Wait a second…

Pale Blue Dot

The European Space Agency’s Jupiter Icy Moons Explorer (JUICE) probe has spotted a habitable planet right here in our solar system — and its sensors are showing several molecules and elements in its nitrogen-rich atmosphere suggesting that organic life could not only survive but potentially thrive on the planet’s largely ocean-covered surface. As you probably already figured out, we’re talking about the Earth. The ESA’s spacecraft was tasked with turning its scientific instruments toward our home planet during a flyby last month, a clever experiment in which both of JUICE’s instruments — the Submillimeter Wave Instrument (SWI) and the Moons and Jupiter Imaging Spectrometer (MAJIS) — collected sufficient data to conclude that the Earth is indeed habitable.

Of course, we already knew that, by virtue of living here. But it’s a clever reality check for the equipment that we’re pointing elsewhere in the cosmos to search for extraterrestrial life; if our best equipment examined the Earth and didn’t find signs of life, it’d be a rude wakeup call for researchers.

“We are obviously not surprised by these results,” said ESA JUICE project scientist Olivier Witasse in a statement. “It would have been extremely concerning to find out that Earth was not habitable!”

“But they indicate that [the instruments] will work very successfully at Jupiter, where they will help us investigate whether the icy moons could be potential habitats for past or present life,” he added.

One World

The ESA’s spacecraft launched in April 2023 and made a flyby of the Earth and the Moon last month. It’s scheduled to perform three more gravity assist flybys to put it on a trajectory to Jupiter: one of Venus next year, and two more around the Earth in 2026 and 2029.

During its most recent flyby of the Earth, the probe’s instruments picked up a number of different molecules, including oxygen, water, ozone, and carbon dioxide, in the Earth’s atmosphere. It even imaged its “surface in infrared light, resulting in information-rich temperature maps,” according to the ESA.

Once it arrives at Jupiter in July 2031, the SWI instrument will analyze its and its icy moons’ composition. The data could indicate whether the latter are not only habitable but even potentially if they’re currently inhabited.

JUICE’s MAJIS instrument will also have a closer look at Jupiter’s clouds and the composition of the atmosphere of it and and its moons.

For decades, scientists have been eager to get a close-up look at Jupiter’s moons. Of special interest is Europa, which scientists believe is home to a subsurface ocean, hidden beneath an icy shell, that could be harboring life.

And it’s not just the ESA’s JUICE that will swing by for a visit. NASA is launching its own spacecraft, the Europa Clipper, as soon as next month.

More on Jupiter’s moons: Spacecraft to Scream Past Earth in a “Double World First” Slingshot Flyby