Archive
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.
12/06/2022 – Ephemeris – The Moon will pass in front of Mars tomorrow night
This is Bob Moler with Ephemeris for Tuesday, December 6th. Today the Sun will be up for 8 hours and 57 minutes, setting at 5:02, and it will rise tomorrow at 8:06. The Moon, 1 day before full, will set at 7:45 tomorrow morning.
Late tomorrow evening we might get to view a really cool event, clouds permitting, when the full moon will cover or in astronomical lingo occult the planet Mars. In the Grand Traverse Region, this will occur for an hour between approximately 10:15 to 11:15 pm. The exact times depend on your location, and can vary by a minute or two over the IPR coverage 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.
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
Mars ingress and egress chart and times for Traverse City, MI. The times will vary by a minute or two in the IPR listening area, ingress being earlier to the west and north and later east and south. Egress times will be earlier west and later east of Traverse City. Mars takes about a minute to completely disappear and reappear again because it’s not an unresolvable point like stars.
Occultation of Mars map. The occultation of Mars by the Moon will be visible from within the bounded area. For Traverse City, MI, Mars will disappear around 10:15 pm, December 7, 2022, and reappear around 11:15 pm.
In astronomical events of solar eclipses and occultations YOU are part of the event. No, not you, but your location. Whether you see the event or not or what time the contacts (ingress, egress) happen depends on your location. And will happen for that location whether you are there, or it’s clear, or not.
12/05/2022 – Ephemeris – Mars will hide behind the full Moon Wednesday night
This is Ephemeris for Monday, December 5th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:02, and it will rise tomorrow at 8:05. The Moon, 2 days before full, will set at 6:36 tomorrow morning.
Late Wednesday night we might get to view a really cool event when the full moon will cover or in astronomical lingo occult the planet Mars. In the Grand Traverse Region, this will occur for an hour between approximately 10:15 to 11:15 pm. The exact times depend on your location, and can vary by several minutes or more. Being a full moon, Mars might be difficult to spot. I’ll have more and hopefully more accurate information tomorrow. When astronomical objects line up like this, it’s called a syzygy. This time it’s a lineup of the Sun, Earth Moon and Mars in nearly a straight line, with both the Moon and Mars in opposition from the Sun on the same night. When the Moon is in opposition, we call it a full moon instead.
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
Mars ingress and egress chart and times for Traverse City, MI. The times will vary by a minute or two in the IPR listening area, ingress being earlier to the west and north and later east and south. Egress times will be earlier west and later east of Traverse City.
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.
12/11/2020 – Ephemeris Extra – Venus will hide behind the Moon for W US, Canada and N Pacific Tomorrow
Tomorrow Saturday, December 12, 2020 Venus will be occulted, or covered, by the thin crescent Moon for the area bounded in the map below. The southern boundary is a thin red line denoting that the event will take place in daylight. For safety sake observe the event from the shadow of a building open to the sky west of the Sun to not inadvertently point binoculars or telescope toward the Sun and cause permanent damage to your eyes. Venus is visible in the daytime. A program like Stellarium will help in locating Venus and determination of the time of the event for your location. Also, for Stellarium, in the configuration window’s Tool tab make sure “Topocentric coordinates” is checked.
The event will NOT be visible from Michigan.
Occultation of Venus World map 12/12/2020. The occultation will be visible within the bounded area. For the area that looks like a lazy figure 8 the occultation will start (on the left) or end as Venus and the Moon rises or sets. For most areas within the bounded area the occultation is a daytime event. Credit Occult4.
02/17/2020 – Ephemeris Extra – The Moon will cover the planet Mars in morning twilight tomorrow, Tuesday the 18th.
Sorry, I missed this until now. Tomorrow morning the 18th Mars will be occulted by the Moon. For Northern Lower Michigan Mars will disappear shortly after 7:10 a.m. The exact time depends on your location, so I can’t be more specific. At that time the Moon and Mars will be in the southeastern sky. Mars is now first magnitude, but will fare poorly in the morning twilight, so I’d suggest finding the Moon and Mars at least 15 minutes earlier with binoculars or telescope. Mars will reappear at the Moon’s unlit side around 8:37 a.m. This is after sunrise, so a telescope will be required to spot it. Hoping for clear skies, though the weather forecast isn’t promising.
A map of where the occultation of Mars will be visible. Created using Occult4.
Where Mars will disappear at the Moon’s sunlit edge. Created using Stellarium.
Mars will reappear at the Moon’s unlit edge around 8:36 a.m. give or take. Created using Stellarium.
11/23/2018 – Ephemeris – The Moon and Aldebaran
Ephemeris for Friday, November 23rd. The Sun will rise at 7:50. It’ll be up for 9 hours and 17 minutes, setting at 5:07. The Moon, at full today, will rise at 5:55 this evening.
Tonight’s full Moon will be accompanied by the bright star Aldebaran, the angry red eye of the constellation Taurus the Bull. Earlier this year we had the last of nearly two years of the Moon every month passing in front of Aldebaran. The tilt of the Moon’s orbit with respect to the Earth’s own orbit of the Sun slides slowly westward with time, so The Moon won’t pass in front of Aldebaran for those of us on Earth again until 2033. This sliding of the Moon’s orbit is called regression of the nodes. A node is where the Moon’s orbital plane crosses the Earth’s. These are places eclipses of the Sun and Moon occur if lined up with the full or new moons. Why regression? The nodal points are moving westward, backward of most motions in the solar system.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Ephemeris Extra – Occultation of Aldebaran visible from the Upper Peninsula and the tip of northern lower Michigan
In the early morning hours of July 10th the very northern part of the IPR listening area will have a chance to see the last occultation of the bright star Aldebaran for at last 15 years. An occultation is where the Moon in this case passes in front of or occults a planet or a star. In astronomy occult means to hide. The event is an occultation. There is no black magic involved. It will be a grazing event, with Aldebaran popping in and out of view at the mountains and valleys at the southern edge of the Moon along a line running south of Mackinaw City and across the eastern tip of the Upper Peninsula.
The Straits of Mackinac area showing the green southern graze line of the Occultation of Aldebaran. Credit Map Google Earth, Graze line by Occult 4.
It’s a clear miss for the Interlochen area, with the star skirting the Moon at it’s 5 o’clock position. The time of the event will be near 4:38 a.m. with the maximum time of the event increasing from west to east at nearly 2,000 miles an hour. At that time the Moon and Aldebaran will be low in the east-northeast and only 7 degrees above the horizon.
Location of the Moon and Aldebaran in the sky at 4:38 a.m. July 10, 2018 from the Interlochen/Traverse City area.
More information on this occultation from Sky and Telescope is here.
This will be the last occultation of Aldebaran visible from around here for the next 15 years. However starting in 5 years there will be a monthly series of occultations of the bright star Regulus, and the next year a series of occultations of the star Spica will begin. That’s just for the Moon with bright stars. The Moon occults many dimmer stars a month. A very important field of occultations is the observation of occultations of asteroids and Kuiper belt objects to discover their size, shape, any satellites and whether they have rings. Go to the International Occultation Timing Association https://occultations.org for more information.
Hat tip to Jerry Dobek, Director of the Joseph H. Rogers Observatory
12/29/2017 – Ephemeris – Last occultation of the star Aldebaran by the Moon is tomorrow night
Ephemeris for Friday, December 29th. The Sun will rise at 8:19. It’ll be up for 8 hours and 51 minutes, setting at 5:10. The Moon, half way from first quarter to full, will set at 5:08 tomorrow morning.
We have one last cool astronomical event that can be seen from here in 2017. Of course, weather permitting. Tomorrow night the Moon will occult the bright star Aldebaran in Taurus the bull from 6:17 to 7:17 p.m. I’m not dabbling with the black arts here, even though I’m using the Occult 4 program to find it. In astronomy occult is a verb meaning to hide, and the event is called an occultation. The Moon will appear to move in front of, or hide the star Aldebaran. At 6:17 p.m. Aldebaran will disappear at the dark edge of the Moon at its 8 o’clock position. Binoculars will be needed to spot the star against the glare of the bright Moon before the event. Aldebaran will pop out from behind the Moon at a bit above the 3 o’clock position at 7:17 p.m.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Occultation visibility map for the occultation of Aldebaran by the Moon for us in the Unites States, the early evening of December 30, 2017. Created using Occult 4 by IOTA.
Occultation start 6:17 p.m. December 30, 2017. as seen from the Grand Traverse area of Michigan. Actual times may vary depending on your location. Created using Stellarium.
Occultation end 7:17 p.m. December 30, 2017. as seen from the Grand Traverse area of Michigan. Actual times may vary depending on your location. Created using Stellarium.
Note the times are for the Traverse City/Interlochen area. It will vary by a few minutes for northern lower Michigan. The position angles of the entrance and exit points of Aldebaran will also be different.
Otherwise use a planetarium program like Stellarium to preview the event. However, set the program for topocentric coordinates. In Stellarium that’s in the Configuration window, Tools Tab and check the Topocentric coordinates box. Topocentric coordinates are the apparent positions for your location on the Earth. So also make sure your location is correct. The geocentric conjunction of the two bodies will be December, 31, 0:49.2 UT, so it will occur after midnight on the morning of December 31st for locations in northern Europe and Asia.
Program Note
The January preview will be an Ephemeris Extra post on December 31st.
11/05/2017 – Ephemeris Extra – There will be an Occultation of Aldebaran tonight*
This posting will not be broadcast.
* Or tomorrow morning, depending where you are.
Ephemeris extra for Sunday, November 5th. The Sun will rise at 7:25. It’ll be up for 10 hours and 5 minutes, setting at 5:25. The Moon, 2 days past full, will rise at 7:01 this evening.
Tonight just after 8 p.m. the bright star Aldebaran will disappear at the left edge of the Moon. Aldebaran is angry red eye of Taurus the bull. The star will reappear at the dark upper right edge of the Moon. Start looking at 8 p.m. or before. Use binoculars or a small telescope to spot the star against the glare of the bright Moon. The star is nowhere as bright as shown in the illustrations below. Star appearances and disappearances appear instantaneous, unlike what the illustrations show.
Aldebaran Occultation begins at 8:07 p.m. EST (1:07 UTC Nov 6th)
Aldebaran Occultation ends at 9:00 p.m. EST (02:00 UTC Nov 6th)
Note the times are for the Traverse City/Interlochen area. It will vary by a few minutes for northern lower Michigan. The position angles of the entrance and exit points of Aldebaran will also be different.
Otherwise use a planetarium program like Stellarium to preview the event. However, set the program for topocentric coordinates. In Stellarium that’s in the Configuration window, Tools Tab and check the Topocentric coordinates box. Topocentric coordinates are the apparent positions for your location on the Earth. So also make sure your location is correct. The geocentric conjunction of the two bodies will be November 6, 2:42.9 UTC, so it will occur after midnight on the morning of November 6th for locations in northern Europe and Asia.
Addendum
Occultation Map for the occultation of Aldebaran by the Moon . Credit Occult 4 program from IOTA.org.
Aldebaran at the start of the occultation at 8:07 p.m. for the Traverse City/Interlochen area. Created using Stellarium.
Aldebaran at the end of the occultation at 9:00 p.m. for the Traverse City/Interlochen area. Created using Stellarium.
11/03/2017 – Ephemeris – The Sun is the topic at tonight’s GTAS meeting
Ephemeris for Friday, November 3rd. The Sun will rise at 8:23. It’ll be up for 10 hours and 5 minutes, setting at 6:28. The Moon, 1 day before full, will set at 8:35 tomorrow morning.
This evening the Grand Traverse Astronomical Society will hold its monthly meeting at the Northwestern Michigan College’s Rogers Observatory at 8 p.m. with a program featuring member Don Flegel in a talk about the Sun. Don’s the keeper of our solar telescope and wanted a good excuse to learn more about the Sun, so he decided to study up and give this talk. That’s how I do it.
After the talk, at 9 p.m. there will be a star party, if it’s clear, to view the heavens including the Moon. The observatory is located south of Traverse City, on Birmley Road between Garfield and Keystone roads.
It’s time to change our clocks again at 2 a.m. Sunday. Turn your clocks back one hour. That’s Fall Back one hour for a bit of extra sleep.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
Don Flegel, in the foreground, with the society’s solar telescope assisting a person viewing the Sun at he Leland Heritage Festival 2017 at Fishtown. Man in the background in the blue cap is Gary Carlisle. The telescope in the middle is mine.
Occultation of Aldebaran by the Moon Sunday Night
Occultation Map for the occultation of Aldebaran by the Moon . Credit Occult 4 program from IOTA.org.
For the Traverse City/Interlochen area:
Aldebaran Occultation start 8:07 p.m. Nov 5th (01:07 UT Nov 6th)
Aldebaran Occultation end 9:00 p.m. Nov 5th (02:00 UT Nov 6th)
I’ll have an Ephemeris Extra posting, Sunday November 5th with more information.
Bob Moler's Ephemeris Blog 