Archive for December 14, 2017

12/14/2017 – Ephemeris – The Moon wanders over to Jupiter this morning

December 14, 2017 1 comment

Dec 14. This is Bob Moler with Ephemeris for Thursday, December 14th. The Sun will rise at 8:11. It’ll be up for 8 hours and 50 minutes, setting at 5:02. The Moon, half way from last quarter to new, will rise at 5:26 tomorrow morning.

This morning the planet Jupiter will appear right below the crescent Moon. Jupiter is hard to miss, even without the Moon to point it out. It is with the rare exception of Mars when being its closest to the Earth the second brightest of the planets, after Venus. Speaking of Mars, which is to the upper right of Jupiter and has a reddish hue, if you’re going to send anything to Mars, next spring is the time to do it. Flight times to Mars are 6 to 7 months. The midpoint of the flight is when Mars is closest to the Earth, which next year is July 31st. NASA’s Insight Lander, grounded in 2016 due to an instrument failure has to wait 26 months for the next launch opportunity in May of next year.

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


The Moon, Jupiter, Mars

The Moon, Jupiter and Mars this morning, December 14, 2017. Earth shine should be visible as shown, though not as prominent. Created using Stellarium.

Hohmann orbit to Mars

A Hohmann lowest energy transfer orbit to Mars. This diagram is for the Mars Exploration Rovers Spirit and Opportunity launched in 2003, arrived in 2004. Solid planets, Spirit launch and arrival. Ghost planets, Opportunity launch and arrival. Credit NASA/JPL.

What’s a Hohmann transfer orbit?  NASA explains.