Astronomers have announced the discovery of several Earth-size planets orbiting a cool red dwarf star named Trappist-1 about 40 light years, or just 235 trillion miles, from Earth (quite close in cosmic terms). Some of these could have water on their surfaces, meaning that life on those planets is a real possibility. Reports the New York Times:
There is not just one, but seven Earth-size planets that could potentially harbor life have been identified orbiting a tiny star not too far away, offering the first realistic opportunity to search for signs of alien life outside our solar system.
Cool red dwarfs are the most common type of star, so astronomers are likely to find more planetary systems like that around Trappist-1 in the coming years. So this discovery portends many more habitable planetary ecosystems in other red-dwarf solar systems in the universe.
Astronomers always knew other stars must have planets, but until a couple of decades ago, they had not been able to spot them. Now they have confirmed more than 3,400, according to the Open Exoplanet Catalogue. Scientists say that even if the planets all turn out to be lifeless, they will have learned more about what keeps life from flourishing, so either way, it’s a win-win.
Trappist-1 is what astronomers call an “ultra-cool dwarf,” with only one twelfth the mass of the sun and a surface temperature of 4,150 degrees Fahrenheit, much cooler than the 10,000 degrees radiating from the sun. Scientists say if our sun were the size of a basketball, Trappist-1 would be the size of a golf ball.
All seven planets are very close to the dwarf star, circling more quickly than the planets in our solar system. The innermost completes an orbit in just 1.5 days. The farthest one completes an orbit in about 20 days. That makes the planetary system more like the moons of Jupiter than a larger planetary system like our solar system.
Scientists say if observations reveal oxygen in a planet’s atmosphere, that could point to photosynthesis of plants. And they add that oxygen together with methane, ozone, and carbon dioxide, particularly in certain proportions, “would tell us that there is life with 99 percent confidence.” What an amazing discovery that would be.
The discovery might also mean that scientists who have been searching for radio signals from alien civilizations have been searching in the wrong places, if most habitable planets orbit dwarfs, which live far longer than larger stars like the sun.
One scientist commented, “If you’re looking for complex biology — intelligent aliens that might take a long time to evolve from pond scum — older could be better. It seems a good bet that the majority of clever beings populating the universe look up to see a dim, reddish sun hanging in their sky. And at least they wouldn’t have to worry about sun block.”
So, what are we to make of this scientific breakthrough in the search for intelligent life in the universe? Several central ideas seem to emerge which should ease our minds about any potential attack from Trappist-1 system aliens:
• If there is intelligent life on one of those planets orbiting that red dwarf, those ETs would be celebrating Christmas every 1.5 to 20 days — now that’s a lot of presents and lots of New Year’s Eve celebrating, which will leave them totally hung over and exhausted with no interest in exploring the universe!
• Sunrise and sunset would be spectacular events featuring the amazing red glow of the Trappist-1 dwarf star. Now who in their right mind would want to leave that behind?
• Since they will be celebrating birthdays at the rate of one every 1.5 or 20 days, any ETs on these exoplanets will be really, really old and not much of a threat to us. They will be long in the tooth and totally uninterested in visiting us.
Hopefully, any aliens from these planets will be friendly ET types who are totally content where they are and will have no interest in colonizing our rich, verdant planet — the “Blue Marble.”
But if they are angry, adventurous, combative, and hostile aliens by nature (as traditionally portrayed in our film), at least they are 235 trillion miles away and probably will be uninterested in making that enormously long trip to a world that is in such turmoil and distress.