New York Aug 4 (IANS) 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.
At first de Pater thought it was the same Northern Cloud Complex seen by the Hubble Space Telescope in 1994 after the iconic Great Dark Spot imaged by Voyager 2 in 1989 had disappeared.
But measurements of its locale do not match signaling that this cloud complex is different from the one Hubble first saw more than two decades ago de Pater added.
A huge high-pressure dark vortex system anchored deep in Neptune s atmosphere may be what is causing the colossal cloud cover said de Pater.
Having a better understanding of Neptune s atmosphere will help give astronomers a clearer picture of this icy giant s global circulation and it might also help shed light on how exoplanet s atmosphere behave.
This has become increasingly more important in the exoplanet realm as a majority of exoplanets found so far are nearly the size of Neptune.
While scientists can calculate their size and mass not much is currently known about exoplanets atmosphere.
--IANS
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