The Earth, along with the rest of the solar system, was born around 4.6 Billion years ago. At that time, Earth was part of the early group of habitable planets to form in the Universe. According to a new theoretical study from the Space Telescope Science Institute (STScI), the vast majority of Earth-like planets has yet to form.
Using data from the Hubble space Telescope (HST) and the Kepler Space Telescope (KST), astronomers were able to come up with a theoretical model of cosmic evolution, detailing how planets will form over the entire lifespan of the Universe.
“Our main motivation was understanding the Earth’s place in the context of the rest of the universe,” said study author Peter Behroozi of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, “Compared to all the planets that will ever form in the universe, the Earth is actually quite early.”
Very early, according to their calculations. Only 8% of the habitable planets that will form over the lifespan of the universe are already in existence, and the Earth is one of them. Most of the raw material to build rocky worlds is being synthesized in the fiery crucibles of stellar cores as you read this sentence, and it will not seed these new planets for billions of years to come.
At the present time, best estimates indicate that there are around 1 Billion rocky planets in the Milky Way, and countless more if you include the other 100 Billion galaxies in the universe. Yet this is a small fraction of the worlds still waiting to form. With so many habitable worlds to come in the future, the possibility that life will evolve again is increasingly likely, though we may not be around to see it.
But we can still hope….