Martian feature help

[Towa]

I've now seen this feature on two previous occassions with both my Tak scope and 120mm Achromat.

In the north a long thin bright feature has been seen, at one end it is a roundish bright spot with a long thin bright streaky feature running across to the limb.

Also another longish bright feature that seems to extend into Tharsis has also been picked-up, but not as clear as the northern feature.

Anyone got any ideas as to what its, is it just a constrast feature between two darker areas? The streaky features are highlighted

in the inverted image.

[Paul G. Abel]

Hi Towa,

I think it is just possible that the bright spot you are seeing is bright clouds over the enormous shield volcano Alba Patera. I have not seen this myself, but then cloud stopped my observations before the region was well in view. There certainly seems to be a lot of cloud activity around the volcanoes along in the Tharsis region.

Have a look at this NASA mars map http://mars.jpl.nasa.gov/mgs/target/marsmap1b.jpg

And see if you think it's in about the same place. Remember north is up (rather than at the bottom) annoyingly! A good result if this is indeed that you have seen!

Best wishes,

-Paul.

[Towa]

Hi Paul

Many thanks for the Nasa image, it certainly does look like Alba Patera region, my previous drawings have the spot in the same region.

On the map where is says Arcadia Planitia (above Amazonis Plantitia) are two parallel darker regions, I think the brighter streak I'm seeing

to the side of Alba Patera is brighter ground running in between them.

I think the bright feature in the south is the bright Chryse region.

I had wondred if it was Vallis Marineris, but that looks further. south. On your oppsition drawing you have Chryse bright,

and I think this is what I'm seeing in my smaller aperture.

[dweller25]

I think the southern streak is Chryse and the northern streak is Nerigos.

[Towa]

D25 has nailed the long bright feature in the North, it's most definitely Nerigos. This puts the bright round feature in Tempe.

It appears on a previous drawing at around 70 - 80 degress.

Have just been reading about a large bright cloud observed in Tempe over the last couple of days, so I think that must be

what I was seeing.