A few hundred years is a huge length of time for humans, but in cosmic terms it’s absolutely tiny. A hundred years in the world of Space could easily be compared to a millisecond for humans. But now scientists have discovered a planet that may have formed in as little as a few hundred years – which beats the former fastest forming planet by about 10 million years.
OK, it hasn’t finished growing yet, but the fact that it can be classified as a planet when it’s only been around for so little time is amazing astronomers all over the world. And the planet’s not the only interesting thing – its sun has only been around for a few hundred thousand years. (By the way, the planet and its sun are around 520 light years from Earth.)
So if this planet’s so young, how did astronomers find it? They used the Very Large Array (VLA) in Arizona to search for wavelengths of radiation that corresponded with pebble-sized lumps of rock (different sizes of rock emit different amounts of heat). They looked for pebbles because they are a vital hint that a planet is being formed.
It may be an intriguing discovery, but does is actually mean anything in terms of knowing more about our Universe? It certainly does – and it is stirring up quite a lot of controversy in the process. When stars form, they develop an area of rocks and gases around them, and these rocks and gases can eventually start to group together too form planets.
People used to think that planets formed when these rocks randomly collided, creating bodies with bigger and bigger gravitational attraction, which led to a sort of runaway growth. But this would take a very long time to produce a planet.
An alternative theory, backed by this latest discovery, is that planets actually form when an area of greater density within the area of rocks orbiting the star starts to contract, a process that could be complete within several thousand years.
OK, the difference between the two methods of planet formation don’t sound huge, but they have massive implications for scientists trying to understand the origins of our Earth. Let’s just hope that the meeting of the British Royal Astronomical Society (where this discovery was announced) won’t turn into a war between feuding scientists.