Do You Know What Color Pluto Really Is?
When New Horizons flew past Pluto, astronomers were shocked to discover that Pluto is actually red. Where is this redness coming from?
On January 19, 2006, NASA launched the interplanetary space probe New Horizons, aimed at the outer reaches of our solar system. Thanks to some extremely complicated math, the nuclear-powered spacecraft zipped past Pluto last year - almost a decade later.
The biggest surprise? Pluto has a rusty coloration across its entire surface, similar to Mars, which suggests that the icy planet may actually contain organic molecules. Scientists think that the red coloring comes from tholins, a compound that is generated when ultraviolet light from the sun breaks down methane and nitrogen. These tholins then rain down upon the surface, coloring everything a rusty red.
This is hugely significant to astrobiologists because tholins can form the backbone of amino acids, one of the basic building blocks of life as we know it. Tholins aren't alive in any biological sense, but they are organic molecules. In fact, some theories posit that tholins and similar compounds sparked the development of life on Earth. We can't create tholins in our atmosphere, but they may have hitched a ride from deep space on a comet or asteroid.
At any rate, the red coloration of Pluto was a genuine shocker for all of space science. Previous to New Horizons, we'd never been able to get a good look at Pluto, and astronomers conjectured that it was most likely a barren, icy rock. Not so. Pluto actually has vast plains of slow-moving ice floes, massive mountain ranges, and even a thin atmosphere with wispy clouds.
Ian has many more details in his report, along with some stunning images. Or for a quick peek, NASA has some nice pictures of Pluto here.
Space.com: New Horizons: Exploring Pluto and Beyond
Astronomy Magazine: Here's why New Horizon's post-Pluto destination is important