Newly Discovered Super-Puff Planets Challenge Density Norms

Astronomers have identified two giant planets with densities lighter than cotton candy. These planets, often referred to as super-puffs, match the size of Jupiter and orbit a star 1,110 light-years from Earth. They are the least dense planets discovered at this size, according to George Dransfield from the University of Oxford.

Dransfield describes these planets as having densities similar to a blob of freshly dispensed shaving foam. Her team published their findings in the Monthly Notices of the Royal Astronomical Society. These planets may appear white or blue, depending on the cloudiness of their atmospheres. While hydrogen and helium likely dominate their composition, further observations by NASA’s Webb Space Telescope are needed to confirm this.

Detected by NASA’s Tess satellite, the two planets are part of the southern constellation Volans, also known as the flying fish. Researchers analyzed the planets’ orbits using telescopes on Earth, measuring their density from a substantial distance of 1,110 light-years. To put that into perspective, a light-year equals nearly 6 trillion miles (9.7 trillion kilometers).

Jupiter’s density surpasses these planets by as much as 35 times. Super-puffs are a rarity in the universe and believed to form in a gas-rich disk surrounding a newborn star. Over time, these planets shed part of their material. Within NASA’s database, among the nearly 6,300 confirmed exoplanets, fewer than 40 qualify as super-puffs.

Dransfield notes studying these extraordinary systems helps scientists piece together the puzzle of planetary formation. It provides insights into our cosmic neighborhood and the mechanisms that yield such unusual celestial bodies.

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