A few weeks ago, as I flipped through my phone’s sciency news feed, I saw an article declaring that astronomers have discovered two more exoplanets, these ones in a star cluster. My initial thought, I’m sorry to admit, was “Who cares?” But the fact that I can be apathetic about something like this is, in and of itself, a huge accomplishment for science.
The first exoplanets were discovered in the 1990’s. For those of you unfamiliar with the term, exoplanet means any planet outside our own Solar System. Since the 90’s, we’ve discovered literally hundreds of exoplanets with thousands more possible sightings that have yet to be confirmed. The early discoveries were all huge planets, larger even than Jupiter, but now the discovery of small, Earth-sized planets is almost routine.
Where we once celebrated merely detecting an exoplanet, scientists now make major exoplanet discoveries with little or no fanfare. They’ve measured the content of exoplanets’ atmospheres. They’ve determined the color of at least one exoplanet. They’ve even found rogue exoplanets wandering aimlessly through space with no star to orbit.
It’s gotten to the point where even a science enthusiast like myself will say in an offhanded manner, “Oh, they found another exoplanet. Yay.” The reason each of these individual discoveries seems so unimpressive is, I think, because we now know the galaxy is full of planets. There are tons of them! It’s completely ridiculous how many there are and in how many strange places (like star clusters) we’re now finding them.
I’m old enough to remember when the idea of planets existing outside our Solar System was an issue of serious scientific debate with many smart people asking if our Solar System might be unique. Now we know otherwise. Recent estimates say every star in the sky has, on average, at least one or two planets orbiting it. Just about the only headline that could come through my sciency news feed and impress me these days is “Scientists discover exoplanet with signs of life.”