Nicolas Cowan grew frustrated analyzing particle collisions at a nuclear physics lab, doing work so arcane that “I could not even explain it to my parents, and my dad is an electrical engineer.” So in 2003, when a professor suggested he hunt for life on distant worlds, he jumped at the chance. Now a 27-year-old doctoral student at the University of Washington, Cowan recently used NASA’s Deep Impact spacecraft to look at Earth from an outside perspective. He hopes his findings will help identify Earth-like planets around other stars.
Others have mapped earth from space. what is unique about your work? Our approach was, if you were some extraterrestrial looking at Earth, what could you figure out based on mathematical analysis of the light it gives off? Instead of taking a snapshot, we looked at Earth in 24-hour blocks to see how reflected light changed over time. It turns out Earth is composed of three things: gray stuff (clouds), blue things (oceans), and red things (continents).
How will this type of research help identify earth-like alien worlds? You can apply what we have done to other planets to decide if it’s worth looking for water vapor in their atmospheres.
You were the first one to map a planet circling another star. how did that happen? We were looking at hot Jupiters [giant gas planets that lie very close to their stars]. A Harvard grad student showed how the brightness of this one planet changed with time. Then we came up with the idea of using the light curve to map what the planet actually looks like.
Describe your worst experience in science. One summer I spent hours sanding down little pieces of semiconductor until they were 100 microns thin. By the end of the summer I could feel the difference between 100 microns and 150 microns. And I was like, “Wow, this is a great skill to have.”
What does a good day outside the lab look like? In the wintertime, backcountry skiing. I picked up surfing when I learned that my sweetheart was pregnant with our son. I’m not going to drag him out onto a glacier when he’s two months old—but bringing him down to the beach? That’s a family activity.
