Breakthrough discovery of planet with more water than Earth

The mysterious planet could be a warm version of the "moon of life" Europa.

The Hubble Space Telescope team from NASA - ESA (US and European space agencies) has successfully observed the smallest exoplanet containing water vapor named GJ 9827d.

This was a groundbreaking discovery for astronomy.

Planet GJ 9827d - (Photo: NASA/ESA)

Planets with Earth-sized bodies and Earth-like conditions — including water and other life-related chemical elements — are what planetary scientists are always looking for.

But there's one huge obstacle: Although more than 5,000 planets, many of which qualify as "Earth-like ," have been found by NASA's TESS planet hunter, they're all very far away.

It is extremely difficult to "look" at their atmospheres to determine the chemical composition of exoplanets that are Earth-sized or just slightly larger than Earth.

Planet GJ 9827d orbits a red dwarf star 97 light-years away in the constellation Pisces and is just twice the diameter of Earth, a small size in the planetary world.

However, by synthesizing observations from 11 times the planet "flipped across" its parent star, Hubble has helped scientists unveil its atmosphere through spectroscopy.

Something precious appeared: Water vapor, one of the top signs representing the possibility of life.

Scientists believe there are two ways this water vapor could have been generated, meaning the planet could be one of two types.

1. One is that it belongs to the group of "sub-Neptunes" , a type of gas planet smaller than Neptune and extremely common in the universe.
2. Second, GJ 9827d is a warmer version of Jupiter's habitable moon Europa , where NASA believes there is a subsurface ocean containing life beneath its icy shell.

The amount of water on this planet is estimated to be about twice that of Earth.

There's some bad news, though: It's about as hot as Venus, so the odds of it being uninhabitable still loom large.

Regardless, the ability to determine the atmospheric composition through spectroscopy on such a small and distant world opened a new page in the history of space exploration.

According to the Hubble team, this method could be applied to a more powerful telescope, the James Webb.

Thirty years younger than Hubble and with a sharper, farther-reaching view, James Webb is expected to reveal the atmospheres of even smaller planets, including those the size of Earth and already showing signs of being hospitable to life.