Adrift in a great sea of stars, we must surely not be alone.
It’s hard not to look at the night sky and think about the possibility of other civilizations out there. From the philosophical speculations of Giordano Bruno to the statistical estimations of Frank Drake, the more we’ve learned about the universe, the more likely alien life seems to be. And yet, in our search for this life, we have heard nothing but silence.
When will we find evidence for life beyond Earth? And where will that evidence be found? University of Arizona astronomer Chris Impey, the author of a book called “Worlds Without End,” is betting that the first evidence will come to light within the next decade or so.
“Spectroscopic data is not as appealing to the general public,” Impey admits in the latest episode of the Fiction Science podcast. “People like pictures, and so spectroscopy never gets its fair due in the general talk about astronomy or science, because it’s slightly more esoteric. But it is the tool of choice here.”
It’s easy to think of Earth as a water world, with its vast oceans and beautiful lakes, but compared to many worlds, Earth is particularly wet. Even the icy moons of Jupiter and Saturn have far more liquid water than Earth. Earth is unusual not because it has liquid water, but because it has liquid water in the warm habitable zone of the Sun. And as a new study in Nature Communications shows, Earth could be even more unusual than we thought.
In our search for life on other worlds, the one we’ve most explored is Mars. But while Mars has the makings for possible life, it isn’t the best candidate in our solar system. Much better are the icy moons of Jupiter and Saturn, which we know have liquid water. And of those, perhaps the best candidate is Saturn’s moon Enceladus.
If we ever find life on other worlds, it is unlikely to be a powerful message from space. It’s certainly possible that an alien civilization specifically sends us a radio message like a scene out of Contact, but the more likely scenario is that we observe some kind of biological signature in an exoplanet’s atmosphere, such as oxygen or chlorophyll. But as a recent study shows, that could be more difficult than we thought.
Here’s a thorny problem: What if life doesn’t always appear on planets that can support it? What if we find more and more exoplanets and determine that some of them are habitable? What if we also determine that life hasn’t appeared on them yet?
Could we send life-bringing comets to those planets and seed them with terrestrial life? And if we could do that, should we?
In a recent study accepted to the Monthly Notices of the Royal Astronomical Society, an international team of researchers led by Texas A&M University investigate how the James Webb Space Telescope (JWST) can detect a variety of exoplanets orbiting the nearest 15 white dwarfs to Earth using its Mid-Infrared Instrument (MIRI) Medium Resolution Spectrograph (MRS). This study holds the potential to expand our knowledge of exoplanets, their planetary compositions, and if they can support life.
We recently examined how and why the planet Venus could answer the longstanding question: Are we alone? Despite its harsh environment on the surface, its atmosphere could be hospitable for life as we know it. Here, we will examine the planet Mars, aka the Red Planet and the fourth planet in our solar system, which has been marveling sky watchers from ancient times to the present day.
We recently examined how and why Saturn’s largest moon, Titan, could answer the longstanding question: Are we alone? It’s the only moon that possesses a thick atmosphere and the only planetary body other than Earth (so far) that has liquid bodies on its surface. These characteristics alone make Titan an enticing location to search for life beyond Earth. In contrast, what if life were to be found in one of the unlikeliest of places and on a planet that is known to possess some of the harshest conditions ever observed?
We recently examined how and why Jupiter’s moon, Europa, could answer the longstanding question: Are we alone? While this small icy world gives plenty of reasons to believe why we could—and should—find life within its watery depths, it turns out our solar system is home to a myriad of places where we might find life. Much like how the Voyager missions gave us the first hints of an interior ocean swirling beneath Europa’s outer icy shell, it was only fitting that Voyager 1 also gave us the first hints of the potential for life on Saturn’s largest moon, Titan, as well.