We have all seen the magnificent close-up images of Jupiters beautiful, chaotic cloud
formations. But what if we could strip away these turbulent, swirling storms? Leaving
only the lower layers of the gas giant and a clear, cloudless upper atmosphere.
Well, it turns out that the universe has already got that covered, and it comes in the form
of an extremely rare gas planet, named WASP -62B.
Astronomers at the Harvard - Smithsonian Center for Astrophysics have recently announced that
they have discovered an extremely rare type of exoplanet, an exoplanet with a clear upper
atmosphere, a cloudless giant. The unusual gas planet, named WASP-62B or
Krotoa by some, is only the second of its kind to be found but is the first "Jupiter
like" cloudless exoplanet ever to be detected. The only similar gas giant, is named WASP-96B
and was spotted in 2018, but is a "Saturn sized" exoplanet, known as a "hot Saturn".
First discovered in 2012, but never closely studied until now, Wasp-62b is located 575
light-years away in the constellation of Dorado. The bizarre planet is 1.39 times the size
of Jupiter, making it 14 times that of Earth, and is roughly half the mass of Jupiter, meaning
that it has a bloated radius and a much lower density.
The cloudless giant orbits a larger, hotter, and more luminous star than the Sun, at a
close distance of 5.2 million miles, which is 8.5 million kilometres and one year on
this bizarre scorched world would only take four and a half Earths days.
This extreme proximity to its host star means that it is classed as a " hot Jupiter" type
exoplanet, the most common type currently found in the galaxy. But WASP -62B is certainly
not a common world, in fact, astronomers estimate that less than 7% of all exoplanets have clear,
cloudless skies, making WASP-62B exceptionally rare.
The unique atmospheric discovery was made when astronomer and graduate student Munazza
Alam was studying the planet's atmosphere as it passed in front of its star, searching
for chemical elements such as potassium and sodium.
However, Alam did not find potassium, instead, the data revealed the strikingly clear signature
of sodium, which according to astronomers is the smoking gun evidence that reveals the
gas giants cloudless, clear atmosphere. When astronomers study worlds such as hot
Jupiters, only small hints of sodium can usually be detected due to clouds and haze obscuring
the signature. However, data collected from WASP-62B revealed the full fingerprint, which
is impossible to see with anything in the way.
Of course, this does not mean that the exoplanet is completely clear, but instead that WaSP-62B
is cloudless at the levels of atmosphere that we are currently able to study and observe.
More research is required, but the discovery of this strange world is important in many
ways, mainly because without the envelope of thick cloud cover, extreme planets like
WASP-62B can be studied in more detail. Allowing astronomers to peer inside, and possibly see
what they are made of, how they formed, and how they are different from gas giants such
as Jupiter. Soon to be operational instruments, such as
the James Webb space telescope will help astronomers observe and study these types of worlds, hopefully
unraveling the translucent mystery.