A couple things to look for on Mars

I was observing Mars tonight with my 8" Dob at powers from 203x to
405x and noticed a couple interesting things. Have you guys noticed:

1. The south polar cap has a small break or rift in it that cuts it in
two unequal pieces!
2. Blue haze on the northeast limb.
3. The western limb is slightly softer than the eastern, indicating
the start of the gibbous phase.
4. Interesting and prominent hook at the end of Sinus Sabaeus.
5. Two large parallel features (like horns) extending east from Syrtis
Major, one vaguer than the other.

Also, I spent nearly an hour on Plato on the Moon and sketched all the
hints of craterlets I could see. Though the "Big Four" were prominent
pits, the rest appeared only as white spots. I later confirmed a
total of nine from David Knisely's ASCII craterlet map (A, B, C-D, g,
h2, p3, f, q2). "p3" may be questionable because my notes only
mention a large white spot in that location. I thought I had a tenth
(craterlet "n") but it turns out that I only saw the prominent white
spot next to it and couldn't resolve the craterlet itself.

Ritesh

(Axel) wrote in message . com...
I was observing Mars tonight with my 8" Dob at powers from 203x to
405x and noticed a couple interesting things. Have you guys noticed:

1. The south polar cap has a small break or rift in it that cuts it in
two unequal pieces!
2. Blue haze on the northeast limb.
3. The western limb is slightly softer than the eastern, indicating
the start of the gibbous phase.
4. Interesting and prominent hook at the end of Sinus Sabaeus.
5. Two large parallel features (like horns) extending east from Syrtis
Major, one vaguer than the other.

Also, I spent nearly an hour on Plato on the Moon and sketched all the
hints of craterlets I could see. Though the "Big Four" were prominent
pits, the rest appeared only as white spots. I later confirmed a
total of nine from David Knisely's ASCII craterlet map (A, B, C-D, g,
h2, p3, f, q2). "p3" may be questionable because my notes only
mention a large white spot in that location. I thought I had a tenth
(craterlet "n") but it turns out that I only saw the prominent white
spot next to it and couldn't resolve the craterlet itself.

Ritesh

Ritesh, The next time you can see so many craters in Plato, you ought
to see if you can detect the rille in the Alpine Valley. I saw it on
one occasion through a 8" Dob when 8 craterlets in Plato were visible,
on about 240X. DR

Hi!

I have seen many of the things you describe...!

Axel wrote:
I was observing Mars tonight with my 8" Dob at powers from 203x to
405x and noticed a couple interesting things. Have you guys noticed:

1. The south polar cap has a small break or rift in it that cuts it in
two unequal pieces!

http://home.online.no/~arnholm/astro...831_0117ut.jpg

2. Blue haze on the northeast limb.

http://home.online.no/~arnholm/astro...827_2159ut.jpg

3. The western limb is slightly softer than the eastern, indicating
the start of the gibbous phase.

haven't seen it.

4. Interesting and prominent hook at the end of Sinus Sabaeus.

See #1 above.

5. Two large parallel features (like horns) extending east from Syrtis
Major, one vaguer than the other.

http://home.online.no/~arnholm/astro...901_2340ut.jpg

Also, I spent nearly an hour on Plato on the Moon and sketched all the
hints of craterlets I could see. Though the "Big Four" were prominent
pits, the rest appeared only as white spots. I later confirmed a
total of nine from David Knisely's ASCII craterlet map (A, B, C-D, g,
h2, p3, f, q2). "p3" may be questionable because my notes only
mention a large white spot in that location. I thought I had a tenth
(craterlet "n") but it turns out that I only saw the prominent white
spot next to it and couldn't resolve the craterlet itself.

Ritesh

If you saw all that, I'm impressed! This is my best
http://home.online.no/~arnholm/astro...14_us5s900.jpg

Clear skies
Carsten A. Arnholm
http://home.online.no/~arnholm/astro/astro.htm
N59.776 E10.457

Is it just me, or is Syrtis Major considerably more sharp-pointed than shown
in Mars Previewer and the maps of a few years ago?

ritesh wrote:

Have you guys noticed:

1. The south polar cap has a small break or rift in it that cuts it in
two unequal pieces!

Yes, that is sometimes referred to as "the Mountains of Mitchel", although
there are no real mountains there. Its commonly seen as the south polar cap
receeds and leaves various outliers along slopes or crater walls.

2. Blue haze on the northeast limb.

Well, I see it more along the northern limb, but in any case, that is most
probably the north polar hood which forms in the northern winter.

4. Interesting and prominent hook at the end of Sinus Sabaeus.

That is Sinus Meridiani, also known as "Dawes Forked Bay". The MER-2
spacecraft ("Opportunity") will be landing near the middle of the marking.

5. Two large parallel features (like horns) extending east from Syrtis
Major, one vaguer than the other.

I am not certain which end you mean, as Syrtis Major is a pretty big marking.
The southern end has several protrusions southeast, with Yaonis Regio along
the eastern edge of the brighter Hellas basin, and Mare Serpentis to its east
(forms almost an arc-like "hook" from the eastern end of the "pipe" of Sinus
Sabaeus). The northern end of Syrtis Major is pointed, but has a faint
northeastern extension (a combination of Niliosyrtis and a few other markings
like Antigones Fons, Cole Palus, ect.). Clear skies to you.

--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 10th Annual NEBRASKA STAR PARTY *
* July 27-Aug. 1st, 2003, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Hi Everyone,

I'm just curious if the original poster mistook the Aurora Sinus region for
Syrtis Major. Granted, I have not had a chance to image Syrtis Major,
so I don't know if there are horns there, but my images of Aurora Sinus
do show "horns" on either side, one forming an "eyebrow" for Solis
Lacus, appropriately the Eye of Mars.
--
----------------------------------------------------------------------
Never be afraid of trying something new for the love of it.
Remember... amateurs built the Ark.
Professionals built the Titanic!


----------------------------------------------------------------------

"David Knisely" wrote in message
...
ritesh wrote:

5. Two large parallel features (like horns) extending east from Syrtis
Major, one vaguer than the other.

I am not certain which end you mean, as Syrtis Major is a pretty big
marking.
The southern end has several protrusions southeast, with Yaonis Regio
along
the eastern edge of the brighter Hellas basin, and Mare Serpentis to its
east
(forms almost an arc-like "hook" from the eastern end of the "pipe" of
Sinus
Sabaeus). The northern end of Syrtis Major is pointed, but has a faint
northeastern extension (a combination of Niliosyrtis and a few other
markings
like Antigones Fons, Cole Palus, ect.). Clear skies to you.

Oh, OK. I haven't got a good look of that region yet, so I haven't
noticed the effect. Thanks for the information.
--
----------------------------------------------------------------------
Never be afraid of trying something new for the love of it.
Remember... amateurs built the Ark.
Professionals built the Titanic!


----------------------------------------------------------------------

"Edward" wrote in message
ink.net...

"David Nakamoto" wrote in message
...
Hi Everyone,

I'm just curious if the original poster mistook the Aurora Sinus region
for
Syrtis Major. Granted, I have not had a chance to image Syrtis Major,
so I don't know if there are horns there, but my images of Aurora Sinus
do show "horns" on either side, one forming an "eyebrow" for Solis
Lacus, appropriately the Eye of Mars.

I was observing mars Friday night and saw the dark north rim of Hellas as
horns or antenna.

Ed

Is it just me, or is Syrtis Major considerably more sharp-pointed than shown
in Mars Previewer and the maps of a few years ago?

Yes the western side of Syrtis Major curves to a sharp point just like
the southeastern coast and Mexican border of Texas!

Ritesh

If you saw all that, I'm impressed! This is my best
http://home.online.no/~arnholm/astro...14_us5s900.jpg

In your excellent image I can see the following craterlets besides the Big Four:

f (easy)
g, h2 (vague hints)
p3 (the white spot that I saw that may harbor a craterlet)
e (barely)
k or n (vaguely)

Ritesh

"Michael A. Covington" wrote in message
...
Is it just me, or is Syrtis Major considerably more sharp-pointed than
shown
in Mars Previewer and the maps of a few years ago?

Just came in from observing and I noticed that too. Actually, to my eye the
maps have (almost) always shown Syrtis Major as too fat and blunt. I thought
it might be related to my smaller aperture (6").

Also, I do know that Syrtis Major undergoes seasonal changes. The pointy
look may be normal for this time of (Martian) year.

Clear Skies,
Craig in Tampa