July 15th was a historic occasion as it marked the first time we were able to see close-up pictures of Pluto’s surface. Traveling at over 30,000 mph, New Horizons snapped some very interesting pictures of the dwarf planet’s surface as it came within 47 thousand miles of it, beaming back to us details never before seen. What New Horizons captured for us was a first glimpse at mountain ranges and deposits of methane & nitrogen ice.
As New Horizons approached Pluto, it was some 3 billion miles away from Earth. If you think about how far away the Sun is from Earth, just multiply that by 32…that’s how deep into space New Horizon has traveled.
With that in mind, try to imagine how it sends back data to us and how long that would take. For perspective, it takes light 8 minutes to travel from the Sun to our Earth. New Horizons has to send back a large chunk of data to us: high res pictures, measurements of the atmosphere and temperature, ultraviolet images, etc. From that distance away, all that data is sent at about 600 to 1200 bits per second–that is to say, about 50 to 100 times slower than the speed of a modern cable modem.
At that rate it would take you about 2 hours to download a standard picture on your cellphone. This means that for the next 16 months New Horizons will be transmitting all the data down to us. However, so far, we already have some stunning images of Pluto’s surface and some surprising discoveries.
The evidence for the mountains’ age can be attributed to the lack of craters at the scene. Like the rest of Pluto, the region would presumably be pummeled by debris from space for billions of years, that is unless recent geological activity had erased those impact sites.
“This is one of the youngest surfaces we’ve ever seen in the solar system,” Moore said.
But what caused these mountains to form over such a relatively short span of time? Unlike the icy moons that orbit the outer gas giants, Pluto cannot be heated by gravitational interactions with a much larger planet. “This may cause us to rethink what powers geological activity on many other icy worlds,” said GGI deputy team leader, John Spencer, of the Southwestern Research Institute in Boulder, CO.
It is most likely that the mountainous region is composed of the same icy bedrock. Although it was recently discovered that Pluto has methane and nitrogen ice deposits, these materials are not strong enough to build mountains. It is more likely that water-ice formed these mountains since water-ice at Pluto’s temperatures acts more like rock, according to GGI lead, Bill McKinnon.