The scientific hunt for life isn't about UFOs

Proof of alien life is likely to come from decades of incremental scientific discoveries, not a blurry video of a UFO speeding through the atmosphere.

The big picture: Instead of a fringe science, the search for life today has become integral to NASA's mission.

• More than any other time in history, researchers have access to huge amounts of data about various points of interest in the solar system and outside of it, getting us closer to knowing whether life might thrive somewhere other than Earth.
• "If you asked scientists 15 years ago, 'Do you think life exists elsewhere?' I think most people would have said no," Ken Farley, a project scientist on NASA's Perseverance mission to Mars, told me.
• Now, he says, most of his colleagues would say it seems very likely. "Simply because there are two planets for every star in the galaxy. That's a lot of stars and a lot of planets."

What's happening: Perseverance, NASA's first mission with a real chance of finding signs of past life on Mars, plans to cache samples for a future mission to pick up and bring back to waiting scientists on Earth.

• Scientists searching the skies for radio signals from other intelligent civilizations have also gotten a boost in recent years with new sources of funding.
• Last year was a landmark moment for those studying Venus, with the discovery that there could be phosphine — an indicator of life — in the planet's clouds. Now, scientists are planning follow-up observations to collect more data about whether the gas really is there.
• The James Webb Space Telescope, slated to launch later this year, will peer into the atmospheres of distant planets in search of oxygen and other life-indicating biosignatures.

The intrigue: UFO videos — and the mysteries they hold — have captured the collective imaginations of the public and the media, with many speculating that they're hints that aliens with faster-than-light technology have visited Earth.

• But the scientific search for life has a far higher burden of proof before even speculating that any given piece of data is evidence of life.
• "Even in the search for life, the general rule we have is, you never presume it's life, even though it's our literal job. Life is the last explanation," Clara Sousa-Silva, a scientist at MIT, told me.
• "And to find a literal UFO — an unidentified flying object — and think, 'Oh, it couldn't be technology that we don't know. It couldn't be a foreign thing. It can't be a visual hallucination.' All of these are not just more likely, and more plausible, they're orders of magnitude more likely."

What to watch: Some in the field are starting to advocate for reframing the habitability of various worlds as a continuum, not a binary of a positive or negative discovery.

• "By studying more places where habitable conditions exist and where life could form, we can have more data points to understand where different worlds are on that spectrum," Morgan Cable, a NASA researcher who studies ocean worlds like Saturn's moons Titan and Enceladus that might harbor life in their subsurface oceans, told me.
• "Certainly, Earth is on one side, and places like the Moon that don't have life are clearly on the other, but there may be worlds that lie somewhere in the middle where life is just starting to gain a foothold."
• And if life did develop independently somewhere else in our solar system, that would likely mean "life will be everywhere in the galaxy," Sousa-Silva said.