With fairly clear skies expected Saturday night into Sunday morning around Wisconsin, be sure to take advantage and try to see some of the Orionid meteor shower. The best viewing window is between midnight and 7 a.m., with 2 or 3 hours before dawn normally the optimal. The moon is in the crescent phase and will be setting Saturday evening before 11 p.m. This is good news as the overnight sky should be good and dark to best see the meteors. You want to get out of the city to get away from as many lights as possible. It is estimated that potentially as many as 15 meteors per hour may be seen.
The Orionid meteors are debris left behind in the orbit of Halley’s Comet. The debris streak from the comet is about 90,000 miles long. It strikes atmosphere and it reaches its peak magnitude every year around October 20-22. This is when the Earth intersects the comet’s orbit. The meteors in the Orionid shower appear to come from just north of the constellation Orion’s brightest start, Betelgeuse. They often radiate outward from that point in all directions. So it is possible to see them in several quadrants of the sky.
Meteors are often called shooting stars, but they are really not stars in any way. Rather they are space rocks and debris burning up as they enter the Earth’s atmosphere some 60 miles above Earth’s surface. It is this “burning up” of the debris that gives us the streaking glow that we can see. The Orionids are very fast meteors, zipping into the Earth’s atmosphere at about 41 miles per second. About half of the Orionid meteors leave persistent trains – ionized gas trails that last for a few seconds after the meteor itself has gone.
Of course you will have to have a good warm coat, gloves, and hat handy to go out and watch in the wee hours of Sunday morning as temperatures will be in the mid or upper 30s. Well, good luck! I hope you see a bunch of shooting stars this weekend.