Return of the King

This month marks the return of Jupiter, the king of planets, to the early evening skies. Watch for it low in the southeast as soon as the sky darkens. You’ll see a brilliant point of light outshining everything else in that area of the sky.

Jupiter is a great target for either binoculars or a small telescope. With just binoculars, you can see Jupiter’s four largest moons. Often called the Galilean Satellites, Io, Callisto, Ganymede, and Europa will appear as tiny dots close to the disk of the planet.

A small telescope won’t just show you the moons of Jupiter, but it can also provide a glimpse of the planet’s colorful clouds. You’ll see what look like faint, parallel stripes across the face of Jupiter. Those are the cloud belts, which continue all the way around the planet due to its fast rotational speed. Jupiter rotates once every ten hours. By comparison, it takes Earth twenty-four hours to complete one rotation!

Meanwhile, red planet Mars spends the month travelling across the constellation of Gemini the twins. You can find it low in the west after sunset. Although Mars is relatively faint and unimpressive in backyard telescopes, keep an eye on it nightly as it heads toward a close encounter with Saturn on the evening of June 17.

Saturn itself is on the move too, but much more slowly. It remains near the center of the faint constellation of Cancer the crab. If you watch carefully throughout the month, you’ll see Saturn approach M44, the Beehive star cluster.

Both Mars and Saturn set earlier every night. This is your last chance to see them before they get lost in the glow of sunset as summer approaches.

If you’re having trouble determining which dots are stars and which are planets, watch them closely. The rule of thumb to follow: usually, stars twinkle, while planets shine steadily.

Spotting the Spot

Jupiter’s most famous feature is the Great Red Spot, a swirling hurricane-like storm nearly three times the size of the Earth. It was first discovered by Italian astronomer Giovanni Cassini back in 1665. That’s right, this storm is well over 300 years old... at least. It’s possibly much older.

Jupiter has many other swirling, oval-shaped storms, but the Great Red Spot remains the largest of them all. Most of the smaller storms are white in color, but in February of this year, one of those white storms turned red too! The storm, nicknamed “Red Jr.,” is about half the size of the Great Red Spot itself. How long it will stay red, nobody knows.

The reason for the red color is not well understood, but it may indicate that the storms are strong enough to churn material up from the lower levels of the atmosphere. The material may turn red when exposed to the ultraviolet light of the Sun over time. This theory might explain how the Great Red Spot’s color has faded and strengthened over the years.

Last month, the Hubble Space Telescope was scheduled to take a close look at Red Jr. As of this writing, images have not been released - so keep an eye online for the latest news. One site to watch is www.redspotjr.com, which has many ground-based images of the storm.

Can the Great Red Spot be seen through a backyard telescope? It’s possible, but it’s not easy. It depends a lot on the weather. Disturbances in the Earth’s upper atmosphere can smear out the view in your telescope. It also depends on the Spot’s color - it sometimes fades.

But most importantly , you have to go out at a time when the Red Spot is facing you! Remember, Jupiter spins quickly, so you’ll have to plan ahead if you want to catch it. Check out the Red Spot calculator on the Sky and Telescope magazine web site to find the best times to look.

If you can’t find it right away, don’t despair! It really is a very tricky thing to find. It takes patience, practice, and plenty of good weather to see it.

Update May 5, 2006: Hubble images of Red Jr. have been released! Check here and here to see!

Spring Star Parties

FREE public star parties are scheduled throughout the Spring. Members of the Barnard-Seyfert Astronomical Society will provide telescopes and commentary on the Moon, planets, and other objects that might be visible. Mark your calendar, and hopefully, we will have clear skies.

• Saturday, May 6, 2006, 8:30 to 10:30 PM at the Adventure Science Center
• Saturday, May, 20, 2006, 8:30 to 10:30 PM at the Visitors Center at Longhunter State Park

Hey, Hey, Hey, it's Astronomy Day!

Saturday, May 6, 2006, is Astronomy Day at the Adventure Science Center. Observe the Sun, learn about telescopes, and meet astronomers from MTSU and Austin Peay State University. Be Blown Away by the wild world of weather or investigate Hubble’s Images of the Infinite in the Sudekum Planetarium. Discover our neighbors in space with JPL Solar System Ambassadors, explore the universe, and more.