‘Hot Jupiter’: You probably wouldn’t want to stay on WASP-121b

Human beings have long been searching for an alternative, habitable planet to fly to when they inevitably destroy their current home. But the exoplanet dubbed WASP-121b probably won’t be labelled as a suitable candidate.

Nearly double the size of Jupiter, and orbiting a star 900 light years from Earth, this particular planet was discovered in 2015. But only this week has the planet given astronomers more insight into what they call “hot Jupiters”.

For starters, the exoplanet has a stratosphere — a layer in a planet’s upper atmosphere that becomes increasingly warmer with height — something that astronomers theorised exoplanets could sustain but could only now substantiate.

“This result is exciting because it shows that a common trait of most of the atmospheres in our solar system — a warm stratosphere — also can be found in exoplanet atmospheres,” Mark Marley, the study’s co-author based at NASA’s Ames Research Centre explains.

“We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system.”

By studying the brightness and wavelengths of light bouncing off the planet, they determined that the atmosphere consists of vanadium oxide and titanium oxide — both not exactly great for humans to inhale, and a far cry from Earth’s life-sustaining cocktail of nitrogen and oxygen.

WASP-121b’s atmosphere is over 2000°C, while its ‘year’ lasts just 1.3 Earth days

The team also determined that the planet does have hot water vapour in its upper atmosphere.

The stratosphere on Earth is particularly important to life on the planet. It houses the ozone layer — a protective barrier of gas that diffuses harmful radiation from the sun. Through this, it also moderates the temperature of the lower atmosphere layer, which is an integral piece to the puzzle of sustaining life.

If there is life on WASP-121b, it would have to overcome some atrocious living conditions.

For one, the planet is so close to its host star that its year — or an entire lap of its orbit around its star — effectively lasts just 1.3 Earth days. NASA also states that “if it got any closer, the star’s gravity would start ripping it apart”. This in turn means an atmospheric temperature of 2500°C — more than toasty enough to melt a number of metals.

While the discovery bodes well for future exoplanet discoveries, researchers still can’t explain why this particular exoplanet has a stratosphere.

Even so, thanks to the planet’s ridiculous heat, proximity to its star and size, we’d probably recommend you avoid holidaying there.

H/T: The Verge