We’ve only had one bright planet adorn the evening sky this winter – Jupiter. He’s certainly generous with his moons, clouds belts and brilliant display, but he’ll soon have company. The planet Saturn edges 4 minutes closer to the evening sky every night.
The ringed one rises around 12:45 a.m. tomorrow morning but by month’s end pops up at 11 o’clock. Either time may be too late for many, but if you’re an early-riser, consider peeking out your window at dawn tomorrow. Like fruit hanging from a twig, the last quarter moon will dangle below Saturn. Although not a particularly close conjunction, the two will be near enough to catch your attention. Closest approach of 3.4 degrees occurs around 1 a.m. (CST).
If you’re feeling brave, take your scope out for a look at its marvelous tipped rings in the dawning sky. Some of my favorite views of planets have been at dawn or dusk. Seen against a deep blue sky, Saturn’s natural glare is lessened and the view more natural and satisfying. Examine the rings closely and you may be able to spot the hairline gap between the outer, narrower A ring and broader interior B ring. The apparently empty space is named Cassini’s Division in honor of 17th century Italian astronomer Giovanni Cassini who discovered the gap in 1675. Under good conditions even a small 3-inch telescope will show the 3,000-mile-wide vacancy. Gravitational interactions by the moon Mimas clear out ring particles to create the gap.
Cassini has many firsts to his credit. He discovered four of Saturn’s moons, co-discovered Jupiter’s Great Red Spot and determined the rotation periods of Jupiter and Mars by careful study of their surface and cloud features. With the help of his assistant Jean Richer, he triangulated the distance to Mars in 1672. Once Mars’s distance was known, Cassini could easily calculate the distances to all the other planets, since the ratio of their distances to the sun was already known through geometry.
He did well. His measurement of the Earth-sun distance was off by just 7%.
It’s no wonder then why his name was chosen for the Cassini mission to Saturn which has been orbiting that planet and its family of moons since July 1, 2004. New pictures are taken all the time, many of which I’ve featured in this blog. Like Cassini himself, his namesake continues blazing a path of discovery.
Recently NASA released a series of photos showing Saturn’s monster storm, the biggest ever recorded in the planet’s northern hemisphere, that began around Dec. 5, 2010 and finally ran out of steam 267 days later. It’s been compared to a hurricane on Earth with its powerful winds, lighting and thunder though on a far grander scale.
Earthly hurricanes derive their energy from warm oceanic waters, while Saturn funnels its power from warm, rising gases in its enormous atmosphere. But there the similarity ends. With no land masses to get in the way and sap the storm of its fury, the leading edge of Saturn’s “hurricane” circled the full 190,000 miles of the planet’s circumference and met up again with its tail! Some have compared it to the mythical serpent Ouroboros eating its own tail. An apt image if there ever was one.
Of course, Cassini was there snapping away the entire time. To read more about the big storm and see additional photos, I invite you to click HERE.