Posts Tagged ‘South Pole’

04/15/2019 – Ephemeris – Why land at the Moon’s south pole?

April 15, 2019 Comments off

Ephemeris for Tax Deadline Day Monday, April 15th. Today the Sun will be up for 13 hours and 28 minutes, setting at 8:27, and it will rise tomorrow at 6:57. The Moon, 3 days past first quarter, will set at 5:53 tomorrow morning.

The hottest piece of real estate on the Moon is the south pole. Unlike the Earth’s south pole and the rest of the Moon, except the north pole, there are mountain tops that are always in sunlight. The Moon has a very small axial tilt, only a degree an a half, compared to the Earth’s 23 and a half degrees which plunges the earth’s poles into a 6 month’s night. Another benefit of the small tilt is that the floors of craters at of near the poles never see sunlight, so are hundreds of degrees below zero and can be cold traps for water vapor from passing or colliding comets. Yes, thar’s water in them thar craters. It’s more valuable than gold, providing oxygen to breathe and hydrogen and oxygen for rocket fuel.

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


South pole ice

The south pole of the Moon where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos.

01/12/2015 – Ephemeris – The world’s faorite constellation: Orion

January 12, 2015 Comments off

Ephemeris for Monday, January 12th.  The sun will rise at 8:18.  It’ll be up for 9 hours and 6 minutes, setting at 5:24.   The moon, 1 day before last quarter, will rise at 1:02 tomorrow morning.

For people the world over who look up and recognize the brighter constellations Orion is perhaps the odd on favorite.  The Big Dipper, a favorite in the northern hemisphere, cannot be easily seen south of the equator.  The Southern Cross cannot be easily be seen north of the equator.  Orion, or parts of him can be seen from pole to pole because he straddles the equator of the sky.  It has 7 bright stars like the Big Dipper, but those seven are brighter than those in the big Dipper.  In the early evening Orion is seen is the southeast.  The three stars of his belt now tipped diagonally from upper right to lower left.  They are in the center of a left leaning rectangle of stars with bright red Betelgeuse to the upper left and bright blue-white Rigel to the lower right.

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


Otion as seem from most of the Earth

Orion from mid latitudes north of the equator. Orion would be upside down if viewed south of the equator. Created using Stellarium.

Orion from near the north pole.

Orion from near the north pole. Created using Stellarium.

Orion from near the south pole

Orion from near the south pole. Created using Stellarium.