NASA made a tremendous announcement today: the most likely possibility so far for an extraterrestrial neighbor!
Trappist-1. A smouldering dwarf star.
They were scouring the skies with a new telescope that measures slight changes in the intensity of light coming from distant stars. The theory is that if a star has an orbiting planet that happens to cross in front of it, we’ll see its light get slightly dimmer. It’s only a slight change in brightness … imagine the change in light level if a fly happened to cross in front of the light in your living-room, and then imagine doing that when the light is a mile away and barely discernible in the distance … but that’s all that it takes.
Not even a year ago, they noticed one star that happened to show two distinct blips at regular intervals. Although they were used to finding stars with an orbiting planet, this one raised their curiosity because it looked like it had two! So they turned all kinds of other telescopes on it to learn more, and discovered not two, but seven different planets!
The science gets even more intriguing than that.
By measuring how much the light dims with each passing, they can get a sense of how big each planets is: all seven are roughly the same size as Earth.
The number of days between each planet’s passing in front of the sun tells them the length of a year on each planet. And when two planets come close to each other, their gravitation influences each other to such an extent that the length of their solar year changes by just a miniscule amount … measurable in only seconds or minutes … which then tells them how much mass or “stuff” is in each of those planets.
And knowing the planet’s mass and its size tells you its density … the first clue to whether they’re mostly rock or mostly water.
And here’s where it all gets so exciting: three of the planets orbit at a distance called “the Habitable Zone,” meaning they’re the right distance away for life to form on them: not so close that any potential life form gets crispy fried, and not too far away that everything’s frozen. And depending on what kind of atmosphere they have … whether they have a lot of greenhouse gases to keep even the distant ones warm … all seven could have liquid water on their surface.
Possibility of life? Check! Actually, make that seven checks!
And the image that NASA left us with following their announcement is breath-taking: the planets are so close to each other that one could stand on one of them and see several of the other planets in the sky as big as our Moon. What a sight!
That’s already a lot of information out of simply looking at flies passing in front of the living-room lamp!?
But now astronomers are turning all kinds of other telescopes on this star system. Some can tell us about the atmosphere around any given planet by measuring how the edge of the planet changes the color of the star’s light when it passes in front of the star (not just the overall dimming that I mentioned above, but also whether the mix of colors changes). The reason for this is the same as why the Moon turns red during a lunar eclipse: the Earth blocks all light from the sun except that light which skirts around Earth’s edge, leaving the Moon lit up only by all the sunsets and sunrises occurring around the globe at that time. Those color changes can tell astronomers whether the atmosphere has oxygen or methane or other gases which are either needed for life or signatures of life.
Even SETI … that bank of telescopes featured in the classic 1997 movie Contact, looking for radio signals from space … has turned its sight on that star system. Unfortunately, nothing yet.
But don’t hold your breath yet for any probes to be sent there: at 39 light years away, it’s just too far out of reach with our current technology.
What an announcement! All the major newspapers around the world are covering this story. It raises all kinds of questions, and images, and hopes, and even fears. It’ll be interesting to see how people respond to this. It goes without saying that I’m particularly interested to see how people of faith respond to this. In a previous blog, I explored an interesting story about how the various major religions of the world would react to the discovery of alien life. Evangelicals didn’t fair so well (and in the comments section at the bottom of the article, there were some truly face-palming replies about the eternal destination of aliens). Let’s see if the story’s accurate.
If history is any lesson for us, I suspect we might soon be hearing theological statements being made about our poor Trappistian neighbors. We’ve done it before. When Europeans began encountering people on other continents, all kinds of theological questions started popping up, and far-fetched conclusions drawn. They couldn’t be descendants of Adam because they weren’t Caucasian enough (just look at any painting of Biblical scenes from before the Renaissance). Besides, how could they possibly have found their way from Mesopotamia (where the Garden of Eden was found) across the wide open ocean to these distant lands separated by ocean? And how did/could they manage to escape Noah’s Flood? So if they were not “of Adam,” then not only did basic civic/human rights not apply to them, but neither did many theological concepts (like salvation). As I said above, I’ve already heard similar things said about extraterrestrials. Let’s hope this new announcement doesn’t stir that up again.
I’m curious about how readers of this blog respond to this news. Does it excite you, or scare you? Do you immediately have expectations … or declarations … based solely on theological grounds?
Tell me what you think …