An international team of researchers have found signs that may determine whether another planet can support life by looking at a planet's magnetosphere.
A magnetosphere is the area of space, around a planet, controlled by the planet's magnetic field, according to NASA. Life on Earth developed and is sustained under the protection of its magnetosphere.
The potential "life clues" were discovered as part of new research that also found solar storms trigger Jupiter's intense "northern lights" that are eight times brighter than normal and hundreds of times more energetic than Earth's aurora borealis.
Magnetospheres protect a planet's atmosphere from the solar wind, said William Dunn, a Ph.D. candidate at University College London Mullard Space Science Laboratory and lead author of the new study.
"Mars and Venus don't have a magnetosphere - although Mars once did have one - so the solar wind continuously sweeps away their atmospheres," Dunn said. "Particularly, it strips hydrogen, which as a lighter element is more prone to being 'blown away.' This removal of hydrogen reduces the amount of water available."
Mars once had huge water oceans, but it no longer does.
All life on Earth needs water to survive.
"This lack of a magnetosphere and the connection to surface water therefore leads to a reduced possibility of habitability by larger multi-celled organisms," Dunn said. "As we start to explore the universe and the question of the existence of life ‘elsewhere' becomes one that we can more readily examine, we will want to consider places with magnetospheres first, since these are more likely to support life."
Aiding in the ongoing research will be data from NASA's Juno spacecraft as it nears Jupiter for the start of its mission this summer.
As part of the mission, Juno will investigate Jupiter's relationship with the sun and the solar wind by studying its magnetic field, magnetosphere and aurora.
"This will give us the unique opportunity to tie together the processes and events that are happening along that boundary with what is happening in the aurora," Dunn said.
Earth's northern lights are seen almost exclusively at nighttime, but Jupiter's northern lights have only been seen during Jupiter's daytime.
"We have no idea what they'll look like at night. Juno will provide the first ever images of the nighttime northern and southern lights at Jupiter," Dunn said.
"Jupiter's aurora are so bright that if you were to sit on Jupiter's clouds and look up at the sky during the day, they would far outshine the light you would see from the Sun," he added.