Yesterday I kept daydreaming about Galileo. Exactly 400 years ago, on January 7, 1610, the famous Italian astronomer spied the moons of Jupiter for the first time and, once he realized what he'd seen a few days later, created a revolution in astronomy that reverberates to this day.

Backyard observing has changed tremendously since Galileo's time. Our telescopes are so much better, our ability to appreciate what we see vastly improved. But we're still limited by local circumstances — by the time and place we choose to set up our scopes, and by the light pollution that almost certainly degrades our view.

Fortunately, this weekend you'll have not one but two chances to view the universe with first-rate equipment and modern detectors from pristine, dark-sky sites. The good folks at Astronomers Without Borders (AWB) have teamed up with the Virtual Telescope project and Global Rent-a-Scope to provide a remote-observing experience for those of us lacking good skies or too busy to drag our own scopes outside.

The effort, called Big Dipper to Southern Cross, features robotic scopes in two hemispheres. Using your computer, you'll watch as experienced observers slew from one object to the next and show how they capture the wonders of the night sky. You'll be able to chat with other participants and with the telescope operator. This event builds on a successful remote-observing effort held by AWB last September.

So if you've ever wondered what remote observing was like, here's your big chance to try it, along with like-minded amateurs from around the world, and at no cost! All you have to do is make sure your computer has Adobe's Flash plug-in and then go to the Big Dipper to Southern Cross event website.

The northern-sky tour takes place today, January 8th, from 20:00 to 22:00 Universal Time (3 to 5 p.m. Eastern Standard Time). The southern-sky tour is Sunday, January 10th, from 12:30 to 14:30 UT (7:30 to 9:30 a.m. EST).