Archive
01/18/2023 – Ephemeris – Let’s see where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, January 18th. Today the Sun will be up for 9 hours and 17 minutes, setting at 5:32, and it will rise tomorrow at 8:14. The Moon, 3 days before new, will rise at 6:28 tomorrow morning.
Let’s see where the naked-eye planets have wandered off to this week. Very early after sunset, Venus might be spotted very low in the southwest by 6 pm. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky by 6:30 or 7 pm. Mars will be above Orion in the east-southeast and near the Pleiades. Jupiter is the brightest of the three and will be in the south-southwest., while dimmer Saturn will be very low in the southwest at that time. Saturn, the westernmost of these bright planets, will set around 7:42 this evening. It’s a bit above and left of Venus. Mercury is now in the morning sky, after it passed inferior conjunction with the Sun on the 7th, that is, it passed between the Earth and the Sun. It should be briefly visible before sunrise by month’s end.
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
Venus and Saturn low in the southwest at 6:15 pm tonight, January 18, 2023. Saturn will probably not be visible yet, but Venus should be plenty bright enough. Created using Stellarium.
All the evening planets before Venus sets are in this panorama looking southward from east to west at 7:15 tonight, January 18, 2023. I dropped lines from some of the dimmer constellations. Click on the image to enlarge it. Created using Stellarium.
Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image of Mars doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. The planets are shown at 7 pm tonight, January 18, 2023. Apparent diameters: Venus 10.77″ and is 93.5% illuminated; Saturn 15.52″, its rings 36.16″; Jupiter 37.32″. Mars 12.25″. Mars’ distance is71.6 million miles (114.4 million kilometers). The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. 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 January 18, 2023. The night ends on the left with sunrise on the 19th. Click on the image to enlarge it. Created using my LookingUp app and GIMP.
01/09/2023 – Ephemeris – The Summer Triangle is still with us in the early evening
This is Ephemeris for Monday, January 9th. Today the Sun will be up for 9 hours and 1 minute, setting at 5:21, and it will rise tomorrow at 8:18. The Moon, 3 days past full, will rise at 7:56 this evening.
The bright Moon is now slowly leaving the evening sky tonight, giving us nearly an hour of dark skies after 7 pm. At 7pm, Orion is holding forth in the east-southeast. At that time, also, the Summer Triangle is still in the sky, west and northwest. The Northern Cross, which is also the constellation of Cygnus the swan, is standing upright in the west northwestern sky. Its top star Deneb, dimmest of the three Summer Triangle stars, will not set for observers north of Traverse City, though it will take a flat northern horizon and exceptionally clear skies to spot it at its lowest in the north. Altair, the southernmost of the triangle stars will set first in the west at 7:57 pm, Vega, the brightest will set in the northwest at 9:41 pm.
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 setting Summer Triangle and Northern Cross in the west and northwestern sky at 7 pm tonight, January 9th.
01/05/2023 – Ephemeris – I’m Sirius about this being the brightest nighttime star!
Jan 5. This is Bob Moler with Ephemeris for Thursday, January 5th. Today the Sun will be up for 8 hours and 56 minutes, setting at 5:16, and it will rise tomorrow at 8:19. The Moon, 1 day before full, will set at 8:33 tomorrow morning.
The brightest nighttime star, Sirius, rises before 8 pm tonight. It can be found by following the constellation Orion’s three belt stars downward to near the east-southeastern horizon. As far as star-like objects go, Jupiter and Venus can always outshine Sirius. Mars can too, but only when it is near the Earth and this early evening when Mars is high in the sky and Sirius is low in the sky. When the Moon clears out of the evening sky, and Sirius rises higher, the other stars of its constellation will become visible. That constellation is Canis Major, Orion’s great hunting dog, from which it gets its nickname: Dog Star. The name Sirius means Dazzling One, an allusion to its great brightness and, being low in the sky, it twinkles mightily.
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
A Sirius finder animation for January/early February at around 8 pm. Even in bright moonlight, the seven bright stars of Orion can be seen. The three stars of Orion’s belt make a great pointer to Sirius. Created using Stellarium, GIMP and LibreOffice (for the arrow).
12/28/2022 – Ephemeris – Taking a look at the bright planets for the last week of the year
This is Ephemeris for Wednesday, December 28th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:09, and it will rise tomorrow at 8:19. The Moon, 1 day before first quarter, will set at 11:46 this evening.
Let’s see where the naked-eye planets have wandered off to this week. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky at 6:30 pm. Mars is in the east. Jupiter is the brightest of the three in the south, while dimmer Saturn is low in the southwest at that time. Mars is above Orion as it rises in the early evening. Saturn, the westernmost of the bright planets, will set around 8:52 this evening. Venus and Mercury are also in the evening sky, but too close to the setting Sun to be easily spotted. At 6 pm, both will be very low on the southwestern horizon, with Mercury just above Venus by three moon-widths. There are now no bright morning planets, though Mars won’t set until 6:32 am in the northwest.
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 naked eye Planets and Moon at 8 in the evening tonight, December 28, 2022. Created using Stellarium.
Waxing crescent Moon as it might appear in binoculars or low power telescope tonight, December 28, 2022. Created using Stellarium, LibreOffice Draw and GIMP
Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image of Mars doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. The planets are shown at 8 pm tonight, December 28, 2022. Apparent diameters: Saturn 15.82″, its rings 36.84″; Jupiter 39.72″. Mars 15.06″. Mars’ distance is 57.8 million miles (93.0 million kilometers). 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 December 28, 2022. The night ends on the left with sunrise on the 29th. Click on the image to enlarge it. Created using my LookingUp app and GIMP.
12/21/2022 – Ephemeris – Winter starts today plus our weekly look at the bright planets
This is Bob Moler with Ephemeris for Wednesday, 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, 2 days before new, will rise at 7:41 tomorrow morning.
Winter begins today at 4:48 pm, just before sunset, from then on until next June the 21st, the Sun, being its farthest south in our skies, will be heading northward again. Let’s see where the naked-eye planets have wandered off to this week. Mars, Jupiter and Saturn will be visible this evening, in the east to southwestern sky at 6 pm. Jupiter is the brightest of the three in the south-southeast, while dimmer Saturn is low in the south-southwest at that hour. Mars is above Orion in the east. Saturn, the westernmost of the bright planets, will set around 9:16 this evening. Venus and Mercury are also in the evening sky, but too close to the setting Sun to be easily spotted. At 6 pm, both will be very low on the southwestern horizon.
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.
Addenda
Winter solstice today
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. This chart is for Traverse City, Michigan, about a third of a degree south of 45º north latitude. Created using my LookingUp app.
The bright planets this week
Panoramic view of planets this evening at 7 pm, December 21, 2022. Click on the image to enlarge it. Created using Stellarium.
Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image of Mars doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. The planets are shown at 7 pm tonight, December 21, 2022. Apparent diameters: Saturn 15.95″, its rings 37.15″; Jupiter 40.64″. Mars 15.92″. Mars’ distance is 54.6 million miles (88.0 million kilometers). The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. 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 December 21, 2022. The night ends on the left with sunrise on the 22nd. Click on the image to enlarge it. Created using my LookingUp app and GIMP.
12/16/2022 – Ephemeris – The Anishinaabe constellation of Winter Maker announces the coming of winter
This is Ephemeris for Friday, December 16th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:03, and it will rise tomorrow at 8:14. The Moon, at last quarter today, will rise at 1:22 tomorrow morning. | The native peoples of the Great Lakes area are the Anishinaabe, composed of the Odawa or Ottawa, and Chippewa or Ojibwe tribes. One of their great constellations is the Winter Maker, whose central part we know as Orion. Instead of turning to face the charge of Taurus the bull, holds his arms outstretched to embrace all the winter stars. His rising in November foretells the coming of winter. His name in their Anishinaabemowin language means North Wind. Now that winter is almost here, he is moving to the southern part of the sky in the evening to reign over the brilliant stars of winter. The star we call Sirius, the brightest nighttime star, is called Gizhii’anung. Anung means “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
The Anishinaabe constellation of the Winter Maker, whose arms will encompass the rest of the winter stars, once they rise later in the evening. Also shown is the Hole in the Sky, which we know as the Pleiades.
12/15/2022 – Ephemeris – Stories of the Pleiades from many lands
This is Ephemeris for Thursday, December 15th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:02, and it will rise tomorrow at 8:13. The Moon, 1 day before last quarter, will rise at 12:16 tomorrow morning.
Let’s look at how some ancient cultures saw the Pleiades, the star cluster that is seen high in the eastern sky these evenings. To the Anishinaabe native peoples around here, the Pleiades is the “Hole in the Sky” or the seven stones that are heated for the sweat lodge ceremony. To the Kiowa, these were sister stars that had been whisked into the sky from the top of Devil’s Tower in Wyoming, where they were threatened by a huge bear. In Norse mythology, these were the goddess Freya’s* hens. The name we know them by has rather misty origins. Some think the Greek name is from the mother of the seven sisters, Pleione. The Greek word for sail is similar to Pleiades, and the appearance of the Pleiades in the morning sky saw the best sailing weather in the Mediterranean.
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.
* Freya is the Norse goddess from which we get the name of the day of the week Friday from. In Latin, the day is named after the goddess Venus.
Addendum
The Greek Pleiades, a painting by Elihu Vedder in the Metropolitan Museum of Art, New York City. Public Domain.
Seven maidens being attacked by a giant bear, having fled to the top of Devil’s Tower in Wyoming. Painting by Herbert Collins, http://www.nps.gov/deto
They are also the Seven Daughters of the Moon and Sun. They loved to dance and play, and when their father, the Moon was low in the sky, would descend to the Earth in a basket to do their thing. On one of their trips to the earth, one of them was captured by a human, and she ended up falling in love with him, and married him. When father Moon found out, he permanently dimmed her star, so now most people now only can spot 6 of the stars. This last bit seems to parallel the Greek story of the lost Pleiad.
12/12/2022 – Ephemeris – Orion and the scorpion
This is Bob Moler with Ephemeris for Monday, December 12th. 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, 4 days before last quarter, will rise at 9 this evening.
The wonderful constellation of Orion the hard luck hunter is seen rising in the east as twilight fades. According to one Greek myth he was killed by the sting of a scorpion, thus he can only rise as the summer constellation of Scorpius the scorpion sets in the southwest, and he must set as the scorpion rises on early spring evenings. By 9 pm, he is located in the east-southeast. His three belt stars are nearly vertically arranged in a line and equally spaced. They point down to the horizon, where the brightest nighttime star Sirius will rise at about 9:20 pm. The belt stars lie within a large rectangle of stars tilted to the left. His shoulders and knees. The top left star is the bright red Betelgeuse. The bottom right star is blue-white Rigel. We’ll explore more of Orion all winter.
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
A panorama showing Orion rising while Scorpius the scorpion is below the horizon. Both the atmosphere and the ground were removed in this view. The horizon is the green horizontal line. Orion, apparently, is so afraid of the scorpion, that he won’t enter the sky until the scorpion is long gone, putting the Sun between the two. This business of the two never being in the sky at the same time only works for observers in the Earth’s Northern Hemisphere. Click on the image to enlarge it. Created using Stellarium
12/09/2022 – Ephemeris – The earliest sunset of the year
This is Bob Moler with Ephemeris for Friday, December 9th. Today the Sun will be up for 8 hours and 53 minutes, setting at 5:02, and it will rise tomorrow at 8:09. The Moon, 2 days past full, will rise at 5:59 this evening.
We are at the period of time of the earliest sunset, in the middle of a 13-day stretch where the Sun sets within the same minute. We are still 12 days from the winter solstice, the day of the shortest daylight hours, on the 21st. The reason is twofold. The Sun is near its farthest position south of the equator, where the longitude lines are closer together, so it takes less time to cross them. 15 degrees in longitude equals one hour in Earth’s rotation. Add to that we are less than a month from Earth’s perihelion in its orbit of the Sun, that is at its closest, and is moving faster than average. The combined effects delay sunrise and sunset, from what they’d be if the Sun was on the equator and the Earth’s orbit was circular. We will have our latest sunrise on January 2nd.
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
How the Sun’s declination affects how rapidly it appears to cross time lines (meridians)
Table of Earliest and Latest Sunrises and Sunsets during the year for Interlochen/Traverse City area of Michigan.
In December the Earth is approaching perihelion, its closest to the Sun, so it moves faster than average. This makes the Sun to appear to move faster eastward against the stars in our sky. This tends to make our sunrises, apparent local noons and sunsets later than they would otherwise be. This makes sunset bottom out early and extends the date of the latest sunrise
For the June or summer solstice around here, the Earth is near aphelion, its farthest from the Sun where the Earth is at its slowest in its orbit. By reflection, the Sun appears to move its slowest against the stars in our sky. This effect works against the high latitude effect, making the effect smaller. Looking at the table above, the days between the earliest and latest times is shorter for the summer solstice than for the winter solstice.
12/07/2022 – Ephemeris – An occultation of Mars and a look at the other naked eye planets.
This is Bob Moler with Ephemeris for Wednesday, 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 full today, will rise at 4:31 this evening.
Let’s see where the naked-eye planets have wandered off to this week. Mars, Jupiter and Saturn will be visible this evening, in the southeastern sky by 6 pm. At that time, Mars will be below, left of the bright full Moon. Jupiter is the brightest of the three in the southeast, while dimmer Saturn is in the south-southeast at that hour. Mars will be hidden behind the Moon from about 10:15 to 11:15 pm tonight for the IPR area. Being a full moon, Mars might be difficult to spot. It may take binoculars to spot it below, left of the Moon by 9:30, and a small telescope when Mars is near the edge of the Moon. The disappearance of Mars will be at the Moon’s 7 o’clock position, and reappearance at the 4 o’clock position. Bobmoler.wordpress.com (you are already here) has more information.
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
Panoramic view of planets and Moon this evening at 7 pm tonight, December 7, 2022. Click on the image to enlarge it. Created using Stellarium.
Mars occultation animation in half hour steps for 9:15 pm, 9:45 pm, 10:15 pm (Ingress), 10:45 pm (mid-occultation), 11:15 pm (egress), 11:45 pm. The Moon and the apparent path of Mars rotates as they cross the sky from east to west. In actuality, the Moon is much brighter than Mars, so picking the planet out tonight will be a challenge. It will take the Moon almost a minute to completely cover Mars, and nearly another minute to uncover it. The plot is centered on the Moon here, but the Moon provides most of the motion here. On average, the Moon moves 12 degrees a day, while Mars moves less than a degree against the starry background. Created using Stellarium and GIMP.
Telescopic views of Saturn Jupiter and Mars (north up) as they would be seen in a small telescope, with the same magnification. The image of Mars doesn’t show it, but the white north polar cap will appear at the top or north limb of Mars. The planets are shown at 8 pm tonight, December 7, 2022. Apparent diameters: Saturn 16.25″, its rings 37.86″; Jupiter 42.55″. Mars 17.05″. Mars’ distance is 51.0 million miles (82.1 million kilometers). This is the closest it comes to the Earth this orbit. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. 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 December 7, 2022. The night ends on the left with sunrise on the 8th. Click on the image to enlarge it. Created using my LookingUp app and GIMP.
World map showing the area that the occultation of Mars will be visible. Occultation visibility will move from west to east. Credit: Occult version 4. This evening in the EST zone is the 8th for Universal Time (UT), or GMT (Greenwich Mean Time) if you’re older.
