10/20/2022 – Ephemeris – Halley’s Comet returns… in little bitty pieces

This is Bob Moler with Ephemeris for Thursday, October 20th. Today the Sun will be up for 10 hours and 44 minutes, setting at 6:49, and it will rise tomorrow at 8:06. The Moon, 3 days past last quarter, will rise at 3:36 tomorrow morning.

Halley’s Comet is back! (Pronounced Hawley’s) Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice-yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the Earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust and ionized gas get blown back into the tail of the comet. Heavier particles will roughly follow in the comet’s orbit. The radiant, a spot above the constellation Orion and below Gemini from which they will seem to come, will rise around 11 pm. So view them any time after that as their numbers will increase until the Moon rises both tonight and tomorrow nights.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The Orionid Radiant is high in the south at 5 a.m. this weekend. Created using Stellarium.

Halley’s Comet orbit with the orbits of the inner planets showing the points at which the debris from the comet intersect with the Earth’s orbit, causing meteor showers. Click on the image to enlarge it. Diagram credit JPL Small-Body Database Browser with my annotations.