02/07/2023 – Ephemeris – A new view on the creation of our Moon

Feb 7. This is Bob Moler with Ephemeris for Tuesday, February 7th. Today the Sun will be up for 10 hours and 5 minutes, setting at 5:59, and it will rise tomorrow at 7:53. The Moon, 2 days past full, will rise at 7:58 this evening.

Is this how the Moon came to be? After the Apollo missions, NASA decided to look at the crust of the Moon which apparently is much like the Earth’s and came up to the conclusion that the Moon was formed by a collision with the Earth by a Mars sized body that they’ve called Thea, named after the mother of the twins Apollo and Artemis. It crashed into the Earth at about a 45-degree angle, and caused a ring of debris around the Earth that would be maintained for a long time. In a newer simulation, the collision could actually create two blobs of material, a large one that became our Moon, in orbit, with about one percent of the Earth’s mass, and a smaller mass that fell back onto the Earth.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

A new simulation on how the Moon formed. Credit: PBS.

1/15/2021 – Ephemeris – What the Chinese Chang’e 5 lunar mission found

This is Bob Moler with Ephemeris for Monday, November 15th. Today the Sun will be up for 9 hours and 34 minutes, setting at 5:14, and it will rise tomorrow at 7:41. The Moon, halfway from first quarter to full, will set at 4:45 tomorrow morning. | Late last year, the Chinese sent an uncrewed spacecraft to the Moon to collect samples of the surface material. That material is called regolith, and they drilled down at least a meter, which they returned to the Earth. An international team of geologists has been studying the material, and we have the first reports. Apparently the material they picked up was dated at 2 billion years, which is an intermediate age to the material picked up by the Apollo missions that dates either 3 billion years or older or 1 billion years. That helps fill gaps in the Moon’s history. Of course, all the material in the solar system is 4.5 billion years old. But the radioactive dating clock is reset when a rock is melted and solidifies.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

Chang’e 5 Landing-Site on full moon map. Created using Virtual Mon Atlas.

12/17/2013 – Ephemeris – The Chinese have landed a rover on the Moon

Ephemeris for Tuesday, December 17th.  The sun will rise at 8:14.  It’ll be up for 8 hours and 49 minutes, setting at 5:03.   The moon, at full today, will rise at 5:45 this evening.

Over the weekend the Chinese landed a spacecraft on the moon with a rover.  The spacecraft was Chang’E 3 and the third of their successful lunar spacecraft.  Name after an ancient moon goddess it deposited a rover named Yutu, or Jade Rabbit named for the goddess’ pet rabbit.  The aim point was to be the beautiful Bay of Rainbows or Sinus Iridium, but it landed just outside it in Mare Imbrium, the Sea of Showers.  Some astronomers think that the actual landing spot is more interesting mineralogically speaking than the original aim point.  Both Chang’E and Yutu are solar powered  and it’s difficult to see them surviving the two-week lunar night,  Night will fall on the site on December 25th or 26th.  Give the Chinese credit though for a flawless landing.

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

Addendum

Chang’E 3 as seen from the Yutu rover.  There’s a lot more pictures and information from Emily Lakdawalla’s Planetary Society Blog, where I got this picture link from.