Scientifically Eccentric: Planet Hunting – Searching for Life in Outer Space

Editor’s note: This article was initially published in The Daily Gazette, Swarthmore’s online, daily newspaper founded in Fall 1996. As of Fall 2018, the DG has merged with The Phoenix. See the about page to read more about the DG.

I work under a red light. My work begins at sunset and ends past 2 a.m. I’m used to my roommate’s comments about my “irregular hours” as a “Lady of the Night.” Believe me – it’s not what you think.

I work at an observatory, doing photometric observations using transit timing duration variation method.[1]  In other words, I hunt for planets. Yes, here at Swarthmore.  This branch of astronomical research is still able to be carried out in the poor astronomy conditions caused by Philadelphia-light polluted skies.

The telescope I work at is just over two years old, but Swarthmore’s connection to planet discovery is nothing new. In 1914, Swarthmore’s Sproul Observatory loaned a 9-inch telescope to search for then-elusive “Planet X”, which would later be renamed “Pluto” (and still later deemed not a planet). Now, observations taken here at the Peter van de Kamp Observatory are part of the Young Exoplanet Transit Initiative (fondly called YETI, for short).

You’re in your dorm room, procrastinating on that problem set, that paper that really needs something (more Foucault?), skimming this article[2], eyes glazing over.

Out your window, the sun sets. The sun sets. The sun sets. No, you didn’t read that wrong.

Welcome to life[3] on GJ 667Cc–the newest planet that could support life.  On February 2, researchers from Carnegie Institute for Science announced their discovery of the exoplanet orbiting in a system of not one, but three stars.

Exoplanets, short for “extrasolar planets,” are celestial bodies orbiting a star other than our sun. It’s a young, hip field. The first exoplanet was discovered as recently as 1991–yesterday, by astronomy standards. (The science dates back to star charts from Mesopotamia and China made as early as 2000 BCE).  The list is now at 755 exoplanets, with the list of possible planets containing as many as 1,230 objects.

Okay, so what makes GJ677Cc so special? Liquid water, or rather, the possibility of liquid water. Like Earth, it’s in “Goldilocks Zone”, an area of orbit where temperatures are not too hot, or not too cold, but just right for liquid water. As astronomers, we’re narcissists. We’re looking in the mirror (quite literally–the telescope works using a series of reflective disks) hoping to see our own reflection. We don’t just want to find planets, but a planet like ours.

We like being able to relate. Even though astronomers realized long ago the universe centered around Earth (geo-centrism is so 1530) we still can’t help our fascination.  A search for “Earth-like planet” yields over 7 million results in Google, and over 2,000. You can’t help but see the “ME” in “MEarth,” a project run by Harvard professor David Charbonneau dedicated to finding planets around stars smaller than our sun (called “M dwarfs”). There’s something comforting about seeing our own reflection in the mirror.

There’s still a lot we don’t know. We don’t know if GJ667Cc has an atmosphere or even a solid surface.  GJ667Cc isn’t the only such planet–Gliese 581d, HD 85512b, and Kepler 22b –but it’s the closest. Astronomically speaking, that is. GJ667Cc is close,  but still 22 light-years away (If you were traveling to it, it’d take you over 25 years, and that’s provided you travel at 99% the speed of light). Even setting aside the problem of NASA’s budget (or lack there of), this isn’t going to happen.

But this fact doesn’t altogether limit what astronomers can do. Not to be thwarted, astronomers have gotten creative. We can tell what a planet is made up of by studying the light itself. Recent techniques look at the light to see signs of it being absorbed by chlorophyll (the pigment that allows for photosynthesis (Arnold, 2002), the other looks at the way light is reflected to detect the presence of proteins and amino acids essential for life as we know it.  (Sparks, 2009). Even if we can’t photograph these would-be Earths, we could detect photosynthesis or key organic molecules.

The prospect of finding an Earth like ours is, however, more complicated. Two articles (Edmunds, 2010; Knauth, 2009) published in Nature argue that the types of plant life on Earth is unique, that, even given “tectonics, running water and the chemical cycles,” little difference give rise to difference of soils and the climate itself, which in turn, give rise to different sorts of life.

While it’s clear that that GJ667Cc or any other Earth-like world is like ours is naïve. Life (if it exists) out there might be unimaginable different from here.[4] We don’t know. But as scientists, we have to start with what we know, so we begin with what’s familiar.

Science pushes boundaries. It has a way of doing that that, getting personal, playing hard to get, acting clingy.  It’s not all smooth sailing. But, we’re going somewhere, not just with exoplanets, but certain subatomic particles, the human genome, medicine, invisibility cloaks[5], and levitating quantum disks[6]– as columnist for The Gazette, I’ll be analyzing what’s on the horizon for us and science. Stay tuned.

Out my window the sun is setting. Back to work.

[1]“Oh, is that what they’re calling it these days?”

[2] “…something something… Peter van de Kamp  (who is that?),..Pluto…not a planet (so sad!) … Young Exoplanet Transit (hmm… there’s indie band name potential)…”

[3] Wait wait wait, you say. Is my hypothetical existence on GJ even possible? Aren’t we assuming the initial conditions for this planet were the same as Earth? Would there even be a Swarthmore College on GJ677Cc? All excellent questions.

[4] Perhaps an uncomfortably familiar concept for Swatties thinking about life post-Swat.

[5] Yes, really. See http://www.cosmosmagazine.com/news/5279/first-portable-invisibility-cloak-created

[6] REALLY really. See http://www.youtube.com/watch?v=Ws6AAhTw7RA

Correction: A previous version of this article misprinted the column author’s name. The author of the column is Sierra Eckert, not Sahiba Gill.