Comet ISON is now next to impossible for many of us to see as it competes with morning twilight and horizon haze. Some of you tried for the comet Saturday morning without success, but those in more tropical latitudes had the edge. Two contributors combined the best of two worlds: low latitude and a view from a mountaintop! The pictures they took show ISON with a pinpoint head and thin tail glowing at about magnitude 3.
NASA’s STEREO Ahead spacecraft has also been shooting high resolution images of the comet as it tracks across the same field of view as Earth and Mercury. We should be able to follow ISON in good resolution via space telescopes and coronagraphs (instruments designed to block the glaring solar disk) all the way through the end of the month, when it finally return to view at dawn.
As we await ISON’s next move, five bright planets await your eyes the next clear night. We’ll begin with Venus. Yesterday it took little effort to spot this sapphire just five minutes after sunset a fist and a half high in the southwestern sky. A half hour later even those who pay little attention to the sky couldn’t have missed it. On Dec. 10 Venus reaches its greatest brilliancy for the year.
Jupiter comes up around 9 p.m. local time in Gemini the Twins. Because we see it against a dark sky, the planet appears almost as bright as Venus but it’s really about 6 times fainter.
You can use Jupiter to help you connect the “dots” to Gemini the Twins, a constellation with two bright stars representing the brothers Castor and Pollux. The pair lies just to the upper left of Jupiter. Once you’ve spotted them, follow the trickles of fainter stars to the right of each star fill in the rest of the constellation.
Next up is Mars which rises in the constellation Virgo around 1 a.m. My recommendation? Don’t bother with it until an hour before sunrise when the planet’s high in the southeastern sky above Mercury and Saturn. That way you get to see all three morning planets at the somewhat reasonable hour of 6 a.m.
Find a place with a wide view to the southeast. Mars is easy to see by color and brightness, but Mercury may require binoculars at first until you know just where to look. Saturn will appear dimmest in part because it’s so low in twilight.
Tomorrow morning the two will be very close together and nearly in conjunction. The time of closest separation is 7 p.m. CST Monday when neither is visible from the western hemisphere. Skywatchers in the eastern hemisphere will see them at dawn on the 26th separated by only 1/3 of one degree.