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Archive for December, 2020

12/31/2020 – Ephemeris – Looking ahead at the eclipses of 2021

December 31, 2020 Comments off

This is Ephemeris for New Year’s Eve, Thursday, December 31st. The Sun will rise at 8:20. It’ll be up for 8 hours and 52 minutes, setting at 5:12. The Moon, 2 days past full, will rise at 6:43 this evening.

I’ve had enough of 2020, and I hope in 2021 that we’ll break the grip of this pandemic. Looking up next year we will get glimpses of three of the four eclipses that will occur in 2021. We will get a chance to see the beginning of an eclipse of the Moon at sunrise as it sets on May 26th. Fifteen days later, on June 10th we will be able to see the Sun rise while being partially eclipsed by the Moon. People in western Ontario, up through northern Canada, then across the North Pole and into Siberia will get to see an annular or ring of fire eclipse of the Sun. On November 19th, clouds willing, we will get to see an almost total eclipse of the Moon that morning with over 97 percent of the Moon covered by the Earth’s inner shadow.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Sun rises in eclipse - June 10, 2021

What might it look like when the Sun will rise in eclipse for the Grand Traverse region of Michigan at about 6:10 am June 10, 2021. Note that you, or actually your location, is involved in what you can see of a solar eclipse. Created using Stellarium.

Lunar Eclipse maximum 4:04 am 11/19/21

What the lunar eclipse maximum might look like at 4:04 am (9:04 UT), November 19, 2021. Created using Stellarium.

There is a fourth eclipse in 2021, a total solar eclipse that is mainly visible in the Southern Ocean and Antarctica on December 4, 2021.

 

 

12/30/2020 – Ephemeris – Let’s take our last look at the naked-eye planets for this year

December 30, 2020 Comments off

This is Bob Moler with Ephemeris for Wednesday, December 30th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:11, and it will rise tomorrow at 8:20. The Moon, 1 day past full, will rise at 5:40 this evening.

Let’s take our last look at the naked-eye planets for this year. Jupiter and Saturn are both low in the southwestern sky around 6 pm. Jupiter is the very bright one. Below and right of it is the dimmer Saturn it by a degree or two moon widths. They crossed paths for us nine nights ago. They can still be seen in the same binocular field. Saturn will set first tonight at 6:57 pm with Jupiter following four minutes later. Quite high in the southeast will be Mars, still in Pisces. Mars’ distance is increasing to 82 million miles (132 million km) away. It will set at 2:29 tomorrow morning. Brilliant Venus will rise at 6:49 am in the east-southeast as it seems to retreat slowly toward the Sun, but actually it’s heading way 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

Jupiter and Saturn in the evening

Jupiter and Saturn low on the southwestern horizon at 6 pm. Created using Stellarium.

Mars with stars of Taurus

Mars with the stars of Taurus the Bull including Aldebaran with the “V” of stars that are the Hyades that mark the bull’s face and the Pleiades. Seen at 8 pm, December 30, 2020. Created using Stellarium.

Binocular Moon

The Moon as it might be seen tonight at 8 pm, December 30, 2020. Created using Stellarium.

Venus in the SE at 7:30 am

Venus in the southeast at 7:30 am. Created using Stellarium.

Telescopic views of some bright planets

The planets as seen in a telescope (north up) with the same magnification for the night of December 30/31, 2020. Times of the display are: Jupiter and Saturn, 6 pm; Mars, 8 pm; Venus, 7:30 am. Apparent diameters: Jupiter, 32.92″; Saturn, 15.26″, rings, 35.54″; Mars, 10.52″, and Venus 10.71″. 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.) Planets whose diameters drop below 10″, or are too close to the direction of the Sun to observe will not be shown. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 30, 2020. The night ends on the left with sunrise on the 31st. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are very close. Click on the image to enlarge. Created using my LookingUp program.

12/29/2020 – Ephemeris – 2020 the bad and the good in astronomy

December 30, 2020 Comments off

This is Ephemeris for Tuesday, December 29th. Today the Sun will be up for 8 hours and 50 minutes, setting at 5:10, and it will rise tomorrow at 8:19. The Moon, at full today, will rise at 4:45 this evening.

2020 has been a terrible year due mostly to the COVID-19 pandemic that cost over 300 thousand American lives. It also saw the end of the 1,000 foot (305 meter) radio telescope dish set into a natural bowl near the north shore of Puerto Rico, 8.5 miles south of the city of Arecibo. The Arecibo Radio Telescope was until earlier this year the world’s largest single telescope. It also possessed a powerful radar transmitter allowing radar imaging of planets, moons and asteroids. It started to collapse several months ago and finally gave way December 1st.

On a positive note we were graced by the bright Comet NEOWISE visible first in the morning, then in the evening last July. It was the brightest comet in the northern skies since Comet Hale-Bopp appeared in 1997.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Arecibo telescope collapse

Aerial view of the Arecibo telescope after the collapse of the 900 ton feed platform suspended above the dish on December 1, 2020. Credit: Ricardo Arduengo/AFP via Getty Images

NEOWISE in the morning

My photograph of Comet NEOWISE at 4:40 am over the west arm of Grand Traverse Bay south of the Discovery Pier off M22. (For non-Michigander astronomers M22 is not the globular star cluster in Sagittarius, but a very scenic Michigan state road.) Click on the image to enlarge.

NEOWISE from backyard over tall shrubery

Comet NEOWISE from backyard over tall shrubbery 11:18 pm July 16, 2020. I didn’t have time to focus properly which actually accentuates the stars.

12/28/2020 – Ephemeris – Some astronomical events of 2020

December 28, 2020 Comments off

This is Ephemeris for Monday, December 28th. Today the Sun will be up for 8 hours and 50 minutes, setting at 5:09, and it will rise tomorrow at 8:19. The Moon, 1 day before full, will set at 8:01 tomorrow morning.

Let’s look at some astronomical and space news for this past year. A year ago the bright red star in the constellation Orion Betelgeuse underwent an unprecedented amount of dimming. It had pretty much recovered its brightness since. The best idea was that it ejected a cloud of dust that obscured part of the star from us. NASA’s Commercial Crew program came through this year with the successful launching of two crews to the International Space Station aboard the SpaceX Falcon 9 rocket and Crew Dragon Capsule. Boeing stood down this year after the failure of their uncrewed Starliner capsule to reach the space station last December. They will try another uncrewed attempt in a few months. I’ll have more tomorrow.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Orion's named stars

Orion’s named stars including the belt stars. Betelgeuse is the bright red in the upper left. Created using Stellarium.

Betelgeuse before and after dimming

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Betelgeuse is one of the few stars close and large enough to be able to image its disk. Credit: ESO/M. Montargès et al.

SpaceX Crew-1 Crew

Astronauts Shannon Walker, Victor Glover, and Mike Hopkins, and astronaut Soichi Noguchi inside the Crew Dragon capsule. Credit: SpaceX.

SpaceX Crew-1 Dragon capsule docking with the International Space Station

SpaceX Crew-1 Dragon capsule docking with the International Space Station. Credit: NASA

 

 

 

12/25/2020 – Ephemeris – Did the “Star” of Bethlehem appear in 3 BC and again in 2 BC?

December 25, 2020 Comments off

Merry Christmas, this is Bob Moler with Ephemeris for Christmas Day, Friday, December 25th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:07, and it will rise tomorrow at 8:19. The Moon, halfway from first quarter to full, will set at 4:53 tomorrow morning.

Many writers of the 2nd and 3rd centuries AD place Jesus’ birth around 2 BC, which had to be before Herod the Great’s death, which I suggest was in 1 BC marked by to a total lunar eclipse. In 3 and again in 2 BC there were star-like conjunctions or apparent joinings of the planets Jupiter and Venus against the backdrop of the constellation of Leo the Lion. A lion is related to Judah, son of Jacob by a blessing the latter gave his 12 sons in Genesis. The first conjunction occurred in August of 3 BC in the morning sky. In June the next year the two planets got together again, this time in the evening sky, just after Jesus would have been born in the lambing season of spring.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

August 12, 3 BC conjunction

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. The ghostly image popping up in the second frame is the thin crescent Moon showing earth shine. Created using Stellarium and GIMP.

The second appearance of the "Star"

On June 16th 2 BC, this time in the evening, Venus and Jupiter seem to coalesce as one, at least to the naked eye. Regulus (The Little King star) is the brightest star in Leo the lion. To the upper right of it is the Sickle, the front part of the lion and his head and mane. Created using Stellarium and GIMP.

12/24/2020 – Ephemeris – Was the Star of Bethlehem a triple conjunction of Jupiter and Saturn in 7 BC?

December 24, 2020 Comments off

This is Bob Moler with Ephemeris for Christmas Eve, Thursday, December 24th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:07, and it will rise tomorrow at 8:18. The Moon, 3 days past first quarter, will set at 3:50 tomorrow morning.

For many years the most popular theory for the origin of the Star of Bethlehem was a triple conjunction of Jupiter and Saturn in 7 BC. This is because, due to Earth’s motion, other planets from our view point seem to reverse course when we pass them or are being passed in the circular racetrack of the solar system. When Jupiter and Saturn approach each other just before they go retrograde or reverse course they have a chance to pass each other, backup and pass again, then going forward to pass a third time. Jupiter and Saturn did that last in 1981, so it’s a reasonably rare occurrence, especially when it happens in front of the constellation Pisces which was supposedly related to the Jews.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Jupiter-Saturn Triple Conjunction

Jupiter and Saturn pass each other three times from May to December in 7 BC against the constellation of Pisces. Reload the page to replay the animation. Created using Cartes du Ciel (Sky Charts) and GIMP.

Retrograde motion explained

Retrograde motion illustrated using Mars in 2018. Created using my LookingUp program.

 

 

12/23/2020 – Ephemeris – Let’s look for the naked-eye planets for this Christmas week

December 23, 2020 Comments off

This is Ephemeris for Wednesday, 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, 2 days past first quarter, will set at 2:49 tomorrow morning.

Let’s look for the naked-eye planets for this week. Jupiter and Saturn are both low in the southwestern sky around 6 pm. Jupiter is the very bright one. Below and right of it is the dimmer Saturn it by a quarter of a degree or half a moon width. They crossed paths for us two nights ago, in 20 years, though not as close. They can still be seen in the same low power telescope field. Saturn will now set first tonight at 7:20 pm with Jupiter following a minute later. Quite high in the southeast and above the 9 day old Moon at that hour will be Mars, still in Pisces. Mars’ distance is increasing to 76 million miles (123 million km) away. It will set at 2:41 tomorrow morning. Brilliant Venus will rise at 6:33 am in the east-southeast as it seems to retreat slowly toward the Sun, but actually it’s heading way 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

Jupiter and Saturn in the twilight

Jupiter and Saturn in twilight at 6 pm or a bit less than an hour after sunset tonight December 23, 2020. Created using Stellarium.

Mars above the Moon

Mars will be seen above the Moon tonight. This is the appearance of both at 6 pm, tonight, December 23, 2020. Created using Stellarium.

Binocular Moon

The gibbous Moon as it might be seen in binoculars this evening at 6 pm December 23, 2020. Created using Stellarium.

Venus in the morning twilight

Venus low in the southeast at 7:30 am December 24, 2020. The morning sky is not as friendly to morning planets as it was earlier in autumn. Created using Stellarium.

Telescopic planets

The planets as seen in a telescope (north up) with the same magnification for the night of December 23/24, 2020. Times of the display are: Jupiter, Saturn, and Mars, 6 pm; Venus, 7:30 am. Apparent diameters: Jupiter, 33.18″; Saturn, 15.32″, rings, 35.70″; Mars, 11.32″, and Venus 10.89″. 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.) I will no longer show planets whose diameters drop below 10″, or are too close to the direction of the Sun to observe. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 23, 2020. The night ends on the left with sunrise on the 24th. I’m afraid that the labels for Jupiter and Saturn will overlap, since the planets are very close. Click on the image to enlarge. Created using my LookingUp program.

 

 

12/22/2020 – Ephemeris – Winter is going to be colder before it starts to warm up in a little over a month

December 22, 2020 Comments off

This is Ephemeris for Tuesday, December 22nd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:05, and it will rise tomorrow at 8:18. The Moon, 1 day past first quarter, will set at 1:47 tomorrow morning.

Now that winter is here, it’s going to get snowier and colder even though the amount of heat the Northern Hemisphere gets from the Sun bottomed out yesterday. There are two consequences of the Earth’s axial tilt with regard to the Sun on the winter solstice. First, the Sun is only up 8 hours 48 minutes. Second at its highest at local noon the Sun is so low, only 22 degrees above the horizon around here that its heat is spread out over a greater area so is diluted to only 40% of the peak heat we get from the Sun at noon on the summer solstice. And on the summer solstice the Sun stays up almost six and three-quarters of an hour longer. Even though it doesn’t feel like it at our latitude winter is 4 days shorter than summer. You’ll find out why in less than two weeks.

Addendum

Solstices

Comparing the sun’s path at the summer and winter solstices. This is a stereographic representation of the whole sky which distorts the sky and magnifies the size of the sun’s path near the horizon.

Earth's position at the solstices and equinoxes

Earth’s position at the solstices and equinoxes. This is an not to scale oblique look at the Earth’s orbit, which is nearly circular. The Earth is actually farthest from the Sun on July 4th. Click on the image to enlarge. Credit: ESO (European Southern Observatory which explains the captions in German and English.

 

12/21/2020 – Ephemeris – Jupiter and Saturn will appear super close tonight

December 21, 2020 Comments off

This is Ephemeris for Monday, December 21st. 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, at first quarter today, will set at 12:45 tomorrow morning.

Today we begin winter and the conjunction or extremely close grouping of Jupiter and Saturn low in the southwestern sky from about 6 to 7 pm. At that time they will be a fifth of the diameter of the Moon apart. Depending on sky conditions, Saturn may not even be visible, lost in twilight or in the glare of Jupiter which is 11 times brighter. A pair of binoculars, or a low power telescope will confirm their appearance, with Saturn to the upper right of Jupiter. Conjunctions of Jupiter and Saturn occur about every 20 years, the last in 2000. The conjunction before that was a triple conjunction like has been proposed for the Star of Bethlehem occurring during the first 11 months of 1981. The next conjunction will be on November 5th, of 2040.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

 

Jupiter and Saturn as they would appear in a low power telescope field

Jupiter and Saturn as they would appear in a low power telescope field tonight December 21, 2020, between 6 and 7 pm. Created using Cartes du Ciel (Sky Charts)

The Earth-Jupiter-Saturn conjunction line of sight.

The Earth-Jupiter-Saturn conjunction line of sight. Created using my LookingUp for Windows program.

Categories: Conjunction Tags: ,

12/18/2020 – Ephemeris – Winter begins Monday morning

December 18, 2020 Comments off

This is Ephemeris for Friday, December 18th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:03, and it will rise tomorrow at 8:16. The Moon, 3 days before first quarter, will set at 9:29 this evening.

Monday will host two astronomical events. The second will be the extremely close conjunction or appearing together of the planets Jupiter and Saturn, which I’ll talk about then. But first, at 5:02 Monday morning winter will begin with the winter or December solstice. The word solstice means Sun stand still. On or about December 21st, the Sun appears to stop moving southward measured at noon and will begin moving northward again. All this is the result of the Earth’s 23 ½ degree axial tilt and our motion around the Sun. Our area of the globe is now receiving less energy from the Sun to support our temperatures, and they will continue to fall for the next month or so even as the Sun rises higher and stays out longer.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Winter solstice

The sun’s daily path through the sky from horizon to horizon on the first day of winter, the winter solstice. Credit My LookingUp program.