Shooting Stars of May

It’s been four months since we have been treated to a decent meteor shower display. You may have braved the cold but clear skies on the morning of January 4th to watch some members of the Quadrantid display blaze across the sky. I counted ten Quads and one sporadic in a 50 minute observing session just before dawn’s early light brightened the sky. Most of the meteors were very short and not very bright. Only a couple of them reached brightness (magnitude) that didn’t even quite rival that of the brightest star in the sky, Sirius. And only a couple passed through several constellations as they traversed the sky in their fiery demise.

Well, reserve an hour or so on the morning of May 6 to watch for the Eta Aquarids meteor shower. Observing conditions are as favorable this year as they can be for this display. Still, it can be a challenge to observe. The Moon (New on the 3rd) will not be a factor, since it will appear as a slender waxing crescent on the evening of the 5th and will set around 10:19 pm. However, the shower’s radiant point is in the Water Urn asterism (looks like a Y-shaped group of stars) of Aquarius and will not rise very high above the eastern horizon during the peak viewing time.

Also, at this time of year, morning twilight (dawn’s early light) actually begins around 3:46 am. At that moment the radiant point within Aquarius is no more than 12 degrees above the eastern horizon. Combine that with the Sun rise time of 5:36 am and you’ve got a short observing window to catch a glimpse of a few meteors.

I would suggest starting your observing run around 3:30 am and continuing for about an hour, or at least until all but the brightest stars fade from view. Pick an observing site well away from any light pollution source and make yourself comfortable in a lawn chair. Scan the sky back and forth from the eastern horizon towards the zenith. Hopefully the temperature will be mild so you won’t miss any meteor due to chilly toes!

Though this meteor shower is best seen from the southern hemisphere, it is unfortunately an old and declining one. The particles we see hitting our upper atmosphere were shed by Halley's Comet long ago and left in orbit about the Sun. Every year the Earth passes through this meteor stream. As such, due to the observing circumstances here in the northeast, you can expect to see perhaps up to twenty swift, yellow Eta Aquarids per hour.

The swarm of particles comprising the meteor stream hits the Earth's upper atmosphere nearly head-on at 41-miles per second. This high-speed collision results in forty percent of the meteors leaving long persisting dust trains. Also, because we will be observing the radiant point near the horizon, this scenario tends to produce “earthgrazers,” shooting stars that blaze long and slow along the horizon. A relatively unobstructed view of the eastern horizon will help to see as many of these earthgrazers as possible before morning twilight swallows up the stars.

Let’s hope the weather will cooperate for this brief shower of shooting stars on the morning of May 6.

And finally, if you haven’t visited any of the local observatories this year to observe the magnificent beauty of Saturn and his rings (now tilted just less than ten degrees from the horizontal), then by all means plan to schedule a trip on the next clear night that public observing is offered. Saturn will be visible all summer long. The view through the large telescopes at these facilities is spectacular. Plus, there is no admission fee for these scheduled sessions. What a bargain for a family night out!

Before packing up the family for a ride out to Seagrave Memorial Observatory (http:/www.theskyscrapers.org) in North Scituate on a Saturday night, or out to Ladd Observatory (http://www.brown.edu/Departments/Physics/Ladd/) in Providence on the next Tuesday night, be sure to check 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.