This week, there will be two close meetings of bright planet and bright star, a very slight eclipse of the moon; and just possibly some northern lights — check www.spaceweather.com each day for “aurora” updates.
But the biggest question for skywatchers this week is whether incoming Comet ISON will start brightening as it goes very close past the close pairing of Mars and the bright star Regulus.
Venus and the heart of the scorpion. Go out a little after 7 p.m. this week and look quite low in the southwest. You should easily see the brilliant Venus.
But do you see a much dimmer point of light about the width of your thumb at arm’s length to the lower left of Venus tonight and tomorrow night? The naked eye may, and binoculars will, reveal this object: the orange-yellow star Antares, which marks the heart of Scorpius the Scorpion.
Weather permitting, Wednesday night is the best night to see Venus and Antares. That is when Antares is just 1 1/2 degrees below Venus — about the width of your little finger at arm’s length. Thursday and Friday, Antares will appear just to the lower right of Venus.
Mars and the heart of the lion. Between 2:30 and 3 a.m. tomorrow, a remarkably close pair of similarly bright lights will rise. The slightly brighter object is blue-white star that marks the heart of Leo the Lion — Regulus.
The slightly dimmer object is the pumpkin-colored planet Mars. Observe them with the unaided eye between 4 and 5:30 a.m., especially in the country, and the contrast of their colors should be enhanced by their proximity to each other.
They have their minimum separation — less than a degree (about the width of a pen at arm’s length?) — tomorrow morning but are only a little farther apart for several days. If you can’t get up so early, you can glimpse the pair well up in the east in the brightening dawn around 6:30 a.m.
Comet ISON glides past Mars and Regulus. The incoming, potentially spectacular Comet ISON — named after the International Scientific Optical Network — is still not brightening as much as we had hoped. You’ll need a fair-sized telescope to glimpse its little “9th or 10th magnitude” hazy patch of head and perhaps a bit of its still-short tail.
But at least we all know where to look for it this week: only about a degree north of Mars. In fact, before dawn on Wednesday, there will be an amazing compact line of Regulus, Mars and Comet ISON, only about 2 degrees long.
Will Comet ISON flame spectacularly in our sky after it grazes near the sun’s surface on Thanksgiving? We still don’t know for sure.
A slightest eclipse of the hunter’s moon. The full moon of October is usually the hunter’s moon, and in 2013 it occurs at 7:38 p.m. Friday. A bit later — actually for quite a while centered around 7:51 p.m. — we ought to be able to notice an extremely subtle eclipse shading on the lower right edge of the moon.
Fortunately, the lower right edge will be bright lunar highlands, so I think we have a real chance to notice even the subtle outer “penumbra” of the Earth’s shadow cast there.
If this slightest shading doesn’t impress you, just wait until April. The total eclipse of the moon will be so amazing I’ve been waiting for it since 1968. In that eclipse the ruddy, deeply dimmed moon will stand very close to the bright star Spica with Mars at its brightest (about 15 times brighter than it is now) not far away.
Prepare for Nov. 3’s sunrise solar eclipse. A few dollars will buy a small piece of shade 14 welder’s glass from local stores or aluminized Mylar “eclipse glasses” from the Internet. Two Mondays from now, I’ll tell how to use them and how to otherwise see Nov. 3’s amazing large partial eclipse of the sun.
Fred Schaaf is a local author and astronomer. He can be reached at: firstname.lastname@example.org.