It’s a Marshmallow World! Astronomers Find ‘Fluffy’ Exoplanet With Density of Sweet Treat
CC BY-SA 2.0 / Per Olesen /
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A place as large as the universe is bound to have a near-infinite variety of combinations of matter, including what scientists are describing as an exoplanet with a density roughly equal to that seen in a marshmallow.
The scientists’ research, which was published in August in The Astronomical Journal, describes an exoplanet designated TOI-3757b that orbits extremely close to its parent star, a cool red dwarf about 580 light-years away.
"Giant planets around red dwarf stars have traditionally been thought to be hard to form," Shubham Kanodia, a planetary astronomer at the Carnegie Institution for Science's Earth and Planets Laboratory and lead author of the paper, said in a statement.
"So far this has only been looked at with small samples from Doppler surveys, which typically have found giant planets further away from these red dwarf stars. Until now we have not had a large enough sample of planets to find close-in gas planets in a robust manner,” he added.
To be clear, TOI-3757b isn’t actually made of marshmallow, a confectionery made of gelatin, water, and sugar that’s been whipped together into a soft-but-solid form. It’s actually a type of gas giant, but for some reason it has an average density of 0.27 grams per cubic centimeter - slightly more dense than your average campfire marshmallow.
However, this exoplanet is massive: even larger than Jupiter, the largest planet in our solar system. Due to its lower density, TOI-3757b is only about 85 times the mass of Earth, as compared to Jupiter, which is 318 times the mass of Earth.
However, this isn’t even the least dense exoplanet astronomers have found. In 2019, a trio of planets were observed orbiting a star about 2,600 light-years from Earth that were nearly the size of Jupiter, but had less than 1% of its mass because they had atmospheres with the density of cotton candy.
TOI-3757b zips around its parent star in just 3.15 Earth days, meaning it’s extremely hot there. Much too hot to be the proverbial candy land any human might want to visit. Instead, we’ll have to make do with the marshmallow world imagined in songs by The Rat Pack.
