For many astronomers, Pluto would be an icy dwarf planet. This is because it is one of the farthest objects in the Solar System. There is evidence, though, that Pluto may be more than just ice and that it might have a sea beneath it.
NASA's New Horizons spacecraft has flown by Pluto last year. During its flyby, it has studied much of the dwarf planet and took photos of it. Now researchers think that beneath all that ice Pluto might have a sea. Brown University geologist Brandon Johnson thinks that more than 100 kilometers of water is trapped beneath Pluto's ice, according to Phys Org.
The focus of the study is Sputnik Planum. It is a 900-kilometer crater that was likely created by an object about 200 kilometers across or even larger. The crater has been chosen since it has much bearing on Pluto's moon, Charon. Sputnik Planum is directly on the tidal axis that the two create, much like how the tides on Earth are affected by the Moon's gravitational pull.
Its position also creates what is called a positive mass anomaly. That means that Sputnik Planum has more mass relative to Pluto's crust. Researchers though find that to be odd as Sputnik Planum as a crater should have a negative mass anomaly.
"An impact crater is basically a hole in the ground," Johnson explained about Sputnik Planum. He also said that with a crater much of the material would have been thrown out because of the impact. Researchers speculate that as material from the crater came out, it has been partially filled in by nitrogen ice. That though still would not account as to why Sputnik Planum has a positive mass anomaly.
The nitrogen ice is said to be not thick enough to create a positive mass anomaly. However, it is speculated further that liquid might be dense enough to create that. It has been theorized that there is likely a layer of liquid beneath the ice that has welled up after the impact and filled up the crater.
The idea of Pluto having an ocean underneath its ice is not new. Science News reports that as early as March, researchers have proposed this to explain the alignment of Charon and Sputnik Planum. Researchers have also reconstructed how the crater was formed and based on various scenarios, the most likely one has the sea layer to be 100 kilometers.
Research continues on this as astronomers and other scientists look into Pluto to find out what else the dwarf planet might be hiding underneath its icy surface, such as the recent iTechPost report that it has X-ray emissions that are baffling scientists.
