Close Encounters

6/17/07 – 6/23/07
by C. Zaitz

Every summer, an email floats around the internet about Mars. The email tells us that no one alive will ever see this again. It’s a once in a lifetime event. Don’t miss it. Then the email says that Mars is as close as it will be for 5,000 or maybe even 60,000 years. However, the same email comes back every year, and most of it is hype. Technically, earth and Mars were closest to each other in August of 2003, but every time earth passes Mars, we have a close encounter. Human eyes can’t discern the difference between when Mars is 35 million miles from us or 40 million miles. It would be like looking at a baseball 400 miles away. You can’t really tell if it’s 50 miles closer with the unaided eye because it’s so small compared to its distance.

Currently, Mars isn’t even a player in the night sky. But there are three planets that are. Jupiter, for one. If you’re looking for close encounters, it happens that we are closer to Jupiter this month than at other times in the year, and it is definitely showing off brightly all night long. “Closest” simply means that we are on the same side of the sun as Jupiter. Imagine a Nascar track with earth on an inside lane and Jupiter further toward the outside edge. Because we are going faster and have less space to travel, we pass Jupiter. As we pass, we are closer than we are at other times. It’s happening now, and it’s a great time to use your binoculars to see Jupiter and its largest moons. If you want a fun project with kids, you can even watch it from night to night and see how the moons move around Jupiter, just like the famous astronomer Galileo did. Use a sketch pad and draw the configuration. Kids (and adults) can actually see something changing in the sky, and you never know what will spark a life-long interest in science. Galileo’s sketches changed the way people thought, and forever put to rest the idea that the earth was the center of everything.

Saturn is also up in the evening sky, but sets an hour or two after dark. Saturn is even more astounding when you see it through a telescope. Often we are jaded by seeing full color giant images of planets and space objects from the Hubble Space Telescope. But there is something special about seeing Saturn through a small telescope. You can’t see color, and it looks tiny, but you can see the rings and even a moon. It’s nearly twice as far away as Jupiter, but it is so distinctive that you really know you’re looking at a planet, not just a bright light. I highly recommend it this summer, especially with kids.

The third bright planet up in the early evening is Venus. She’s been especially showy lately, high in the west during evening twilight, and shining more brightly than airplane headlights. Her reflective clouds send a lot of sunlight our way, and because you can see her at sunset, she’s the planet you’ll notice most. At the end of June, she’ll be close to Saturn, and this will be the prettiest close encounter of all. Just look to the west as it gets dark enough to see them, around 9:45-10 pm.

Until next week, my friends, enjoy the view.