A recent discovery about the Earth’s water has made the possibility of life existing beyond our solar system much more likely.
Scientists have discovered that Earth’s water was present on Earth before the giant impact that created the moon. Previously, it was understood that Earth’s water was carried to Earth in a series of later asteroid and comet bombardments – but it turns out that the water was around far before that.
This may not seem significant at face value, but it has implications for our understanding of how life may have developed on Earth – or how it could still exist elsewhere. Earth’s water surviving a gigantic impact means that water could have survived giant impacts elsewhere too, making it far more likely that life exists outside of our solar system – or has existed at one point or another.
Dr. Richard Greenwood, the lead researcher on the study from the Open University, stated that “Because water is such a vital ingredient for life, we rightly see it as precious. Our research shows that water is also extremely resilient and can survive an event as catastrophic as two planets colliding.”
In order to come up with this conclusion, the scientists on the research team compared the oxygen composition of moon rocks brought back to Earth by Apollo astronauts with that of volcanic rocks discovered deep in Earth’s water. There was only a small difference between the rocks in Earth’s water and the rocks discovered on the moon. If water on Earth had arrived after the gigantic impact that created the moon, the elements in the rocks should have had significant differences.
The findings were reported in the journal Science Advances, and essentially states that Earth’s water has been around a lot longer than we previously thought.
The giant impact that may have created the moon is thought to have occurred around 100 million years after the solar system formed. While the impact on Earth is most relatable to us as a species, there’s significant evidence that exoplanets in other star systems experienced these same large collisions.
“Because this worked for the Earth and the moon, it must also work for planets beyond our solar system…exoplanets with water on their surfaces may be much more common than we previously thought. And where there is water, there could also be life,” Dr. Greenwood added.
While the knowledge that Earth’s water was around for quite a while gives us hope that we may not be alone in the galaxy, it doesn’t bring us any closer to actually discovering said life. Practically, there may not be a lot that comes from this new knowledge. However, with a better understanding of Earth’s water and our planet’s history, we may be able to approach the exploration of new planets with the knowledge that the possibility of alien life is much more feasible.