Using the Moon to Rediscover Life on Earth

Earthshine observation technique used in this experiment.

Now, you may be thinking, "Why is it important that we just rediscovered life on Earth? We know life exists on Earth so how is this important?" The European Southern Observatory (ESO), under the lead of Michael Sterzik, conducted an experiment that provides a creative solution for looking for life on exoplanets (planets outside our solar system). By looking at the light Earth reflects off the moon, the ESO was able to observe how the light polarized. This technique is called earthshine observation. From this polarization, the researchers at the ESO were able to determine key signatures of reflection from the moon that serve as indicators for key bio-signatures such as plant life or weather. Since this experiment was conducted on Earth, researchers looking for life on other planets can use Earth as a benchmark for other planets. This experiment and the information obtained from it are extremely useful when exoplanets cannot be observed due to starlight being very intense near some exoplanets.

Michael Sterzik, a co-author on the research, has multiple papers that discuss optics and searches for new stars in distant solar systems. It is easy to see how his past research has been synthesized into a new and creative way of finding life on planets other than our own. As the head of the ESO, he certainly has the expertise of the domain of star and planetary observation. Optics is also another area of expertise of Sterzik, which could explain how it was used in an analogous way to find life on Earth. By taking the concepts in optics and applying them to searching for planets with life, a new and creative method has come to fruition. Using his extensive knowledge of both fields and collecting information from both, we can see that the creative process arose from combining two unlike studies. In a way, it can be compared to Steve Wozniak's use of analogy to create something new. By observing how light behaves on our planet, we can compare certain traits of it to exoplanets and hopefully determine if we are not alone in this universe.

As for what others think of this finding, there is a unanimous curiosity of what this study will herald in the future as the ESO begins to scan exoplanets for signs of life. The creative solution to use Earth as a test subject was praised by professors at Purdue, Harvard, and the general community of astronomers as the findings have been reported across numerous websites in the scientific community. Overall, this technique is an important innovation in hopefully one day finding signatures of life on other planets.