This story comes from our special January 2021 issue, "The Beginning and the End of the Universe.” Click here to purchase the full issue.
The question “Are we alone?” has long permeated our collective psyche. As early as the second century A.D., humankind was recording stories of aliens and space travel: Lucian of Samosata’s
A True Story features a war between the inhabitants of the Sun and the Moon. And a simple look at ancient mythology tells us that humankind has wondered what might exist among the stars for far longer.
With modern instruments, astronomers have discovered more than 4,000 planets orbiting other stars, and many of these exoplanets are far more exotic than we could have imagined. What kind of life could exist on a world with two or three suns? Or a world made of diamond? How about one where it rains glass? The universe is a really, really big place, so the possibilities are almost endless.
Before we go too far down the rabbit hole, there are many worlds that appear Earth-like — meaning they’re in a stable orbit around a G–type star and they sit in the star’s habitable zone, where liquid water can exist on the planet’s surface. Scientists have even found multiple ocean worlds in our own solar system, such as Jupiter’s and Saturn’s moons Europa and Enceladus, which both hide oceans beneath their icy shells.
Still, the universe is strange, and, as Dr. Malcolm says in Jurassic Park, “Life, uh, finds a way.” If science has learned one thing from science fiction, it’s that extraterrestrial life could be beyond even our wildest dreams. But life still has to follow some basic rules.