Archive for August 5, 2019

08/05/2019 – Ephemeris – Previewing the Perseid meteor shower

August 5, 2019 Comments off

Ephemeris for Monday, August 5th. Today the Sun will be up for 14 hours and 30 minutes, setting at 9:03, and it will rise tomorrow at 6:34. The Moon, 2 days before first quarter, will set at 12:01 tomorrow morning.

After the Moon sets in the morning hours for the next week and a half the numbers of meteors visible will increase each night. These are members of the Perseid meteor shower of August. The peak this year is expected to be during the morning of the 13th. However by then the Moon will be nearly full. These meteors are the result of debris left along the orbit of Comet 109P/Swift-Tuttle shed by innumerable visits to the inner solar system. Every year at this time the Earth passes through this trail of debris which intersects its orbit giving rise to the meteor shower. We call them the Perseids, because they appear to come from the direction of the constellation Perseus the hero, which is first seen in the early evening low in the northeast.

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


Perseid Radiant

The Perseid radiant is located off the highest star in Perseus as it ascends the sky at about 10:30 p.m. The Perseid radiant is circumpolar for observers in northern Michigan. Click on the image to enlarge. Created using Stellarium.

Swift-Tuttle 1992 plot

The passage of Comet 109P/Swift-Tuttle through the inner solar system November 1, 1992 to January 30, 1993. The meteoroids shed by the comet on its numerous trips close to the Sun lie close to that orbit. Note that its orbit intersects with the Earth’s orbit. That’s where the Earth will be around August 12-13 every year. Created using my LookingUp program.