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04/20/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, April 20th. Today the Sun will be up for 13 hours and 44 minutes, setting at 8:34, and it will rise tomorrow at 6:48. The Moon, 3 days before last quarter, will rise at 1:51 tomorrow morning.
Let’s search for the naked-eye planets for this week. There is one bright planet in the evening sky. Mercury may be spotted around and after 9:15 this evening very low in the west-northwest and be visible for the next half hour or so. After that, the planet action shifts to the morning sky. The other 4 naked-eye planets are there. By 6 am, the planets will be spread out low from the east to southeast with brilliant Venus moving closer to Jupiter, lowest in the east. Dim Mars will be to the right and a bit above Venus, while brighter Saturn will be right and above Mars. Saturn will rise tomorrow at 4:27 am, with Mars following at 4:55. Venus will rise at 5:19 tomorrow morning, followed by Jupiter at 5:39 am. The Moon will be in the south at 6 am.
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 in the evening at 9:15, or about 40 minutes after sunset tonight, April 20, 2022. Created using Stellarium.
Annotated Binocular Moon. What the Moon might look like tomorrow morning, April 21, 2022. Created using Stellarium, GIMP and LibreOffice.
Translations
Mare Frigoris – Sea of Cold
Mare Humorum – Sea of Moisture
Mare Imbrium – Sea of Showers
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Oceanus Procellarum – Ocean of Storms
Note that Mare is pronounced Mar-é
Parade of the morning planets at 6 am or about 45 minutes before sunrise tomorrow, April 21, 2022. Created using Stellarium.
Views of Venus, Saturn, and Jupiter (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 6:00 am, April 21, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Venus 18.01″, 64.0% illuminated; Saturn 16.24″, its rings 37.82″; Jupiter 34.24″. Mars is not shown, its apparent diameter is 5.56″ and is 90.2% illuminated. The moons of Jupiter and Saturn may not be visible in twilight. Io transiting the face of Jupiter definitely will not be visible. Jupiter is shown here much dimmer compared to its moons than it actually is. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on April 20, 2022. The night ends on the left with sunrise on the 21st. Notice that all the naked-eye planets are in the morning sky now, with the Moon still hanging out in the evening sky. Click on the image to enlarge it. Created using my LookingUp program.
04/19/2022 – Ephemeris – A constellation memorializing a real person
This is Ephemeris for Tuesday, April 19th. Today the Sun will be up for 13 hours and 41 minutes, setting at 8:32, and it will rise tomorrow at 6:49. The Moon, 3 days past full, will rise at 12:37 tomorrow morning.
High in the southeast at 10 p.m. is a tiny and faint constellation of Coma Berenices, or Berenice’s Hair. In it are lots of faint stars arrayed to look like several strands of hair to the naked eye. The whole group will fit in the field of a pair of binoculars, which will also show many more stars. The story behind it was that Berenice was a real Queen of Egypt, whose husband was away at war. This was in the days when the Greeks ruled Egypt after Alexander conquered it. She offered her golden tresses to the gods for the king’s safe return. The hair, was placed in a temple. However, the offering disappeared when the king returned. Ever since then, the constellation of Coma Berenices has been seen to commemorate the queen’s sacrifice.
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
Coma Berenices and neighboring constellations at 10 p.m. in mid-April. Note that only the upper right star of the upside down L shape actually belongs to the cluster. Click on the image to enlarge it. Created using Stellarium.
Approximate 7 power binocular field of view (FOV) of the Coma Berenices Cluster. Created using Cartes du Ciel (Sky Charts).
04/18/2022 – Ephemeris – Arcturus, the fourth-brightest nighttime star*
This is Ephemeris for Monday, April 18th. Today the Sun will be up for 13 hours and 38 minutes, setting at 8:31, and it will rise tomorrow at 6:51. The Moon, 2 days past full, will rise at 11:17 this evening.
The fourth-brightest nighttime star* is now up in the east these evenings. It is Arcturus, a bright star with an orange hue. It can be found otherwise by finding the Big Dipper and tracing out and extending the curve of the handle and saying the phrase “Follow the arc of the handle to Arcturus”, to remember the name of the star and how to find it. Arcturus is about 37 light years from us and is moving quite rapidly across the sky, compared to most stars, but one would not notice it to the naked eye in one’s lifetime. Arcturus is slightly more massive than our Sun, and about 7 billion years old, and is entering its red giant stage of life after using all the hydrogen fuel in its core. Our Sun, being slightly less massive, will survive on hydrogen a bit longer.
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.
*Or 5th brightest star, depending on which list you look at. Arcturus and Vega, which is just above the horizon in the northeast at 10 pm, are nearly the same brightness, however Vega is white while Arcturus is orange, making brightness comparisons difficult visually. Stellarium, however, reports Vega is a slightly brighter magnitude 0.00, while Arcturus is 0.15. My older lists say Arcturus is the 4th brightest star. I’m an older guy, so I’m sticking with it.
Addendum
How to find Arcturus nearly a month into spring. Arcturus is in the east in the evening. The Big Dipper is high in the northeast standing on its handle. To find and remember the name of this star, simply follow the arc of the handle to Arcturus. Created using Stellarium and GIMP.
I’ll have more tidbits about this remarkable star throughout the spring and summer. Can’t wait? Search for Arcturus on this blog.
04/06/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, April 6th. Today the Sun will be up for 13 hours and 2 minutes, setting at 8:16, and it will rise tomorrow at 7:12. The Moon, 3 days before first quarter, will set at 2:16 tomorrow morning.
Let’s search for the naked-eye planets for this week. There is one bright planet in the evening sky, but too close to the Sun to be seen. Mercury passed behind the Sun last Saturday and will be visible later this month, so the planet action still shifts to the morning sky. The other 4 naked-eye planets are there, though Jupiter is too close to the Sun to be seen. Late winter and early spring mornings aren’t the best for spotting planets close to the Sun, since they tend to lie low in the southeastern sky. Venus, Mars, and Saturn will rise within 16 minutes of each other by 5:35. By 6:30, they will be low in the east-southeast with dim Saturn to the right and a bit above Venus, and much dimmer Mars to the left and below Saturn.
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
Annotated crescent Moon animation of the Moon tonight, April 6, 2022. The annotations are the official names in Latin of the seas of Tranquility, Crises, Nectar, and Fertility. Created using Stellarium.
Venus, Mars and Saturn as they might be seen around 6:30 tomorrow morning, April 7, 2022. Created using Stellarium.
Views of Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 6:30 am, April 7, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Venus 20.38″, 58.2% illuminated; Saturn 15.92″, its rings 37.08″. Mars is not shown, its apparent diameter is 5.30″ and is 91.2% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on April 6, 2022. The night ends on the left with sunrise on the 7th. Notice that all the naked-eye planets are in the morning sky now, with the Moon still hanging out in the evening sky. Click on the image to enlarge it. Created using my LookingUp program.
04/04/2022 – Ephemeris – Two apparent planetary encounters tonight and tomorrow morning
This is Ephemeris for Monday, April 4th. Today the Sun will be up for 12 hours and 56 minutes, setting at 8:14, and it will rise tomorrow at 7:16. The Moon, 3 days past new, will set at 12:10 tomorrow morning. | We have action at both end of the night tonight. This evening the Pleiades, or Seven Sisters star cluster, will be seen just above and right of the three-day old crescent Moon. The cluster will be at the one o’clock position from the Moon at 9 pm. At the other side of night, at 6:30 tomorrow morning, Venus will be shining brilliantly in the east-southeast and the planets Mars and Saturn will be very close together. This type of appearance is called a conjunction. Mars will appear about three-quarters of a moon diameter below and left of the slightly brighter Saturn. Mars is getting slowly brighter as the Earth creeps up on it, to overtake it this December. It’s currently 165 million miles (266 million kilometers) away.
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 and the Pleiades and Hyades tonight at 9 pm EDT, April 4, 2022. The Moon appears near the stepsister star clusters tonight. In Greek mythology, these two star clusters were indeed stepsisters, fathered by the god Atlas with different mothers. Created using Stellarium with additional captions in LibreOffice.
A Saturn-Mars conjunction with brilliant Venus nearby as it might look like tomorrow morning, April 5, 2022. Created using Stellarium with labels added in LibreOffice.
03/30/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, March 30th. Today the Sun will be up for 12 hours and 40 minutes, setting at 8:07, and it will rise tomorrow at 7:25. The Moon, 2 days before new, will rise at 7:31 tomorrow morning.
Let’s search for the naked-eye planets for this week. There are no bright planets in the evening sky, so the planet action shifts to the morning sky. All five naked-eye planets are there, though Jupiter and Mercury are too close to the Sun to be seen. Late winter and early spring mornings aren’t the best for spotting planets close to the Sun, since they tend to lie low in the southeastern sky. Venus, Mars, and Saturn will rise within 6 minutes of each other by 5:46. By 6:30, they will be low in the east-southeast with much dimmer Mars to the left of Venus, with Saturn between and a bit below them. Monday, April 4th Mars will appear closest to Saturn, scooting below the ringed planet that evening, so they will appear close together both Monday and Tuesday mornings.
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
What the morning planets might appear as at 6:30 tomorrow morning, March 31, 2022. They may be brighter than they actually appear. Created using Stellarium.
Telescopic views of the Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 6:30 am, March 31, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Venus 23.52″, 55.0% illuminated; Saturn 15.78″, its rings 36.76″. Mars is not shown, its apparent diameter is 5.18″ and is 91.7% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on March 30, 2022. The night ends on the left with sunrise on the 31st. Notice that all the naked-eye planets are in the morning sky now, with the Moon still hanging out in the evening sky. Click on the image to enlarge it. Created using my LookingUp program.
03/29/2022 – Ephemeris – Finding zodiacal light
This is Ephemeris for Tuesday, March 29th. Today the Sun will be up for 12 hours and 37 minutes, setting at 8:06, and it will rise tomorrow at 7:27. The Moon, 3 days before new, will rise at 7:10 tomorrow morning.
The evening sky will stay dark for the rest of the week, so it’s time to look for the zodiacal light in the evening. It is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. It’s a glow whose wide base is in the west that extends upwards and to the left. Right now, the end of astronomical twilight is about 9:49 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around 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
The western sky at 10:22 pm, March 25, 2019. Mars appears below the Pleiades in zodiacal light. Credit, mine – Canon EOS Rebel T5, 18mm f.l., f/3.5, 8 sec. ISO 12,800.
I’ve added the approximate ecliptic line from an image I took from a year earlier.
My article in April’s Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society, about zodiacal light.
One of the hardest of the night sky phenomena to spot is zodiacal light. The top picture above is my last photo of the zodiacal light. The photo is showing it brighter than it looks to the naked eye.
Zodiacal light is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is near the ecliptic, the plane of the Earth’s orbit, along which lie the constellations of the zodiac.
This glow seems to have been first recorded by the Arabs around 630 CE. It was first recognized as a morning phenomenon as a false dawn, appearing before the first real glow of astronomical twilight. This false dawn was a big deal for the Islamic faithful, whose morning prayers must be made after the true dawn, or astronomical twilight, when the center of the Sun is 18° below the horizon.
How I usually recognize that I’m looking at the zodiacal light is kind of like not seeing the forest for the trees. That is, in certain parts of the sky, the sky doesn’t seem as dark as other parts. It helps to know where the zodiacal light is supposed to be. Once found, you’ll know what to look for, so finding it in the future will be easier.
In February 2017, on a relatively warm, but clear night, I went out to the Dune Climb at the Sleeping Bear Dunes. Part of the parking lot was plowed. I set up my tracking mount with my 5” scope that had a camera mount to photograph Orion and the Milky Way around Cassiopeia, Perseus and Taurus.
Having not thought about zodiacal light at the time, but while examining and processing the images later on, I began to notice that parts of the sky background not associated with the Milky Way were not as dark as I expected. It was on the side of the Milky Way closest to the ecliptic. These were telephoto shots, so the pyramidal shape of zodiacal light was not apparent. However, in recreating the sky at the time of the observations using Stellarium, it confirmed that it was the area where zodiacal light would be present.
What causes zodiacal light? The cause is dust, micron sized dust from comets and asteroids. Most of these lie in and near the plane of the solar system, which is why zodiacal light is centered on the ecliptic and the constellations of the zodiac and increases in brightness toward the Sun.
The free planetarium program Stellarium (stellarium.org) has added a zodiacal light effect in recent releases. Click on the Sky and viewing options icon at the left edge of the window, In the Sky tab there is a checkbox for zodiacal light and an intensity value to be selected. In order to see the effect, the Atmosphere icon at the bottom of the viewing window must be turned off. The effect is very subtle.
It is best seen around the vernal equinox in the evening and autumnal equinox tn the morning because at these times the ecliptic is closest to vertical. In the evening it tilts to the left, in the morning it tilts to the right. The closer one is to the equator, the more vertical the zodiacal light will appear. It would be a year-round phenomenon for observers in the tropics.
As an aside, Brian May, lead guitarist for the rock band Queen, with an uncanny resemblance to Sir Isaac Newton, earned a PhD in astrophysics in 2007 with his dissertation: A Survey of Radial Velocities in the Zodiacal Dust Cloud. It analyzed the motions of the particles of dust that make up the zodiacal dust cloud, which produces zodiacal light.
The best time to see this phenomenon will be the last week of March to the first few days of April 2022, before the Moon is a couple of days old.
03/28/2022 – Ephemeris – Finding the Great Bear
This is Ephemeris for Monday, March 28th. Today the Sun will be up for 12 hours and 34 minutes, setting at 8:05, and it will rise tomorrow at 7:29. The Moon, 3 days past last quarter, will rise at 6:47 tomorrow morning.
The Big Dipper is now reaching for the zenith in the northeast at 10 p.m. The seven bright stars are second to Orion in the west as the seven brightest stars in a constellation. If you looked up a list of constellations, you’d find that the Big Dipper isn’t there. Ursa Major or the Great Bear is the constellation of which the Big Dipper is a part. The seven bright stars of the dipper are the rump and long tail of this constellation. The rest of the bear, including his head and legs, are delineated by dimmer stars. An anatomical problem is its long tail, which was drawn in by the ancients of the old world. Their explanation was that a god had grabbed the bear’s stubby tail, whirled the bear around his head, and threw it into the sky, thus stretching its tail.
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 Great Bear (Ursa Major) finder animation. It shows the stars only, then the Big Dipper, Then the lines of the constellations Ursa Major and Ursa Minor (Lesser Bear and Little Dipper) as a bonus, and finally the constellation artwork. The orientation is for about 9:30 pm on the latter days of March. We are looking high in the northeast. In Northern Michigan, the bear’s front paw is near the zenith at that time. Created using Stellarium and GIMP.
03/25/2022 – Ephemeris – Over the weekend there will be the continued gathering of morning planets
This is Bob Moler with Ephemeris for Friday, March 25th. Today the Sun will be up for 12 hours and 25 minutes, setting at 8:01, and it will rise tomorrow at 7:34. The Moon, at last quarter today, will rise at 4:56 tomorrow morning.
Over the weekend there will be the continued gathering of morning planets, Venus, Mars and Saturn, culminating on Monday morning when the waning crescent Moon will join the group by slipping beneath them. During the three day period between Saturday and Monday mornings at a specific time, like 6:45 am, about 45 minutes before sunrise, these planets will be in the east southeast and quite low in the sky. A low horizon in that direction will help, especially when the Moon joins the group, because it will be lower than the three planets. Over the weekend Venus and Mars will keep their separation with Mars to the right and a bit below Venus. Saturn will scoot below Venus, moving to the right. The Moon will move below the group Monday morning.
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 grouping of Venus, Mars, Saturn and the Moon which will develop over the mornings of Saturday, March 26th through Monday, March 28, 2022. Created using Stellarium and GIMP.
03/24/2022 – Ephemeris – A native constellation that’s a warning
This is Bob Moler with Ephemeris for Thursday, March 24th. Today the Sun will be up for 12 hours and 22 minutes, setting at 8:00, and it will rise tomorrow at 7:36. The Moon, 1 day before last quarter, will rise at 3:59 tomorrow morning.
The Anishinaabe peoples of the Great Lakes Region, which include the Ottawa and Chippewa Indians, have several constellations of spring. The first of them is Curly Tail, or the Great Underwater Panther, who lurks under the ice in lakes. It uses the stars of Leo the lion’s backward question mark, in the southeast at 9:30 in the evening, as its curved tail and the small knot of stars that are the head of Hydra the water snake as its head. The head of Hydra is below the constellation of Cancer, and in the south-southwest and to the right of the backwards question mark of Leo. The warning he gives is to keep off the thinning ice or break through and be snatched by the great panther that lives below.
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
An animation showing the stars centered in the southeastern skies, the “official” constellations and the Anishinaabe constellation of Curly Tail and the Great (Underwater) Panther. Approximate time is 9:30 pm March 24th. Click on the image to enlarge. Created using Stellarium and GIMP.
