Massive Earth-sized storm on Neptune spotted

New York : Astronomers have spotted a storm system nearly the size of Earth near Neptune's equator, a region where no bright cloud has been seen before.

"Seeing a storm this bright at such a low latitude is extremely surprising," said Ned Molter, an astronomy graduate student at the University of California-Berkeley.

"Normally, this area is really quiet and we only see bright clouds in the mid-latitude bands, so to have such an enormous cloud sitting right at the equator is spectacular," Molter said in a statement released by the university on Thursday.

Molter spotted the storm complex near Neptune's equator during a dawn test run of twilight observing at W. M. Keck Observatory on Maunakea, Hawaii. The findings showed that useful observations can be made during twilight, a time most astronomers consider unusable because it is not dark enough.

This massive storm system, which was found in a region where no bright cloud has ever been seen before, is about 9,000 kilometres in length, or one-third the size of Neptune's radius, spanning at least 30 degrees in both latitude and longitude.
Molter observed it getting much brighter between June 26 and July 2.

"Historically, very bright clouds have occasionally been seen on Neptune, but usually at latitudes closer to the poles, around 15 to 60 degrees north or south," said Imke de Pater, Professor of Astronomy at University of California, Berkeley, and Molter's adviser.

"Never before has a cloud been seen at or so close to the equator, nor has one ever been this bright," de Pater added.