In his new book Exoplanets: Diamond Worlds, Super Earths, Pulsar Planets, and the New Search for Life Beyond Our Solar System (Smithsonian Press, 2017), Mason astronomy professor and NASA scientist Michael Summers shares the latest research on exoplanets, which are planets beyond our solar system. The book was written with co-author James Trefil, Robinson Professor of Physics at Mason.
Can you tell us about the exoplanets you’ve been researching?
These are entirely new categories of planets that we have discovered. We’ve found planets that are all water, or around 95 percent water. We’ve found planets of carbon at high pressure—diamond—that are geologically active, with volcanoes that spew out liquid carbon that freezes into diamond crystals on the surface. We’ve found planets that circle two, three, and even four stars. It rarely gets dark on such planets. We’ve also found planets that are much like the Earth—terrestrial, but that are 17 times more massive. There are at least a dozen new categories of planets that we didn’t even know existed before we began discovering exoplanets. It’s so bizarre that we just never would have expected that kind of diversity of planets.
What started your interest in astronomy?
When I was about six years old, my father gave me a small telescope. It was tiny—you could carry it in one hand. I had no idea what I was doing with it, but I took it out to our backyard and set it up. I saw this bright yellow light in the sky, so I pointed it at that. It turned out to be Saturn. I can still see it in my mind. I went and read that that planet is 90 times bigger than the earth. It really intrigued me. In high school, I took all the science and math courses I could, and in college I got into physics and astronomy and used their telescopes. Eventually I had opportunities to use the largest telescopes on Earth and to work with NASA’s space program. It has been an exciting career.
How long have you been at Mason?
About 17 years. I was at the Naval Research Laboratory before I joined Mason, but their focus was more on the Earth, and I was getting interested in other planets at the time. So I came to Mason and have been building up the atmospheric sciences group, the astronomy program, space weather and planetary sciences, and I’ve also been working with students in astrobiology—the search for life on other planets. At Mason, I’m close to where a lot of space policy and exploration decisions are made—D.C., NASA headquarters, and the Goddard Space Flight Center, where spacecraft for deep space are built and tested and where the James Webb Space Telescope is being built for deployment in 2018. I’m also close to the Applied Physics Laboratory, where we have mission operations for the New Horizons Spacecraft. So the location as Mason has been a great opportunity for me.
Do you think the ways we’re looking for life on other planets might be off because other life forms could be so different from us?
That’s a very good question. In the 1960s and 1970s, the approach of listening with radio telescopes for life elsewhere was all the rage. That approach is the focus called SETI [Search for Extraterrestrial Intelligence]. Intelligence probably does go through technological phases where it uses of electromagnetic communication, or radio waves. If you look at the past century, the Earth went through a period of being very noisy in radio wavelengths. But now it’s getting less so because we’re using cable. We’re using beamed communication as well, both much more efficient. So the actual radio signature of civilization on Earth is decreasing. So maybe an advanced civilization wouldn’t have any signature at radio wavelengths at all. Maybe they would do something completely different. Maybe radio wavelengths to them would be like smoke signals to us, and instead they use vastly powerful lasers or gravitational waves to communicate. I suspect we will be very surprised when we do detected advanced civilizations. They will seem like magic to us.