Hubble captures stunning image of a comet's brush past Mars

Hubble captures stunning image of a comet's brush past Mars
This composite image shows the relative positions of Mars and comet Siding Spring during its flyby on Sunday. (NASA, ESA, PSI, JHU/APL, STScI/AURA)

Anybody need some new space wallpaper?

NASA has just released this image of comet Siding Spring's close brush past Mars, and it is thrilling.


The image you see above -- a fuzzy white comet hovering above a glowing rust-colored planet -- is actually a composite of several images taken by the Hubble Space Telescope on Saturday and Sunday.

There are a few reasons that Hubble could not take a picture like this in a single shot. For one, Mars is 10,000 times brighter than its cometary visitor, making it impossible to see details of Siding Spring and Mars in one exposure.

Also, the two objects were racing past each other during their near-rendezvous on Sunday. At least one of the objects would have been blurry if Hubble tried to take an image of them simultaneously.

The starfield that the two bodies are set against was provided by the Palomar Digital Sky Survey.

Despite being a bit of a cut and paste job, NASA officials say the image accurately illustrates the distance between Siding Spring and Mars at the time of the comet's closest approach.

It also accurately represents the relative sizes of the two bodies.

"We know how big Mars is -- it's an enormous planet -- smaller than the Earth, but bigger than the moon. And even though the nucleus of the comet is just 500 meters across [1/3 of a mile], the coma and the tail are enormous," said Jim Green, director of NASA's planetary science division in an interview with The Times. "Hubble really demonstrates how big these comets are."

At the time of closest approach at 11:28 p.m. Saturday, comet Siding Spring was just 87,000 miles from Mars -- about one third of the distance between the Eath and the moon.

Green said this rare encounter of planet and comet, which might happen just once every million years, should provide scientists with lots of new data, as well as the rest of us with more amazing images.

"Mars got blanketed in cometary material and we observed it, our orbiters were right up close and personal," he said. "But this Hubble image is great because it steps back and puts everything in context."

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