Archive for May 4, 2021

05/04/2021 – Ephemeris – We cross Halley’s Comet debris this week

May 4, 2021 Comments off

This is Bob Moler with Ephemeris for Tuesday, May 4th. Today the Sun will be up for 14 hours and 23 minutes, setting at 8:51, and it will rise tomorrow at 6:26. The Moon, 1 day past last quarter, will rise at 4:20 tomorrow morning.

The Eta Aquariid meteor shower will reach their peak for us Thursday morning the 6th. The Eta Aquariids are caused by bits of Halley’s Comet, passing the Earth’s orbit heading out from the Sun. The Orionids of late October are debris of Halley’s comet passing the Earth’s orbit heading in toward the Sun. The Eta Aquariids are named for the star nearest the radiant of the meteor shower. The constellation of Aquarius has many shower radiants, which is why the shower is named for a star in Aquarius. The radiant rises shortly before 3:30am and astronomical twilight begins an hour later. There’s perhaps another half hour of visibility after that. The peak will occur Thursday morning where 20 meteors per hour or more might be seen.

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


The sky dome for 4:30 am May 6, 2021. The Eta Aquariid radiant is near Jupiter. It looks like
two other minor meteor showers are active then with only a handful of meteors an hour
compared to the Eta Aquariids’ somewhat higher rates. The funny looking “n” character
next to Aquariid is the Greek letter Eta. Chart created using Stellarium.
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.