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09/16/2020 – Ephemeris – Let’s look at a the naked-eye planets for this week. Plus thoughts on phosphine in Venus’ atmosphere
This is Ephemeris for Wednesday, September 16th. Today the Sun will be up for 12 hours and 27 minutes, setting at 7:50, and it will rise tomorrow at 7:24. The Moon, 1 day before new, will rise at 7:20 tomorrow morning.
Let’s look at a the naked-eye planets for this week. Jupiter and Saturn are both low in the southern sky at 10 pm. Jupiter is the very bright one. To the left of it will be the somewhat dimmer Saturn. They are now seemly to close a tiny bit since Jupiter is resuming its eastward motion, and they will cross paths in December. Jupiter will set first at 1:37 tomorrow morning with Saturn following at 2:19. The next planet visible will be Mars which will rise at 9:15 pm. Its now down to 41.3 million miles (66.6 million kilometers) away, as the Earth slowly overtakes it at the rate of about 2.1 million miles (3.1 million kilometers) the last week as the Earth begins to pull abreast of it. Brilliant Venus will rise at 3:42 am as it retreats toward the Sun.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Planets visible at 10 pm or about 2 hours after sunset with the zodiacal constellations tonight September 16, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.
Mars, Venus and the zodiacal constellations and Orion at 6 am or an hour and a half before sunrise tomorrow morning September 17, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.
The planets as seen in a telescope (north up) with the same magnification for the night of September 16/17, 2020. Times of the display are: Jupiter and Saturn, 10 pm; Mars, Midnight; Venus, 6 am. Apparent diameters: Jupiter, 42.31″; Saturn, 17.59″, rings, 40.96″. Mars, 21.24″, and Venus 17.09″. Mars also displays an enlargement showing surface detail. 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 September 16, 2020. The night ends on the left with sunrise on the 17th. Click on the image to enlarge. Created using my LookingUp program.
Breaking planet news
Yesterday there were a rash of posts on social media and other sources to the effect “Is there life on Venus?” This was due to an article released in Nature Astronomy that the compound phosphine was discovered in the Venusian atmosphere. Phosphine (PH3) on the Earth, at least, is mostly produced by life processes. I’m still absorbing all of this so check out articles by Dr. Phil Plait (The Bad Astronomer) and Steven Novella (Skeptic’s Guide to the Universe) for less technical takes on the discovery.
Venus is the subject of two of the four proposed discovery program missions that NASA announced this past June. one of them DAVINCI+ will be looking at the atmospheric chemistry and might get a boost and some tweaks due to the phosphine discovery. DAVINCI+ will drop through the atmosphere. The best mission for this would be a balloon floating in the Venusian atmosphere above the sulfuric acid clouds. The Russians did it in 1986. Anyway any mission to Venus is many years away.
I’ll have more for the Ephemeris program itself when I know more.
09/15/2020 – Ephemeris – The dolphin and the arrow, small summer constellations
This is Bob Moler with Ephemeris for Tuesday, September 15th. Today the Sun will be up for 12 hours and 30 minutes, setting at 7:52, and it will rise tomorrow at 7:23. The Moon, 2 days before new, will rise at 6:01 tomorrow morning.
Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is nearly overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Delphinus and Sagitta finder animation. Created using Stellarium and GIMP.
09/14/2020 – Ephemeris – Not exactly a mermaid
This is Bob Moler with Ephemeris for Monday, September 14th. Today the Sun will be up for 12 hours and 33 minutes, setting at 7:54, and it will rise tomorrow at 7:22. The Moon, 3 days before new, will rise at 4:42 tomorrow morning.
Nearly 2000 years ago the southernmost of the constellations of the zodiac was Capricornus which is a water goat. That’s why the latitude on the Earth where the Sun is overhead on the winter solstice is called the Tropic of Capricorn. Not any more, Sagittarius, one constellation west past Jupiter and Saturn this year, has that honor today. Actually Capricornus does need the press. It’s large, but made up of dim stars. To me it looks like a 45 degree isosceles triangle, long side up, but which all the sides are sagging. The constellation is found low in the south-southeast at 10 p.m. The image that is supposed to be represented by the stars is that of a goat whose hind quarters are replaced by a fish’s tail, not a mermaid but a mergoat.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Capricornus finder animation for September 14, 2020 at 10 pm for western Michigan. Note that the Teapot of Sagittarius is pouring its contents on the southwestern horizon is to the right. Created using Stellarium and GIMP.
Important seasonal latitudes on the Earth. Source: worldatlas.com
09/11/2020 – Ephemeris – A virtual star party tonight
This is Ephemeris for Friday, September 11th. Today the Sun will be up for 12 hours and 42 minutes, setting at 7:59, and it will rise tomorrow at 7:18. The Moon, 1 day past last quarter, will rise at 1:19 tomorrow morning.
The Grand Traverse Astronomical Society will host a virtual star party at 9 pm tonight. It is via the Zoom app for the smart phone, tablet or computer at zoom (dot) us. Instructions and a link can be found on the society’s website gtastro.org. It will be hosted by Dr. Jerry Dobek, astronomy professor at Northwestern Michigan College. During a virtual star party the images are produced real time or near real time using a telescope mounted CCD camera. That is if it’s clear. Images of dimmer objects like star clusters or nebulae, what we call DSOs or deep sky objects may take exposures of several seconds or minutes to build up an image. But have the advantage of being in color. If cloudy we’ll have a virtual, virtual star party.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
09/10/2020 – Ephemeris – The bright star Deneb will pass overhead tonight, what does that mean?
This is Ephemeris for Thursday, September 10th. Today the Sun will be up for 12 hours and 45 minutes, setting at 8:01, and it will rise tomorrow at 7:17. The Moon, at last quarter today, will rise at 12:29 tomorrow morning.
Around 11 pm tonight the bright star Deneb in Cygnus the Swan and the northernmost star of the Summer Triangle will be overhead, or just about at the zenith. Just as on the Earth we have a coordinate system of longitude and latitude for position east-west and north-south, we have the same for the celestial sphere the imaginary sphere of the heavens east-west is called right ascension and north-south is declination. I’m going to ignore right ascension’s relation to longitude. Declination directly relates to latitude in that a star the with the same declination as your latitude will pass directly overhead. Deneb’s Declination is about 44 degrees 20 minutes north. Check the GPS on your smart phone to see how close your latitude is to that.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Celestial coordinates are actual projections of earthly coordinates. CNP = Celestial North Pole, CSP = Celestial South Pole are directly above the earthly poles. Same with Celestial Equator. Therefore a star or any celestial object passes overhead or at the zenith for locations with the same latitude on the Earth. That’s what the diurnal or daily circle is as the Earth rotates.
09/09/2020 – Ephemeris – Let’s look at a the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, September 9th. Today the Sun will be up for 12 hours and 48 minutes, setting at 8:03, and it will rise tomorrow at 7:16. The Moon, 1 day before last quarter, will rise at 11:48 this evening.
Let’s look at a the naked-eye planets for this week. Jupiter and Saturn are both low in the southern sky at 10 pm. Jupiter is the very bright one. To the left of it will be the somewhat dimmer Saturn. They seem to be separating a teeny bit due to the Earth’s motion now, but they will cross paths in December. Both planets will be up until the morning hours with Jupiter setting first at 2:05 tomorrow morning and Saturn following at 2:47 am. The next planet visible will be Mars which will rise at 9:44 pm. Its now down to 43.3 million miles (69.7 million km) away, as the Earth slowly overtakes it at the rate of about 2.3 million miles (3.8 million km) a week as the Earth begins to pull abreast of it. Brilliant Venus will rise at 3:30 am as it retreats toward 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 with the zodiacal constellations at 9 pm tonight September 9, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.
Jupiter, Saturn and Mars with the zodiacal constellations at 11 pm tonight September 9, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.
Mars, the Moon, Venus and the zodiacal constellations and Orion at 6 am tomorrow morning September 10, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.
The last quarter Moon as it might be seen in binoculars at 6 am tomorrow September 10, 2020. Created using Stellarium.
The planets as seen in a telescope (north up) with the same magnification for the night of September 9/10, 2020. Times of the display are: Jupiter and Saturn, 9 pm; Mars, Midnight; Venus, 6 am. Apparent diameters: Jupiter, 43.21″; Saturn, 17.77″, rings, 41.39″. Mars, 20.26″, and Venus 18.04″. Mars also displays an enlargement showing surface detail. 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 September 9, 2020. The night ends on the left with sunrise on the 10th. Click on the image to enlarge. Created using my LookingUp program.
09/08/2020 – Ephemeris – The Anishinaabe folk saw a moose where we see Pegasus
This is Ephemeris for Tuesday, September 8th. Today the Sun will be up for 12 hours and 51 minutes, setting at 8:05, and it will rise tomorrow at 7:15. The Moon, 2 days before last quarter, will rise at 11:14 this evening.
Yesterday I talked a bit about the constellation of Pegasus the flying horse ascendant in the east these September evenings. The Anishinaabe peoples of our area had no horses until after the Europeans arrived, but they did imagine a large four legged mammal here, the Mooz or Moose, spelled M-o-o-z and pronounced something like Moonz*. The Moose is upright, or will be when he is in the south. In the evening now he is in the east, his body is a large square of stars we call the Great Square of Pegasus standing on one corner. From the top star extend his neck and head. His great antlers cover the official constellation of Lacerta the lizard made of a zigzag of unremarkable faint stars. Unlike Pegasus the whole moose made it into the sky.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mooz finder animation displaying both Western Pegasus and Lacerta constellations and Anishinaabe Mooz constellation for 10 pm in early September. Credit Stellarium (both star lore images are embedded in Stellarium). The Anishinaabe image is from Ojibwe Giizhig Anung Masinaaigan – Ojibiwe Sky Star Map created by A. Lee, W. Wilson, and C. Gawboy.
*Information on Mooz and its pronunciation can be found in the Ojibwe Peoples Dictionary at https://ojibwe.lib.umn.edu/main-entry/mooz-na. The language of the Ojibwe, Ojibwemowin is another name for Anishinaabemowin, the language of the Anishinaabe peoples.
09/07/2020 – Ephemeris – A first look at the autumn stars arriving: Cassiopeia and Pegasus
This is Ephemeris for Labor Day, Monday, September 7th. Today the Sun will be up for 12 hours and 54 minutes, setting at 8:07, and it will rise tomorrow at 7:14. The Moon, 3 days before last quarter, will rise at 10:46 this evening.
In the evening as summer wanes and the Sagittarius teapot tips its contents on the southwestern horizon the constellations of autumn rise in the east. There’s the W shape of Cassiopeia in the northeast, which is so far north it never really leaves us in northern Michigan. Pegasus the flying horse of Greek mythology is perhaps the most famous of the autumn constellations, and easiest to find. Its body, a large square of four stars, is in the east, standing on one corner. It is known as the Great Square of Pegasus. Only the front half of the horse is in the sky, and he’s flying upside down with his neck and head extending to the right from the rightmost star. His galloping front legs extend upward from the top star.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Northeast to southwest Panorama around the horizon at 10 pm tonight, September 7, 2020 showing the constellations discussed. Click on the image to enlarge. Created using Stellarium and GIMP.
09/04/2020 – Ephemeris – What area of the Moon is the Artemis program interested in?
This is Ephemeris for Friday, September 4th. Today the Sun will be up for 13 hours and 3 minutes, setting at 8:13, and it will rise tomorrow at 7:10. The Moon, 2 days past full, will rise at 9:40 this evening.
Where will Artemis missions land when they get to the Moon? The Apollo missions mostly landed on the flat lunar seas which were really lava plains. The Artemis missions are headed to the Moon’s south polar regions. The Moon, unlike the Earth has very little axial tilt, so some of the crater floors at the poles are forever in shadow and near absolute zero, so are cold traps for volatile matter like water. Satellites over the years have found hydrogen over the south pole of the moon hinting that there is water ice there from impacting comets. There’s also crater peaks that are always in sunlight where solar panels can be erected to provide power throughout the month long lunar day. On the Moon, water is more precious than gold. There’s water in them thar craters!
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The south pole of the Moon where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos. Notice a theme in the crater names here?
09/03/2020 – Ephemeris – Why is the new NASA Moon landing program called Artemis?
This is Ephemeris for Thursday, September 3rd. Today the Sun will be up for 13 hours and 6 minutes, setting at 8:14, and it will rise tomorrow at 7:09. The Moon, 1 day past full, will rise at 9:20 this evening.
Why is the new NASA crewed Moon landing program called Artemis? And why is it crewed, and not manned? Artemis was a Greek deity and Apollo’s twin sister. He was the god of the Sun and she was goddess, among other things, of the Moon. So she has a greater connection to the Moon than Apollo did. Spacecraft now-a-days are crewed, rather than manned to denote that both sexes are chosen to be astronauts in nearly equal numbers now. Of course that’s crewed spelled c-r-e-w-e-d, not c-r-u-d-e, though they sound the same. Deities of the Moon tend to be female be they Artemis, Cynthia, Luna, Selene, or Chang’e. Astronomers use Cynthia, Luna, and Selene (pronounced Sel-e-nae) in naming various aspects of the Moon and Chang’e is the goddess that the Chinese name their lunar landers after.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The logo chosen by NASA for the Artemis Program. The blue crescent at the bottom represents the earth. The gray ball at the top is the Moon. The curved red path is the stylized return path from the Moon to the Earth of the Orion capsule. Credit: NASA.
Artemis, goddess of the hunt and the Moon. Credit: Disney (Fantasia) source Daily Kos.
Bob Moler's Ephemeris Blog 