In 2009, the Vatican hosted a meeting aimed at assessing the impact on the Catholic church of discovering extraterrestrial life. There was nothing to worry about, the Vatican said, as any aliens would still have been created by a universally powerful God.
Then in 2015, an apparently Earth-like planet was discovered 1,400 light years away from our planet, in the constellation Cygnus. Officially named Kepler 452b, the planet was deemed to be so similar to Earth that it was nicknamed “Earth 2.0” and “Earth’s cousin,” and its discovery generated huge excitement. Here was a planet, people said, that might harbor intelligent life.
The Vatican’s chief astronomer, Rev. Jose Gabriel Funes, said the discovery of Kepler 452b was great news. “It is probable that there was life, and perhaps a form of intelligent life,” he said, going somewhat further than any scientist. Nor is there any conflict between the existence of alien life and Catholicism, he added. Well, he would. In reality, the discovery even of some kind of alien bacteria would cause the greatest upset to Rome since Henry VIII filed for divorce.
Religious institutions aside, evidence of alien life would be a game changer. It’s hard to think of another scientific discovery that would have as great an impact. Perhaps it would do for philosophy, and for our view of our planet, what Charles Darwin’s theory of evolution did for our view of our place in nature. It would connect us directly with the rest of the cosmos. It would (one hopes) inspire a firm and meaningful commitment to careful stewardship of this planet.
Sadly I’m not about to report the discovery of alien life. But John Livingston, a Ph.D. student at the University of Tokyo, has recently helped discover 44 planets outside of our solar system. Such planets — known as exoplanets — were until recently only theoretical, but are now being observed in ever greater numbers. They inspire great excitement among astronomers.
“It was also gratifying to verify so many small planets,” says Livingston. “Sixteen were in the same size class as Earth, one in particular turning out to be extremely small — about the size of Venus — which was a nice affirmation as it’s close to the limit of what is possible to detect.”
Livingston worked with professor Motohide Tamura of the University of Tokyo to combine astronomical data from NASA’s Kepler space telescope, the European Space Agency’s Gaia space telescope, as well as ground-based telescopes. This enabled them to confirm the existence of 44 new planets. They published their findings in The Astronomical Journal.
“Four of the planets orbit their host stars in less than 24 hours,” says Livingston. “In other words, a year on each of those planets is shorter than a day here on Earth.”
You might be wondering why we study such things. Most exoplanets are incredibly far away. Even traveling at the speed of light, something very far from possible, it would take 1,400 years to reach Kepler 452b. The closest exoplanet orbits the star Proxima Centauri, and is just over four light years away. That’s 40 trillion kilometers. It would take tens of thousands of years for us to reach it with our best rockets.
Livingston says that finding new planets gives us good options for studying alien atmospheres. It’s conceivable that we could spot the signs of life just by looking at the composition of gases in a planet’s atmosphere. But they also tell us how planets form. “The investigation of other solar systems can help us understand how planets and even our own solar system formed,” says Livingston. “The study of other worlds has much to teach us about our own.”
Exoplanets inspire wonder and many people want to do more than merely observe them from afar: they want to visit them. Yuri Milner, a Russian billionaire and venture capitalist, is a space enthusiast. He is funding a $100 million project to research the feasibility of sending a laser-powered spacecraft to Proxima Centauri. If we could accelerate a small spacecraft to 20 percent of the speed of light, it could reach the nearest exoplanet in just 20 years.
In the space of a generation, we could conceivably receive images from a planet in another part of the galaxy. As to whether it is safe to attempt to reach out to alien worlds, we’ll have to examine the arguments in a future column.
Rowan Hooper is managing editor of New Scientist magazine. He tweets at @rowhoop and his new book, “Superhuman: Life at the Extremes of Mental and Physical Ability,” is out now.
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