Category Archives: exoplanets

aliens, exoplanets, exploration

Lighting up the Night

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Would Aliens Do That?

A nighttime view of Beijing's city lights splashing out to space. Earth's night-time side is aglow with light splashed carelessly to space. Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center

We humans spend a lot of money turning our lights on at night.  We light up our houses, our parking lots, our highways, our high-rise buildings—you name it. If we build it, we light it up.  You don’t have to go to space to know that we have a love affair with illumination. That’s because light pollution is a constant on every continent. But, somehow, it seems more obvious when you see it from space.

Astronauts living and working on orbit since the dawn of the Space Age have shown us in countless images how Earth’s brightly lit cities glitter like diamonds on the night-time face of our planet. To any visitor from another planet coming to visit us, those lights have a simple message: here is a civilization that is so wealthy that it can spend money lighting up the night-time sky. Here are beings who want to advertise their presence to the cosmos.  Here is evidence of intelligent life!

Actually, our alien visitors wouldn’t have to be all that close to detect our light pollution and make some guesses about our civilization. If they had powerful enough telescopes, observers on distant planets could simply watch Earth as we turn our lights on at night. Our planet’s dark side could be detectable with a powerful enough telescope and the right kind of observational techniques.

Will alien civilizations splash their lights to space? If so, Harvard astronomers think we could use those lights to detect their existence. Credit: David A. Aguilar (CfA)

The idea is not so farfetched as it sounds. Two researchers representing Harvard University’s Center for Astrophysics and Princeton University have suggested that Earth-bound astronomers use that exact method to search for life on other planets beyond our solar system.  Those changes, if astronomers can spot them, could be due to artificial illumination, and that would signify the existence of intelligent life on distant worlds.  (You can read more about the research behind the idea here).

It’s an intriguing twist on the search for extraterrestrial civilizations, and with the pace of advancements in telescope technology, such research is not that far off in our future.  But, I have to wonder: would every civilization be so wasteful of its resources by lighting up the sky?  I suppose we’ll find that out when we spot those distant worlds and spy out their cities and roadways and parking lots and other places they choose to illuminate, just as we do here on Earth.

Want to see more images of Earth at night? Browse through the Earth from Space website. and you’ll see our planet in all its glory, as witnessed through the eyes and cameras of Earth-orbiting astronauts.

astronomy, astronomy news, exoplanets, Kepler mission, star wars planet

Two Suns

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and the Planet that Orbits Them

This artist's concept illustrates Kepler-16b, the first planet known to definitively orbit two stars -- what's called a circumbinary planet. The planet, which can be seen in the foreground, was discovered by NASA's Kepler mission. Image credit: NASA/JPL-Caltech/T. Pyle.

It’s all over the news today—the Kepler Mission has found a planet called Kepler-16b that has two suns its sky. It is, in essence, orbiting two stars.  And, of course, the Star Wars comparisons to Tatooine are ricocheting around the blog-o-sphere and news media sites faster than you can say “Kessel Run.”

It’s completely appropriate to think back to that place in a galaxy far far away that has captivated so many fans of the Star Wars universe. I remember being completely awed by the view of the two suns setting in that alien sky, and yet it felt organic and real to me.  Maybe that’s a tribute to the artists at LucasFilm and the care they took to make it seem real.  But, as one of those artists—John Knoll, visual effects supervisor at Industrial Light & Magic—said about the story released today, “Working in film, we often are tasked with creating something never before seen. However, more often than not, scientific discoveries prove to be more spectacular than anything we dare imagine. There is no doubt these discoveries influence and inspire storytellers. Their very existence serves as cause to dream bigger and open our minds to new possibilities beyond what we think we ‘know.'”

That’s what’s so cool about today’s planetary discovery announcement.  It takes us to alien worlds that we now KNOW exist.  This exploration has moved from science fiction to science fact.  That world is there and those stars are there, and NASA-funded scientists and missions help us look at them. In fact, exoplanet discovery is a world-wide science industry. Earlier this week, scientists at the European Southern Observatory announced that they’d found more than 50 new exoplanets, using a specialized instrument attached to the La Silla Observatory in Chile. Among their finding are 16 super-Earths, worlds that are more massive than Earth but much less massive than the gas giant planets.  At least one of those planets exists on the edge of its system’s habitable zone, which is the distance from its star where an Earth-like planet could have liquid water on its surface.

Now, Kepler16-b isn’t the hot, desert world of Tatooine. It’s not a super-Earth. It’s actually about the size of Saturn, made of of half rock and half gas, and is cold. Really cold.  The stars it orbits are smaller than our Sun. One of them is only about 20 percent the size of our warm, yellow star. This means they’re dwarf stars. Kepler-16b takes 229 days to orbit its suns, and it is just far enough away that liquid water would not exist on its surface. So, there’s likely not life there.  (If you want more details on the discovery and the orbital information, check out the Kepler announcement here.)

But, let’s say there were intelligent life forms on that planet.  They would be different from us simply because the evolution of life on any planet is going to depend on the materials and elements available in that particular star-and-planet-system’s birth cloud. And, that raises a lot of very interesting conjectures about what life would evolve to be like on a planet with two suns, where the temps are low and the magnetic field environments would be different from ours.  Imagine two “solar wind” streams.  Imagine trying to tell time!  Early civilizations wouldn’t be able to use simple sundials.  What would they use?  How would they live?  What would they look like? And what would the weather be like on such a world?  These may be questions that science fiction writers can and will answer in stories about this place.  Perhaps they already have.   Time to go read some more SF and learn about the cosmos!