Second ‘Great Spot’ discovered on Jupiter
A second Great Spot has been discovered on Jupiter by University of Leicester astronomers, rivaling the scale of the planet’s famous Great Red Spot and created by the powerful energies exerted by the great planet’s polar aurorae.
Dubbed the ‘Great Cold Spot’, it has been observed as a localised dark spot, up to 24,000 km in longitude and 12,000 km in latitude, in the gas giant’s thin high-altitude thermosphere, that is around 200K (Kelvin) cooler than the surrounding atmosphere, which can range in temperature between 700K (426?C) and 1000K (726?C). The results are published in Geophysical Research Letters.
Dr Tom Stallard, Associate Professor in Planetary Astronomy and lead author of the study, said: “This is the first time any weather feature in Jupiter’s upper atmosphere has been observed away from the planet’s bright aurorae. “The Great Cold Spot is much more volatile than the slowly changing Great Red Spot, changing dramatically in shape and size over only a few days and weeks, but it has re-appeared for as long as we have data to search for it, for over 15 years. That suggests that it continually reforms itself, and as a result, it might be as old as the aurorae …read more
