When we look at Jupiter, we see the top of it's atmosphere, and it's weather layer. The weather layer contains a lot of interesting features, such as jet streams, vortices, storms, and these things called "hot spots." Hot spots are basically like holes in the clouds, because they appear very dark in visible light, but in infrared light, they appear very bright. This indicates that we are seeing deeper down into warmer layers of the atmosphere. We've studied these hot spots with the Galileo Atmospheric Probe in 1995. The probe descended into Jupiter's atmosphere through a hot spot, taking measurements.
In 2000, a series of still images were compiled into time-lapse movies of Jupiter's atmosphere. In these movies, we can see Rossby waves that caused North-South meanderers in the jet stream. When looking at hot spots, we can see similar waves, but instead of moving North and South, they are moving up and down in the atmosphere. The downward portion of the wave pushes air down into warmer layers in the atmosphere, causing any clouds to evaporate and prevent other clouds from forming. These downward portions are believed to be the hot spots we see, which will help us better coordinate future probes sent to Jupiter.
The 1,500 active volcanoes worldwide are creating a minefield for pilots who have to be on watch for volcanic ash clouds capable of causing major damage.Read Story >