Archive
Ephemeris: 07/09/2024 – The Moon Tonight – Mare Crisium
This is Ephemeris for Tuesday, July 9th. Today the Sun will be up for 15 hours and 22 minutes, setting at 9:29, and it will rise tomorrow at 6:07. The Moon, halfway from new to first quarter, will set at 11:53 this evening.
Tonight’s four-day old crescent Moon will be seen in the west at about 10:30 PM, though it’s visible much earlier than that. Binoculars will show a small gray round area near the right edge of the Moon which is seen in the full moon as the eye of the Man in the Moon. The feature is called Mare Crisium or the Sea of Crises. And is an Oval 385 by 354 miles in extent. However, it is elongated east to west rather than what it appears to be, north to south. That is due to foreshortening because it is near the limb of the Moon and thus curved away from us. So we are looking at it at an oblique angle. Mare Crisium is thought to be the result of an impact of an asteroid that occurred nearly 4 billion years ago during the Late Heavy Bombardment.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.
Addendum
Ephemeris: 06/13/2024 – The Apollo 11 flag
This is Ephemeris for Thursday, June 13th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:29, and it will rise tomorrow at 5:56. The Moon, 1 day before first quarter, will set at 2:06 tomorrow morning.
Tomorrow is Flag Day. That got me to thinking about the flags that the Apollo astronauts planted on the Moon and what state they are in. We know the Apollo 11 flag was blown down by the blast of the ascent stage engine when they left the Moon because it was planted too close to the lunar module. The other five flags are still standing. However, there’s some speculation as to what color they are. Are the colors bleached out by the ultraviolet of the sun’s light, which is unimpeded on the Moon? The flags may be bleached completely white. There was nothing really special about the flags that NASA used for the Apollo mission so they weren’t especially prepared to withstand the rigors of being out and undiluted sunlight.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.
Addendum
09/27/2019 – Ephemeris – Apollo 50th anniversary talk tonight in Thompsonville
Ephemeris for Friday, September 27th. Today the Sun will be up for 11 hours and 55 minutes, setting at 7:31, and it will rise tomorrow at 7:36. The Moon, 1 day before new, will rise at 7:09 tomorrow morning.
Tonight to commemorate the 50th anniversary the Apollo 11 landing on the Moon, I will present the illustrated talk Apollo and the Race to the Moon at 7 p.m. at the Betsie Valley District Library in Thompsonville. Afterwards, if it’s clear, members of the Grand Traverse Astronomical Society will host a star party featuring Saturn and Jupiter and some of the brighter deep sky objects. In the talk I’ll explore the Apollo 11 mission, the engineers, astronauts and all the crewed and robotic missions that paved the way for the successful lunar landings. I’ll also look at the Soviet space program their triumphs, plans, and ultimate failure to beat the Americans to the Moon.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Apollo and the Race to the Moon Title slide
07/22/2019 – Ephemeris – Apollo 11 heads home
Ephemeris for Monday, July 22nd. Today the Sun will be up for 15 hours and 1 minute, setting at 9:19, and it will rise tomorrow at 6:19. The Moon, 2 days before last quarter, will rise at 12:27 tomorrow morning.
50 years ago after a bit more than 2 hours working on the surface of the Moon, Neil Armstrong and Buzz Aldrin climbed back into the Lunar Module to stow the 48 pounds of samples they had taken and to rest up for the return trip to the Command Module and Mike Collins circling above them. After docking, they transferred the samples to the command module and jettisoned the LM. Then they fired the Service Module engine for 2 and a half minutes to send them back to Earth, and landing them in the Pacific Ocean on July 24th. Not knowing if they were contaminated by lunar pathogens, the crew was quarantined for 21 days. The crew was released from Quarantine on August 10th.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Lunar lander’s ascent module approaching the command module with Earth in the distance. Credit NASA.
The crew in a like raft in bio contamination suits after splashdown.. Credit NASA.
Left to right Neil Armstrong, Michael Collins, Buzz Aldrin accept greeting form President Nixon on the USS Hornet. Credit NASA.
07/19/2019 – Ephemeris – 50 years ago tomorrow humankind set foot on the Moon
Ephemeris for Friday, July 19th. Today the Sun will be up for 15 hours and 7 minutes, setting at 9:22, and it will rise tomorrow at 6:16. The Moon, 3 days past full, will rise at 11:14 this evening.
On this day, 50 years ago the combined Apollo 11 spacecraft Command and Service module with attached Lunar Module dropped into orbit of the Moon. The crew spotted a glow coming from the Aristarchus region, still on the night side of the Moon. Armstrong and Aldrin entered the LM to power it up and to get it ready for landing. The next day they undocked from the Command Module and began their 2 hour 33 minute descent to the Moon’s surface. As they neared the surface The astronauts found out they were going to miss the planned landing area and would land in a more boulder strewn area. Armstrong took control and guided the LM to a safe landing with less than 30 seconds of fuel remaining. The Eagle had landed.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Left to right Neil Armstrong, Mission Commander; Michael Collins, Command Module Pilot; and Buzz Aldrin, Lunar Module Pilot. Credit: NASA.
The Saturn V for the Apollo 11 mission lifts of from Pad 39A. Credit: NASA.
Aldrin with the PSEP instrument looking back at the LM. Credit NASA/Neil Armstrong.
Lunar Reconnaissance Orbiter image of the Apollo 11 landing area. Compare the location od the objects in the picture above with this image. The flag was blown down by the lift off of the Ascent module when the Astronauts left the Moon. Credit NASA/LRO.
07/16/2019 – Ephemeris – 50 years ago today the Apollo mission left for the Moon
Ephemeris for Tuesday, July 16th. Today the Sun will be up for 15 hours and 12 minutes, setting at 9:25, and it will rise tomorrow at 6:13. The Moon, at full today, will rise at 9:30 this evening.
50 years ago today at 11:32 a.m. Eastern Daylight Time the most powerful rocket ever built roared into life. The Saturn V, a three stage rocket, 363 feet tall, which in turn launched two spacecraft, the Command and Service modules, and the Lunar Module, and three astronauts on their journey to destiny, Neil Armstrong, Edwin (Buzz) Aldrin, and Michael Collins. It was the start of the Apollo 11 mission. It happens that tonight the namesake of the rocket, the planet Saturn is to the right of the Moon. At launch the Moon was two days old, a thin crescent in the west that evening. Four days later they would be orbiting the Moon, and Armstrong and Aldrin would be descending to the Moon’s surface.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
Apollo 11
Left to right Neil Armstrong, Mission Commander; Michael Collins, Command Module Pilot; and Buzz Aldrin, Lunar Module Pilot. Credit: NASA.
The Saturn V for the Apollo 11 mission lifts of from Pad 39A. Credit: NASA.
The Moon and Saturn tonight, 11 p.m. July 16, 2019. In reality the Moon will be so bright that Saturn will be almost overwhelmed. Created using Stellarium.
Here’s an excellent podcast series from the BBC: 13 Minutes to the Moon.
Partial Lunar Eclipse
The partial lunar eclipse today is not mentioned in the program because it is not visible locally.
Partial Lunar Eclipse of July 16, 2019. Click on image to enlarge. Credit NASA/GSFC/F. Espenak.
05/14/2019 – Ephemeris – The Apollo 11 crew weren’t alone at the Moon
Ephemeris for Tuesday, May 14th. Today the Sun will be up for 14 hours and 47 minutes, setting at 9:03, and it will rise tomorrow at 6:14. The Moon, 3 days past first quarter, will set at 4:54 tomorrow morning.
By the time Apollo 11 launched on July 16th, 1969 the Soviet union had its two launch failures of their massive lunar rocket the N-1 that year. In a last ditch attempt to scoop the United States, literally, the Soviet Union launched their Lunar 15 spacecraft that was to return a sample of the lunar surface material before Apollo 11 could return from the Moon with theirs. The Soviets launched Luna 15 on July 13th, and entered lunar orbit on the 17th. It descended to the lunar surface while Armstrong and Aldrin were still on the Moon. However communication was lost during descent and it crashed into the Sea of Crises several hundred miles northeast of where the Eagle had landed. The US was kept apprised of the Lunar 15 mission by the Soviets.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Luna-15 type vehicle the Soviets sent to the Moon to bring back surface samples. Credit NASA.
09/25/2017 – Ephemeris – Lets look at the Moon tonight
Ephemeris for Monday, September 25th. The Sun will rise at 7:33 a.m. It’ll be up for 12 hours exactly, setting at 7:33 p.m. The Moon, 2 days before first quarter, will set at 10:52 this evening.
Let’s take a look at the crescent Moon tonight. It will be fairly low in the southwestern sky this evening. Four of the gray lava plains called seas are now visible in binoculars or small telescopes. Nearest the right limb of the Moon is the Sea of Crises, next nearest if the Sea of Fertility. A small sea next to that is the Sea of Nectar. Above that, mostly exposed to sunlight is the Sea of Tranquility. The Sun is just rising at Tranquility Base, where Apollo 11 landed, where the Lunar Module’s descent stage still lies, forlorn and empty. Below that is the beautiful crater Theophilus with its central peak. It is 61 miles (101 km) in diameter, and its crater walls rise over 13,000 feet (4,400 meters) above the crater floor.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The annotated crescent moon tonight, September 25, 2017. Created using Virtual Moon Atlas. Click on the image to enlarge.
The Apollo 11 landing site in one photograph by the Lunar Reconnaissance Orbiter. There are many with varying Sun angles in the Internet. Search for: Apollo 11 LRO images. Credit NASA.
10/06/2016 Ephemeris – Viewing the Moon tonight
Ephemeris for Thursday, October 6th. The Sun will rise at 7:47. It’ll be up for 11 hours and 25 minutes, setting at 7:13. The Moon, 3 days before first quarter, will set at 10:44 this evening.
Tonight the waxing crescent Moon will appear between Saturn on the right and Mars on the left. In a small telescope the Sea of Tranquility is now mostly in daylight. The Sun will rise on the Apollo 11 landing site about one this afternoon. The landing site cannot be seen from the Earth, it’s artifacts are too small. The Lunar Reconnaissance Orbiter has to get down to about 15 miles altitude to photograph them. The craters of Theophilus, Cyrillus and Catharina are seen to the south of Tranquility. Just south of them there looks like a wrinkle in the Moon surface. It’s the Altai Scarp, which is named for the Altai mountains of central Asia. The three craters border the small Sea of Nectar. The lunar seas are basins of solidified lava.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Moon Chart for tonight (October 6, 2016) at 9 p.m. showing the areas discussed above. Created using Virtual Moon Atlas.’
The Apollo 11 landing site in one photograph by the Lunar Reconnaissance Orbiter. There are many with varying Sun angles in the Internet. Search for: Apollo 11 LRO images. Credit NASA.
07/20/2015 – Ephemeris – July 20th anniversaries
Ephemeris for Monday, July 20th. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21. The Moon, 4 days before first quarter, will set at 11:34 this evening, and tomorrow the Sun will rise at 6:16.
July 20th is a special date for this country’s space program and a personal one. On July 20, 1969 Apollo 11 landed on the Moon, the greatest achievement in the history of space flight. Seven years later the robot lander Viking 1 landed on Mars. NASA wanted it to be July 4th, 1976, the Bicentennial, but couldn’t find a smooth landing site in time. My own connection to the date came in 1963, my first total solar eclipse. We traveled to Quebec province along side the St. Maurice River. To view 60 seconds of totality. It was the first of four successful total solar eclipse trips I’ve been on.. I’m looking forward to my 5th on August 21st 2017, two years from now which is related to my first, I’ll tell you about that in my blog.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Neil Armstrong about to step off the LM onto the surface of the moon, July 20, 1969. Credit: NASA.
First image sent back from Viking 1 after landing on Mars, July 20, 1976. Credit: NASA/JPL. Click on image to enlarge.
Video of July 20, 1963 eclipse from the air. I got only one picture of the eclipse and it wasn’t very good. https://www.youtube.com/watch?v=OT3EW0KIjCc.
The date on the YouTube page is incorrect. It is July 20, 1963. I remember the corona being somewhat wedge-shaped, wider to one side than the other. Other than that it was a typical quiet sun corona.
In the program above I mentioned that the August 21, 2017 solar eclipse was related to my first total solar eclipse. This is the relationship: A couple of centuries BC the Chaldean astronomers of ancient Babylonia discovered that eclipses repeated in a cycle lasting 6,585 1/3 days. That’s 18 years 10 or 11 and 1/3 days depending on the number of leap years spanned. That period was called the Saros by Sir Edmund Halley or comet fame. So each eclipse would be visible 1/3 of the Earth farther west. Note that there are many Saros cycles occurring at the same time, and that eclipses of a particular Saros gradually move northward or southward. So to have an eclipse recur at the approximate same longitude one must wait 3 Saros cycles. or 54 years and one month approximately. Thus the third Saros of the July 20, 1963 total solar eclipse will be August 21, 2017. This Saros series (145) is moving southward. In 1963 it crosses the US at Alaska and Maine. Quebec was closer for us, s we went there. Good thing too. Maine was clouded and rained out. For us the clouds parted at the beginning of the eclipse. The 2015 eclipse will cross the continental US from Oregon to South Carolina.
A squished image of the July 20, 1963 eclipse path. Right click on the image and select view image to get a correct image. (works in Firefox).
A squished image of the August 21, 2017 eclipse path. Right click on the image and select view image to get a correct image. (works in Firefox).
Bob Moler's Ephemeris Blog 