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Ephemeris: 11/08/2024 – The Jade Rabbit on the Moon
This is Bob Moler with Ephemeris for Friday, November 8th. Today the Sun will be up for 9 hours and 50 minutes, setting at 5:21, and it will rise tomorrow at 7:32. The Moon, 1 day before first quarter, will set at 11:24 this evening.
Tonight’s Moon is just a few hours before the instant of first quarter which is officially at 12:56 tomorrow morning. The ancient Chinese saw in the gray areas of the Moon, we call seas, a rabbit, a pet of Chinese moon goddess Chang’e, its name was Yutu. These have become the names of the Chinese lunar landers and rovers. The top half of that rabbit is visible in the gray areas called maria, or seas. Early telescopic astronomers thought they were actually water filled basins. It turned out to be lava plains, actually floors of huge craters, from asteroids that hit the Moon 4 billion years ago during the late heavy bombardment. The top body of the rabbit is at the top part of the moon it descends to the lower right with his head and ears. The rabbit is also known as the Jade Rabbit. The rest of him is visible when the moon is full. Yutu has a real presence on the Moon, as the names of the two Chinese rovers that landed on the Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 11/07/2024 – The Moon wobbles from Earth’s point of view
This is Ephemeris for Thursday, November 7th. Today the Sun will be up for 9 hours and 53 minutes, setting at 5:22, and it will rise tomorrow at 7:31. The Moon, 2 days before first quarter, will set at 10:08 this evening.
The nearly seven day old Moon appears very low in the southwestern sky tonight. It appears as a fat crescent. The small sea called Mare Crisium or Sea of Crises, near the west edge of the Moon is a good indicator of what we call libration, that is the Moon’s slow wobbling back and forth over the month as it orbits the Earth. One can judge the amount of libration by the distance of that small round sea from the edge of the Moon. This happens because the Moon’s rotation is steady while its orbital velocity around the Earth is not, because its orbit is slightly elliptical. So sometimes the rotation gets ahead of its revolution about the Earth, and sometimes it’s behind. Right now that libration is pushing that small sea towards the edge of the Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 11/06/2024 – Where are the naked eye planets this week?
This is Ephemeris for Wednesday, November 6th. Today the Sun will be up for 9 hours and 55 minutes, setting at 5:24, and it will rise tomorrow at 7:29. The Moon, 3 days before first quarter, will set at 8:56 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted low in the southwestern sky by 6 PM, about half an hour after sunset. It will set at 7:22. Saturn will be in the southeast at 7 PM. Jupiter will rise at 7:17 PM in the east northeast, and be a good object for the small telescope about an hour later. By 6:00 AM tomorrow Jupiter will be high in the west southwest, among the winter stars, while reddish Mars, which rises tonight near 10:16, will be high in the south. Jupiter and Saturn are good planets to view with a small telescope, while Venus and Mars will appear very small and featureless. These last two will improve next year when they move closer to us.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 11/05/2024 – Bright Jupiter is now seen earlier in the evening
This is Ephemeris for Election Day, Tuesday, November 5th. Today the Sun will be up for 9 hours and 58 minutes, setting at 5:25, and it will rise tomorrow at 7:28. The Moon, 4 days before first quarter, will set at 7:51 this evening.
There’s a bright star in the east these evenings. It is extremely bright. If Venus wasn’t around in the evening in the southwest, one might mistake it for Venus. Well this bright star is not a star at all, but the planet Jupiter. Jupiter is the solar system’s largest planet. It is by and large the easiest planet to observe with a small telescope, which will also reveal four of its many moons, which I think is approaching 100 now. (It’s hard to keep track of them.) These four moons were the same ones discovered by Galileo over 400 years ago. Jupiter’s moons move quite rapidly compared to the Earth’s moon. From night to night Jupiter’s moons shift around. Their motions can also be detected over the period of an evening, or night.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 11/04/2024 – The Milky Way in Autumn
This is Ephemeris for Monday, November 4th. Today the Sun will be up for 10 hours and 1 minute, setting at 5:26, and it will rise tomorrow at 7:26. The Moon, 4 days past new, will set at 6:58 this evening.
As of yesterday the sunsets and sunrises have slipped back an hour so we have darker evenings and brighter mornings, as we came back to Standard Time. It seems odd that we spend less time of the year under Standard Time than we do under Daylight Time. Anyway, looking at the evening sky we see that Venus tonight will be above the four-day-old crescent Moon in the southwest after sunset. By 7 PM the northernmost star of the Summer Triangle, Deneb in Cygnus the swan or the Northern Cross, will be almost directly overhead. And the Milky Way at that time will run from northeast, overhead to the southwestern horizon. Remember tomorrow is Election Day. Make sure you cast your ballot before the end of voting tomorrow, if you haven’t already.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 10/30/2024 – Our weekly look at the whereabouts of the naked-eye planets
This is Ephemeris for Wednesday, October 30th. Today the Sun will be up for 10 hours and 14 minutes, setting at 6:33, and it will rise tomorrow at 8:20. The Moon, 2 days before new, will rise at 7:28 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted low in the southwestern sky by 7 PM, about half an hour after sunset. It will set at 8:18. Comet Tsuchinshan-ATLAS is definitely a binocular object and will be a third of the way up to the zenith in the southwest around 8 PM. It will set at 11:17 PM. Saturn will be in the southeast at 8 PM. Jupiter will rise at 8:42 PM in the east northeast, and be a good object for the small telescope about an hour later. By 7:00 AM tomorrow Jupiter will be high in the west southwest, among the winter stars, while Mars, which rises tonight near 11:30, will be high in the south.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Ephemeris: 10/29/2024 – A star for Halloween
This is Ephemeris for Tuesday, October 29th. Today the Sun will be up for 10 hours and 17 minutes, setting at 6:34, and it will rise tomorrow at 8:18. The Moon, 3 days before new, will rise at 6:24 tomorrow morning.
Not all the ghosts and goblins out Thursday night will be children. One is out every night because it’s a star. Its name is Algol, from the Arabic for Ghoul or Demon Star. It’s normally the second-brightest star in the constellation Perseus the hero, visible in the northeast this evening. The star is located where artists have drawn the severed head of Medusa, whom he had slain. Medusa had snakes for hair so that she turned all who gazed upon her to stone. Algol is her still glittering eye. The star got this name before astronomers found out what was really wrong with it. They found out that it does a slow wink every two days, 21 hours, because it is two stars that eclipse each other. Her next 9-hour wink, is centered at 2 AM Halloween morning.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Stellarium tends to show variable stars and a brightness about halfway between the brightest and dimmest magnitudes. However, Algol stays at its peak brightness most of the time, so it usually appears as bright as Mirfak which, in the image above, is to its upper left. It’s only during the eclipse that it appears dimmer than Mirfak. That’s how you can tell that Algol is in eclipse.
Here is where to go to find out when Algol is going to be in eclipse in the next week or so: http://www.astropical.space/algol.php
Ephemeris: 10/28/2024 – The Pleiades or Seven Sisters and their half sisters
This is Ephemeris for Monday, October 28th. Today the Sun will be up for 10 hours and 20 minutes, setting at 6:36, and it will rise tomorrow at 8:17. The Moon, halfway from last quarter to new, will rise at 5:22 tomorrow morning.
The beautiful star cluster of the Pleiades is seen low in the east northeastern sky after 9:00 PM. It is also known as the Seven Sisters. It has been known as a group of female stars in many cultures. Also, the Ancient Greeks, because they thought that the Pleiades shape looked something like a sail, Also, Pleiades is very close to the Greek name for sail, and that its appearance in the morning sky in early summer heralded the beginning of the summer sailing season on the Mediterranean Sea. According to Greek mythology the Pleiades have half sisters, also seven in number, with the same father, Atlas, but a different mother, called the Hyades which rises about an hour later, and fills out the face of Taurus the bull.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Ephemeris: 10/25/2024 – Finding the Pleiades or Seven Sisters
This is Ephemeris for Friday, October 25th. Today the Sun will be up for 10 hours and 28 minutes, setting at 6:40, and it will rise tomorrow at 8:13. The Moon, 1 day past last quarter, will rise at 2:09 tomorrow morning.
A marvelous member of the autumn skies can be found low in the east northeast after 9 in the evening. It is the famous star cluster called the Pleiades or the Seven Sisters. I might also add the ‘Tiny Dipper’. Many people can spot a tiny dipper shape in its six or seven stars, and mistake it for the Little Dipper. With binoculars, one can see over a hundred stars that appear, along with the dipper shape of the brightest. In photographs, the Pleiades actually contain wisps of the dust they are currently passing through. In Greek mythology, the sisters were daughters of the god Atlas and Pleione. The most people can see is six stars. The reason, according to mythology, is that one of the sisters married a mortal, dimming her star.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Ephemeris: 10/24/2024 – Looking at Comet Tsuchinshan-ATLAS for the rest of the month
This is Ephemeris for Thursday, October 24th. Today the Sun will be up for 10 hours and 31 minutes, setting at 6:42, and it will rise tomorrow at 8:12. The Moon, at last quarter today, will rise at 1:01 tomorrow morning.
Looking at the rest of the month in viewing Comet Tsuchinshan-ATLAS in dark skies, we find it moving away from us and dimming rapidly. It will be moving across the constellation of Ophiuchus and it will be mostly in the west southwestern sky, And will need a pair of binoculars or a small telescope to spot. The comet has an easily seen tail, even when it becomes dim and only visible in binoculars. It should still have a tail. Comets sport two tails, a dust tail the bright tail that we see on comets, and a narrower ion tail. The ionized gas of the ion tail is driven back by the solar wind while the dust tail is predominantly affected by the pressure of sunlight itself. When close to the Sun it is moving more sideways, so the tails will appear to separate.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Bob Moler's Ephemeris Blog 