Ceres Geology |
Ceres Geology |
Jan 22 2014, 06:14 PM
Post
#1
|
|
Rover Driver Group: Members Posts: 1015 Joined: 4-March 04 Member No.: 47 |
Paper out tomorrow: http://www.bbc.co.uk/news/science-environment-25849871
Very exciting that we will visit this world soon! |
|
|
Jan 25 2014, 12:32 PM
Post
#2
|
|
Junior Member Group: Members Posts: 30 Joined: 3-October 07 From: Fátima - Portugal Member No.: 3927 |
... and the diagram of the paper suggest it only happens when Ceres is in certain parts of its orbit. As the Ceres orbit has an eccentricity of 0,080 and an orbital period of 4,6 years, is it possible that Dawn spacecraft will be able to stay in Ceres orbit until its perihelion and so, to tentatively observe the surface spots from where this water vapour is originated? |
|
|
Jan 25 2014, 11:34 PM
Post
#3
|
|
Member Group: Members Posts: 102 Joined: 8-August 12 Member No.: 6511 |
As the Ceres orbit has an eccentricity of 0,080 and an orbital period of 4,6 years, is it possible that Dawn spacecraft will be able to stay in Ceres orbit until its perihelion and so, to tentatively observe the surface spots from where this water vapour is originated? Ceres' last perihelion was September 2013, just four months ago. Aphelion will be at the end of 2015 and the next perihelion in April 2018. Dawn will arrive there in late March 2015 and (IIUC) currently has a nominal one-year mission. So it will certainly be there through aphelion. It would have to hang around another two years for perihelion. I don't see anything that would prohibit this, though some orbital manipulation may be required -- lower orbits burn fuel faster, as the spacecraft has to make more adjustments. If the water vapor production really is driven by sublimation -- a reasonable assumption, but who knows -- then we'd expect it to be peaking in the months after perihelion when Ceres' surface is warmest, i.e. right around now. So in that sense Dawn would be arriving at exactly the wrong time. But we really don't know. We'll start getting respectable imaging of Ceres' surface a couple of months before Dawn arrives, i.e. January 2015. So... we wait. Doug M. |
|
|
Lo-Fi Version | Time is now: 21st June 2024 - 02:24 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |