Space buffs will know it’s easy to get caught up in the many exciting developments, from flights to the surface of the moon to new discoveries in exoplanet science. But as an astronomer, what really worries me right now is something that has been largely ignored here on Earth and could have profound implications for how we understand the development of life on our planet and one of its most unique features. : our oceans.
With a little noise, ahead Vera S. Rubin Observatory in Chile, on April 27, an important construction milestone was celebrated. Workers at telescope applied a reflective coating to the primary mirror, giving it the ability to capture light from extremely dim objects in the night sky that we currently cannot detect on a regular basis.
With this critical component of what will be one of the most powerful telescopes on Earth, we will be able to shed light on a question that has puzzled scientists for decades: Where did our oceans come from??
On the topic: How did the Earth get water? Scientists are now looking for clues in “hyperactive comets.”
We know that the Earth’s oceans were a key component for the development of life, but we are still not sure how they developed. Some of us think that our oceans were brought to us by ice comets and asteroids from a larger point in the solar system. Similarly, recently discovered interstellar objects such as ‘Oumuamua and 2I/Barysov can tell us about how oceans are delivered to planets around other stars.
Certain chemical properties of Earth’s oceans are unlike what we would expect if water had been present during Earth’s formation. Astronomers believe that the water must have been delivered after Earth formed, potentially from comets originating in the far reaches of the solar system, such as Kuiper belt or the Oort cloud. However, when the European Space Agency (ESA) The Rosetta mission Measured properties of water on comet 67P/Churyumov-Gerasimenko, these chemical characteristics do not match the characteristics of our oceans.
Part of the answer comes from learning more about one of the biggest new mysteries in the solar system: dark comets.
We recently discovered seven dark comets hiding in nearby asteroids Earth. These objects are disguised as asteroids – rocky bodies that do not have water ice. However, we have noticed that dark comets are accelerating in a strange way.
Comets are small bodies, such as asteroids, that also contain ice, such as water and carbon dioxide. As the comet heats up as it approaches the sun, this ice turns to gas and is blown off the surface, creating a rocket-like acceleration and a tail of gas and dust.
These dark comets accelerate like comets, but do not have tails that are obvious to our telescopes. If they have water ice on them, perhaps they could deliver Earth’s oceans.
If dark comets do contain water, they may be the missing link in our understanding of where our oceans came from. It is possible that they, or dark comets like them in the past, had water that resembles our oceans.
‘Oumuamua was the first large body to be seen passing through the interior Solar system which came from another star system—our first interstellar object. Like dark comets, Oumuamua masqueraded as an asteroid because it had no obvious comet tail, but it accelerated like a comet. We now think that Oumuamua—and dark comets—contain ices that were invisible to us, and that these unusual ices contribute to their acceleration as they heat up and become gases.
Astronomers have discovered rocky planets orbiting other stars that may harbor oceans and life. Now we know that these exoplanetary systems have ejected enough interstellar objects, such as ‘Oumuamua and Borisov, into the galaxy that a small fraction of them should pass through our solar system. Just as dark comets could have given us our oceans, bodies like these interstellar objects could have carried the ingredients needed for life to develop on rocky planets around other stars – like our Earth.
On the topic: 10 exoplanets that may have alien life
The fact that we recently discovered the first interstellar object and the first dark comets means that we are only at the tip of the iceberg. There are probably many more such cloaked comets – both from interstellar space and the solar system – lurking undetected in the neighborhood of our planet.
The Rubin Observatory is now one step closer to having access to observational sensitivities orders of magnitude greater than we have today. Soon we will be able to find hundreds of interstellar objects in our solar system and see the acceleration of many new dark comets.
Could dark comets and interstellar objects be the source of life Earth-like planets? With the Rubin Observatory, we have a chance to understand these entirely new populations in the Solar System and potentially where we came from.
Daryl Seligman is a research associate in the Department of Astronomy at Cornell University. His research focuses mainly on theoretical and computational planetology and astrophysics.