Archive
12/30/2016 – Ephemeris – Looking ahead at the eclipses of 2017
Ephemeris for Friday, December 30th. The Sun will rise at 8:19. It’ll be up for 8 hours and 51 minutes, setting at 5:11. The Moon, 1 day past new, will set at 6:53 this evening.
Looking ahead at astronomical events of the 2017. There is one big one that all of us astronomers, both amateur and professional are looking forward to. That is the total eclipse of the Sun on August 21st, where the center of the Moon’s shadow will sweep across the continental United States from Oregon to South Carolina. The closest this path of totality will get to our area is around Carbondale, Illinois. For the Grand Traverse area the Sun will be some 75% covered by the Moon. As kind of a warm up event, we’ll have a slight eclipse of the Moon February 10th, where the Moon will enter the Earth’s outer partial shadow, nearly grazing the Earth’s inner shadow in the early evening. It’s called a penumbral lunar eclipse.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
This is the maximum of the February 10th penumbral lunar eclipse. The Moon will appear to move diagonally down to the left. It is shown at maximum eclipse at 7:45 p.m. (0:45 UT February 11). Created using Cartes du Ciel.
Shadows are, of course, invisible unless they are cast on an object, so the Moon would appear alone, though the upper left part of it would be noticeably dimmer than the opposite side.
A screen cap of the map showing the path of totality of the August 21, 2017 total solar eclipse from NASA’s eclipse page. Credit: NASA and Google Maps. Click on image to enlarge.
Click here to go to the page where this interactive map is located. The magenta marker with GD is the point with the greatest duration of totality of 2 minutes 40.2 seconds. The green marker with GE denotes where the Moon’s umbral shadow is the widest. Clicking on any point on the map will pop a balloon shows all the eclipse information for viewing it from that place. The partial eclipse can be seen from all fifty states, though in Hawai’i the Sun rises with the eclipse in progress.
Here in the Grand Traverse Region, the Moon will encroach on about 8/10ths of the Sun’s diameter, covering 75% of the Sun’s face.
What the maximum eclipse would look like with proper filtering at Traverse City, MI. Created using Stellarium.
Eclipse Times for Traverse City
Eclipse Starts 12:58:03 p.m.
Maximum Eclipse 2:20:15 p.m.
Eclipse Ends 3:40:51 p.m.
Magnitude of the eclipse 0.798
Obscuration of the Sun 75.1%
This is an inkling of what a totally eclipsed Sun looks like. No photograph can do it justice. Ya gotta be there! The solar corona displayed during the July 10, 1972* total solar eclipse from Prince Edward Island. Credit Bob Moler.
* Update: Thanks for the heads up on the typo: NationalEclipse.com.
Program Note:
I’ve developed a PowerPoint slide presentation highlighting my four total eclipses and a look at future eclipses. I will be happy to give this presentation to school groups and organizations free of charge except for mileage reimbursement over 50 miles. Contact me at bob@bjmoler.org.
December 31st – the longest day, really.
December 31st will be 24 hours and 1 second long. This “leap second” will be added as the 61st second of the minute 6:59 p.m. EST (23:59 UT). The reason is that the Earth’s rotation is slowing down ever so slightly, compared to the atomic clocks at the Bureau of Time. There is some discussion of eliminating this leap second. Most scientists want to use a constant time stream, and don’t give a hang about the rotation of the Earth. The exact time which is also affected by special and general relativity is used by GPS navigation satellites. A one second jump in time, at our latitude (45° north) is equivalent of the earth’s rotation of about two tenths of a mile. I hope everyone’s coordinated on this.
03/22/2016 – Ephemeris – Really difficult lunar eclipse to spot at sunrise*
Ephemeris for Tuesday, March 22nd. The Sun will rise at 7:41. It’ll be up for 12 hours and 17 minutes, setting at 7:58. The Moon, 1 day before full, will set at 7:48 tomorrow morning.
The Paschal full moon is tomorrow morning. I’ll explain more about it on Thursday as we get closer to Easter this coming Sunday. However as the Moon sets for our region it will be in eclipse. It’s not a big deal partial or total lunar eclipse, but a penumbral eclipse, where the Moon slips into the Earth’s outer shadow, where the Sun’s light is partially cut off by increasing amounts from the edge of the penumbra to the totally blocked umbral shadow. As the Moon is setting tomorrow morning after 7:30 a.m., it may be showing a dusky lower left edge, the part of the Moon closest to the center of the Earth’s shadow. It might difficult to see the effect, though the bright skies may actually help by washing out the light of the Moon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
* The eclipse, such as it is, will not be visible east of us around 86º west longitude, and be more visible west of us.
Addendum
How lunar eclipses occur. Credit NASA/Fred Espenak.
This eclipse, however the Moon will dip only into the outer penumbra.
The Eclipse diagram for the March 23, 2016 penumbral eclipse of the Moon. Credit Fred Espenak/NASA/GSFC.
Here’s a link to the original pdf of the image above.
Maximum eclipse will occur at 7:47 a.m. EDT (11:47 a.m. UT)
What the progress of the eclipse is like at 7:40 a.m. The sky will be bright because the Sun will be rising at that time. Created using Cartes du Ciel (Sky Charts).
My 9/27/2015 lunar eclipse experience
This is an elaboration of an email sent to a fellow amateur astronomer who was completely clouded out and asked how we did.
From mid-eclipse, about 10:45, to the end of totality it was almost perfectly clear, We had light clouds after that to the end of the partial phase. Then it clouded up again. My impressions of the eclipse brightness at totality was that it was a bit darker than usual, but I may be wrong. However, I have had wretched luck in being able to view lunar eclipses. We were virtually wiped out by clouds with the two lunar eclipses last year, and we’ve had the same luck for the many eclipses occurring before. I may be out of practice.
From the animation of the satellite images from Sunday night. The red circle points to the hole, really a notch in the clouds that allowed us to see the last part of the lunar eclipse. Our low clouds were warm in the infrared, so show as a very light gray. Credit NOAA/Environment Canada.
How to view tonight’s lunar eclipse if you are clouded out or on the wrong side of the planet
There will be a live webcast of the lunar eclipse from the Coca Cola Space Science Center in Columbus, Georgia if they’re not cloudy. Go here.
Tip of the old observer’s cap to spaceweather.com. If you haven’t yet subscribe to their free email notification service.
The partial phase of the eclipse starts at 9:07 p.m. EDT. Totality lasts from 10:11 p.m. to 11:23 p.m. when the ending partial phase commences. The partial phase will end at 12:27 a.m.
09/25/2015 – Ephemeris – There will be a great lunar eclipse Sunday night
Ephemeris for Friday, September 25th. The Sun will rise at 7:33. It’ll be up for 12 hours and 1 minute, setting at 7:35. The Moon, 2 days before full, will set at 5:34 tomorrow morning.
Lets check out Sunday’s total lunar eclipse. It will be visible from the entire contiguous 48 states, and in its entirety from Colorado, eastward. The partial phase will start at 9:07 p.m. Totality will begin at 10:11 p.m. and extend to 11:23 p.m. when the Moon should appear red in color, illuminated by the combined sunrises and sunsets occurring on the Earth at that moment. The eclipse will end at 12:27 a.m. The eclipse is perfectly viewable with the naked eye or binoculars. For those who want company and commentary as to what’s going on, the Grand Traverse Astronomical Society will provide two locations from which to view the eclipse. The NMC Observatory, south of Traverse City and Platte River Point, part of the Sleeping Bear Dunes National Lakeshore, both weather permitting.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The next lunar eclipse visible from our area will be January 31, 2018 which will achieve totality just before the moon sets. The next lunar eclipse will be January 20-21, 2019 which will start late in the evening. The problem being that January is a pretty cloudy month around here.
We’re closer to the next solar eclipse, which will be a total eclipse visible at midday, and the center line of the path of totality which will pass from Oregon to South Carolina, passing just south of St. Louis Missouri and north of Nashville Tennessee. For more on the 2017 eclipse check out this NASA eclipse page.
09/24/2015 – Ephemeris – Looking forward to Sunday’s Lunar Eclipse
Ephemeris for Thursday, September 24th. The Sun will rise at 7:32. It’ll be up for 12 hours and 4 minutes, setting at 7:36. The Moon, half way from first quarter to full, will set at 4:20 tomorrow morning.
Lets check out Sunday’s total lunar eclipse. It will be visible from the entire contiguous United States, and in its entirety from Colorado, eastward. The partial phase will start at 9:07 p.m. The total phase will begin at 10:11 p.m. and extend to 11:23 p.m. when the ending partial phase will start. The eclipse will end at 12:27 a.m. The eclipse is perfectly viewable with the naked eye or binoculars. For those who want company and commentary as to what’s going on, the Grand Traverse Astronomical Society will provide two venues from which to view the eclipse: The Northwestern Michigan College’s Rogers Observatory, south of Traverse City on Birmley Rd. and Platte River Point at the end of Lake Michigan Road off M22, part of the Sleeping Bear Dunes National Lakeshore, weather permitting.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The following is an excerpt from my September 1 post.
The eclipse occurs on the 28th for Universal Time. It’s the evening of the 27th for us. 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.
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:
- P1 – 8:11:47 p.m. Enter the penumbra (unseen). By about 8:30 the duskiness on the left edge of the moon will start to be noticeable.
- U1 – 9:07:11 p.m. Enter the umbra (partial eclipse begins).
- U2 – 10:11:10 p.m. Totality begins.
- Mid eclipse 10:48:17 p.m.
- U3 – 11:23:05 p.m. Totality ends, egress partial phase begins.
- U4 – 12:27:03 a.m. Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
- P4 – 1:22:27 a.m. Penumbral phase ends (unseen).
Note: The duskiness of the penumbral phase of the eclipse can be enhanced by viewing through sunglasses.
During the total phase, light leaks in around the Earth due to the bending of light in the Earth’s atmosphere, so the Moon is illuminated by the collective sunrises and sunsets around the globe. This usually gives the Moon a coppery hue, that some are now calling a blood moon. Occasionally, due to volcanic eruptions the Moon can become very dark.
This full moon is also the Harvest Moon and for those who care, a supermoon, it having reached perigee earlier that day.
Weather permitting there will be two GTAS venues to view this eclipse. The first will be the NMC Rogers Observatory. The second will be at the Sleeping Bear Dunes National Lakeshore at Platte River Point at the end of Lake Michigan Road. The site will be open for the visible parts of the eclipse from 9 p.m. to 12:30 a.m.
09/21/2015 – Ephemeris – Next Sunday’s total lunar eclipse
Ephemeris for Monday, September 21st. The Sun will rise at 7:28. It’ll be up for 12 hours and 14 minutes, setting at 7:42. The Moon, at first quarter today, will set at 1:02 tomorrow morning.
It’s six days to the total lunar eclipse next Sunday night. The eclipse starts just after 9 p.m. and ends shortly before 12:30 a.m. Of the remarkable four eclipse string at every possible lunar eclipse opportunity, this last one is the best for us, in that it occurs in the evening. The others were in the morning our time or occurred around the time of moon set around here. So if clear skies prevail we will have a wonderful and beautiful total lunar eclipse. Lunar eclipses occur at full moon when the Sun, Earth and Moon line up close enough for the Moon to enter the Earth’s shadow. Generally this only occurs about 1 out of 6 full moons. Eclipses of the Sun and Moon normally appear in pairs. The solar eclipse already occurred 8 days ago.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
NASA eclipse chart portion. In the eastern US the Date will be September 27. Subtract 4 hours from UT to get EDT (Eastern Daylight Time) Credit: NASA/ Fred Espanek.
Here’s the link to the full chart.
09/01/2015 – Ephemeris – Previewing September – Part 2: Total Lunar Eclipse
Ephemeris for Tuesday, September 1st. The Sun will rise at 7:04. It’ll be up for 13 hours and 15 minutes, setting at 8:19. The Moon, 3 days past full, will rise at 10:07 this evening.
Today in part 2 of the September preview we look ahead at this month’s total lunar eclipse on Sunday evening the 27th. This is the last of four total lunar eclipses in a row that started last year April, continuing last October and this April. Only this past April’s eclipse was visible in clear skies here, but all we could see was the beginning partial phase from here. We will get to see, clouds willing, the whole eclipse between 9 p.m. and 12:30 a.m. Lunar eclipses only can occur at full moon, when the Sun, Earth and Moon are lined up so that the Earth’s shadow falls on the Moon. The Moon will be completely immersed in the Earth’s shadow for over an hour then. You can mark it on your calendars, but I will be reminding you about it all the week before.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The following is my article from September’s newsletter of the Grand Traverse Astronomical Society the Stellar Sentinel. Note as with the above tines, the times here are Eastern Daylight Time.
The Last of a Quartet of Lunar Eclipses
The last of a quartet or tetrad of consecutive total lunar eclipses will occur Sunday night September 27th. The others were either clouded out or started too late for totality to be visible from here. We are hoping for good weather for this one.
Lunar eclipses or eclipses of the Moon, as these events are also called, only occur at full moon when the Earth’s shadow is cast upon the Moon. Unlike a solar eclipse, of which the partial phases are dangerous to gaze upon without special protection, a lunar eclipse is perfectly safe to view throughout.
How lunar eclipses occur. Credit NASA/Fred Espenak.
There are three kinds of lunar eclipses or phases of lunar eclipses: penumbral, partial, and total. A total eclipse passes through all three phases. In the penumbra the Sun’s light is increasingly cut off from the outside to the inside of the shadow called the umbra, where all direct sunlight is cut off. Depending on the path of the Moon, it can cut through only the penumbra, in which the eclipse is barely noticeable, a penumbral eclipse; pass only partially through the umbra, a partial eclipse; or immerse completely in the umbra to produce a total eclipse.
Lunar eclipses are easiest to see, because one only has to be on the night side of the Earth to see it. In a solar eclipse, the Moon’s shadow is too small to cover the earth, since it’s only a quarter the size of the Earth, so one has to be in a band a few thousand miles wide to spot the partial phase and has to be in a very narrow couple hundred mile wide path to see the brief totality. We’ll revisit this in 2016 in preparation for the country spanning total solar eclipse of August 21, 2016.
Eclipses, both lunar and solar occur in seasons nearly 6 months apart, which usually have one of each two weeks apart. Occasionally with a central eclipse of one to have two of the other two weeks before and two weeks after.
The reason for this is because the Earth and Moon’s orbits are tilted at about a 5° angle, and the point where they cross, 180° apart is slowly rotating clockwise. This gives us two eclipse seasons a year that slowly move earlier in the calendar. It is only when the Sun is near where the orbital planes cross that we have a chance for an eclipse, otherwise the Moon is too far north or south.
After this eclipse, the next total lunar eclipse will be January 21, 2019. However the Moon will set while in totality for us on that one.
If you’d like to explore eclipses further, check out this NASA website: http://eclipse.gsfc.nasa.gov/eclipse.html.
The eclipse occurs on the 28th for Universal Time. It’s the evening of the 27th for us. 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.
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:
- P1 – 8:11:47 p.m. Enter the penumbra (unseen). By about 8:30 the duskiness on the left edge of the moon will start to be noticeable.
- U1 – 9:07:11 p.m. Enter the umbra (partial eclipse begins).
- U2 – 10:11:10 p.m. Totality begins.
- Mid eclipse 10:48:17 p.m.
- U3 – 11:23:05 p.m. Totality ends, egress partial phase begins.
- U4 – 12:27:03 a.m. Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
- P4 – 1:22:27 a.m. Penumbral phase ends (unseen).
Note: The duskiness of the penumbral phase of the eclipse can be enhanced by viewing through sunglasses.
During the total phase, light leaks in around the Earth due to the bending of light in the Earth’s atmosphere, so the Moon is illuminated by the collective sunrises and sunsets around the globe. This usually gives the Moon a coppery hue, that some are now calling a blood moon. Occasionally, due to volcanic eruptions the Moon can become very dark.
This full moon is also the Harvest Moon and for those who care, a supermoon, it having reached perigee earlier that day.
Weather permitting there will be two GTAS venues in northern lower Michigan to view this eclipse. The first will be the Northwestern Michigan College Rogers Observatory, south of Traverse City, MI. The second will be at the Sleeping Bear Dunes National Lakeshore at Platte River Point at the end of Lake Michigan Road off M22. These sites will be open for the visible parts of the eclipse from 9 to midnight.
Of course the eclipse can be seen from your yard with no optical aide whatsoever.
The partially eclipsed Moon setting through a thin clouds and the neighbor’s swing set at 7:09 EDT April 4, 2015. Taken with a Motorola Droid Razr phone through 10X50 binoculars. Credit: Bob Moler.
04/04/2015 – Yay, it was finally clear for a lunar eclipse!
Well, of course the sky was clear for this eclipse. This is the third of a tetrad of lunar eclipses visible from the US. For this one we in Michigan are located too far east to see totality, although it was the first to be clear for. The image below shows that we just ran out of sky.
The last eclipse of the tetrad will be on the evening (for us) of September 27th 2015.
The partially eclipsed Moon setting through a thin cloud and the neighbor’s swing set at 7:09 EDT April 4, 2015. Taken with a Motorola Droid Razr phone through 10X50 binoculars. Credit: Bob Moler.
10/13/2014 – Ephemeris – Columbus uses knowledge of eclipses to get supplies from the natives
Ephemeris for Columbus Day, Monday, October 13th. The sun will rise at 7:55. It’ll be up for 11 hours and 6 minutes, setting at 7:01. The moon, 2 days before last quarter, will rise at 11:04 this evening.
On Columbus’ 4th voyage to the Caribbean he was stranded on Jamaica. For a while the natives of the island fed Columbus and his men. However due to the thievery of some of his crew, these people no longer trusted Columbus any refused them any more supplies. Columbus consulted a table of eclipses and found that a lunar eclipse was to occur on February 29th that year (1504), and that at his location the moon would rise in eclipse. He went to the leader of the people and said that they had displeased their god by refusing his crew food, and that the god would turn the Moon red in anger. The native peoples saw the red moon rising and promptly gave Columbus the supplies he wanted.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Christopher Columbus showing the lunar eclipse. From Camille Flammarion – Astronomie Populaire 1879, p231.
For more information in the Internet – search for Columbus lunar eclipse
Bob Moler's Ephemeris Blog 