Comet Siding Spring shines in ultraviolet in this image obtained by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. Credit: Laboratory for Atmospheric and Space Physics/University of Colorado; NASA
As Comet Siding Spring passed close by Mars on Sunday (Oct. 19), NASA’s newest Mars spacecraft took a time-out from its commissioning to grab some ultraviolet pictures of its coma. What you see above is hydrogen, a whole lot of it, leaving the comet in this picture taken from 5.3 million miles (8.5 million kilometers).
The hydrogen is a product of the water ice on the comet that the Sun is slowly melting and breaking apart into hydrogen and oxygen molecules. Because hydrogen scatters ultraviolet light from the Sun, it shows up rather clearly in this picture taken by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft.
Check out more recent pictures of Siding Spring below.
Is this an image of Comet Siding Spring? It’s the only fuzzy object in the field photographed on Sol 3817 (October 19) by the Opportunity Rover. Click for original raw image.
Comet Siding Spring near Mars in a composite image by the Hubble Space Telescope, capturing their positions between Oct. 18 8:06 a.m. EDT (12:06 p.m. UTC) and Oct. 19 11:17 p.m. EDT (Oct. 20, 3:17 a.m. UTC). Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA
Another photo, just in, taken of the comet and Mars today (Oct. 19) by Rolando Ligustri. Beautiful!
Comet 2013 A1 Siding Spring on October 17, 2014, with two days to go until its Martian encounter. Very dense Milkyway starfield in the background with many darker obscured regions. Credit and copyright: Damian Peach.
By Elizabeth Howell
Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.