Today’s forecast: Sunny, with clouds rolling
in overnight, highs of 3300 degrees and a chance of…. silicate downpours?? Hi there fellow alien folk, Trace here for
DNews. Obviously, we’re not talking about Earth with
that forecast. Instead, this is a possible weather forecast
for distant “hot Jupiter” exoplanets, according to new observations by NASA’s
Kepler space telescope: we know the weather on other planets! “Hot Jupiters” are one of the most commonly
found types of exoplanet. Like Jupiter, they’re these massive gas giants,
but they orbit crazy close to their stars — making them, HOT. Like really, REALLY hot. As in as hot as a blow torch, hot. Because they are so close to their stars,
hot-Jupiters can orbit in less than 10 days. This means they become “tidally locked”
with their stars — one hemisphere is always facing the star in daylight, while the opposite
is in constant night. We know this, because of Kepler. Not Johannes, the telescope named after him. Kepler was launched in 2009 and is an an ace
exoplanet hunter (even though it broke in 2013 and couldn’t move at all, but that’s
another story). When a planet passes in front of a star, it
blocks a tiny amount of starlight, and the space telescope measures the amount and timing
of that dimming and can then extrapolate the size and orbital period of the passing planet
— this is called a “transit.” We have whole videos about it. But, Kepler doesn’t only detect the dimming
starlight of exoplanets; it can also detect the light reflecting off exoplanets and see
the glow of their heated atmospheres! This adds a whole new dimension to the study
of these extrasolar planets! Now we can get to know their weather. In a new study published recently in The Astrophysical
Journal, astronomers were able to measure the amount of light being reflected from these
hot-Jupiters as they orbit their stars. Using the glow of the heated atmosphere, the
paper details how many clouds there are, what chemicals those clouds are made of, AND even
where those clouds appear in the sky! Depending on the chemical composition of the
exoplanet, the clouds could be in different places or have different colors, and for the
hottest “hot-Jupiters”, the atmosphere would glow like the embers of a fire after
the hellish heating from the exoplanet’s star! You can see the full range on the different
exoplanet temperatures and chemical compositions here. Space is so awesome! The researchers could even tell what the rain
on the planet would be like — which is definitely alien — for example, some of these exoplanets
could drizzle silicate crystals. Basically, certain chemicals in the atmosphere
condense and “rain out,” just like water would here on our planet. Obviously these planets are hundreds of light-years
away, so Kepler can’t resolve tiny features like “exo-clouds” DIRECTLY. Instead, the researchers used Kepler’s observation
and combined that with models for weather and climate cycles here on Earth! They used this to create models for the possible
weather conditions in alien atmospheres. A similar study published recently in the
journal Nature Astronomy learned that another hot-Jupiter has clouds of the mineral corundum;
corundum forms rubies and sapphires here on Earth. Can you imagine how beautiful those clouds
would appear from orbit?! Look, understanding the weather on massive,
hellishly-hot worlds hundreds of light-years away may not seem super important, but revealing
the weather systems on these hot-Jupiters adds another level of understanding about
the rich diversity of alien atmospheres out there. And, as astronomical techniques become more
sophisticated, it seems likely that we will one day be able to study the weather systems
on nearby Earth-sized exoplanets, perhaps revealing just how habitable these places
could be for alien life. I say again, space is so. AWESOME. Hot-Jupiters sound pretty terrifying, but
they’re actually not the worst.To learn more about these crazy planets, check out
our terrifying video on exoplanets here. But how do you think these space meteorologist
fare in comparison to your local meteorologist? Tell us about it in the comments, make sure
you subscribe for more DNews and thanks for watching.