October 2008 astronomy events

October starts with Mars and Venus very low in the west at sunset. Jupiter remains in Sagittarius in the south. Saturn is a morning object, shining in the twilight at the belly of Leo. Mercury is about to be in conjunction with the sun on the 6th, so don't even bother to look for it yet.

Mars, so low after sunet, will be a tough find all month. Venus is as easy to spot as ever, even so low, because it's so bright. Jupiter continues a westward motion, setting a little earlier each night. And Saturn remains beneath Leo, also continuing a westward motion and rising earlier each morning. Mercury emerges from conjunction so quickly it seems to want to catch up to Saturn. But experienced planet watchers know it won't.

Mercury The messenger comes to a halt against the morning sky background on the 15th, then begins retrograde motion. Retrograde means when you compare its position only to the stars behind it, the planet is moving eastward. You would expect it to start rising a little closer to sunrise then. However, the motion of the earth and other planets makes things a little more complicated than that. Mercury actually reaches greatest elongation on the 22nd when it's 18 degrees west of the sun. This isn't one of the better greatest elongations at which to see Mercury. It's at perihelion (the orbital point closest to the sun) just days before on the 17th. The moon is south of Mercury on the 27th.

Venus This month's Venus-Moon conjunction is on the 2nd. Depending on the time zone you're in, there may be a second Venus-Moon conjunction this month. The next one is on November 1 at 8h UTC. If you're far west enough, it will still be on October 31st. Venus is north of Antares on the 27th.

Mars The moon passes Mars on the 1st and the 30th.

Jupiter Jupiter is at eastern quadrature on the 6th. That means just when the sun sets, the big planet will be right on the meridian. The moon passes south of Jupiter on the 7th.

Saturn The moon passes north of the ringed planet on the 25th. If you have a telescope and can observe Saturn's rings, do it. Now through next September, they'll get harder and harder to see because Saturn's apparent tilt with respect to Earth's is lessening. Next September 4th, we will have an edge-on view of Saturn's rings. These ring-plane crossings happen every 14 years.

Other events The moon occults Antares on the 4th. Much of Australia and some of Indonesia will be able to see it. The moon occults Antares again on the 31st. Only a few island dwellers or shipboard watchers in the South Atlantic will see it. This month's full moon is on the 14th, just two days after it reaches ascending node. In other words, the moon has just crossed the equator northward and the full moon is showing at mid-height from the higher latitudes. The Orionid meteor shower is expected to peak around the 22nd. The Taurid meteor shower could put on a good show around its peak time of the 31st, according to one researcher. Other sources say the peak will be on November 5th for the southern Taurids, and November 12th for the northern Taurids.