Moon and Jupiter
The longer nights of autumn and winter give skywatchers at high-northern latitudes plenty of time to enjoy one of nature’s most spectacular light shows: the aurora borealis — the northern lights. These curtains of light shimmer to life as charged particles from the Sun hit atoms of nitrogen and oxygen high in the atmosphere, causing them to glow.
But Earth isn’t the only planet with auroras. In fact, the most powerful auroras are on the giant planet Jupiter, which keeps company with the Moon tonight. Jupiter is to the lower left of the Moon during the evening, and even closer to it as they set in the wee hours of tomorrow morning. The planet looks like a brilliant star.
For the most part, the auroras on Jupiter aren’t created by the Sun. Instead, they’re energized by charged particles from the volcanic moon Io. Some of the particles belched out by the volcanoes get an electric charge, then they’re swept up by Jupiter’s powerful magnetic field. They follow the magnetic field all the way to Jupiter, where they ram into the upper atmosphere in giant rings around the magnetic poles.
While most of the glow from the auroras on Earth is in the form of visible light, the auroras on Jupiter glow across the entire electromagnetic spectrum, from radio waves to X-rays. And they produce enough energy to power all the cities on Earth — a limitless supply of energy from glowing curtains of light.
More about Jupiter and the Moon tomorrow.
Script by Damond Benningfield, Copyright 2011
For more skywatching tips, astronomy news, and much more, read StarDate magazine.