New Horizons space probe makes history
July 13, 2015
There is not much science knows about Pluto. The celestial body was first seen - and classified as a planet - 85 years ago. But there is a good reason we know so little about it: Pluto is located at the Kuiper belt - the outer limits of our solar system.
Sixty years ago, the astronomer Gerard Kuiper suggested there was an orbital region located between five and 10 billion kilometers from the sun populated with celestial bodies.
Today scientists know there are indeed hundreds of thousands of bits of ice flying around the eponymous Kuiper belt. The icy bits are most probably left over from the creation of the planets.
For its part, Pluto hasn't been a "planet" since a 2006 meeting of the International Astronomical Union (IAU). It was decided then that for a celestial body to be considered a planet it needed to feature a spherical orbit. And that cancelled Pluto out.
Most of the bodies in the Kuiper belt are less than 50 kilometers in diameter. Pluto has a diameter of 2,300 kilometers, making it one of the largest bodies. It is similar in size to Eris, which was discovered in 2005. Planet Earth by comparison has a diameter of 12,742 kilometers.
Pluto's secrets
There are many things scientists hope to learn about Pluto. For one, does it have an ocean? Of what does the atmosphere consist? What effect do Pluto and its largest moon, Charon, have on one another? And what does it mean for Pluto's other moons?
"Pluto and its [moon] Charon represent an unknown world for planetary science," says Professor Tilman Spohn, director of the German Aerospace Center's Institute of Planetary Research in Berlin.
As a result, researchers all over the world were extremely excited about the first images that New Horizons has sent.
Spohn was looking forward to even more: it may be possible to discover "ecological niches," in which "it may be possible to imagine the development of simple lifeforms."
It's thought, as with the Comet 67p/Churyumov-Gerasimenko, that the ice formations in the Kuiper belt are probably untouched or unchanged by geological processes. So Pluto could reveal a lot about the earliest moments of our solar system.
But it's unlikely New Horizons will deliver any evidence of extraterrestrial life.
No other spacecraft has travelled so fast
Exploring the Kuiper belt is not only so difficult because the New Horizons probe, which weighs 500 kilograms, has had to travel so far - but it's also had to beat the sun's gravitational pull.
On January 19, 2006, New Horizons was launched aboard an Atlas V Rocket. It was the first of its kind, using a booster system that immediately took the craft on a trajectory away from the sun.
It was with a physical trick that New Horizons was able to reach a speed of 50,400 kilometers per hour: it flew by the planet Jupiter on February 28, 2007, and used its gravitational field as a catapult. New Horizons thus became the fastest spacecraft and holds that record to this day.
New Horizons is carrying a world of instruments on board. They are controlled by the Applied Physics Laboratory (APL) at Johns Hopkins University in Laurel, Maryland, in the United States.
The probe, which is about the size of a piano, has been fitted with a large parabolic antenna to make this possible. But it has to be quick: New Horizons has just two days time to take all the shots it can of the dwarf planet.