By Mike Lynch
Saturn’s a wonderful sight through even a small telescope, with its gorgeous ring system that spans more than 150,000 miles in diameter, circling a planet that has a girth of 75,000 miles.
All this month Saturn and Earth are at their closest approach to each other, less than 820 million miles between, and 150 million miles closer than when we last saw Saturn in late September.
It is also visible all night long because Earth lies in a nearly straight line between Saturn and the sun right now. That puts Earth and Saturn at opposite ends of the sky or in “opposition.”
About 10 p.m. look for two bright stars in the fairly low southeastern sky, oriented diagonally. The brighter of the two on the lower left is Saturn. The shiner on the upper right is the star Spica, the brightest star in constellation Virgo the Virgin.
This month it’s best to wait until 11 p.m. or midnight to view Saturn through your scope so Saturn is high enough to avoid the murky effect of Earth’s atmosphere.
Take long uninterrupted views of it to get your eye used to the light level in the eyepiece field. The clarity of Saturn can vary from minute to minute due to high winds in the Earth’s atmosphere.
Acclimate your eyepiece to the temperature and start out using a lower magnification, working up to the higher powers.
Saturn is made up mainly of hydrogen and helium, and by itself is not all that exciting to see through a scope. The ring system, though, is a whole other story. The rings are only about 50 feet thick and made up of billions and billions of ice covered rocks ranging from the size of dust grains to boulders bigger than garbage trucks.
It’s believed that they are the pulverized remains of one or two of Saturn’s moons that wandered a little too close to Saturn in their lopsided orbits and were literally blown to bits by the planet’s tremendous gravitational tides.
If your view of Saturn is clear enough you may see that the ring system is actually a family of thinner rings with gaps. The biggest gap, which looks like a black ring, is close to the outer edge. It’s called the Cassini Division and is more than 2,500 miles wide. Cassini is also the name of the spacecraft that’s been orbiting Saturn and has sent back amazing pictures and data, even the sounds of thunder and lightning from storms in Saturn’s turbulent atmosphere.
You may also see up to six or seven tiny starlike objects, some of Saturn’s many moons. The Cassini spacecraft has photographed water plumes gushing from Enceladus, one of tiniest moons.
It’s believed that tidal forces from the much more massive Saturn are strong enough to heat up Enceladus’ interior enough for liquid water. Wherever there’s liquid water, there’s at least a small chance of some kind of life. Stay tuned, there’s bound to be more about this possibility in years to come.
Mike Lynch is an astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of “Stars, a Month by Month Tour of the Constellations.” Check his website, www.lynchandthestars.com.
The Everett Astronomical Society: www.everettastro.org/.