Last week I told you how the rest of the summer is a wonderful time to watch Jupiter. It's by far the brightest starlike object in the night time sky.

No other star or planet is even close, and this month, Jupiter is visible all night long, crossing the low southern skies. It rises at sunset and sets at sunrise, and through even the smallest of telescopes or even binoculars, there's much you can see on the largest planet in our solar system.

Even with a pair of binoculars you can see Jupiter more clearly than Galileo did in 1610 with his homemade telescope.

As I told you last week in Skywatch, when you telescope Jupiter, all you can really see is a façade of atmosphere and cloud bands that completely encase the king of the solar system.

Through even a small telescope you can see at least some of the cloud bands, especially the two brighter ones that run on either side of Jupiter's equator.

If our own atmospheric conditions are favorable, you can also see additional cloud bands or even Jupiter's biggest red spot, which is actually like a super giant hurricane which has been swirling for hundreds of years.

By atmospheric conditions I'm not just talking about the cloud cover where you're watching Jupiter from, but also the high jet stream winds which can also muddy the view. The best thing to do is watch Jupiter for as long as you can on any given night, as seeing conditions can rapidly change and you can get those wonderfully clear views of the Jovian giant.

Just as Galileo was, I know you'll also be fascinated by watching Jupiter's four largest moons orbiting the planet in periods of two to 17 days. They look like tiny little stars on either side of Jupiter, and it's fun seeing their positions change from night to night.

One of the things I really enjoy is watching one or more of the moons cross in front of the face of Jupiter, but that can be tricky because they easily blend in with the cloud bands. I think it's actually easier to see the shadows they cast on Jupiter's cloud tops because they're visible as distinct contrasting black dots.

The great thing is that you don't need a very big telescope to see that. Again, Earth's atmosphere has to cooperate with what astronomers call good "seeing" conditions, so patience is a big virtue when it comes to chasing moon shadows.

An essential tool for this is the Web site from the University of Maryland: www.astro.umd.edu/~lgm/astr120_fall97/jupiter.html which you'll want to put in your favorites. It's a diagram of the positions of Jupiter's moons, as well as the position of the red spot on the rapidly rotating planet.

It also will tell you when one of the moons and its shadow is crossing Jupiter's face. The moons themselves will be depicted by a white dot across Jupiter's face and their shadows will be black dots. Just set the time ahead to anytime in the future to see if any shadowy events are taking place that night or any other upcoming night.

Just a word of caution here, the displayed diagram is an upside down inverted view which is helpful because most telescopes also give you an inverted image.

There's another program you can use from Sky and Telescope Magazine that also is useful but a little more complex. Just Google in "SkyandTelescope.com ¿ Planets ¿ Chasing the Moons of Jupiter", and follow the steps.

The easiest moon shadows to see cross Jupiter are those of Ganymede and Callisto, Jupiter's largest moons. In fact, Ganymede, at 3,269 miles wide, is even bigger than the planet Mercury. These larger moons make larger shadows.

Jupiter's smaller moons, Io and Europa, orbit closer to the big planet and are tougher to see. Consider them the big prize in moon shadow spotting.

Incidentally, Io and Europa are Jupiter's most fascinating moons.

Io is without a doubt the most volcanic body of the solar system. Because of Jupiter's tremendous gravity and tidal force the rocks that make up the interior of Io are constantly rubbing against either other, generating massive interior friction and tremendous heat and resulting in the constant volcanoes of Io.

In fact, Io was dubbed the "pizza" planet because when it was first photographed by space probes, the surface was a mix of red and yellow colors because of all the volcanic activity. The Galileo spacecraft that orbited Jupiter for more than eight years charted a total of 120 volcanoes on Io.

Europa, in my opinion, is even more fascinating because its entire surface is a giant sheet of cracked ice.

Once again, because of Jupiter's tidal forces and interior friction, it's thought to be warm enough to have a slushy ocean of water under that ice cover.

Where there's liquid water, who knows, maybe there's some life. I doubt there are bass swimming around, but who knows what will be found if we ever auger our way through that ice.

Good luck watching Jupiter's moons and their shadows. It's challenging and a lot of fun!

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, "Pennsylvania Starwatch", available at bookstores and at his Web site www.lynchandthestars.com.