Mars' SPC

On the morning of the 29th at 10:15Z I noticed the east 2/5 of the SPC
was retreating further southward than the other 3/5 of it. It appeared
rather crimped where it departed from the major melt line.
It also seemed to have a slightly more buff color to it.
I was using a 9.6" f/7.4 newtonian with P-5,6 seeing.

Anyone see this?

Dan Chaffee

Dan Chaffee wrote:

On the morning of the 29th at 10:15Z I noticed the east 2/5 of the SPC
was retreating further southward than the other 3/5 of it. It appeared
rather crimped where it departed from the major melt line.
It also seemed to have a slightly more buff color to it.
I was using a 9.6" f/7.4 newtonian with P-5,6 seeing.

Anyone see this?

Dan Chaffee

Dan,

I've seen what you're talking about in several telescopes recently, and
others with me have seen it as well. There's a crimp in the melt band,
sort of an "S" shape. I first saw it this last Friday but I hadn't
observed Mars for a couple weeks before that. I observed it again on
Sunday. IIRC, the smallest scope I saw this in was a 90 mm (although it
was a Tak double fluorite) and it was easy in a Tak 6-inch refractor and
larger scopes. It seems to me that the unmelted part of the cap within
the "S" is a little brighter than the rest of the cap but some others
think that's an illusion due to contrast effects.

It'll be fun to watch it if it actually changes noticeably in the next
few months.

Mike Simmons

(Dan Chaffee) wrote in message ...
On the morning of the 29th at 10:15Z I noticed the east 2/5 of the SPC
was retreating further southward than the other 3/5 of it. It appeared
rather crimped where it departed from the major melt line.
It also seemed to have a slightly more buff color to it.
I was using a 9.6" f/7.4 newtonian with P-5,6 seeing.

Anyone see this?

Dan Chaffee

I've seen and imaged the same feature on the SPC the 29th at 02:45 UT
with my MK67DL with a seeing III-IV Antoniadi.

The image will be shortly available on my website in the mars section.

Regards

Andrea T.

My Astronomy Pages at:
http://www.geocities.com/andreatax/index.htm