It was hard to pick one single topic this week for Starwatch, so consider this an astronomical holiday season potpourri.
An annihilated comet
Ok, as I said last month, beware of Comet ISON hype.
In my opinion, between a handful of irresponsible astronomers and a hype hungry media that touted ISON as the "comet of the century," a true disservice was served upon the science of astronomy. In fact, even one of the more popular astronomical magazines was blatant in grossly overselling ISON. Could it be to boost circulation?
However, the majority of astronomers believed ISON would be vaporized when it reached its closest approach to the sun Nov. 28, and that is exactly what happened. Even deep freeze comets from the outer reaches of the solar system don't deal all that well when they pass within a million miles of the sun, as Ison did. Even if Comet ISON had survived, there was very little chance it could even be seen with the naked eye. I have to admit, as ISON got sucked closer to the sun, I got a little sucked in by the hype. I do regret that. There, I got that off to my astronomical chest.
A crescent Venus
Lately, I've been getting phone calls and e-mails about the super bright star in the low southwestern sky in the evening twilight. That's no star, but our solar system neighbor, Venus. The planet named after the Roman goddess of love is just about as bright as it ever gets in our sky.
That bright beacon of a planet that set at the end of evening twilight is only about 32 million miles from Earth right now. Actually to be more accurate, I should say that Venus and Earth are about as close as they can be in their respective orbits. Venus is very close to the sun now and will cross almost directly in front of the sun next month, something astronomers call inferior conjunction.
Despite how bright Venus is in the sky, it's normally not much of a telescope target because it has a very opaque cloud cover. If you check it out in a small telescope or even an average pair of binoculars, Venus will look like a tiny thin crescent moon. You'll love it. Since Venus orbits the sun inside the Earth's orbit, it goes through phases shape changes just like our moon. Like our moon, the only light we see from Venus is reflected sunlight.
A brilliant Jupiter
At the other end of early evening sky another bright beacon is beckoning us. Jupiter, the largest planet in our solar system,, is rising in the northeast sky, easily seen at 8 p.m., if not sooner. As December continues, Jupiter starts out the evening higher and higher in the sky. You can't miss it because it shines a little to the left of the majestic constellation Orion the Hunter. Right now, it's just under 400 million miles from Earth, a lot farther away than Venus, but since it has more than ten times the diameter of Venus, Jupiter's darn near as bright as our Venusian neighbor.
Jupiter is a great target for even small telescopes. Maybe there's telescope on your Christmas list? You can see up to four of its brighter moons - they resemble tiny little stars on either side of Jupiter - depending on where they are in their 2 to 17 day orbits. You can also see some of Jupiter's brighter cloud bands made of ammonia, methane and other gases. I'll have more on Jupiter next month.
Highest full moon of the year
Officially, the full moon this month is Tuesday, but for all practical purposes, it's nearly full tonight. You can't help but notice the moon this coming week takes a very high arc across the sky. In fact, around midnight Tuesday and Wednesday, the full moon will be about as high as it gets in our sky. When you have a full moon in mid- to late-December like we have this month, the moon takes the same high arc across the sky as the sun does on first day of summer. Enjoy your moon bath this week.
(Lynch is an amateur astronomer and author of the book, "Stars, a Month by Month Tour of the Constellations." Contact him at mikewlynch@comcast.net.)
