Jul 02, 2014 I Paul Seaburn

Hey E.T. – Does Earth Look Livable to You?

Fans of Mysterious Universe know that we like to report on exoplanets and moons that look like they could sustain life. That “look” comes from our vast array of orbiting and terrestrial telescopes trained on all corners of the universe. If we’re looking out, is anyone looking in? And if they are, do they see Earth as a place that could sustain their life?

You may remember NASA’s Lunar Crater Observation and Sensing Satellite, or LCROSS, which penetrated the lunar surface in 2009 on its mission to find water as well as other data on the Moon. A group of NASA astrophysicists recently went back to that data to analyze three observations LCROSS took looking back at the Earth to determine the accuracy of its trajectory.

Lcross 570x570
Artist's depiction of Lunar Crater Observing and Sensing Satellite Separation.

The astrophysicists used the data instead to look at Earth as an exoplanet. Previously, astronomers using Earth’s reflection off the Moon predicted the intensity of the glint given off by its 75% water surface. The NASA researchers found that the glint was not as intense as predicted and that it varied depending on the wavelength. Also, it was brighter when the Earth was in its crescent phase.

Since we already know that there’s life on Earth (how high of a form is up for debate), this information will come in handy when designing future telescopes to search for habitability and life indicators. While high brightness in the crescent phase could indicate an ocean on an exoplanet, it can also be caused by clouds. The LCROSS researchers also found that ozone, another indicator of habitability, appeared most strongly in ultraviolet observations.

In a recent paper on this research published in The Astrophysical Journal, lead researcher Tyler Robinson of NASA’s Ames Research Center stressed the benefit of this Earth look-back analysis:

By studying Earth now, you can ensure that we don't accidentally engineer the telescope of the future and find out we didn't build it strong enough.

Let’s hope E.T. has the same idea.

Paul Seaburn
Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.

Join MU Plus+ and get exclusive shows and extensions & much more! Subscribe Today!