No two planets are alike, and they’re all pretty weird. What are those strange dark blobs in Venus’ atmosphere? Is it common for planets to have hemisphere-sized magma oceans? Can anything survive on Proxima b after its local star belched out a colossal stellar flare?
Wherever we look, something exotic and bonkers turns up. As it happens, WASP-127b, an exoplanet about 332 light-years away from us, is no different. As reported by Space.com, the atmosphere of this gas giant – one that’s around 40 percent larger than Jupiter but features a staggering 82 percent less mass – contains some distinctly “weird stuff”.
Said stuff is comprised of metals, including sodium, lithium and potassium, and potentially water. As this is already one of the least dense worlds ever discovered, the identification of these gorgeous traces of alkali metals just adds another enigma on top of an already sizable pile of puzzles.
Using the Gran Telescopio Canarias, an international team from the University of Cambridge and the Astrophysics Institute of the Canaries (IAC) took a good look at WASP-127b, which has no other comparable world that we’ve yet discovered.
It’s been described as “heavily inflated”, and it orbits an incredibly bright star once every 4.17 days. That proximity means that its surface temperature is roughly the same as the lava coming out of Kilauea right now.
So yes, it’s bizarre, based on what we know about exoplanets: an extremely hot, super gassy, weirdly light balloon of a planet. Now, according to the team’s Astronomy & Astrophysics paper, it also has plenty of these metals in its skies too.
It’s arguably the lithium that’s the most interesting part of the discovery. Both the star, WASP-127, and the exoplanet itself are oddly packed with this particular metal. This suggests that the cloud of material that formed this one-planet system was also rich in lithium, but where did it come from?
Right up near the top of the Periodic Table of Elements, lithium was created near the beginning of the universe, perhaps before most stars had formed. Much of the cosmos’ supply, however, appears to be generated through the violence of stars.
The team here mention that the lithium could have originated from the debris generated by a supernova, the violent destruction of stars several times more massive than our very own. It’s also suggested that stars belonging to the “asymptotic giant branch” group could be to blame, whose pulsating layers of burning gas can eventually fling off huge dusty shells into space.
There’s a chance a nova might be responsible, though. Novae occur when white dwarfs – the glowing remnant cores of dead stars that have used up their hydrogen – gravitationally steal fresh hydrogen from another nearby star.
When this hydrogen suddenly ignites, it generates a huge, bright explosion, and studies have shown this can blast off plenty of beryllium-7 into space. This is an unstable isotope, and it just so happens to turn into lithium relatively quickly.
Whatever it was, it happened long, long ago, so all we can do for now is speculate. Incidentally, the team's observations point to WASP-127b's skies being 50 percent clear, which means it’s a good world for stargazing should you ever manage to land on it and not die immediately.