Mars Reconnaissance Orbiter photographs Comet Siding Spring

During Comet Siding Spring’s flyby of Mars on Sunday Mars Reconnaissance Orbiter was able to capture an image of the comet’s nucleus.

Prior to its arrival near Mars astronomers estimated the nucleus or comet’s core diameter at around 0.6 mile (1 km). Based on these images, where the brightest feature is only 2-3 pixels across, its true size is shy of 1/3 mile or 0.5 km.

Mars orbiters survive comet fly-by

Press releases from science teams for Mars Reconnaissance Orbiter, MAVEN, and Mars Odyssey confirm that all three spacecraft are functioning properly after Comet Siding Spring’s fly-by of Mars today.

All three spacecraft also did observations of the fly-by, the data of which will take a few days to download. Stay tuned.

Update: Europe’s Mars Express and India’s Mangalyaan orbiters are also reported to have escaped damage during the fly-by.

Protecting the Mars orbiters from comet flyby

Engineers are repositioning the American spacecraft orbiting Mars so that they will be better protected by the planet when Comet Siding Spring flies past on October 19.

The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle — estimated to be about one-fiftieth of an inch (half a millimeter) across — could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.