Archive
10/15/2013 – Ephemeris – Correction to last Thursday’s Comet ISON program
Ephemeris for Tuesday, October 15th. The sun will rise at 7:58. It’ll be up for 10 hours and 59 minutes, setting at 6:57. The moon, 3 days before full, will set at 5:21 tomorrow morning.
Last week I went out to verify the statement that Comet ISON was visible in binoculars that I talked about last Thursday. That turned out to be incorrect. After two failed attempts last Tuesday and Wednesday mornings from my back yard. I had to find a darker location to out flank Traverse City and try to spot the comet with my 11 inch telescope. The comet turned out to be a faint smudge in the indicated spot. The sky wasn’t even dark in that direction, almost due east due to zodiacal light, visible on autumn mornings due to dust in the inner solar system. Zodiacal light is usually hard to spot until it becomes a nuisance. Advanced amateurs have indeed photographed it, tail and all, but visually the comet isn’t much at this stage.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Comet ISON and Mars at 6 a.m. for 7 days starting October 10, 2013. Created using SkyCharts (Cartes du Ciel).
I’ll have a new weekly chart tomorrow. Mars and Comet ISON are sliding past Regulus now. See spaceweather.com for images of Comet ISON. By the end of this week the Moon’s light will interfere.
10/14/2013 – Ephemeris – Columbus greatest and luckiest mistake
Ephemeris for Columbus Day, Monday, October 14th. The sun will rise at 7:56. It’ll be up for 11 hours and 2 minutes, setting at 6:59. The moon, 3 days past first quarter, will set at 4:12 tomorrow morning.
Today we celebrate Christopher Columbus’ big mistake. Mistake? Yes, mistake. Back in 1492 anyone with any education at all knew the earth was round. It was known since the Greek mathematician and geographer Eratosthenes calculated the circumference in the 3rd century BC. Columbus error was in misjudging its size. Columbus though the earth was only 18 thousand miles in circumference, which would put the east coast of Asia 3,000 miles west of the Spanish coast. Most academics held the circumference was nearer 25,000 miles, the correct value, putting Asia some 10,000 miles out. Columbus was very lucky that there was a continent in between. The native peoples, however, were not so lucky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 