Long known as the Blue Planet, Earth may be showing its colors across the universe as well. For the last decade, we have been looking for exoplanets and have been finding them in far bigger bunches than we expected. But, How many of them are inhabitable? Scientists may have hit on a way for us to tell which planets can sustain life before we make travel plans by looking at their signature. I’d hate to get there and find out I needed to bring an oxygen tank.
Something new has come along. A way of telling the color signature of a planet. This is not spectoscropy which has been around for a long time and tells us what elements were used in creating a light ray. This tells us much more about a planet. Right now, if we pick a blue planet out of the sky without its signature, it could mean a gas giant just because it also has nitrogen in its atmosphere. But if there is no oxygen, we all do not need another vacation that will totally leave us breathless.
Rayleigh scattering is what makes our atmosphere so blue when the Sun’s light bounces around the molecules of the atmosphere. But, it does more than color the sky for those below. It also makes us the Big Blue Marble that we can see from space and maybe from other planetary systems. If we can look at the Earth’s signature, we can narrow down what might be an earth-like planet with all of the comforts from home.
Revealing the true colors of an exoplanet will help us understand how it is creating its reflection. Is it because the life sustaining elements are in abundance or is it because it is an icy and gassy planet with no firm footing to stand on or oxygen to breathe? It might be important if you want to know the SPF factor before stepping outside.
The Earth’s signature is actually much more than a blue marble. If we look at its photometry we can see several shades of life. The biggest shade still remains blue but there are more subtle colors of life if we only look. The ozone layer actually adds a greenish tint to the spectrum. To complete the trifecta, there is also red which comes from the continental mass along with the green vegetation that covers much of the globe.
The graph reading actually looks more U-shaped but the reading is significant enough to encourage hope for future travel to other planets in our descendant’s future if we can find an exoplanet with a reading similar to Earth’s signature. Pack the bags, Mable. We’re going to Arcturus!!