The iron rain would be extremely dense and
pack a pretty good punch, according to the
research team whose study appears in the
journal Nature.
“It’s like in the heavy steel industry on Earth
where they melt iron, and so you see this
melting, flowing metal. That’s pretty much
what we are talking about here,” Lovis told The
Associated Press.
Discovered just a few years ago, the planet
designated Wasp-76b is nearly twice the size
of Jupiter, the largest in our solar system,
yet takes less than two days to orbit its star.
Because the planet’s rotation matches the time
it takes to complete one orbit, the same side
always faces the star.
So it’s always daytime on the star-facing side,
with clear skies. And it’s always nighttime on
the night side, where temperatures fall to
about 2,700 degrees Fahrenheit (1,500 degrees
Celsius) and the sky is continually overcast with
iron rain, according to the researchers.
Strong wind — gusting at more than 11,000
mph (18,000 kph) — constantly sweeps some
of the vaporized iron from the day to night side
of the planet. Inside the day-to-night transition
zone, clouds appear to form as temperatures
begin to drop.
“Surprisingly, however, we do not see the iron
vapor in the morning” as night transitions back
into day, lead scientist David Ehrenreich of the
University of Geneva said in a statement.
The astronomers concluded the most
likely explanation is that it rains iron on
the night side.