Archive for May 23, 2016

05/23/2016 – Ephemeris – Mars was at opposition yesterday and will be closest next Monday

May 23, 2016 Comments off

Ephemeris for Monday, May 23rd.  Today the Sun will be up for 15 hours and 7 minutes, setting at 9:13.  The Moon, 2 days past full, will rise at 10:45 this evening.  Tomorrow the Sun will rise at 6:05.

Yesterday the planet Mars passed a point where it was opposite in the sky from the Sun.  Astronomers call it opposition.  This is a time when a planet is normally its closest to the Earth, since the Earth is more of less directly between the planet and the Sun.  But due to Mars’ quite elliptical orbit, it is still approaching the Sun, and though the Earth is nudging ahead of it a bit, Mars won’t be closest to the Earth until next Monday, the 30th, 8 days after opposition.  On that day it will be about 650 thousand miles (1 million, 46 thousand km) closer to the Earth than it was yesterday.  On the 30th that will be 46.7 million miles (76.2 million km) away.  The next closest approach in 26 months will be a bit closer yet.

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


Mars Closest Approaches

Mars closest approaches from 2003 to 2018. Created by my LookingUp program.

Apparent sizes

Selected Martian Closest Approaches Apparent Sizes from 2003 to 2018. Created using Cartes du Ciel (Sky Charts).  Note that ” is seconds of arc.  1″ = 1/3600 of a degree.  The Moon and Sun are about 1,800 seconds of arc in diameter.

Also note that at the star party last Saturday night Mars looked great, even though it was low in the sky.