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08/15/2022 – Ephemeris – Saturn moves into the evening sky
This is Ephemeris for Monday, August 15th. Today the Sun will be up for 14 hours and 3 minutes, setting at 8:48, and it will rise tomorrow at 6:46. The Moon, halfway from full to last quarter, will rise at 10:55 this evening.
Yesterday, Saturn was in opposition to the Sun. I’m not implying an argument here. Opposition is when a planet is opposite the Sun in the sky, so it rises around sunset and sets around sunrise. That means Saturn is the closest it can get to us this year. For the record, that’s 836 million miles (1,345 million kilometers). Saturn will first appear tonight in the southeast when it gets dark enough, say around 9:15 to 9:30 pm. It is in the constellation of Aquarius now. It is moving northeastward in our skies, or it would if it weren’t at opposition, and moving backward or retrograde as the Earth is, in effect, lapping Saturn in our eternal race around the Sun. Saturn’s rings appear to slowly get skinnier as the planet moves to an equinox, where its rings, which orbit its equator, will tilt edgewise to the Sun, and the Earth in 2025.
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
Display of the solar system out to Saturn, with added line showing Saturn’s location opposite the Sun from the Earth. This make the Earth nearly in line from the Sun to Saturn. This is the time that Saturn would be closest to the Earth. Credit: my LookingUp app. I wanted to use NASA’s Eyes, but there were too many interplanetary spacecraft near the Earth. The Earth was crowded out by spacecraft labels.
How the appearance of the rings change as Saturn orbits the Sun. Credit: NASA Hubble.
05/30/2022 – Ephemeris – There might be a spectacular meteor shower/storm tonight after midnight!
This is Ephemeris for Memorial Day, Monday, May 30th. Today the Sun will be up for 15 hours and 18 minutes, setting at 9:19, and it will rise tomorrow at 6:00. The Moon is new today, and won’t be visible.
Comet Schwassmann-Wachmann 3, SW3 for short began to breakup in 1995, 27 years ago. Two large chunks of the comet’s nucleus and dozens of smaller pieces have been seen. We expect a vast debris field to be expanding from the remnants of the comet, unseen. Astronomers, calculating what happened to that unseen debris cloud, expect the Earth to run into a part of it around 1 am (EDT, 5 hours UT), give or take, tomorrow morning. Causing, if we’re lucky, a meteor shower or meteor storm. The radiant point from which the meteors seem to come is from between the Big Dipper’s handle and the bright star Arcturus. They will appear all over the sky. I’m crossing my fingers on this one, it could be great, or it could be nothing.
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
Position of the Tau Herculid radiant at 1 am, May 31, 2022. However, meteors will appear all over the sky, but could be traced back to the radiant. These meteors will appear to travel a lot slower than the Perseid meteors of August. Created using Stellarium for the star field and LibreOffice for annotations.
Comet Schwassmann-Wachmann 3 Hubble Space Telescope images from 2006 showing the breakup of the comet. Credit: NASA.
05/27/2022 – Ephemeris – There could be a spectacular meteor display Tuesday early morning, or nothing!
This is Bob Moler with Ephemeris for Friday, May 27th. Today the Sun will be up for 15 hours and 13 minutes, setting at 9:16, and it will rise tomorrow at 6:02. The Moon, 3 days before new, will rise at 5:03 tomorrow morning.
Comet Schwassmann-Wachmann 3, SW3 for short began to breakup in 1995, 27 years ago. Two large chunks of the comet’s nucleus and dozens of smaller pieces have been seen. A vast, unseen debris field is expected to be expanding from the remnants of the comet. Astronomers, calculating what happened to that unseen debris cloud, expect the Earth to run into a part of it around 1 am (EDT, 5 hours UT), give or take, on Tuesday, May 31st (That’s late Memorial Day night). Causing, if we’re lucky, a meteor shower or meteor storm. The radiant point from which the meteors seem to come is from between the Big Dipper’s handle and the bright star Arcturus. They will appear all over the sky. I’m crossing my fingers on this one, it could be great, or it could be nothing.
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
Position of the Tau Herculid radiant at 1 am, May 31, 2022. However, meteors will appear all over the sky, but could be traced back to the radiant. These meteors will appear to travel a lot slower than the Perseid meteors of August. Created using Stellarium for the star field and LibreOffice for annotations.
Comet Schwassmann-Wachmann 3 Hubble Space Telescope images from 2006 showing the breakup of the comet. Credit: NASA.
05/26/2022 – Ephemeris – There may be a spectacular meteor storm Tuesday am or nothing!
This is Ephemeris for Thursday, May 26th. Today the Sun will be up for 15 hours and 11 minutes, setting at 9:16, and it will rise tomorrow at 6:03. The Moon, halfway from last quarter to new, will rise at 4:42 tomorrow morning.
Early risers tomorrow morning should be able to see, if it’s clear, the planet Venus just above and right of the waning crescent Moon. The last of the visible Moon-planet encounters this month. Another event this month may be the Tau Herculid meteor shower. This may be a spectacular meteor shower, or nothing. It would be the result of the breakup of Comet Schwassmann-Wachmann 3 that started back in 1995. SW3, as it’s known for short, has a 5.44 year orbit of the Sun, so we only get a good look at it about every 11 years currently. As the nucleus breaks up, the debris field widens, with time. The comet will pass close to the orbit of the Earth in a few months. The comet’s orbit comes closest to the Earth’s orbit on May 31st. If the debris cloud has widened enough by now, the Earth should intercept it around 1 am our time that 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
Position of the Tau Herculid radiant at 1 am, May 31, 2022. However, meteors will appear all over the sky, but could be traced back to the radiant. These meteors will appear to travel a lot slower than the Perseid meteors of August. The meteor storm, if it occurs, should peak around 1 am. However, there is an uncertainty with the time or if the meteor will show up. Created using Stellarium for the star field and LibreOffice for annotations.
Comet Schwassmann-Wachmann 3 Hubble Space Telescope images from 2006 showing the breakup of the comet. Credit: NASA.
05/13/2022 – Ephemeris – Remember, there is going to be an eclipse of the Moon late Sunday night!
This is Bob Moler with Ephemeris for Friday, May 13th. Today the Sun will be up for 14 hours and 45 minutes, setting at 9:02, and it will rise tomorrow at 6:15. The Moon, 3 days before full, will set at 5:28 tomorrow morning.
There is going to be an eclipse of the Moon running from late Sunday night into the early Monday morning hours. That’s the night of May 15/16. By 10:30 pm, there will appear a noticeable “bite” out of the lower left edge of the Moon as it enters the Earth’s inner shadow, called the umbra. The shadow will creep across the Moon for the next hour. And by 11:30 the Moon is completely immersed in the Earth’s inner shadow. By now, one will notice that the shadow is not completely black. The Moon usually has a dim reddish hue caused by all the simultaneous sunrises and sunsets around the Earth. This is the total phase of the eclipse, which will last until almost 1 am. The Moon will slowly exit the inner shadow by 2 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
The eclipse occurs on the 16th for Universal Time, because the eclipse events take place after 8 pm EDT on the 15th. The Moon travels through the Earth’s shadow from right to left. What are seen are points of contact with the shadow and mid-eclipse. From Five Millennium Canon of Lunar Eclipses (Espenak & Meeus) NASA, with additions.
Contact times are labeled P1, U1, U2, U3, U4, and P4. P2 and P3 are omitted because they are synonymous with U1 and U4, respectively. Times are EDT unless noted:
- P1 – 9:32:07 pm (1:32:07 UT) Enter the penumbra (unseen). By about 10 pm, the duskiness on the left edge of the moon will start to be noticeable. Wearing sunglasses to dim the bright Moon will help show the effect.
- U1 – 10:27:53 pm (2:27:53 UT) Enter the umbra (partial eclipse begins).
- U2 – 11:29:03 pm (3:29:03 UT) Totality begins.
- Mid-eclipse 12:11:28.8 am (4:11:28.8 UT)
- U3 – 12:53:56 am (4:53:56 UT) Totality ends, the egress partial phase begins.
- U4 – 1:55:07 am (5:55:07 UT) Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
- P4 – 2:50:48 am (6:50:48 UT) Penumbral phase ends (unseen).
Solar eclipse by the Earth as photographed by Surveyor 3, which had landed on the Moon, April 24, 1967. The Earth was seeing a lunar eclipse at the time. Light seeps into the Earth’s shadow at the Moon’s distance due to atmospheric refraction. The amount of light depends on the atmospheric conditions at the time. Great volcanic eruptions can cause a very dark, nearly invisible, eclipsed Moon. Credit: NASA.
Update 7:30 pm, May 15th
In note for P1 time: Expected actual visibility of penumbral shadow is changed to 10 pm (2 hr UT).
05/12/2022 – Ephemeris – There will be a total eclipse of the Moon this Sunday night/Monday morning
This is Ephemeris for Thursday, May 12th. Today the Sun will be up for 14 hours and 43 minutes, setting at 9:01, and it will rise tomorrow at 6:16. The Moon, halfway from first quarter to full, will set at 5:06 tomorrow morning.
Late Sunday night through early Monday morning May 15/16 there will be a total eclipse of the Moon which will run from 10:28 pm Sunday night to 1:55 Monday morning. I’ll be more specific tomorrow. Also known as lunar eclipses, these only occur at full moon when the Moon crosses the earth’s shadow. Usually, the Moon passes too far north or south to run into earth’s shadow. In only in one in six full moons does this happen. To see it, one has to be on the night side of the Earth. And it has to be clear at your location, a big problem around here. Our last lunar eclipse in November was clouded out from my location, which is usually my luck with lunar eclipses. However, May is a better month. Here’s hoping.
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
How lunar eclipses occur. Credit NASA/Fred Espenak.
The eclipse occurs on the 16th for Universal Time, because the eclipse events take place after 8 pm EDT on the 15th. The Moon travels through the Earth’s shadow from right to left. What are seen are points of contact with the shadow and mid-eclipse. On the world map, locations in the white or light part of the map can see all or part of the eclipse. From Five Millennium Canon of Lunar Eclipses (Espenak & Meeus) NASA, with additions by me.
Contact times are labeled P1, U1, U2, U3, U4, and P4. P2 and P3 are omitted because they are synonymous with U1 and U4, respectively. Times are EDT unless noted:
- P1 – 9:32:07 pm (1:32:07 UT) Enter the penumbra (unseen). By about 9 pm, the duskiness on the left edge of the moon will start to be noticeable. Wearing sunglasses to dim the bright Moon will help show the effect.
- U1 – 10:27:53 pm (2:27:53 UT) Enter the umbra (partial eclipse begins).
- U2 – 11:29:03 pm (3:29:03 UT) Totality begins.
- Mid-eclipse 12:11:28.8 am (4:11:28.8 UT)
- U3 – 12:53:56 am (4:53:56 UT) Totality ends, the egress partial phase begins.
- U4 – 1:55:07 am (5:55:07 UT) Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
- P4 – 2:50:48 am (6:50:48 UT) Penumbral phase ends (unseen).
10/04/2021 – Ephemeris – Why we can’t talk to the Perseverance rover on Mars right now
This is Ephemeris for Monday, October 4th. Today the Sun will be up for 11 hours and 32 minutes, setting at 7:17, and it will rise tomorrow at 7:46. The Moon, 2 days before new, will rise at 6:30 tomorrow morning.
NASA is no longer sending commands to its Perseverance rover or any of its assets roving or orbiting Mars now. The reason isn’t particularly sinister. It’s the approximately 26 month Mars solar conjunction. The Sun is a noisy radio source, and commands sent to or data received from these martian assets could be garbled. This affects everyone’s assets on or orbiting Mars, which includes the Europeans, India, China and the United Arab Emirates. For NASA, communication restrictions started two days ago and will last until the 14th. This will give the folks at JPL who are operating the Curiosity and Perseverance rovers some time off, and time to plan the next few months of activity.
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
Mars in solar conjunction. Looking at the inner solar system. Mars, near the bottom of the image, is 244.6 million miles (393.9 million kilometers) from Earth. Click on the image to enlarge it. Credit NASA’s Eyes app.
Mars beyond and to the upper left of the Sun yesterday. It’s tough to get intelligible radio signals through the solar corona. Credit: NASA/ESA SOHO* spacecraft. The annotation is mine.
* SOlar and Heliospheric Observatory, spacecraft in halo orbit around the Lagrangian L1 equilibrium point about 930,000 miles (1,500,000 kilometers) sunward of the Earth. This keeps the satellite roughly between the Sun and the Earth, instead of moving ahead of the Earth because it’s closer to the Sun.
07/05/2021 – Ephemeris – Happy Aphelion Day
This is Bob Moler with Ephemeris for Monday, July 5th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:30, and it will rise tomorrow at 6:04. The Moon, halfway from last quarter to new, will rise at 3:24 tomorrow morning.
Today, the Moon and Sun are at their farthest from the Earth. For the Moon it’s called apogee, for the Sun it’s called aphelion. At 10:48 this morning the Moon will be at that point 251,842 miles (405,300 kilometers) away. The Sun will be farthest at 10:59 pm at a distance of 94 million, 452 thousand miles (152 million, 6 thousand kilometers) away. Because of the gravitational pull of the Moon and planets on the Earth, and the Pull of the planets, especially Jupiter on the Sun, the aphelion and perihelion or closest date in January don’t occur on the same date or same distance every year. The date wanders by a day or two each year. The entire distance variation for the Earth is plus or minus 1.5 million miles (2.4 million kilometers) over the year, but makes summer the longest season by a few days because the Earth moves slower when farther from the Sun, than when it is nearer.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4). They may be different for your location.
Addendum
The Earth’s orbital ellipse, somewhat exaggerated, showing perihelion, aphelion and the seasons. Credit “Starts with a Bang” blog by Ethan Siegel.
Currently, summer is the longest season at 93.65 days, while winter is the shortest season at 88.99 days. (Source: Astronomical Tables of the Sun, Moon and Planets, Third Edition by Jean Meeus)
06/09/2021 – Ephemeris – The Sun will be partially eclipsed as it rises tomorrow morning
I’ll review the planets tomorrow. However, tomorrow morning, if it’s clear down to the northeastern horizon, we will get to observe, safely, the Sun rise while being in eclipse. Here’s today’s program:
This is Ephemeris for Wednesday, June 9th. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:27, and it will rise tomorrow at 5:57. The Moon, 1 day before new today, will rise with the Sun at 5:57 tomorrow morning.
The Moon rising with the Sun will also be eclipsing the Sun, so the Sun will have a big bite taken out of its left side as it rises tomorrow. We will be witnessing the last 40 some minutes of the eclipse as the Sun rises. The Sun is dangerous to look at. If you have eclipse glasses from the 2017 eclipse, use those. Otherwise, use pinhole projection from one side of a box to the opposite side. The longer the box, the bigger and dimmer the image. If using a corrugated cardboard box, make a big hole at the pinhole end, cover it with a thin piece of cardboard or aluminum foil. Punch several holes of various sizes spaced out on that end to project multiple images of the Sun, so you can choose the best to view. Good luck!
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Pinhole projection is the simplest way to project the Sun’s image. A long box can be used to project the image inside. The diameter of the pinhole is a compromise between sharpness and brightness of the image. The farther the image is projected, the larger and dimmer it is. The throw of the image can be increased by using a mirror masked with a quarter of an inch or larger hole and sending the image 10 or more feet away. Credit NASA.
A Stellarium creation of what the eclipsed Sun would appear about 10 minutes after rising as seen from the Traverse City/Interlochen area.
The visibility map for the June 10, 2021 annular solar eclipse. In an annular eclipse, the Moon is too far away and appears too small to cover the face of the Sun. So, at maximum, a ring of bright Sun surrounds the Moon. It’s sometimes called a ring of fire. For locations within the big floppy figure 8, the eclipse either ends near sunrise (bottom lobe) or starts near sunset (top lobe). The double line with the ellipses in it is the path of where the ring is visible, the path of annularity. Locations within the grid on the right will see a partial eclipse. Credit: NASA/GSFC/Fred Espenak, adapted from https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2021Jun10A.GIF
06/08/2021 – Ephemeris – The Sun will be partially eclipsed as it rises Thursday
This is Ephemeris for Tuesday, June 8th. Today the Sun will be up for 15 hours and 29 minutes, setting at 9:26, and it will rise tomorrow at 5:57. The Moon, 2 days before new, will rise at 5:22 tomorrow morning.
Thursday morning we in Michigan will witness the last moments of a solar eclipse as the Sun rises. The Sun will be partially eclipsed at sunrise north of a line from North Dakota to South Carolina. For those in a path that will run from the north shore of Lake Superior across western Ontario, through parts of Hudson Bay, to clipping the North Pole and into Siberia will see an annular eclipse. That is, the Moon is too far away, and small to cover the face of the Sun, leaving a bright ring or annulus. A ring of fire, some would say. For us, the Sun will rise around 5:57 am with the Moon taking a big chunk out of its left side. That chunk will recede until the Sun will appear whole again around 6:42 am. I’ll discuss how to view this eclipse tomorrow.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A Stellarium creation of what the eclipsed Sun would appear about 10 minutes after rising as seen from the Traverse City/Interlochen area.
The visibility map for the June 10, 2021 annular solar eclipse. In an annular eclipse, the Moon is too far away and appears too small to cover the face of the Sun. So, at maximum, a ring of bright Sun surrounds the Moon. It’s sometimes called a ring of fire. For locations within the big red floppy figure 8, the eclipse either ends near sunrise (bottom lobe) or starts near sunset (top lobe). The double line with the ellipses in it is the path of where the ring is visible, the path of annularity. Locations within the grid on the right will see a partial eclipse. Credit: NASA/GSFC/Fred Espenak, adapted from https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2021Jun10A.GIF
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