It’s called Comet C/2013 A1 Siding Spring, and NASA officials are hoping it will provide astronomers with vital clues to the history of the Earth.
Astronomers have been closely tracking the comet and will continue to follow it even after it passes Mars. Most of the data will take at least a day or two to reach astronomers and a year and a half to be fully examined, according to Carey Lisse, an astrophysicist from Johns Hopkins University.
Mr. Lisse believes the close fly-by could provide an opportunity to take the first photograph of a comet from another planet.
“Indeed, we’re getting ready for a spectacular set of observations, but there are some hazards involved,” Jim Green, director of the Planetary Science Division of NASA, told reporters in a briefing Thursday afternoon.
The dust particles from Siding Spring could be wide enough to reach Mars, which could cause damage to NASA’s Mars Orbiter Mission. However, the risk to the orbiter is significantly lower than what was previously predicted. NASA was able to move all spacecraft to the opposite side of the planet to avoid damage.
Siding Spring is projected to make its closest approach to Mars on Oct. 19. The comet will miss the Red Planet by just 88,000 miles — about 10 times closer than any identified comet has ever flown past earth, according to NASA’s California-based Jet Propulsion Laboratory. An event like this only happens about once every million years, according to Mr. Green.
Comet Siding Spring is the first so-called Oort Cloud to ever come into Earth’s solar system. Oort Clouds originate from a very distant spherical shell of icy bodies surrounding the solar system, according to NASA.
“Because Siding Spring has never been “heat-treated” before, the incoming comet likely remains largely unchanged since its formation 4.6 billion years ago,” according to the website Space.com. The comet’s “composition and behavior should provide clues about the conditions that existed at the birth of the solar system.”
The comet is between a half-mile and 5 miles in diameter, with a 100,000-mile long-coma (the nebulous cloud surrounding the comet’s head) and a 300,000-mile-long tail. The comet could be older than Earth, according to Mr. Lisse.
NASA has numerous assets aiming toward Mars and Siding Spring to photograph and study its impact on the Martian atmosphere. Siding Spring is not expected to be visible by the naked eye from Earth.
The Planetary Society believes the comet could be brighter than anything that is in our sky other than the sun and moon, but astronomers aren’t hyping Siding Spring as much as they did 2012’s Comet ISON, which left astronomers and viewers extremely disappointed after it was not nearly as prominent as forecast.
Kelly Fast, program scientist at the Planetary Science Division, praised the coordination of the observation teams and stressed the need to get it right.
“There’s one shot at this, and this is the time to do it,” Ms. Fast said.
NASA officials said there will be ample opportunity to follow the comet online, including a Google Hangout for people to see all of the information available on the subject. There will also be links on Twitter and Flickr for those interested in following Siding Spring’s progress.
• Mark Pace can be reached at mpace@washingtontimes.com.
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