January 29, 2014
NASA Preparing Martian Spacecraft For Close Passing Comet
Brett Smith for redOrbit.com - Your Universe Online
Scientists at NASA said they are busy prepping for observations of a comet that is expected to streak across the Martian sky later this year.
Comet Siding Spring, officially dubbed C/2013 A1, is projected to pass about 10 times closer to Mars than any identified comet has ever flown past Earth.
"Our plans for using spacecraft at Mars to observe comet Siding Spring will be coordinated with plans for how the orbiters will duck and cover, if we need to do that," said Rich Zurek, Mars Exploration Program chief scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Spacecraft at Mars could possibly glimpse the nucleus of the comet since it will come within about 86,000 miles of the planet. Scientists are also concerned the dust the comet nucleus sheds in the coming months could jeopardize spacecraft orbiting Mars in October.
Comet Siding Spring was identified on January 3, 2013 from Australia's Siding Spring Observatory. At that time, it had been farther away from the sun than Jupiter. Additional information gathered by scientists at several different institutions allowed for the determination of the comet’s trajectory as it passes Mars.
According to NASA, Siding Spring's nucleus will pass Mars at about one-third of the distance between Earth and the Moon. However, observations throughout the year will continue to refine estimates of the comet's path.
Tracking of the comet will be conducted using resources found on Earth, orbiting Earth, on Mars and orbiting Mars. NASA's Hubble Telescope, along with the NEOWISE orbiter, has already been tracking the comet to determine its characteristics, as well as understand amounts and sizes of the comet’s particulate matter emissions. Infrared data collected from NEOWISE has indicated that Comet Siding Spring is dusty and dynamic.
As the comet draws near Mars, NASA assets both around the Red Planet and on Earth will be used to examine this representative of the outer Solar System.
"We could learn about the nucleus -- its shape, its rotation, whether some areas on its surface are darker than others," Zurek said.
NASA said cameras on its Mars rovers might be able to spot meteors in the sky – an indication of the amount of particles streaming from the comet. However, they said they expected most of the meteors to hit the Martian atmosphere in daytime sky rather than at night.
"A third aspect for investigation could be what effect the infalling particles have on the upper atmosphere of Mars," Zurek said. "They might heat it and expand it, not unlike the effect of a global dust storm."
Concerned about potential damage to their assets, NASA scientists said the brightness of Siding Spring is an indicator of how much of a threat it will present to spacecraft at Mars.
"It's way too early for us to know how much of a threat Siding Spring will be to our orbiters," said Soren Madsen, Mars Exploration Program chief engineer. "It could go either way. It could be a huge deal or it could be nothing -- or anything in between."
The space agency said it would use two main strategies to lower that risk to orbiters: strategically position them behind Mars and to orient them so that the most sensitive parts are not directly in the line of fire.
Image Below: NASA's NEOWISE mission captured images of comet 2013 A1 Siding Spring, which is slated to make a close pass by Mars on Oct. 19, 2014. Credit: NASA/JPL-Caltech