May 6, 2010

The Astronomy of Mother's Day

May 6, 2010: Looking for a great Mother's Day gift? Your search is over.

Mom wants a wake up call.

The Astronomy of Mother's Day (Moon-Venus 200 pixels)
Venus and the Moon over Daytona, Florida, in April 2010. This is what the Moon-Jupiter conjunction will look like on Mother's Day. Photo credit: Ben Cooper.

At dawn on Sunday, May 9th--Mother's Day--the crescent Moon and Jupiter are getting together for a lovely conjunction. Only 5 degrees of arc will separate the two bright celestial delights as they hang together in the sunrise-colored sky. Mom doesn't even have to go outside. A glance out any east facing window will frame the show quite nicely:.

It may be worth noting how much more you can see with the aid of a small telescope. There are four big moons circling Jupiter—Io, Europa, Ganymede and Callisto, also known as the "Galilean satellites." Galileo discovered them 400 years ago using little more than a pirate's spyglass. The shadowy mountains and craters of the crescent Moon are also wonderful targets. Almost any optics you can find around the house will serve the purpose.

Only Mom can tell you if this is going too far at 5:30 in the morning.

In rare cases, Mom will not want to be woken up at the crack of doom--er, dawn. She might even refuse to get out of bed. If this happens, you'll need a backup plan.

Good news: There's also a nice display at sunset. Just as the sun is going down and the sky is fading to a deep cobalt blue, two bright lights will pop out of the twilight: Venus and Sirius. You can't miss them (especially Venus) shining halfway up the western sky:. They're not as close together as Jupiter and the Moon, but what they lack in proximity, they make up for in luminosity. Venus is the brightest of all planets and Sirius is the brightest of all stars. Set in twilight like jewels on velvet, Venus and Sirius are an unforgettable sight.

Remember that small telescope? Point it at Venus. The second planet from the sun shines with a pearly, unwavering glow that can only be described as otherworldly. Swing over to Sirius. The distant star sparkles like a diamond with sudden rainbow-colored glints. (Quick astronomy lesson: stars twinkle but planets do not. You're welcome, Mom.)

Heavenly pearls and diamonds are a nice way to wrap up the day—especially if you misjudged that wake up call.

Happy Mother's Day!


Author: Dr. Tony Phillips | Credit: Science@NASA

More Information

Mother's Day sky maps: , .

Why do stars twinkle? -- (Cornell University)