Artist’s concept of a mushball in the atmosphere of a giant planet. A new study says that such mushballs – basically giant hailstones – may explain the missing ammonia in the atmospheres of Uranus and Neptune. Image via NASA/ JPL-Caltech/ SwRI/ CNRS/ Europlanet Society.
The case of the missing ammonia
On Earth, hailstones – icy pellets of frozen water – fall from the clouds like snow or rain. Other planets, for example giant Jupiter and Saturn, have hail, too. On the giant planets, hailstones are called mushballs. They’re larger and slushier on the inside than earthly hailstones. In mid-September 2021, the Europlanet Society said that mushballs can explain a missing substance on the ice giants Uranus and Neptune. The substance is the chemical compound ammonia. And these scientists said that mushballs on Uranus and Neptune carry ammonia deep down into the planets’ thick atmospheres, where earthly telescopes can’t detect it.
Tristan Guillot from the J.-L. Laboratory Lagrange in France presented the results of the new study at the virtual Europlanet Science Congress 2021, September 13 to 24.
Until now, scientists have been puzzled about why ammonia seems to be scarce in Uranus’ and Neptune’s atmospheres. The atmospheres of the two ...