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07/20/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

July 20, 2022 1 comment

This is Ephemeris for Wednesday, July 20th. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21, and it will rise tomorrow at 6:17. The Moon, at last quarter today, will rise at 1:13 tomorrow morning.

Let’s search for the naked-eye planets for this week. All but one of the naked-eye planets are in the morning sky, That one is Mercury, too close to the Sun to be seen in the evening. At 5:15 am tomorrow, the planets will be spread out from brilliant Venus low in the east-northeast to Saturn higher in the south-southwest. Mars will be a lot higher than Venus in the east-southeast. The waning crescent Moon will be just right of Mars. Jupiter is farther to the right in the southeast. Mars is dimmer than Jupiter, but is slowly getting brighter as the Earth creeps up on it. Saturn ends the line of planets lower than Jupiter in the south-southwest. Tonight, Saturn will rise about 10:30 pm, though it won’t be an official evening planet until it rises before sunset, which won’t happen until mid-August.

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 morning planets and the Moon at 5:15 am tomorrow morning, July 21, 2022. The planets and Moon actually appear in a straight line in the sky, being placed along the ecliptic, or path of the Sun in the sky. The ecliptic is a great circle on the celestial sphere. Click on the image to enlarge it. The span of the planets from Venus to Saturn is 129 degrees. Click on the image to enlarge it. Created using Stellarium.

Last quarter moon with labels

Animated last quarter Moon at 5:15 tomorrow morning, July 21, 2022, with labels. Created using Stellarium 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
Mare Vaporum – Sea of Vapors
Montes Apenninus – Apennine Mountains
Oceanus Procellarum – Ocean of Storms
Sinus Iridium – Bay of Rainbows
Sinus Medii – Central Bay

Note that Mare is pronounced Mar-é

Telescopic views of Venus, Saturn and Jupiter

Views of Saturn, Jupiter, and Venus (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:15 am, July 21, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Saturn 18.56″, its rings 43.24″; Jupiter 43.47″. Mars is not shown, its apparent diameter is 7.84″; Venus 11.10″. 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).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on July 21, 2022. The night ends on the left with sunrise on the 21st. Notice that all the naked-eye planets except Mercury are in the morning sky now. Click on the image to enlarge it. Created using my LookingUp program.

07/06/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

July 6, 2022 Comments off

This is Bob Moler with Ephemeris for Wednesday, July 6th. Today the Sun will be up for 15 hours and 26 minutes, setting at 9:30, and it will rise tomorrow at 6:04. The Moon, at first quarter today, will set at 1:32 tomorrow morning.

Let’s search for the naked-eye planets for this week. All the naked-eye planets are in the morning sky, although Mercury is too close to the Sun to be seen. On the 16th, it will leave the morning sky, crossing over to the evening sky. At 5 am tomorrow, the planets will be spread out from brilliant Venus low in the east-northeast to Saturn higher in the south. To the right and above of Venus, in the east-southeast, will be the Mars. Jupiter is a bit higher in the southeast. Mars is dimmer than Jupiter, but is slowly getting brighter as the Earth creeps up on it. Saturn ends the line of planets in the south. Tonight, Saturn will rise about 11:30 pm. It won’t be an official evening planet until it rises before sunset. That won’t happen until mid-August.

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

Tonights Moon with labels

First quarter Moon tonight with prominent features labeled. Created using Stellarium, GIMP and LibreOffice.

Morning planets at 5 am, seen on a flattened horizon

The morning planets at 5 am tomorrow morning, July 7, 2022. The planets actually appear in a straight line in the sky, being placed along the ecliptic, or path of the Sun in the sky. The ecliptic is a great circle on the celestial sphere. Click on the image to enlarge it. The span of the planets from Venus to Saturn is 113 degrees. Click on the image to enlarge it. Created using Stellarium.

Morning planets seen in a stereographic view

Distortions of rendering a spherical sky on a flat plane. The morning planets as seen in a stereographic view where great circles, like the ecliptic and horizon, are either circles or straight lines. In this image, the ecliptic, orange line, runs through the center of the plot, so it appears straight. In the real sky, both the planets and the horizon appear to be in straight lines. This assumes that your horizon is flat. Click on the image to enlarge it. Created using Stellarium.

Telescopic views of Venus, Saturn and Jupiter

Views of Saturn, Jupiter, and Venus (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:00 am, July 7, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Saturn 18.32″, its rings 42.68″; Jupiter 41.68″. Mars is not shown, its apparent diameter is 7.41″ and is 85.4% illuminated; Venus 11.60″, 87.5% illuminated. Jupiter’s 4th Galilean moon, Io, is missing because it is in Jupiter’s shadow. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on July 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. Click on the image to enlarge it. Created using my LookingUp program.

03/08/2022 – Ephemeris – It’s International Women’s Day

March 29, 2022 Comments off
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11/09/2021 – Ephemeris – The Moon, Saturn and the return to standard time

November 9, 2021 Comments off

This is Bob Moler with Ephemeris for Tuesday, November 9th. Today the Sun will be up for 9 hours and 48 minutes, setting at 5:20, and it will rise tomorrow at 7:33. The Moon, 2 days before first quarter, will set at 9:48 this evening.

Ever since new moon, the Moon has been moving eastward each night. It will be approaching Saturn tonight, and pass south or below Saturn at mid-morning tomorrow. By tomorrow night, the Moon will have moved just past Saturn, on its way toward Jupiter. The return to standard time since Sunday has darkened our evenings and lightened our mornings. We are about 30 days from the earliest sunset on December 9th, just 18 minute earlier than tonight’s sunset. Our sunrise has a longer time to go to reach last week’s late sunrise times, all the way to January second. Thanks to Congress’s messing around with it, we are on daylight saving time for a longer part of the year than standard time. Don’t get me started.

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

Viewing the Moon’s passage by Saturn and Jupiter for three nights, November 9, 10 and 11, 2021. Created using Stellarium, and GIMP.

10/12/2021 – Ephemeris – It’s Ada Lovelace Day!

October 12, 2021 Comments off

This is Bob Moler with Ephemeris for Ada Lovelace Day, Tuesday, October 12th. Today the Sun will be up for 11 hours and 8 minutes, setting at 7:02, and it will rise tomorrow at 7:56. The Moon, at first quarter today, will set at 11:50 this evening.

Saturn has stopped its retrograde or westward motion against the stars of Capricornus and today has resumed its normal eastern motion.

Ada Lovelace, or more properly Augusta Ada King, Countess of Lovelace, was the daughter of Lord Byron and worked for Charles Babbage, and is considered the first computer programmer. She devised a way to use the same punch cards that were used on the Jacquard loom to store and run her programs, even though Babbage was unable to complete his mechanical computer the Analytic Engine in the mid 1800s. This day is set aside to celebrate the accomplishments of all the women of Science, Technology, Engineering and Math, (STEM). The computer language Ada, named after her, was created for the US Department of Defense.

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

Ada Lovelace

Ada, Countess of Lovelace (1815-1852) considered the first computer programmer, even though the machine she wrote code for was never completed. Credit: Science & Society Picture Library.

Part of the Analytical Engine

Part of Charles Babbage’s Analytical Engine on display, in 1843, left of center in this engraving of the King George III Museum in King’s College, London. Unknown engraver.

08/11/2021 – Ephemeris – Let’s search for the naked-eye planets for this week, and meteors tonight

August 11, 2021 Comments off

This is Bob Moler with Ephemeris for Wednesday, August 11th. Today the Sun will be up for 14 hours and 13 minutes, setting at 8:54, and it will rise tomorrow at 6:42. The Moon will be 3 days past new tonight.

Let’s search for the naked-eye planets for this week. Venus and the Moon will be close together tonight, with Venus below and right of the waxing crescent Moon by 9:30 tonight. Venus will set at 10:18 pm. With the Moon following at 10:50. By 10 pm, Jupiter and Saturn will be seen low in the southeastern sky. The brighter Jupiter will be easy to spot at that hour. Saturn will be dimmer, but a bit higher and to its right. Tonight and especially in the morning hours tomorrow, the Perseid meteors will be at their peak. These bits of Comet Swift-Tuttle, liberated by the comet’s prior passes in through the warmth of the inner solar system, will flash into incandescence as they enter the Earth’s atmosphere at interplanetary speeds.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Venus and the Moon

Venus and the 3-day-old Moon ion evening twilight at 9:45 tonight, August 11, 2021. Created using Stellarium.

Binocular Moon

The Moon as it might appear in binoculars tonight, August 11, 2021, with earth shine on its night side, illuminated by the bright Earth in its sky.
Created using Stellarium.

Jupiter and Saturn in the evening

Jupiter and Saturn in the southeastern sky at 10:30 in the evening tonight, August 11, 2021. Created using Stellarium.

The naked-eye planets as seen in small telescopes

Telescopic view of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening, at 10 pm August 11, 2021. Apparent diameters: Venus, 13.40″; Saturn 18.57″, its rings 43.26″; Jupiter, 49.00″. Jupiter’s moon have a cluster of events in the evening. See below. 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).

                Jupiter's Satellite events
Moon Event EDT (pm-11th, am-12th) UT (12th)
Europa Shadow enters 10:00 pm 02:00
Europa Transit starts 10:25 pm 02:25
Io Eclipse starts 10:41 pm 02:41
Europa Shadow exits 12:51 am 04:51
Ganymede Occultation ends 1:06 am 05:06
Io Occultation ends 1:11 am 05:11
Europa Transit ends 1:12 am 05:12

The above times were determined using Stellarium, and may be off by several minutes.
Shadow events are when a satellite’s shadow is cast onto the face of the planet
Transit events are when the satellite passes in front of the planet
Eclipse events are when a satellite  passes through the planet’s shadow
Occultation events are when the satellite passes behind the planet

Planets and the Moon overnight tonight

Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on August 11, 2021. The night ends on the left with sunrise on the 12th. Click on the image to enlarge. Created using my LookingUp program.

Perseid Radiant finder automation

Perseid Radiant finder automation for midnight, August 11th. Created using Stellarium and GIMP.

More on the Perseids on Monday and Tuesday’s posts.

 

08/02/2021 – Ephemeris – Saturn is closest to us and enters the evening sky today

August 2, 2021 Comments off

This is Bob Moler with Ephemeris for Monday, August 2nd. Today the Sun will be up for 14 hours and 36 minutes, setting at 9:06, and it will rise tomorrow at 6:31. The Moon, 2 days past last quarter, will rise at 1:55 tomorrow morning.

Today the ringed planet Saturn is at opposition, that is, opposite the Sun in our sky, rising at sunset and setting at sunrise. Saturn, then, is as close to us as it can get at 832 million miles (1,339 billion kilometers). Its rings are getting noticeably thinner now. Their narrow dimension is less than the planet’s diameter. Saturn’s axis and rings, which orbit over its equator, keep the same orientation in space as it orbits the Sun, just as the Earth’s axis does, giving us our seasons. Saturn’s seasons last nearly seven and a half of our years. Since about 2017, the rings have been closing, imperceptibly at first, but by March 2025 they will be edge-on, and will disappear, since for their great breadth of 175,000 or so miles (282,000 kilometers), they are less than 100 feet thick.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Saturn and rings tonight

An enlarged view of Saturn and its rings as created by the program Cartes du Ceil (Sky Charts). Note that the globe of Saturn now extends past the narrow dimension of the rings. The rings will continue to narrow  until March 23, 2025.

Categories: Uncategorized

07/26/2021 – Ephemeris – Albireo, a colorful double star in Cygnus the swan

July 26, 2021 Comments off

This is Ephemeris for Monday, July 26th. Today the Sun will be up for 14 hours and 52 minutes, setting at 9:15, and it will rise tomorrow at 6:23. The Moon, 3 days past full, will rise at 11:15 this evening.

Alberio is the name given to the star that is in the beak of the constellation of Cygnus the swan, which is high in the east these evenings. It is also at the foot of the asterism or informal constellation of the Northern Cross. To the naked eye Alberio looks like a single star, however even in small telescopes* its true nature is revealed. It is a double star whose individual star colors are strikingly different Its brightest star is yellow, and the dimmer star is blue. While star colors are subtle, these two, due to their apparent closeness, make an obvious color contrast. Unlike what your interior decorator says: In stars blue is hot, yellow, orange and red are cool. Also, it turns out that Alberio’s component stars don’t orbit each other. It is what is called an optical double. The blue star is a bit farther away than the yellow one, though they’re both around 430 light years away.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

* It will take at least about 20 power magnification to split. Binoculars won’t do it.

Addendum

Albireo finder animation

Animated Albireo finder chart. Albireo is located in the head of Cygnus the swan, or at the base of the Northern Cross. Tagged stars are, beside Albireo, the stars of the Summer Triangle: Deneb, Vega and Altair plus the star at the junction of the upright and crosspiece of the cross, Sadr. Created using Stellarium.

Albireo photographed in a telescope

Albireo, captured at high magnification by the staff of the Smithsonian Institution.

07/21/2021 – Ephemeris – Let’s search for the naked-eye planets for this week

July 21, 2021 Comments off

This is Ephemeris for Wednesday, July 21st. Today the Sun will be up for 15 hours and 2 minutes, setting at 9:20, and it will rise tomorrow at 6:18. The Moon, 2 days before full, will set at 4:13 tomorrow morning.

Let’s search for the naked-eye planets for this week. Venus can be spotted low in the west-northwest twilight by 10 pm. It will set at 10:49 pm. Venus will be spending the rest of summer low in the western sky, and not be as conspicuous as it usually is as the Evening Star. Mars’ visibility is a real problem. It will be to the right and below Venus in the evening, and will set at 10:35 pm. It’s much dimmer than Venus. The bright star Regulus will be just below and left of Venus tonight. Saturn will be seen low in the southeast in the evening, with Jupiter rising later and best in the morning sky. Saturn will rise at 9:49 pm. Brighter Jupiter will rise at 10:41 pm, both in the east-southeast. By 5:30 am, these two planets will be in the southern sky in the morning twilight.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Venus and Mars in evening twilight

Venus and Mars in evening twilight at 10 pm, about 40 minutes after sunset, tonight, Julyn21, 2021. Regulus, the first magnitude star in Leo, will appear just below and left of Venus. Click on the image to enlarge it. Created using Stellarium.

The Moon, Saturn, and Jupiter at 11 pm

The Gibbous Moon, Saturn, and Jupiter at 11 pm, tonight, July 21, 2021. The Moon is above the spout in the asterism of the Teapot in Sagittarius. Click on the image to enlarge it. Created using Stellarium.

Binocular Moon

The gibbous Moon as it will look like in binoculars or small telescope tonight, July 21, 2021. Created using Stellarium.

Jupiter Saturn in the morning

Jupiter and Saturn with the bright autumn star Fomalhaut, seen in morning twilight at 5:30. Created using Stellarium.

Telescopic view of the bright planets_2300-072121

Telescopic view of the bright planets (north up), with the same magnification, this evening, July 21, 2021. Apparent diameters: Venus, 12.17″; Saturn 18.56″, its rings 43.24″; Jupiter, 47.70″. Mars has an apparent diameter of only 3.71″ and is not represented. 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).

Planets and the Moon overnight tonight

Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on July 21, 2021. The night ends on the left with sunrise on the 22nd. Click on the image to enlarge. Created using my LookingUp program.

 

Categories: Uncategorized

06/16/2021 – Ephemeris – Let’s search for the naked-eye planets for this week

June 16, 2021 Comments off

This is Bob Moler with Ephemeris for Wednesday, June 16th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:30, and it will rise tomorrow at 5:56. The Moon, 1 day before first quarter, will set at 1:55 tomorrow morning.

Let’s search for the naked-eye planets for this week. Venus can be spotted low in the west-northwest twilight by 10 pm or a little after. Venus will set at 11:04 pm. Mars can be found in the west-northwest at 10:30 tonight, It’s in Cancer and by next Wednesday will pass in front of the Beehive star cluster which can be easily seen in a pair of binoculars. Check it out each night before then and watch Mars approach the cluster, now to its upper left. Mars will set at 11:55 pm. Jupiter and Saturn, are in the morning sky. Saturn will rise at 12:12 am. It’s seen with the stars of Capricornus. Brighter Jupiter, to the left of Saturn, will rise at 1:01 am. By 5 am, these two planets will be in the south-southeast in the morning twilight.

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

Addendum

Venus in evening twilight

Venus in evening twilight at 10 pm or a half hour after sunset tonight over a sea or Lake Michigan horizon. Venus is a bit less than 10 degrees altitude. Created using Stellarium.

Moon, Mars and Venus tonight

The Moon, Mars and Venus at 11 pm or an hour and a half after sunset tonight over a sea or Lake Michigan horizon. Click on the image to enlarge. Created using Stellarium.

Mars and the Beehive star cluster

Mars and the Beehive star cluster at 11 pm tonight as they might be seen in binoculars. Created using Stellarium.

Binocular Moon

The Moon as it might appear tonight in binoculars or small telescope tonight. Created using Stellarium.

Jupiter and Saturn in the morning

Jupiter and Saturn at 5 am or an hour before sunrise tomorrow morning. Created using Stellarium.

Telescopic views of Venus, Saturn and Jupiter to scale

Telescopic views of Venus, Saturn and Jupiter. Venus at the same magnification. Venus, seen at 10 pm, will be 10.72″ in diameter. Saturn at 5 am will be 18.00″ in diameter, its rings 44.43″ in extent. And Jupiter will be 43.43″. The normal cutoff for whether to show a planet here is an apparent diameter of 10″ or greater. Mars doesn’t make the cut, its apparent diameter will be 3.98″ tonight. The ” symbol means seconds of arc (1/3600th of a degree). 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 June 16, 2021. The night ends on the left with sunrise on the 17th. Click on the image to enlarge. Created using my LookingUp program.