Down to Earth With: Marc Kuchner

by Erin Wayman
Wednesday, May 23, 2018

Marc Kuchner likes to joke that when he feels sociable at a party, he tells fellow guests that he is an astronomer. But when he wants to be left alone, he says, he tells them he is an astrophysicist. At NASA’s Goddard Space Flight Center in Greenbelt, Md., Kuchner spends his time thinking about planets outside the solar system and looking for ways to better see them — and he’s devoted some of his time to working on the Terrestrial Planet Finder, a proposed NASA mission to look for and image Earth-like exoplanets. For his work on improving the detection and understanding of exoplanets, SPIE, an international society that advances light-based research, awarded him the group’s Early Career Achievement Award earlier this year.

But being an astrophysicist/astronomer is only one of Kuchner’s titles. He is also a country music songwriter. In the last year, two of his songs have played on the radio, and Music Connection Magazine named his song “Start Now” Best Demo of 2008.

Kuchner recently talked with EARTH’s Associate Editor Erin Wayman about his two passions.

EW: When did you start studying exoplanets?

MK: When I was in grad school. There were exoplanets known at the time, but they were all weird. They were all very massive, close to their stars — nothing really known like [the planets of] the solar system. And there still isn’t a known planet that’s really like Earth. We keep getting closer and closer to finding Earth-like planets. But we still haven’t found them. If you can find something that’s Jupiter-like, then maybe you can find something that’s Earth-like.

EW: In studying exoplanets, you’ve come up with the concept of a carbon planet. What’s that?

MK: When people started finding planets, they tended to assume they were somehow copies of what we have in [our] solar system. I took pleasure in pointing out to the astronomical community that we don’t really understand why the planets in the solar system have the compositions that they have. So I wrote some papers suggesting little tweaks to our ideas on how planets form. What if things were slightly different? What if the carbon-oxygen ratio in the nebula was a little bit different than it is in the sun? Then you could end up with planets that condense out of graphite and carbides like silicon carbide. You might end up with a carbon planet.

EW: If you went to a carbon planet, how would it be different from Earth?

MK: Really, the idea of a carbon planet is an idea about what it’s like in the middle, not exactly about what it’s like on the surface because the surface of the planet doesn’t necessarily have the same composition as the center. You could make up a story. For example, on the surface of a carbon planet … you might expect to see outcrops of rock like diamonds or silicon carbide. And then all kinds of interesting chemistry would occur. If there were some oxygen-rich parts of the planetary system and they delivered water or other volatiles to the surface of the carbon planet, you can imagine an atmosphere of carbon monoxide. I guess I kind of picture it being a little like Los Angeles. [Laughs] The ground covered with hydrocarbons, like tar. A smoggy atmosphere.

EW: How are you involved with the Terrestrial Planet Finder?

MK: The important thing that the Terrestrial Planet Finder does, that some of the other telescopes don’t do, is that it can take spectra of a planet. [With spectral data,] you can actually learn about the chemistry in the atmosphere — find out whether it has water or oxygen. When I was a postdoc, I worked on trying to come up with some new optical techniques that would make the TPF work better.

EW: Such as?

MK: The optical technique that I came up with was something called a Band-Limited Mask. We all have this mental picture of a star as something that has points shooting out of it. The points have nothing to do with what the star actually looks like. The points come from light that bounces around the telescope, or that bounces around in your eye. So the TPF needs to eliminate all that scattered light in order to see planets because otherwise they’ll be swamped by those spikes. The TPF is designed to not have those kinds of distractions.

EW: Does your work in astronomy in any way relate to your work as a songwriter?

MK: [Laughs] It sure does. Something I learn in one endeavor applies to the other. It’s not so much about the technical parts of building a song or building an astrophysical theory or paper. It’s more about life as a creative person. I sort of think of my astronomical papers as my — you know, if I have a good one, it’s like a hit paper. [Laughs] You’re known in the music business for your hits; you’re known in astronomy for your hits. I’ve learned a lot about marketing in both astronomy and the music business.

EW: Have you always wanted to write songs?

MK: I discovered songwriting when I was in graduate school when I was regularly going to Palomar Observatory. Well, a third of the time the sky is cloudy, [laughs] so I started bringing my guitar up to the mountain. I started out by writing silly songs about astronomy. I’d take a song over to one of the other domes, and I’d play it for one of the other astronomers. Sometimes the songs were stupid. Sometimes they were stupid but clever, and other astronomers would pass them around. They’d get excited about them.

EW: When did you start writing country songs?

MK: I took a year off from graduate school. I tried to learn about the music business. I answered an ad in the paper for a recording studio that was looking for an intern. It turned out it was the recording studio of the country star Dwight Yoakam. So just by chance, I was suddenly surrounded by experts in country music.

EW: If you could accomplish one goal in astronomy and one goal in music, what would they be?

MK: A Nobel Prize and a hit song.

EW: Which will be easier to accomplish?

MK: I think they’re both really hard. But it’s fun trying.