Something for Everyone

Well, March was a wash. Literally and figuratively. Locally Rhode Island set a new record rainfall total. And that means stargazers didn’t spend much time observing. We can’t wait for cloud-free skies, and I hope April wasn’t true to the rhyme “…March winds bring April showers….” As we move into May, I’ve got several observing highlights to tell you about, including beautiful Saturn, the planet Venus, and a meteor-ocre (sic) shooting star display.

First up in May is the Eta Aquarid meteor shower. This display is best seen in the southern hemisphere, but we can usually expect perhaps 15-20 meteors per hour at peak. Unfortunately the last quarter Moon will brighten the sky so much that an observer will see only one-half of that peak rate.

Also, the meteors radiate from the Water Urn asterism (looks like a Y-shaped group of stars) in Aquarius, which rises around 2:00 a.m. Only as this constellation climbs higher into the sky will an observer see the number of meteors increase before twilight begins. This timing provides a very short observing window. Concentrate your gaze low in the southeastern sky.

This stream of particles was shed by Comet Halley and left in orbit about the Sun. Every year the Earth passes through this meteor stream. These yellow and very fast shooting stars fall from the sky at 41 miles per second, often leaving long persisting dust trains behind them as they disintegrate in the Earth’s upper atmosphere. If the weather cooperates, try to observe one or two before you head off to work.

For those of you with telescopes you should take advantage of this observing season to observe Saturn. Saturn was closest to the Earth back in March, but it still presents a beautiful image through even a small telescope.

Saturn’s rings are only inclined just less than two degrees from the horizontal during May. Despite this low inclination (tilt), they are easily visible. An observer can still see “space” between the disk of Saturn and the rings. After June, the rings will begin to “open up” as our perspective changes as the Earth more quickly orbits the Sun. By January 2011, they will be inclined about ten degrees. They won’t reach their maximum inclination until 2017.

Depending upon the size of your telescope you can observe about five of the larger of Saturn’s 61 moons. Titan is bright and easy to identify as it tracks back and forth from one side of Saturn to the other while orbiting this beautiful world.

During May, Venus will continue to be the very bright object in the western sky after sunset. On the 15^th between 8:15 and 8:30 p.m. look for a very thin crescent Moon below and to the right of Venus. The following evening, a waxing crescent (getting a little larger), will be to the upper left of Venus. Try to capture an image of either of these beautiful sky scenes with your digital camera.

Right now Venus is a boring object to view through a telescope. Venus goes through phases like the Moon, and it now presents a tiny gibbous phase for us to observe. As Venus catches up to the Earth, and the Sun-Venus-Earth angle changes, Venus’ apparent telescopic size will increase whereas its phase decreases. That is, during mid-May it will be gibbous (75% lit). In mid-August it will appear half-lit (50%) like a first quarter moon. Then during October it will be a large crescent. Start your telescopic observations around June and try to make an observation of Venus every couple of weeks or so. Use the same telescope and magnification each time. You’ll be amazed at how much the image changes.

And remember to keep in mind that you cannot see any surface features on our neighboring world, since Venus is perpetually shrouded in clouds.

Don’t forget you can visit any of the local observatories to marvel at the beauty of the heavens. On the next clear Saturday night take a ride out to Seagrave Observatory (http:/www.theskyscrapers.org) in North Scituate. Or, on the next clear Tuesday night stop by Ladd Observatory (http://www.brown.edu/Departments/Physics/Ladd/) in Providence. Check out their websites for the public night schedules and opening times.

Both of these facilities offer a unique observing experience.

Keep your eyes to the skies.

David A. Huestis