Oh My Science: Earth Might Not be the Only Earth!

Courtesy of NASA Johnson Space Center

Courtesy of NASA Johnson Space Center

I’m a science fiction fan. I love Asimov, Card, Heinlein, Le Guin and tons of other “old school” science fiction writers. Thinking about where we are going after this earth ends, what technology will be able to do and the limits of humanity are common themes in sci-fi, and this week, some of those themes have had a realistic update. On Nov. 4, a really, really cool discovery was published about how there are many more earth-like planets in our galaxy than we previously thought. At the University of California at Berkeley and the University of Hawaii, scientists in the astronomy labs with access to the Kepler space telescope stumbled on something pretty grand: there may be tens of billions of earth-like planets here in our very own Milky Way.

What are the implications?

1. There could be a lot of life out there right now that we can’t contact or don’t know about

To be a habitable planet like ours, a planet needs to have the perfect temperature for life to evolve. Supposedly, things like water and carbon are very important for life, so having conditions where liquid water and so on is very important for having a habitable planet. Let’s say life did end up evolving on a couple of these billions of planets. Let’s say one of these life forms evolved to be intelligent enough to be able to contact us via radio waves or some other kind of signal. Let’s say those messages were sent thousands or millions of years ago. Let’s say we’re about to get them.

Courtesy of NASA Johnson Space Center
Courtesy of NASA Johnson Space Center

Ah, us on our little blue marble. A speck of dust in a galaxy of billions of other sister planets.

Yeah. Mind blown.

Of course there are things to consider, like if we would be able to understand the messages, if the life forms are somehow differently sentient, or if they’re based off of another atom besides carbon, or any number of variance that could arise from different paths of evolution. The sentiment is still there; there is an increasingly likely chance that we are not the only life in the universe.

2. We could have a place to go once we destroy earth or when the sun burns out

If humans were to ever leave Earth, either through destruction, waiting for the sun to become a red giant and eventually fade to a planetary nebula or overpopulation, we would need a new place to go. This also means we need to get moving on the whole “let’s make a spaceship that can travel near light speed” thing. Luckily, with this new discovery, we have plenty of options. One of the earthy planets is only about 12 light years away! We could get there in something like 250,000 years with our current technology, assuming we were pointed directly at their solar system.

Space is intimately linked with humanity’s trajectory. There may be a time when humans can travel through space more easily and can potentially make these other planets home; I say discoveries like this can ease the mind a little and let us know it doesn’t have to be over.

With that melancholic note, here’s some extra reading. For those of you who are more curious, I’ve included a few links if space is your jam (see what I did there?).

1. The original article.
Petigura, E.A., Howard, A.W., & Marcy, G.W. (2013) Prevalence of Earth-size planets orbiting Sun-like stars. PNAS, USA.
PDF: http://www.pnas.org/content/early/2013/10/31/1319909110.full.pdf+html

2. A short story by Isaac Asimov on the inevitable heat-death of the universe (it’s beautifully written and bittersweet).

3. A great book on what we do after the sun explodes and we have to go find other planets (also very beautiful, has some nice science-y ideas, and takes a very realistic approach to the mood and functioning of societies of colonists).
The Songs of Distant Earth by Arthur C. Clark, 1986.