[X] My Assistant

[djellison]

Earth is roughly 45 degrees from the Sun now as viewed from Mars.

34.331 degrees right now ( see attachment)

Curiosity (as with MER ) typically gets its commands direct from earth at about 9.30am local time in a window up to 30 minutes long. Can't see the Earth....can't do the uplink. Can't do the uplink...can't start the rovers daily activities until later, reducing the time available for activities.

Right now Earth is an evening star. It rises just to the left of the 'northern' most base of Mt Sharp - a bearing of 69 degrees. Sunrise (in LMST) is 05:55. earthrise is 08:23 - 2.5hrs after Sunrise.

Any local topography can of course delay the Earth 'rising'.

Topography like this - http://mars.jpl.nasa.gov/msl/multimedia/ra...251M_&s=527 - could easily add a 20 degree mask to the horizon in the direction of the Earth (infact, I can see cases there of 25 degrees or more) - which would add a further 1 -> 1.5 hours to the Earth Rise time. Thus the Earth may only locally 'rise' as much as 4 hours after a nominal 'sun rise'. So that means you have to push your DFE uplink time from 9:30 to a LEAST 10am, and ideally 10:30 to allow the Earth to be well above the local horizon. Thus - between uplink and sunset, we would have lost about an hour of usable time.

This is a situation that will be even worse once we're at the base of Mt Sharp - apart from times when Earth is a 'morning' star and rises 2 - 3 hours before the Sun does. In 150 sols time, Earth will rise at 02:50 LMST, 2.5hrs before Sunrise - so the masking wont actually be a problem. But another couple of hundred sols after that - it'll eat into the day again.

Yes - orbiters can be used (and are used for pretty much every single bit of downlink) - but to forward commands onto the rover via UHF requires a longer lead-time, and interrupts the daily planning cycle significantly. You would see symptoms similar to restricted sols almost constantly.

( For those that don't have it - grab Mars 24 to see Sunrise/Sunset Earthrise/Earthset times http://www.giss.nasa.gov/tools/mars24/ )

Attached thumbnail(s)

 

[walfy]

Wow, already a toe dip in the dune!

Attached thumbnail(s)

 

[fredk]

Love the view through the gap. Anaglyph:

Cross-eyed:

[Phil Stooke]

http://www.midnightplanets.com/web/MSL/ima...CAM00253M_.html

And a look over the dune. Oh yeah, that's a lot smoother!

Phil

[ap0s]

Wow, already a toe dip in the dune!

A little more than just a toe

[charborob]

Sol 528 navcam pan of the gap. Nice view beyond.

(Done with Photoshop. Can't seem to be able to join the dune crest correctly.)

[fredk]

It rises just to the left of the 'northern' most base of Mt Sharp - a bearing of 69 degrees.

Thanks for all the numbers. It's clear that evening star Earth pushes you to later DTE uplinks, and topography can make that worse.

The particular orientation of the gap, though, helps in this case. On this map I've sketched a few lines with 69 degree bearing. Passing more or less straight through should mean neither cliff will block the earth - see the green line:

However, getting close behind one cliff or the other could cause problems - see the red lines. Still, the cliffs are only a few metres tall, so to block the sky more than 10 degrees up you'd need to be closer than roughly 20 metres to the cliff.

Of course the route we take through the gap will be dictated by surface conditions - they must allow us to keep sufficiently far from the cliffs.

[Ant103]

Sol 528 Navcam pan

[jvandriel]

The view on Sol 527.

Jan van Driel

[jvandriel]

My view of the Sol 528 NL B panorama.

Jan van Driel

[atomoid]

interesting (de)constructions around here.
dune edges terminating 'into' the gap makes for amusing stereograms

[CosmicRocker]

The protruding outcrop just right of center in this image seems to have some interesting co!ors that might be worthy of further study. I think I am detecting a greenish cast, which would suggest chemically reduced iron and the possibility that organic compounds could have been preserved in the rock.

[jvandriel]

Another view of the Sol 528 NL B panorama. ( Added and removed a few images )

Jan van Driel

[Guest_Actionman_*]

The protruding outcrop just right of center in this image seems to have some interesting co!ors that might be worthy of further study. I think I am detecting a greenish cast, which would suggest chemically reduced iron and the possibility that organic compounds could have been preserved in the rock.

Looks promising, we should be doing a slow walk-by in that area it looks like

[Gerald]

Two false-color versions, this one showing enhanced hue with reduced brightness differences, after some white-balancing:

The bluish-greenish hue of the rock becomes obvious.

This image enhances colors similar to the rock as dark:


Not quite obvoius to me is, whether the almost unique color is due to reduced dust covering by inclination, texture and wind, due to reflected or scattered sunlight, or due to composition.