It’s been a marvelous ride to find earth-sized, earth-like planets around other stars and it begs the question: What next? What should we humans be doing next that could give us yet a deeper, more profound vision of our place in the universe.
My research for the last 25 or 30 years has been centered on discovering planets that orbit other stars. It was actually considered pseudoscience. Looking for planets was like looking for little green men and people would be embarrassed when I told them that I was going to try to find planets around other stars. People realized that I had lost it. Maybe my credibility as a scientist was over.
Back in the 1980’s and early 1990’s we started not knowing if we would find even a single planet. We finally found a Jupiter 2 and we found some more Jupiter-sized planets. Over the years we’ve been finding planets smaller and smaller – now the size of the earth.
We have this marvelous, magical new technique for finding earth-sized planets around other stars and it’s using the NASA space-borne telescope called Kepler. It simply watches the star and it tries to determine whether a star dims repeatedly as an earth-sized planet crosses in front of the star. We learn that a planet is there, we learn how long it takes the planet to go around in its orbit and we learn the size of the planet because the bigger the planet, the more light from the star it blocks.
I feel like we’ve been given some kind of gift in our generation - the gift of knowing that our home planet is not a rarity, it’s not a quirk. There are millions, probably billions of earth-sized planets at lukewarm temperatures. Some of them with more water, some less water. Some of them dry deserts, some of them water-worlds but many of them having the conditions suitable for biology, some of them with continents that would be necessary for the species that evolve to develop technology.
A really profound question for humanity is whether or not these planets we’re finding around other stars, especially the earth-like planets, are habitable. And could we visit? Is there a future for humanity in which we will travel to the stars and colonize these earth-like planets?
It’s not clear and I think it’s a great question for our species. Will we ever actually travel to the stars?