MSL - Astronomical Observations, Phobos/Deimos, planetary/celestial observations and more |
MSL - Astronomical Observations, Phobos/Deimos, planetary/celestial observations and more |
Jun 29 2013, 05:25 PM
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Senior Member Group: Members Posts: 4247 Joined: 17-January 05 Member No.: 152 |
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Aug 16 2013, 03:18 PM
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Solar System Cartographer Group: Members Posts: 10167 Joined: 5-April 05 From: Canada Member No.: 227 |
Revisiting the Phobos images:
http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=5511 This is a very nice comparison of the apparent sizes of Phobos, Deimos and our Moon seen from their respective planets... but check the caption: "The size-comparison image of Earth's moon, on the right, is also oriented with north up." Sorry, JPL buddies, but not so - this looks like a distant Galileo encounter 2 image, and the north pole is at right, pretty much at the middle of the terminator - it's almost looking down on the pole. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Aug 16 2013, 05:28 PM
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#3
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Member Group: Members Posts: 238 Joined: 15-January 13 Member No.: 6842 |
Interesting, the image shows that Phobos is approx as wide as the Moon in the widest part, and half as wide in the short part. Stellarium shows a much smaller Phobos as seen from Mars, 0.125 degrees or approx 1/4th of the Moon diameter, but perhaps Stellarium is not the most precise software in that regard. What is Phobos' angular size as shown in Celestia?
P.S. I plugged the numbers from the JPL link into an online calculator at http://www.1728.org/angsize.htm and the result is 0.2 degrees, slightly less than half the full moon. -------------------- Curiosity rover panoramas: http://www.facebook.com/CuriosityRoverPanoramas
My Photosynth panoramas: http://photosynth.net/userprofilepage.aspx...;content=Synths |
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