Archive
12/11/2020 – Ephemeris – More on the Geminid meteor shower peaking this weekend
This is Ephemeris for Friday, December 11th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:02, and it will rise tomorrow at 8:11. The Moon, 3 days before new, will rise at 5:33 tomorrow morning.
This weekend and specifically Sunday evening to Monday morning the Geminid meteor shower will be at its peak, with up to 120 meteors appearing an hour in the early morning hours of Monday. The meteors will appear to come from near the star Castor, the northernmost star of the constellation of Gemini the twins. Castor and Pollux are the namesake stars at the head of Gemini. While they will seem to come from a specific point in the sky, they will be seen all over the sky, and be traced back to the point. They are coming in on parallel trajectories, just as straight railroad tracks recede to a point in the distance. Let’s hope for clear skies. The meteor shower lasts all night.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Star Chart for 7 pm, or about 2 hours after sunset. December 13, 2020. Click on image to enlarge. GemR is the location of the Geminid radiant low in the northeast. Click on image to enlarge. Created using my LookingUp program.
All sky chart of the Geminid Radiant 1 am Dec 14, 2020. GemR is the location of the Geminid radiant nearly overhead in the southeast.
All sky chart of the Geminid Radiant 6 am Dec 14, 2020. GemR is the location of the Geminid radiant in the west.
12/10/2020 – Ephemeris – The Geminid meteor shower will reach its peak Sunday evening and Monday Morning December 13/14, 2020
This is Bob Moler with Ephemeris for Thursday, December 10th. Today the Sun will be up for 8 hours and 52 minutes, setting at 5:02 pm which will signal the beginning of the Jewish feast of Chanukah. Sunrise tomorrow will be at 8:10 am. The Moon, 3 days past last quarter, will rise at 4:13 tomorrow morning.
The Geminid meteor shower, the most active meteor shower of the year will be at its most active Sunday night and Monday morning. This year the Moon will be new on Monday and won’t interfere. Our problem is that it’s December, one of the cloudiest months of the year. The Geminid meteors will seem to come from near the star Castor, the second brightest star in Gemini. The actual source of the meteors is the asteroid or rock comet Phaethon. If it is an asteroid it comes closest to the Sun of any asteroid. It has been observed by spacecraft shedding dust when it’s heated near the Sun. It is probably a dead comet.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Star Chart for 7 pm, or about 2 hours after sunset. December 13, 2020. Click on image to enlarge. Click on image to enlarge. Created using my LookingUp program.
All sky chart of the Geminid Radiant 1 am, or about 7 hours after sunset, Dec 14, 2020. Click on image to enlarge.
All sky chart of the Geminid Radiant 6 am, or about 2 hours before sunrise, Dec 14, 2020. Click on image to enlarge.
12/09/2020 – Ephemeris – A look at the naked-eye planets for this week
This is Ephemeris for Wednesday, December 9th. Today the Sun will be up for 8 hours and 53 minutes, setting at 5:02, the earliest sunset, and it will rise tomorrow at 8:09. The Moon, 2 days past last quarter, will rise at 2:55 tomorrow morning.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 6 to 7 pm. Jupiter is the very bright one. Above and left it by one and a half degrees or three moon widths will be dimmer Saturn. They are slowly closing, so they will cross paths for us on the evening of December 21st and be seen in the same low power telescope field that evening. Jupiter will set first tonight at 8 pm with Saturn following at 8:08. Quite high in the southeast at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 65.3 million miles (105.2 million km) away. It will set at 3:10 tomorrow morning. Brilliant Venus will rise at 5:58 am in the east-southeast as it retreats slowly towards the Sun, but actually it’s heading around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets seen at 6:30 pm or about an hour and a half after sunset December 9, 2020. Animation showing non-annotated sky and then with annotations. Click on the image to enlarge. Created using Stellarium and GIMP.
Venus and the waning crescent Moon at 6:30 am on December 10, 2020. Created using Stellarium.
The waning crescent Moon as it might appear in binoculars or a small telescope at 6:30 am December 10, 2020. Created using Stellarium.
The planets as seen in a telescope (north up) with the same magnification for the night of December 9/10, 2020. Times of the display are: Jupiter, Saturn and Mars, 6:30 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 33.85″; Saturn, 15.51″, rings, 36.13″; Mars, 13.18″, and Venus 11.32″. Io is transiting Jupiter and will be generally invisible. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts).
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 9, 2020. The night ends on the left with sunrise on the 10th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
12/08/2020 – Ephemeris – Finding Taurus the bull
This is Ephemeris for Tuesday, December 8th. Today the Sun will be up for 8 hours and 54 minutes, setting at 5:02, and it will rise tomorrow at 8:08. The Moon, 1 day past last quarter, will rise at 1:39 tomorrow morning.
Orion is the big splashy constellation in the east southeast by 9 in the evening. Above it is another famous constellation Taurus the bull. Its face is a letter V shape of stars on its side with the open end of the V to the left. The bright star at the lower left end of the sideways V is the ruddy star Aldebaran, the Bull’s angry bloodshot eye. The bull is charging down at Orion. The Pleiades, also known as the seven sisters, is the cluster of stars in his shoulder, above the V. The stars in the face of Taurus, except for Aldebaran belong to a star cluster like the Pleiades, but closer and older, called the Hyades. In Greek mythology the Hyades are half sisters to the Pleiades, all fathered by the god Atlas.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Three views of Taurus the bull and Orion the hunter for 9 p.m. on December 8th. Created using Stellarium and GIMP.
The Pleiades (right) and the Hyades (left) in this photograph I took January 4, 2016. The orientation is a bit different from how it appears in early December.
12/07/2020 – Ephemeris – Looking forward to the best of winter: Orion
This is Ephemeris for Monday, December 7th. Today the Sun will be up for 8 hours and 55 minutes, setting at 5:02, and it will rise tomorrow at 8:07. The Moon, at last quarter today, will rise at 12:25 tomorrow morning.
Orion, the central constellation of the winter evening sky will be completely risen by 9 this evening. Then it can be seen low in the east-southeast it’s upright rectangle of stars tilted to the left. The topmost star to the left in this rectangle is the famous red giant star Betelgeuse, which is reportedly dimming again. It’s in Orion’s shoulder. In his other shoulder is Bellatrix, a name known to Harry Potter fans. In his knees are Rigel, a blue-white giant star and Saiph. In the center of the rectangle are three stars in a straight line, now almost vertically arranged, Orion’s belt. And below his belt what seem to be three more stars, his sword. In the center of the sword stars can be found, with binoculars or telescope, Orion’s most famous feature, the Great Orion Nebula.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Orion early December finder animation for 9 pm December 7th. Created using Stellarium and GIMP.
Orion’s named stars including the belt stars. Cursa, though named belongs to the neighboring constellation Eridanus the river. Created using Stellarium.
12/04/2020 – Ephemeris Interuptus part 2 – We are on! (Update)
It’s hell to wake up in a hospital on your 79th birthday when you are feeling fine. I’m still being poked and prodded. I’m pretty sure that Wednesday’s problem was the Ghost of Stroke Past. Getting out of here today in time is the goal now. I’m sincerely sorry if anyone will be disappointed if I can’t give the talk.
Follow yesterday’s instructions to connect if I can get them up.
Thanks, and keep looking up!
Update 12/04/2020 2:19 pm
I have been released from the hospital. We are back on for the “In Search of the Star of Bethlehem”. Go to http://www.gtastro.org before 8 pm to join the meeting. Note the society will be holding a board meeting from 7 p.m. before the main meeting. Anyone is invited to listen in if they want. We have no state secrets.
12/02/2020 – Ephemeris – A look at the naked-eye planets for this week
This is Ephemeris for Wednesday, December 2nd. Today the Sun will be up for 9 hours and 1 minute, setting at 5:03, and it will rise tomorrow at 8:02. The Moon, 2 days past full, will rise at 6:51 this evening.
Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky from 7 to 8 pm. Jupiter is the very bright one. Above and left it by 2 degrees or 4 moon widths will be dimmer Saturn. They are slowly closing, so they will cross paths on the evening of December 21st and be seen in the same telescope field that evening. Jupiter will set first tonight at 8:20 with Saturn following at 8:32. Quite high in the southeast at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 60.2 million miles (97.0 million km) away. Mars will set at 3:27 tomorrow morning. Brilliant Venus will rise at 5:40 am in the east-southeast as it retreats slowly towards the Sun, but actually it’s heading around behind the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets with the Mon rising at 7 pm tonight December 2, 2020. Click on the image to enlarge. Created using Stellarium.
The Moon as it might be seen tonight at 9 pm, December 2, 2020. Created using Stellarium.
The planets as seen in a telescope (north up) with the same magnification for the night of November 25/26, 2020. Times of the display are: Jupiter, Saturn and Mars, 7 pm; Venus, 6:30 am. Apparent diameters: Jupiter, 34.28″; Saturn, 15.63″, rings, 36.41″; Mars, 14.27″; and Venus, 11.57″. Mars also displays an enlargement showing surface detail. Mars was closest to the Earth this go-a-round on October 6. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 2, 2020. The night ends on the left with sunrise on the 3rd. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are getting very close. Click on the image to enlarge. Created using my LookingUp program.
11/30/2020 – Ephemeris – We’ve entered an eclipse season
This is Bob Moler with Ephemeris for Monday, November 30th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:03, and it will rise tomorrow at 8:00. The Moon, at full today, will rise at 5:22 this evening.
This morning we had a slight eclipse of the Moon, where the Moon entered only the southern part of the Earth’s penumbral or partial shadow. On December 14th, at the next new moon there will be a total eclipse of the Sun that will be visible from South America. We are now in an eclipse season which lasts about 35 days. In that time two or rarely three eclipses can be fit in. The next eclipse season is 5 months and 18 days away in late May and early June 2021. Then there will be, for Michigan, the start of a lunar eclipse visible just before sunrise on May 26th and the end of a solar eclipse visible at sunrise on June 10th. Those two eclipses will just be teasing us. Our next nearby total solar eclipse is less than three and a half years away on April 8, 2024.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A diagram showing eclipse seasons. Though only solar eclipses are shown, it also includes lunar eclipses. Three months later (actually only a month later) the shadows of each are either too far north or south to fall on the other. Click on the image to enlarge. Credit: NASA/JPL
11/27/2020 – Ephemeris – There will be a slight eclipse of the Moon Monday morning
This is Ephemeris for Native American Heritage Day, Friday, November 27th. Today the Sun will be up for 9 hours and 9 minutes, setting at 5:05, and it will rise tomorrow at 7:57. The Moon, 3 days before full, will set at 6:02 tomorrow morning.
Early Monday morning there will be a penumbral eclipse of the Moon. It’s not much of an eclipse to look at, but it is an eclipse to open the last eclipse season of this year. I’ll have more on that Monday, but the lunar eclipse on Monday will a slight one, where no part of the Moon disappears into the Earth’s inner shadow. The top part of the Moon will look a bit darker than the bottom part for a time, that’s all. The Earth and the Moon are illuminated by the Sun, and it isn’t a point light source. Your shadow isn’t sharp. The fuzziness at the edge of your head’s shadow on the ground in the sunlight is your penumbra. The maximum part of the eclipse will be at 4:44 am (09:44 UT)with the effect seen within a half hour of that time. The effect is best seen with sunglasses to dim the Moon.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The maximum of the penumbral lunar eclipse at 4:44 am EST (9:44 UT) Monday, November 30, 2020. The upper right part of the Moon will have a dusky appearance. The effect should be visible from about 4:15 to 5:15 am (09:15 to 10:15 UT). I find it’s best to view the Moon with sunglasses to reduce the Moon’s glare to better see the effect. Created using Stellarium.
Penumbral lunar eclipse with Earth’s shadow at maximum. The outer ring is the outer edge of the penumbra the Moon’s outer shadow where so little sunlight is cut off as to not be discernible. The inner circle is the edge of the umbra, the darkest part of the Earth’s shadow, where almost 100% of the Sun’s light is cut off. The Moon will be in the western sky at this time, and its motion with respect to the Earth’s shadow is to the upper left. Created using Cartes du Ciel (Sky Charts).
11/26/2020 – Ephemeris – A look at Saturn (planet and god) in mythology
This is Ephemeris for Thanksgiving Day, Thursday, November 26th. Today the Sun will be up for 9 hours and 11 minutes, setting at 5:05, and it will rise tomorrow at 7:55. The Moon, 4 days before full, will set at 4:59 tomorrow morning.
Over the next 25 days Jupiter and Saturn will draw together to be in conjunction. And like I said Tuesday, I don’t know what that means astrologically, since I don’t believe in that stuff. I find the universe quite indifferent to my fate or the fate of anything happening on the third rock. Saturn, which will seem to cross paths with Jupiter on the evening of December 21st, a few hours after winter starts is named after the Roman god of agriculture and periodic renewal among others. He is depicted carrying a scythe, and even today we see him as the Grim Reaper, and at the end of the year as Father Time. The Saturn is the Roman counterpart of the Greek Cronus a Titan, the bringer of old age. It’s a fitting name for the slowest of the naked-eye planets, known from antiquity, taking almost 30 years to shuffle its way around the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Saturn and rings from the Cassini spacecraft, plus the aurora oval in ultraviolet. Credit: NASA/JPL/Space Science Institute
A statuette of Cronus (Saturn) shown holding a scythe and an hour glass. Source: https://respuestas.tips/quien-es-cronos-en-la-mitologia-griega/
