Héctor Arce is an assistant professor in the Astronomy Department who teaches a freshman seminar called The Search for Extraterrestrial Life.

The Herald interviewed him about his expertise in astrobiology, or the study of life’s origins on Earth, a field that attempts to determine what conditions are needed to support habitation by simple or complex life forms, in order to inform the search for life on other planets.

Professor Héctor Arce takes on a satellite dish in a staring contest.

YALE HERALD: How would you evaluate the current research being done on extraterrestrial life?

HÉCTOR ARCE: As you probably know, we haven’t found any. But first, we are finding many more planets outside our solar system. That tells us that planets are common in our galaxy, and that maybe there is life on one of them out there. We still don’t know, but it increases the chances. The other thing is that we’re finding more and more extremophiles—these are organisms, usually unicellular, that live in very extreme environments. And so, if you can see that life can be abundant in very harsh conditions, then it is possible that planets out there that don’t have the nice “peaceful environment” here on Earth could also harbor life.

YH: Can you explain NASA’s latest mission, LCROSS, in the context of the search for extraterrestrial life?

HA: There have been different pieces of evidence that point to the possible existence of water on the Moon. When we first went to the Moon and brought back the rocks to analyze, they showed that the Moon was pretty dry. But then later on, very recently, there have been certain things that show an excess of hydrogen in certain regions of the Moon. That hydrogen could come from either being released by water molecules or being released by other kinds of molecules that have hydrogen.

There’s a very good chance that comets impacted the Moon. Comets are full of snow and ice, and the water from those comets could have stayed there on the Moon in the regions that are in perpetual darkness. The main aim of LCROSS is to slam a rocket against the Moon to get a plume of dust and vapor, or whatever came out of that crater, and then analyze it and see if we can detect water in that plume. If there was water in the crater, then we should be able to detect it with the LCROSS instrument and ground-based telescopes on Earth.

YH: What would the overall implications of water on the Moon be?

HA: It is very unlikely that there is life on the Moon. But if there’s water, then the probability for finding life is higher. Now, this is ice that may be on the Moon and it’s extremely cold.

We’ve found extremophiles that live in very cold water, but we haven’t found any that live in solid ice. But it could tell us something about how the water on Earth was delivered. Also, the Moon could be a source of water if we ever establish a base there, and hydrogen from the water could be used to fuel rockets. I’m interested more in the science, but there are other people more interested in the exploration.

YH: How practical and beneficial would it be to establish a base on the Moon or mine the asteroid belt?

HA: Right now, I do not think that it’s practical. But maybe in the future, if the costs get cheaper and the technology gets advanced in such a way that it’s easy for us to do that, then it should be done. If we are running out of resources here, and there are some out there in the asteroid belt, I don’t see why we can’t exploit them. But that’ll be very long-term.

YH: Why are these topics relevant to our lives here on Earth?

HA: Of course they are not relevant to day-to-day life, but different missions done by NASA and by the European space agencies have required the production of certain technologies that have been helpful for other areas, including medicine and transportation. If we keep developing technology for other missions, that will help with the development of technologies for everyday use.

Maybe not every day, but for certain useful things here on earth. The other thing is that maybe, just maybe, if we establish a base on the Moon, it will be easier to send missions to the outer solar system from the Moon because of the lower gravity there. You would need smaller rockets, compared to if you want to launch them from Earth.

Finally, as humans, we are always searching for knowledge. This is basic knowledge—where we came from and how our solar system was formed.