Planets in January - Getting the most from that new telescope...

Observer's Notebook for January, 2001

by John Rummel

As you decompress from the hectic holiday season, take a few minutes during the cold, dark evenings of January to appreciate the brilliant winter skies. If you have a telescope, or received one recently as a gift, even better. This winter presents several excellent opportunities to test and appreciate your new instrument.

Venus: Our first telescopic target is Venus. To the naked eye, Venus is simply a brilliant star - brighter than any other object in the sky this month except the sun or moon. Venus shines so brightly because it's cloudy atmosphere is an excellent reflector of light. Through your telescope at moderate power, Venus will not be round. In mid-January, it will present a nearly perfect "last quarter" phase (50% illuminated). Since Venus is nearer to the sun than the Earth, it goes through phases just like the moon, and for exactly the same reason - we see only part of its sunlit side as it slides between us and the sun. The photo shown here was taken when Venus was a bit further along in its orbit, hence a bit more of a crescent. Be warned though, Venus is so bright that its magnified image (e.g., through the telescope) can actually be painful! There's no danger, but after looking for awhile you might have a purple "floater" in front of that eye.

Jupiter: Jupiter is a telescopic delight. From the ever changing positions of the four Galilean moons to the subtle and fascinating cloud bands on the planet, Jupiter can occupy the patient observer for hours. Look first at the planet itself. How many cloud bands can you see? Jupiter's rich atmospheric activity means observers are never lacking for details to sketch and observe. Patience and higher powers may reveal the great red spot. Don't be surprised if you can't see it though. It's not really red, more of a muted salmon. Viewing it through small to modest backyard telescopes is a real challenge. The picture shown here gives a good feel for what can be seen through a modest backyard telescope at about 75x magnification. Jupiter's moons are bright enough to be naked-eye objects - if they weren't so close to the dazzling planet itself. Galileo was the first to observe them through his homemade telescope, and used them as an important piece of evidence to demonstrate that not everything revolves around the Earth - the prevailing idea in those days.

Saturn: No object dazzles newcomers to astronomy more than Saturn. I have given hundreds of people their first look at this magnificent planet, and almost without exception, their is a gasp and a wordless utterance of amazement - "Wow!" I've even had people accuse me of trying to trick them - they believe I must have a picture at the other end of the telescope.

Saturn's rings draw the attention immediately. If you have a clear sky and calm conditions, see if you can spot the Cassini division - a gap in the rings. Several of Saturn's moons may also be visible. They don't line up as neatly as Jupiter's moons, but any faint objects you see in the vicinity may be some of Saturn's twenty-some moons.

  Photo by Mike McDowell, July 1, 1999. Celestron C8 with Connectix Color Quickcam. Visit Mike's web site here.
  Artistic rendition of what Jupiter would look like through a modest backyard telescope. Mike McDowell.
  Artistic rendition of what Saturn would like like through a modest backyard telescope. Mike McDowell.


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