SJAA Ephemeris May 2001 | SJAA Home | Contents | Previous | Next

The Shallow Sky in May

Akkana Peck

As May opens, Jupiter and Saturn are low in the west at dusk, and you can still catch a little detail on them and watch the motion of their moons. Try to find them right at sunset, or even earlier if you can - you'll see more detail when they're higher in the sky.

But the real target of the month is Mars. Mars isn't at opposition this month - that doesn't happen until the middle of next month - but if you want to see as much detail as possible during the few weeks around opposition when it will be closest to us, now is the time to start practicing, even though you have to stay up past midnight to get a good view. Our small red neighbor is already pretty close - about half an AU at this month's end - and even a small telescope should be enough to show some of the planet's major features, like the dark feature of Syrtis Major (shaped roughly like India) and the huge, pale impact feature Hellas. Larger telescopes will show more detail - sometimes you can see clouds around the volcanic region of Tharsis, and this year, with the planet barely tilted at all as viewed from our location, we might get a good view of the challenging Sinus Meridiani area.

How do you identify these features? The RASC Observer's Handbook, which many club members bought at SJAA meetings, has a decent Mars map in it. The drawing isn't great, but the labelled features give a good idea of what a telescopic observer might hope to see. Planetarium programs are more useful, if you can find one that shows features on Mars correctly oriented as they appear at a specific time. Guide (Windows), Starry Night (Windows and Mac), and XEphem (Linux) are some programs which offer this feature. It might also be worth searching the web for a freeware program called "Mars Previewer", which was useful in the last opposition for showing the orientation of Mars and its features.

If you don't have a computer handy, or don't want to hassle with bringing one out into the field with you, try a globe. Replogle makes a nifty mini Mars globe which is often available for not much money in combination with an earth globe (out of date) and a moon globe (not the best quality but sometimes useful). Try large toy stores (I bought mine two oppositions ago in the Great Mall).

The outer planets - Uranus, Neptune, and Pluto - all rise late and are best viewed well after midnight. More on those planets in columns to come.

The inner planets, Venus and Mercury, are both morning objects now. Early risers (or people pulling all-nighters) can get a lovely view of a large crescent Venus throughout most of the month.

Mail to: Akkana Peck
Copyright © 2001 San Jose Astronomical Association
Last updated: July 19, 2007

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