Why did a European spacecraft suddenly confirm the obvious: Earth is indeed inhabited?

The existence of life on Earth – this obvious fact is being confirmed by European scientists. Why is that?

ESA's JUICE probe is finally headed to Jupiter, but on August 20, it took a quick look at Earth and returned a very interesting report: Earth is indeed habitable! A fact that was supposed to be self-evident.

The JUICE probe launched in April 2023 and is currently traveling through the Solar System on an eight-year journey to explore Jupiter and its three moons, Ganymede, Callisto and Europa, all of which are thought to have liquid oceans beneath their icy crusts.

During its flyby of Earth on August 20, JUICE was able to successfully identify water in Earth's atmosphere , as well as carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (the "CHNOPS" elements, which are the most common elements in living organisms ). And in doing so, scientists were able to further confirm the requirements necessary for life to exist on Earth.

The Pacific Ocean as seen by ESA's MAJIS instrument during an Earth probe on 20 August 2024 from a distance of 8,700km at three different wavelengths.

It may sound strange at first, but the JUICE spacecraft and its team have good reasons for conducting these tests.

Specifically, JUICE is testing the effectiveness of two new instruments during the flyby of Earth. These two instruments include: Moon and Jupiter Imaging Spectrometer (MAJIS) and Submillimeter Wave Instrument (SWI) . Both instruments are used to detect signs of life.

Conducting the experiment and reporting the results back to Earth (where life is definitely present) will help prove that the MAJIS and SWI instruments will be very successful in the Jupiter exploration mission. The icy moons of Jupiter are the subject of JUICE's research to see if they are potential habitats for past or present life.

Once the instruments are working properly, JUICE will set out to study icy regions of Jupiter's moons.

The three horizontal bands show different images of Earth. Each image was taken at a different wavelength, meaning they reveal different features and information about the planet below.

When JUICE reaches Jupiter, it will perform similar tests on the planet's icy moons to determine whether they could support life. So doing a trial run on Earth, the only body in the Solar System known to harbor life, is the best way to ensure the instruments are properly calibrated.

During its flyby of Earth, JUICE also collected data on the composition of the atmosphere, including oxygen, ozone, and carbon dioxide. Scientists plan to study oxygen levels in particular as a point of comparison with the Jupiter system. Then they will know whether the oxygen levels outside could support Earth's current biological activity.

So while it may not be news that Earth is habitable, JUICE's research into our planet is significant in itself . With such good results, the JUICE spacecraft is now almost ready to head towards Jupiter !