's War of the Worlds Musical (Auckland, New Zealand 28th Sep 07).

Love those coincidences :-).

Cheers,
Brent.

nicktoop · Post by **nicktoop** » Mon Oct 01, 2007 6:51 pm

When I do a simple aboutbrightness/contrast enhancement of this photo using Paintshop Pro circular forms about 20m across appear to be present in the dark area. They do not apear to correlate with the surface structure of the internal illuminated face.

jumpjack · Post by **jumpjack** » Tue Oct 02, 2007 7:49 am

How can I know the direction from which the sun light comes in this photo?

http://lc84.altervista.org/marte/immagi ... 2-edit.jpg

The PDS labelonly specifies vertical angle: what about the horizontal one?!? Does the light come from left, right, down, downleft...?

And how can I know the spacecraft longitude with respect to the crater? Was it to the left or to the right of it while taking the picture?

All of these data are needed to properly estimate hole's data (dept, slope,...)

Any help?

I already did some estimations, but if sun light is coming from right rather than left, and if the spacecraft is to the left of the hole.... this would have interesting consequences!

BMAONE23 · Post by **BMAONE23** » Tue Oct 02, 2007 2:05 pm

It would appear to me that the camera is tracking almost exactly over head in both images but that the sun is shining from about 5pm in the first image thereby lighting the first tier but casting Dark Shadows on the remainder, and that the sun is shining at about the 2pm position (lower left in both cases) thereby illuminating farthar (more directly) down into the hole. But perhaps someone that really Knows will respond.