Nine years ago, a spacecraft called New Horizons broke a world speed record when it left our planet. It headed straight for the least-known corners of the solar system. On Tuesday it made history flying by Pluto.
Advertisement
NASA spacecraft approaches new horizons with dwarf planet Pluto flyby
For nine years, NASA's New Horizons spacecraft has been travelling through our solar system. On its way, it's visited an asteroid and the planet Jupiter. Now, it's reaching its goal: Pluto.
Image: JHUAPL/SwRI
First glimpse of Pluto
This is one of the most recent images of Pluto - taken by NASA's New Horizons spacecraft. By Tuesday the pictures will become sharper and better as the unmanned probe gets closer and closer to the dwarf planet.
Image: picture-alliance/dpa/NASA/JHUAPL
Just a stone's throw away
The big day is July 14 - and long awaited by NASA researchers. New Horizons will pass Pluto from a distance of 12,000 kilometers, which seems far away. But let's compare: the distance from our moon to Earth is thirty times as far, so 12,000 kilometers is pretty close! And this is how things will look, with Pluto's largest moon Charon in the background.
Image: JHUAPL/SwRI
The planet that wasn't to be
Seven months after New Horizons launched, the International Astronomical Union (IAU) cancelled Pluto's planetary status. It is now referred to as a "dwarf planet" as its solar orbit is not sufficiently circular - it is more elliptic. It was the first time the IAU had defined what constitutes a "planet," and came because too many objects had been discovered in the solar system.
Image: picture-alliance/Bildagentur-online/Saurer
Comparison by size
The planets closest to the Sun are Mercury, Venus, Earth and Mars. Then there's the dwarf planet Ceres, followed by the giants Jupiter, Saturn, Uranus und Neptune. On the outer fringes of the solar system there are two tiny dots: Pluto and its moon Charon. New Horizons data shows Pluto's diameter to be a little larger than previously thought, at around 2,370 kilometers (1,473 miles).
Image: picture-alliance/dpa
Not all of Pluto's moons are round
It is hoped New Horizons will investigate Pluto's moons, and discover, for instance, the true size of Styx. It is one of Pluto's moons, and is thought to have a diameter of somewhere between eight and 28 kilometers. The probe took its first pictures of Charon, Nix and Hydra in January and February. In April, it got shots of Kerberos. But NASA expects higher resolution images very soon.
Image: NASA/ESA/A. Feild (STScI)
Wild dance in the lunar orbit
The moon Nix spins around wildly in its lunar orbit. These are not pictures taken by New Horizons, but a computer simulation by NASA scientists, based on existing data. What makes things complicated is that Nix not only circles in an orbit around Pluto, but is also influenced by the gravity of Charon - so the one moon is also a moon of another moon.
New Horizons is equipped with three optical instruments, which can take pictures in a large variety of spectral bands. Two plasma spectrometers can analyze particles such as those emitted by the solar wind. The spacecraft also features dust sensors and radiometers.
Image: JHUAPL/SwRI
"Big" camera
Here, engineers are installing the Long Range Reconnaissance Imager (LORRI) on the New Horizons probe. LORRI is a digital camera that registers wavelengths of visible light: the heaviest part of the 8.6 kilogram camera is its 5.6 kilogram telescope.
Image: NASA
Best part of a decade
New Horizons was launched on January 19, 2006, from the Cape Canaveral Air Force Station in Florida, aboard an Atlas V rocket. The spacecraft immediately entered a trajectory designed to overcome the Earth's gravity and that of the sun. To do that it needed a speed of more than 16 kilometers per second - that's more than 58,000 kilometers per hour (37,000 mph), and with it a world record.
Image: NASA
Farther and farther from the sun
The trajectory of New Horizons has taken it straight for the far reaches of our solar system. On its way, New Horizons has visited the asteroid 132524 APL, as well as the planet Jupiter, which the probe passed at a distance of 2.3 million kilometers. It collected data about Jupiter's atmosphere, its magnetosphere, and its moons.
Image: NASA
Coming soon: "new and improved" images!
NASA was able to fix a few technical difficulties with New Horizons recently and the spacecraft is now again fully operational. Hopefully, nothing will now stop it from delivering fascinating new pictures of the dwarf planet Pluto.
Image: JHUAPL/SwRI
11 images1 | 11
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.