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Ephemeris: 03/14/2024 – It’s Pi Day!
This is Ephemeris for Pi Day, Thursday, March 14th. Today the Sun will be up for 11 hours and 52 minutes, setting at 7:48, and it will rise tomorrow at 7:54. The Moon, 3 days before first quarter, will set at 1:47 tomorrow morning.
Yes, it’s Pi day that’s the Greek letter π for 3.14 approximating the ratio of the circle’s circumference to its diameter, which scientific and technical people celebrate by baking a pie P-I-E and carving the Greek letter π on the top.
Tonight around 9 or 9:30 when it gets dark, is a good time to use the Moon to find the Pleiades, the Seven Sisters star cluster. The Pleiades will appear above the crescent Moon this evening, so it’s a good time to locate them if you haven’t already. We only have about another month viewing the Pleiades in the evening. And we have one more passage of the Moon by the Pleiades next month before they disappear from the evening sky.
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
There’s another Pi day that some celebrate. A well-known approximation of pi is the fraction 22/7ths. Europeans and others write dates in day/month order, so July 22nd is also a Pi Day: 22/7.
Ephemeris: 02/16/2024 – The Moon will appear near the Pleiades tonight
This is Ephemeris for Friday, February 16th. Today the Sun will be up for 10 hours and 29 minutes, setting at 6:12, and it will rise tomorrow at 7:40. The Moon, at first quarter today, will set at 3:03 tomorrow morning.
The moon will pass south, or below, the star cluster called the Pleiades, or Seven Sisters, this afternoon. By this evening the Pleiades will be seen to the lower right of the Moon. However, you will need a pair of binoculars to see them, because the first quarter Moon is quite a bit brighter than the stars of the Pleiades. The moon will again pass the Pleiades in March on the 14th, where the Pleiades will appear above and left of the Moon. And again, on April 11th, where the Moon will pass south of the Pleiades during the day, and the cluster will be to the lower right of the Moon by evening. They will appear closest together in our evening sky on May 8th. Unfortunately, they will be low in the sky in the west at sunset.
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
Ephemeris: 07/21/2023 – Antares just looks weird
This is Ephemeris for Friday, July 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:20, and it will rise tomorrow at 6:18. The Moon, halfway from new to first quarter, will set at 11:34 this evening.
We’ve had our Fourth of July fireworks over two weeks ago, but there’s one star still celebrating as a sparkler. That’s Antares in Scorpius the scorpion low in the south tonight. We in Michigan always see Antares low in the south. It’s a bright red giant star which twinkles mightily, and since it’s low in the sky, it spits and sputters all kinds of colors due to our atmosphere’s turbulence, and the fact that we’re looking through so much of it at Antares. At it’s highest, due south, we are seeing it though 3 times more atmosphere than we would be if it was overhead. The more magnification one uses with binoculars or a telescope, the greater the sparkler effect. It is even called in sometimes as a UFO.
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
The name of the star Antares means “Rival of Mars”. “Ant” meaning anti, “Ares”, the Greek equivalent to the Roman god Mars. The reason is their similar reddish color. Antares is red because it is a cool star, a red giant. Mars is red due to its red dust, colored by iron rust. The planet passes Antares about every 23 1/2 months. Mars will next pass Antares on December 8th, 2023. However, the event will not be visible, because both the star and the planet will be too close to the Sun in the morning sky then. Their next meeting, or conjunction, after that, on November 17th, 2025 will be in the evening sky, but still too close to the Sun to be spotted. The conjunction after that will be in the evening sky, again rather close to the Sun, on October 28, 2027. For these three encounters, Mars will be north or above Antares, and dimmer than the star.
04/25/2023 – Ephemeris – The Moon is passing Mars today
This is Bob Moler with Ephemeris for Tuesday, April 25th. Today the Sun will be up for 13 hours and 57 minutes, setting at 8:40, and it will rise tomorrow at 6:40. The Moon, 2 days before first quarter, will set at 2:50 tomorrow morning.
Tonight, the Moon and the planet Mars will appear close to each other. The Red Planet will appear just below and left of the waxing crescent Moon. Mars is a lot dimmer than it was last December. That’s because it is a lot farther away than it was back then, 157 versus 51 million miles (253 versus 82 million kilometers). Mars is the planet with the greatest distance variation percentage over its synodic period, that is, from opposition to the next opposition. It also has the longest synodic period, at 26 months on average. That’s why opportunities to launch spacecraft only occur every 26 months. The least energy it takes to get to Mars occurs when a spacecraft is launched a few months before opposition, when Mars is at its closest, to arrive several months after opposition.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum
The Moon and Mars as they should appear in the west tonight, April 25, 2023, at 10 pm. Created using Stellarium.
Illustration of the route Mars 2020 (Perseverance) took to arrive at the Red Planet, including several trajectory correction maneuvers (TCMs) to adjust its flight path. Credit NASA/JPL.
01/30/2023 – Ephemeris – Two planetary events are happening today
This is Ephemeris for Monday, January 30th. Today the Sun will be up for 9 hours and 44 minutes, setting at 5:48, and it will rise tomorrow at 8:03. The Moon, 2 days past first quarter, will set at 4:34 tomorrow morning.
Today, the planet Mercury was seen as far away from the Sun as it can get for this time of year in the morning sky. It’s called “greatest western elongation”, and it’s distance from the sun and angle is 25 degrees. It’s going to stay pretty close to that for about the next week or so, it’ll be visible if it ever clears up. This is about the latest time one can see Mercury morning elongations this for this time of year. We’re running out of the correct angles for it. This evening, if it’s clear, the planet of Mars will appear near the waxing gibbous Moon. Early on in the evening Mars will be to the upper left of the Moon, which will be approaching it by about its own diameter every hour, until about 1 o’clock in the morning when Mars will it’s closest above the Moon it should be a striking sight.
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
12/23/2022 – Ephemeris – Hunting for the Star of Bethlehem: Venus and Jupiter appear to merge… twice!
This is Ephemeris for Friday, December 23rd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:06, and it will rise tomorrow at 8:18. The Moon is new today, and won’t be visible.
My favorite astronomical solution to the puzzle of the Star of Bethlehem are two conjunctions of Jupiter and Venus that occurred against the stars of the constellation of Leo the lion 10 months apart on August 12th 3 BCE and June 16th 2 BCE. Leo at that time was associated with Jacob’s son Judah and the land of Judea. The first conjunction occurred in morning twilight. The second in the evening. The first conjunction was close, though someone with excellent eyesight might pick them apart, but the second, would be impossible to separate without a telescope, which wouldn’t be invented for another 16 centuries. And Jesus would have been born in the spring during lambing season when shepherds would have been out all night with their flocks, protecting them. The eclipse that Herod died after would have been on January 10th, 1 BCE, which occurred three months before Passover, enough time for all the palace intrigue* to happen between the lunar eclipse and Passover.
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.
* See yesterday’s post for more information here.
Addendum
The Babylonian concept of the constellation Leo. They called it Urgulu, meaning lion. It represented their god Latarak. The star they called Sharru, meaning King we know as Regulus, which is the diminutive of king.
Here is an animation created using Stellarium of Jupiter and Venus, the brighter of the two seeming to coalesce on August 12, 3 BC in the early morning twilight. That ghost object that flashed on for one date was the Moon. Created using Stellarium and GIMP.
On June 16th 2 BC, this time in the evening, Venus and Jupiter seem to coalesce as one, at least to the naked eye. Created using Stellarium and GIMP.
Venus appeared among Jupiter’s moons on June 16, 2 BC. Of course, no one had a telescope back then. The telescope wouldn’t be invented for another 16 centuries. Stellarium cannot create the real brightness difference between Jupiter and Venus. Venus would be simply dazzling compared to Jupiter, being 12 times brighter. Venus, being an inner planet, shows phases like the Moon. At this time, Venus would have been near its greatest eastern elongation or separation from the Sun, so it would appear as a tiny first quarter moon. Galileo discovered that Venus had phases and orbited the Sun, in the early 17th century. Created using Stellarium.
Merry Christmas!
12/22/2022 – Ephemeris – Hunting for the Star of Bethlehem: When did Herod the Great Die – Part 2
This is Ephemeris for Thursday, December 22nd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:05, and it will rise tomorrow at 8:17. The Moon, 1 day before new, will rise at 8:56 tomorrow morning.
According to the Gospel of Matthew, Jesus was born in the last years of the reign of Herod the Great, and the Jewish historian Josephus puts Herod’s death shortly after an eclipse of the Moon. There may have been an error in the Josephus history that has been propagated since the middle of the 16th century, that when corrected shifts the eclipse in question forward three years to 1 BCE. The conjunctions of Jupiter and Saturn of 7 BCE would be four years too early. Under this scenario, Jesus would have been born in the spring of 2 BCE, the time of year when shepherds would indeed be out at night with their flocks, because this was lambing season. What the Magi would have seen was, on two occasions, the planets Venus and Jupiter appear to merge into a single star.
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
This is a timeline I developed of the events surrounding the Birth of Jesus. On the top line in yellow are the two eclipses of the Moon that occurred in the time period we’re interested in: 4 BCE and 1 BCE. One of then was the eclipse Josephus mentions that occurred shortly before the death of Herod the Great, who was alive to greet the Magi, who came to Jerusalem seeking the newborn King of the Jews. The second line highlights 3 and 2 BCE that the early Christian writers Irenaeus, Tertullian and Clement of Alexandria based Jesus’ birth year to Roman events which can be pegged to the Roman Calendar which has a direct relationship to our own calendar. The next line contains hits based on the Crucifixion of Jesus at age 33, where the Last Supper was a Seder on the first day of Passover. The next line with C and P are two censuses of Augustus in our time period. The next to the last line shows the relation of the triple conjunction in 7 BCE with Jesus’ birth and Herod’s death. The bottom line related the two Venus-Jupiter conjunctions with Jesus’ birth and Herod’s death.
Where the lunar eclipse of March 13 of 4 BCE was a slight partial eclipse. The lunar eclipse of January 10 of 1 BCE was total, which occurred three or four months before Passover. Herod’s death and the chaos that ensued, according to Josephus, before Passover also means the March 13, 4 BCE eclipse, occurring 1 month before Passover does not provide the length of time for all these events to transpire:
- Josephus mentions an eclipse of the moon.
- Herod went beyond the river Jordan to the warm baths at Callirrhoe by the Dead Sea.
- He knew he was near death as the treatments failed, so he returned to Jericho.
- Before he did, he had his soldiers paid a bonus.
- He ordered all the principal men of the Jews to meet with him under penalty of death. Those who did come, were imprisoned at the Hippodrome to be killed upon his death.
- Herod then attempted suicide.
- Herod’s son Antipater attempted to take the throne, and was executed.
- Five days later, Herod died.
- Herod had bequeathed the kingdom to another son, Archlaus, who then organized the funeral for Herod.
- The funeral procession could have taken up to 25 days.
- Then there were 7 days of mourning after that.
- Archlaus sent his generals to Caesar on his behalf to have him declared King.
- The people were beginning to demand lighter taxes and the release of those whom Herod had imprisoned.
- At that point, Josephus mentioned that Passover was approaching.
- Finally, it was Passover.
Obviously, all these events could not be squeezed into one 29 to 30 lunar month in 4 BCE. Defenders of the 4 BCE death of Herod would say that the Passover mentioned was the next year’s Passover, giving 12 or 13 months for the events to occur. In that case, why mention Passover at all?
Missing from the timeline above is Luke’s mention of Quirinius being Governor of Syria. However, there is a problem. Luke states the at the time of Jesus’ birth that Quirinius was Governor of Syria. The problem is that he wasn’t Governor of Syria until 6 and 7 CE, at least 8 years after the events of the Nativity. And the question of who was Governor of Syria wouldn’t have mattered until 6 CE, when Judea actually became part of the Province of Syria. In the period we’re looking at, Quintilius Varus was Syria’s governor. Could the two names be switched due to a copyist error? Anyway, this was before Judea became part of Syria, so it wouldn’t have mattered who was governor of Syria when Jesus was born. Luke’s account is not much help in dating the year of Jesus’ birth.
Tomorrow, I’ll finish up with the two conjunctions of Jupiter and Venus against the stars of Leo, which was the celestial sign of Judah and the land of Judea.
12/20/2022 – Ephemeris – Hunting for the Star of Bethlehem: When did Herod the Great Die – Part 1
This is Ephemeris for Tuesday, December 20th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:04, and it will rise tomorrow at 8:16. The Moon, 3 days before new, will rise at 6:20 tomorrow morning.
In looking for the year Jesus was born and the appearance of the Star of Bethlehem, we look to the latter years of Herod the Great’s reign. Jewish historian Josephus recounts that Herod died shortly after an eclipse of the Moon occurred. The date of that eclipse, according to many historians, was March 13th, of 4 BCE and before Passover, a month later. The Greek text of Matthew states that Herod’s visitors, looking for the newborn King of the Jews, were Magi. Magi were priest-astrologers of the Zoroastrian Religion of Persia. That being the case, the Star could have been the triple conjunction of Jupiter and Saturn against the constellation of Pisces, when three times Jupiter passed Saturn between the end of May and early December of 7 BCE.
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
The Jupiter-Saturn triple conjunction of 7 BC. Click on the image to enlarge and animate. This animation is at 5-day intervals. The conjunctions took place against the stars of Pisces the fish, a constellation thought, in those days, to be associated with the Jews. The Moon will be popping in and out of the view. It ends in February of 6 BC, when Mars and the Moon enters the picture. Click on the image to enlarge it. Created using Cartes du Ciel and GIMP.
Above is an animation of the triple conjunction of Jupiter and Saturn of 7 BCE in 5 day steps. The body popping in and frame is the Moon. The first conjunction was on May 29th. Both planets stopped their eastward motion around July 6th. Astrologically, they became stationary and began their westward or retrograde motion. The second conjunction was on October 11th. Both planets stopped their westward or retrograde motion on November 1st. Again they were stationary to resume their normal eastward motion. The third and last conjunction was on December 8th. Two months later, on February 21st, of 6 BCE, Mars joined the group as they all move off to the western sky in the evening. Using this triple conjunction as the Star of Bethlehem, Jesus would have been born in the late autumn of 7 BCE or early winter of 6 BCE.
This lunar eclipse candidate for the eclipse that heralded the death of Herod the Great, and the favorite, since the time of Johannes Kepler, is the lunar eclipse of March 13, 4 BCE. It was a partial eclipse, only visible in the predawn hours. This eclipse occurred one lunar month before Passover.
Too little time for all the events Josephus describes. A better lunar eclipse occurred a bit less than three years later. Those defending the 4 BCE eclipse sometimes suggest that the Passover mentioned by Josephus was the next year’s Passover of 3 BCE. If it was the next year’s Passover, why mention Passover at all?
Tomorrow I’ll take a break to look to the naked eye planets, and to the winter solstice. Winter begins tomorrow! Thursday I’ll look to a better lunar eclipse and begin to explore another Bethlehem Star candidate.
05/02/2022 – Ephemeris – The Moon and Mercury together where we can see them
This is Bob Moler with Ephemeris for Monday, May 2nd. Today the Sun will be up for 14 hours and 17 minutes, setting at 8:49, and it will rise tomorrow at 6:29. The Moon, 2 days past new, will set at 11:02 this evening.
The two-day-old thin sliver of a Moon will be left and above Mercury this evening. About the best time to spot them is between 9:30 and 10:15 pm, low in the western sky. They will be seen in the west-northwest. As we move through the week, the Moon will move away from Mercury to the east, while Mercury heads back toward the Sun and, dimming as it goes. Mercury is the closest planet to the Sun and averages 40 percent of the Earth’s distance from the Sun, so it is never seen at our northerly latitude outside of twilight. Mercury has the most elliptical orbit of the major planets. And it happens that at the best times to see Mercury, on spring evenings and autumn mornings, Mercury is at its nearest to the Sun. Southern Hemisphere observers get a better look at it because their best observing times are when Mercury is farthest from the Sun.
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
Mercury and the 2-day-old Moon as they might appear at 9:30 pm, or about 40 minutes after sunset tonight, May 2, 2022, looking low to the west-northwest. Aldebaran, slightly dimmer than Mercury, is the star to the left of the Moon. Created using Stellarium.
04/25/2022 – Ephemeris – The moon is passing the morning planet parade
This is Bob Moler with Ephemeris for Monday, April 25th. Today the Sun will be up for 13 hours and 58 minutes, setting at 8:40, and it will rise tomorrow at 6:40. The Moon, 2 days past last quarter, will rise at 5:16 tomorrow morning.
Over this and the next couple of mornings, the waning crescent Moon will be passing the four morning planets. This morning it was below and between Saturn and Mars. Tomorrow morning, the Moon will be between and below Mars and Venus. Wednesday morning the Moon, Venus and Jupiter will make a nice right triangle with Jupiter above and a bit left of the Moon and Venus will appear above and a bit to the right of it. There’s some motion between Venus and Jupiter. While both are traveling eastward when comparing them to the stars, Venus is moving eastward faster, and is moving toward the Sun in our sky. Jupiter is moving away from the Sun from our vantage point. They will cross paths on Saturday.
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
The Moon passing the morning planets from Sunday to Wednesday mornings 4/24 to 4/27/2022. Note also the approach of Jupiter and Venus. Their paths will cross on Saturday, 4/30/2022. Click on the image to enlarge it. Created using Stellarium and GIMP.
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