SJAA

Ephemeris

Shallow Sky

Akkana Peck


Mars continues to brighten and increase in size in March as it approaches its opposition on April 24. At the beginning of March, it rises before 11, and by the end of the month it's rising at 9 p.m.. If you have any interest in the red planet, be sure to start now if you want to be able to see detail during the opposition! Features on Mars are subtle, and observing them takes practice, perhaps more so than any other planet. The best way is to start observing Mars a few months before opposition - that means NOW! - and learn now to identify features. By the time the actual opposition comes, you'll be an expert.

It's late summer on the red planet's northern hemisphere (the one pointed toward us). The polar caps may still be retreating, so watch carefully from week to week and see what changes. It's fun to make sketches of the features you observe on planets; no matter what level your drawing skills (which will improve if you sketch planets often!), try making a sketch of the features you see, then compare it with what you see a week or two later. You might be surprised at the changes!

Hellas is expected to be bright, which means that it may be easy to mistake for the polar cap. Dark features visible should include Syrtis Major (a fairly easy feature which looks rather like India), and possibly Sinus Meridianus and Solis Lacus, the "Eye of Mars", which I found difficult to see in the last Mars apparition.

A Mars globe (see last month's column) or good computer program (GUIDE and STARRY NIGHT are two which show Mars features) can be invaluable for telling the two apart.

Ambitious observers may want to watch for the blue Syrtis cloud, which should appear dark green when viewed with a yellow filter, and for limb clouds (try a blue or violet filter).

There's more information on observing Mars on the ALPO page: http://www.lpl.arizona.edu/~rhill/alpo/mars.html

Meanwhile, while you're waiting for Mars to rise, take a look at Mercury, Venus, Jupiter, and Saturn all clustered in the evening sky.

Saturn is the showpiece: still high in the sky in the early evening, the ringed planet is still a beautiful sight in any size telescope.

Venus is the unmistakably bright evening star, gaining altitude rapidly as March progresses, passing as it climbs first Jupiter, and then Saturn. On March 19, it sits only 2 1/2 degrees away from Saturn, with a slim crescent moon also nearby. Should be a lovely sight for naked-eye and binocular observers! Venus' disk remains gibbous all month.

At the beginning of March, Mercury is low in the western sky in evening twilight, and will lose altitude rapidly as the month wears on, becoming unobservable by mid-month and reaching inferior conjunction on the 19th. Get your Mercury looks in while you can! To the telescopic observer it should change rapidly from half-illuminated to crescent phase. On the 6th it passes within 4 degrees of Jupiter.

Don't miss your last chance for some time to get a look at Jupiter! The king of planets is low in the western sky at sunset, and will disappear behind the sun by the end of the month. The equatorial bands and the Galilean moons will still show, but this low in the sky, it will be tough to see much else. Bid a fond farewell to Jupiter: come back soon!

Uranus and Neptune are low in the dawn sky, too close to the sun for good observation. Pluto is a bit ahead of them, near the meridian by dawn, and should be observable by ambitious early risers.


Akkana Peck; last updated: October 04, 2007 Prev Next