New Horizons - The Mysteries of Pluto Unveiled

At 9pm on July 14^th 2015, the NASA New Horizons mission team received a very important phone call..

New Horizons had completed the first ever flyby of Pluto. It took over nine years and three-billion miles to complete, but has finally given us our first detailed glimpse of the ex-planet at the end of the solar system. It looks like Pluto was definitely worth investigating.

The New Horizons space probe has been designed to function with a minimal power input. It required less than 200 Watts of Power to reach Pluto - that’s less than a pair of light bulbs. Compared to a grand piano in size, New Horizons weighs just 478 kilograms^[1]. Image credit: NASA/JHUAPL/SwRI

Pluto's New Horizons

[EDIT - June 2014] This article is now also available as a video, thanks to a group of media students at Sheffield Hallam University who created an animated version of our article. For more information, read about how we partner with universities to create videos.

  

“Pluto is dead”, according to Mike Brown (in How I Killed Pluto and Why it Had it Coming), but that doesn’t mean we shouldn’t go there. In fact, this is one of the reasons why we are going there. Unsurprisingly, given the distances involved, we know very little about Pluto (“You may think it’s a long way to the shops, but that’s just peanuts to space,” to quote Douglas Adams in The Hitchhiker’s Guide to the Galaxy).

We're used to seeing detailed pictures of our neighbouring planets like Mars, but this is the best image we have of Pluto - taken by the Hubble Space Telescope in 1994. So what does Pluto really look like? Image credit: NASA/HST

Discovered in 1930, Pluto remains something of a mystery, as astronomers are a long way from understanding its origin. Pluto is one of many rocky and icy bodies which form the Kuiper Belt, in the outer region of the solar system. Pluto was discovered by Clyde Tombaugh in a systematic search for a planet beyond Neptune. Its high surface reflectivity initially made it appear larger than it actually is. Pluto was initially considered as a planet, before the International Astronomical Union officially defined what a planet was. At one point Pluto was thought to be a rogue moon of Neptune.