Archive for October 18, 2018

10/18/2018 – Ephemeris – Halley’s Comet returns as the Orionids

October 18, 2018 Comments off

Ephemeris for Thursday, October 18th. The Sun will rise at 8:02. It’ll be up for 10 hours and 50 minutes, setting at 6:53. The Moon, 2 days past first quarter, will set at 2:32 tomorrow morning.

Halley’s Comet is back! (Pronounced Hall-ee’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, still affected by the pressure of sunlight and the gravitational pull of the Sun and planets end up roughly following the comet’s orbit. In the morning after the Moon sets should be the best time to see them. They will seem to come from a spot above Orion and below Gemini.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Halley's meteor shower
We get two meteor showers from Halley’s Comet. The Orionids, when Halley is approaching the inner solar system, and the Eta Aquariids when it’s leaving. Credit my LookingUp program.

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