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09/17/2021 – Ephemeris – The Moon has an atmosphere of sorts; Plus, I capture Inspiration 4 passing overhead
This is Ephemeris for Friday, September 17th. Today the Sun will be up for 12 hours and 24 minutes, setting at 7:49, and it will rise tomorrow at 7:25. The Moon, 3 days before full, will set at 4:24 tomorrow morning.
Jupiter, tonight, will be above the Moon. Everyone knows that the Moon is airless, that is has no atmosphere. That is not strictly true. Apollo astronauts saw glows and crepuscular rays in the direction of the Sun before its rising an after it set as they orbited the Moon. In 2013 NASA sent an orbiter spacecraft named LADEE to the Moon to investigate. LADEE stands for Lunar Atmosphere and Dust Environment Explorer. It orbited low over the Moon’s equator. The atmosphere of the Moon consists of some gasses like sodium, neon, argon and helium plus dust electrostatically charged by the Sun’s x-ray and ultraviolet emissions and sent aloft, up to many kilometers. The dust will fall back down, but the gasses will be dissipated by the solar wind. It’s very tenuous.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.
Addenda
Jupiter, Saturn and the Moon tonight at 9 pm tonight, September 17, 2021. Jupiter will be moving to be directly below Jupiter by one in the morning. Created using Stellarium.
Apollo 17 twilight ray sketches. Credit: NASA/Apollo 17 Astronauts.
Artist’s depiction of LADEE in orbit of the Moon. Courtesy NASA.
Inspiration 4 spacecraft caught flying over Northern Michigan
The thin vertical streak on the left side of the image is the Inspiration 4 spacecraft against the stars of Hercules in a 15 second exposure with a Canon Rebel T5 camera, f/3.5, ISO 6400, 18 mm fl. The famous Keystone of Hercules asterism is to the upper right of center. It’s a bit out of focus due to my problem seeing the screen at a high angle. (Getting old). It was quite dim, so I actually couldn’t see it in the moonlight. Credit: mine.
I was guided to the time and place in the sky by heavens-above.com.
05/05/2014 – Ephemeris – LADEE is no more but its mission goes on
Ephemeris for Monday, May 5th. The sun rises at 6:27. It’ll be up for 14 hours and 24 minutes, setting at 8:52. The moon, 1 day before first quarter, will set at 2:09 tomorrow morning.
The Lunar Atmosphere and Dust Environment Explorer or LADEE spacecraft that was in a close orbit of the moon to sniff out the Moon’s tenuous exosphere of gases and dust, augured into the moon’s far side April 17th as planned. This was just the end of the data acquisition phase of the mission. The data will be pored over for years to develop a picture of the lunar environment. This will aid lunar explorers to come both robotic and human. Something similar is happening to the Kepler mission to find transiting planets of other stars. The data gathering phase is over but there was an announcement a week or such ago of an earth sized planet in a stars habitable zone. Discoveries will go on for years.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Artist’s depiction of LADEE in orbit of the Moon. Courtesy NASA.
More about the LADEE Mission is here.
08/22/2013 – Ephemeris – A new mission to the moon starts next month
Thursday, August 22nd. The sun rises at 6:53. It’ll be up for 13 hours and 42 minutes, setting at 8:36. The moon, 2 days past full, will rise at 9:11 this evening.
Though we all know that the moon is airless, surrounded by a better vacuum that we can pump down on the earth. Nonetheless the moon has a tenuous atmosphere of gas and dust. Next month NASA has scheduled the launch of another unmanned spacecraft to the moon. This one is LADEE, an acronym for Lunar Atmosphere and Dust Environment Explorer. It will take 30 days to reach the moon and will measure the dust and tenuous atmosphere of the moon. It will looking for the high altitude glows seen by the Apollo astronauts above the moon. There is also a demonstration laser communication system, at least six times faster than current radio technology.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Artist’s depiction of LADEE in orbit of the Moon. Credit: NASA Ames / Dana Berry.
Bob Moler's Ephemeris Blog 