[X] My Assistant

[djellison]

Frames at 10s intervals instead of the 20s intervals (iirc) they used to have.

CODE

706 p2663.06 17  17  0   0   0   34   pancam_deimos_transit_R8

Duration (hhmmss)   =  00:12:45
Data Vol (Mbits)    =      0.84

Doug

Attached image(s)

 

[djellison]

The more data sets they have on these events, the more they can bring in the limits of +/- on variables. Imaging at 10s gives another step in the level of accuracy available. It helps constrain the orbits of the moons, and mean better targeting for observations from orbit.

For total 'wow' factor, I'd very much like to see 10s sampled Navcam imagery of the terrain during a Phobos eclipse, as it gets quite dark during those. Pity there was no chance to do this from Husband hill, as the shadow might have even been visible racing across Gusev crater.

It would mean forgoing the Pancam imagery of the sun during that time, but ... it'd be cool

Doug

[fredk]

For total 'wow' factor, I'd very much like to see 10s sampled Navcam imagery of the terrain during a Phobos eclipse, as it gets quite dark during those. Pity there was no chance to do this from Husband hill, as the shadow might have even been visible racing across Gusev crater.

It would mean forgoing the Pancam imagery of the sun during that time, but ... it'd be cool

Doug

That would be cool, but unfortunately Phobos only covers around 1/3 of the surface area of the sun, so that means you'd only be in the very diffuse penumbra. It's very hard to notice it when the sun is 1/3 covered by our moon during a solar eclipse. But in our case the sunlight dims very slowly, on a timescale of hours. For Mars, a Phobos eclipse lasts 30 seconds or so. So if you were standing there, I think you would notice a very subtle dimming if you payed close attention.

The width on the surface of Mars of the gradient part of Phobos' shadow (ie the distance from the outer edge of the penumbra to the outer edge of the region where Phobos is entirely in front of the sun) is equal to the diameter of Phobos, for an overhead eclipse. That's roughly 20km, depending on Phobos' orientation. So even from the summit of Husband, with a horizon distance on the order of 20km, you'd need a very wide view to see the extent of that gradient on the horizon (seeing it closer would be even harder). So a hazcam shot might have shown something very subtle (if there were any eclipses to see at that time!).

Actually though, I think with a pair of hazcams, one when the shadow was on the horizon and one a minute or so later or before, you could quite easily reveal the shadow using the dust devil diferencing technique. This could be doable from somewhat high ground.

That animation was nice, Doug. I've made gifs in the past with 10 second pauses each frame to achieve "real time", but the interpolation you've done between frames makes a big difference - did you do that interpolation by hand or was it some morphing app?