Archive

Archive for September 10, 2024

Ephemeris: 09/10/2024 – What last Saturday’s opposition from the Sun means

September 10, 2024 Comments off

This is Ephemeris for Tuesday, September 10th. Today the Sun will be up for 12 hours and 45 minutes, setting at 8:01, and it will rise tomorrow at 7:17. The Moon, 1 day before first quarter, will set at 11:17 this evening.

Last Saturday the planet Saturn moved in opposition to the Sun. It’s not an insurrection or anything, but Saturn was opposite the Sun in the sky. At that time Saturn would be closest to the Earth of some 806 million miles (900 km). Saturn is 9 1/2 times the distance of the Earth to the Sun so over the year as Saturn moves from opposition through conjunction with the Sun to opposition again it does not vary in size very much, unlike Venus and Mars which are closer to us and vary a lot in size over their period around our sky. Saturn is now an evening planet and so will become a fixture in our evening skies for the next 4 or so months. It lies in a star poor part of the sky so it’s easy to find. Saturn’s rings are now nearly edge on to us so in a small telescope Saturn looks like a tiny disk stapled onto the sky with the staple being a bright line through the planet.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.

Addendum

Comparing Saturn’s and Mars’ images at their nearest and farthest distances from the Earth as seen through a telescope. Saturn is 9 1/2 times Earth’s distance from the Sun (solar distance) while Mars is 1 1/2* times Earth’s solar distance. At opposition the planet’s distance from the Earth is the planet’s solar distance minus the Earth’s solar distance. At solar conjunction the planet’s distance from the Earth is the planet’s solar distance plus the Earth’s solar distance. Created using Cartes du Ciel (Sky Charts), Libreoffice Draw and GIMP.

* Mars has a fairly elliptical orbit and next January’s opposition is almost at its farthest. In 2003 Mars was as close as that it has gotten in 50,000 years, or so they tell me. At that time Mars’ apparent size was 72% larger than it will be next January. Mars has its closest oppositions to the Earth every 15 or 17 years. The last time it occurred was in 2018, and the next time will be in 2035.

Categories: Concepts, Ephemeris Program, Planets Tags: ,