March of the Planets

After a winter mostly bereft of planets, March skies give us something to look forward to, along with (I hope) warmer, clearer and more pleasant evenings.

Saturn is ideally placed for observing this month, visible all night and transiting before midnight at nearly seventy degrees up. Take a look at how much the rings have closed since last year - we’re viewing them at a fairly shallow 14–degree angle now (last year it was more like 18 degrees). Is it easier or harder now to see ring features like the small gaps in the outer ring?

Venus shines high in the evening sky. A telescope will show it as gibbous.

Mercury is visible in morning skies this month, and here in the northern hemisphere it never gets very high. Mars, too, is visible in the mornings, and on the night of March 25 it has a relatively close encounter with Uranus - they’ll pass within a degree of each other. Neptune and Pluto are morning objects as well, but neither is very well placed for observing - you’re better off waiting a few months if you want to go hunting the outer reaches of our solar system.

Jupiter rises an hour or so after midnight. If you’re trying the Messier Marathon this month, Jupiter makes a nice break in the middle of all those Ophiuchus globulars. If you’re worried about ruining your night vision, try looking at Jupiter with your other eye, the one you don’t normally use to observe. It’ll preserve night vision in your good eye, but it’s a good exercise for another reason: if you’re like me, you may find that your non–observing eye isn’t nearly as well trained to see detail, and you may have a surprisingly hard time picking out normally features. It’s a good reality check for public star parties, so you don’t start expecting first–time observers to see that cool swirling festoon coming off the trailing edge of the Great Red Spot. Remember when you were starting out and had trouble seeing the equatorial bands and the polar regions?

We’ll unfortunately miss most of this month’s total lunar eclipse on March 3. The central part of the earth’s shadow (called the umbra) will already have crossed the moon by the time it rises for observers in San Jose, at 5:06pm. The rising moon will still be shaded by the outer part of the shadow (the penumbra), but that will be extremely difficult to see - it’ll probably look like any other full moon rising. But cheer up - we’ll get a nice lunar eclipse later this year on August 28.

Early March evenings are a good time to observe the Zodiacal light.

This faint band of light, rising from the horizon along the line ecliptic, is caused by sunlight reflecting off the tiny dust–sized particles left over from the formation of our solar system. This is a naked–eye sighting requiring dark skies - telescopes and binoculars will be no help here, but it’s a great way to start a Messier Marathon evening. Ironically, the RASC Observers Handbook suggests that Venus is so high and so bright that it might actually make the zodiacal light more difficult to see. What do you think? I’m skeptical, and I’d be interested in hearing from anyone who looks for the Zodiacal Light and finds that Venus makes it more difficult.

Around the end of the month, we’ll have a very close encounter with an asteroid dubbed 2006 VV2. VV2 will pass us at only eight times the distance of the moon. That’s close! The asteroid, about 2 km in diameter, still won’t get very bright - about 10th magnitude at its brightest - but since it’s so close, you’ll be able to see it move against the background stars after watching for only a few minutes.

Closest approach is March 30th, when it will be heading south through the center of Leo, but you can pick it up on the 26th as it passes near Polaris. Google for “2006 VV2” as the time approaches (don’t forget the quotes - you want Google to look for the whole phrase) to get finder charts and other information.

For anyone who missed seeing Comet McNaught in January and really needs a comet fix, periodic comet 2P/Encke, believed to be the source for the Taurid meteor shower, may become bright enough to be visible in binoculars in Pisces and Aries around the end of the month and stretching into early April. Not much of a substitute for missing the spectacular McNaught, but at least dedicated comet watchers have something to look for.

On March 11 at 2am, Daylight Savings Time begins. That’s three weeks earlier than the date in years past. A couple of years back Congress decided that Daylight Savings Time wasn’t confusing enough, so they passed the Energy Policy Act of 2005 and changed the date of the switch.

The fall change, in November, will be a week later than usual.

So on Saturday night, set your clocks forward an hour and prepare to stay up later waiting for dusk. And check in on your computers and PDAs on Sunday morning to see if anyone told them about the Energy Policy Act. Current operating systems should get it right, but older computers may need their clocks reset.