Pluto has fascinated scientists and science fiction fans alike since its discovery in 1930 by Clyde Tombaugh, and it’s the most famous dwarf planet in our solar system—but that doesn’t mean we know everything there is to know about it. Recently, NASA made headlines with the news that they had discovered an ocean beneath the icy crust of this faraway celestial body, making Pluto the only known body in our solar system to have one. So what did NASA discover about Pluto? What does this mean about Pluto’s atmosphere, and what does it tell us about life beyond Earth?
The New Horizons probe
NASA’s New Horizons probe was launched in 2006 with the purpose of studying the solar system. The probe took a little under nine years to make its way to Pluto and it has been sending back information ever since.
The most recent data collected includes that on July 14, 2015, New Horizons crossed the space between Earth and Pluto (approximately 3 billion miles) at the speed of 31,000 miles per hour–the fastest man-made object ever.
The 5 biggest questions answered
- Is Pluto a planet? Yes, but now it is referred to as a dwarf planet.
2. What are some of the other dwarf planets in our solar system? Neptune, Ceres, Makemake and Eris.
3. How big is Pluto compared to Earth and the Sun? The diameter of Earth is 12,706 km and the diameter of the Sun is 1.4 million km; this makes the diameter of Pluto about 2,380 km. In comparison, Earth is 148 times larger than Pluto. The radius of the Sun is 696,000 miles; making its radius 108 times greater than that of Pluto.
4. Why did scientists originally decide to demote Pluto from planet status?
5. When astronomers started finding more and more objects like Pluto orbiting the sun far beyond Neptune in the early 2000s (a region now called Kuiper Belt), they realized that there must be an outer limit for these objects’ orbits around the sun.
The recent flyby
After a nine-year journey, NASA’s New Horizons space probe, which was launched in 2006, recently made a flyby of the dwarf planet Pluto. This is the first time any spacecraft has ever visited the planet. In a historic moment, the probe sent back detailed images and data of its atmosphere and surface. The images show what appears to be mountains of ice or frozen gases that form layers on top of each other like sheets on a bed. What scientists will learn from this information may not be known for months or years. But it seems clear that there are many similarities between Earth and Pluto’s landscape. One major similarity is the chaos regions – areas of broken, older terrain thought to have been created by tectonic forces – found on both planets. Another key similarity is nitrogen glaciers flowing through their respective valleys in Greenland and Charon (a large moon orbiting around Pluto). These findings indicate that many geological processes operate similarly on both planets despite them being so far apart in distance.
Global haze discovered
The haze is much more widespread than we expected, said science team member Fran Bagenal of the University of Colorado Boulder. We had thought it might be more or less uniform, but instead, it forms a pattern of bands circling the planet. This discovery is important because it shows us that there are patches on Pluto that have been fogged over for some time. It will take a while before we can confirm whether these regions were once covered in liquid nitrogen ice and became covered with haze when the ice was gone or if they were never covered in nitrogen ice to begin with.
Surface composition
When the New Horizons probe reached its destination, it found a surface that was much more diverse and active than scientists had expected. The planet has glaciers of water, nitrogen, and methane ice. Additionally, there are signs of volcanism on the planet’s surface. There is also a broad field of dunes as well as many craters on the planet’s surface. These images help scientist get a better understanding about how planetary bodies form and change over time.
Elevation variations discovered
Of all the images, one of the most fascinating was a series of pits that might have been created by flowing nitrogen ice. The pits range in size from 300 feet (91 meters) to 400 feet (122 meters) wide and up to 1,600 feet (488 meters) deep. They were found along Pluto’s Sputnik Planum, informally named for Earth’s first artificial satellite. We don’t know whether these are coming from some volcanic activity under the surface or whether they are just cracks in the glacial ice we see on top of it, principal investigator William McKinnon said.
Craters are common
The most common type of crater is a simple bowl-shaped crater. The Earth has many craters from asteroid and meteor impacts. Craters are created when an object hits the surface at high speed. The impact creates a shockwave that spreads out, breaking rock into pieces and throwing them outward in all directions from the point of impact. This material makes a blanket of debris on the surface, which may harden to form an irregular circular or elliptical rim. In time, this rim may break up as new craters are formed nearby.
It can take millions of years for all the dust and fragments thrown out by an impact to settle back down so that new impacts do not happen in exactly the same spot.
Something odd about its moons
Astronomers knew before New Horizons’ flyby that Charon had a deep canyon running along its center, but they weren’t sure how many other craters or valleys there were. Instead, they found three more, including one called Serenity Chasma. Serenity Chasma is approximately 600 miles long and 8 miles deep. The team also found evidence of water ice on the surface of Pluto’s moon Nix, which is about 45 miles wide on average. The frozen world has a surface of about 80% nitrogen ice and 20% methane ice
While exploring Pluto’s neighborhood, New Horizons also discovered four other small moons in orbit around the planet – Kerberos, Styx, Nix and Hydra.
An encounter with a Kuiper Belt Object (KBO) may be possible in the future
The Kuiper Belt is a region of our solar system that lies beyond the orbit of Neptune, with an area spanning from about 30 AU to 55 AU from the Sun. Objects in this region are called Kuiper Belt Objects (KBOs). The existence of KBOs was hypothesized before their discovery, and it is believed that there are at least 200 million objects larger than 60 kilometers across in the belt. One such object, Eris, is 27% more massive than Pluto. Many astronomers believe that the evidence discovered so far points to the fact that there may be one or more undiscovered planets out in the Kuiper Belt.
