London, Jan 10 : A new research has led astronomers to speculate that the extremely hot temperature of a planet 170 light years from Earth, might be a result of another planet colliding with it from the same system.
According to a report in New Scientist, the planet, known as 2M1207B, is orbiting a brown dwarf and has bizarre properties that astronomers have been struggling to explain from quite some time.
For one, the light spectrum of the planet suggests it is a scorching 1300 degree Celsius.
Though this blazing temperature might be because of the relatively young age of the planet, the estimates do not fit in with other observations. That's because if the planet is really so large and hot, its infrared glow should be about 10 times brighter than is actually observed, which is not the case here.
Now, two astronomers - Eric Mamajek of the CfA (Center for Astrophysics) and Michael Meyer of the University of Arizona in Tucson, US, have come up with an explanation for the extreme temperature of the planet.
According to them, the planet is actually much smaller than previously believed, and is only blazing hot today because it was recently hit by another planet in the system.
Because 2M1207B is a little less massive than Saturn and weighs 72 times that of Earth, if a planet weighing 8 Earths thumped it, the energy released would be tremendous. This would be enough to explain its heat if the collision happened within the last 100,000 years, the astronomers added.
In support of the idea, the astronomers point out that giant collisions appear to have taken place in our own solar system.
The Moon, for example, is thought to have come together from debris produced when the Earth was hit by an object about one-tenth its mass about 4 billion years ago. Giant collisions have also been invoked to explain why Uranus's rotation axis is tilted over so much, and why Venus spins backwards compared to the other planets.
Future measurements of the planet's light spectrum could test the theory by revealing the strength of gravity on the planet's surface, and thus how massive 2M1207B really is.