Archive
03/31/2017 – Ephemeris – Previewing April Skies
Ephemeris for Friday, March 31st. The Sun will rise at 7:24. It’ll be up for 12 hours and 44 minutes, setting at 8:09. The Moon, 3 days before first quarter, will set at 12:35 tomorrow morning.
The second quarter of the year begins with April Fools Day tomorrow. Daylight hours in the Interlochen/Traverse City area and will increase from 12 hours and 47 minutes tomorrow to 14 hours 12 minutes on April 30th as spring really takes hold. The altitude, or angle, of the sun above the southern horizon at local noon will be 50 degrees tomorrow and will ascend to 60 degrees on April 30th. The altitude of the sun in the Straits area will be a degree lower. The actual time of local apparent noon this month for the Interlochen/Traverse City area, when the sun passes due south, will be about 1:43 p.m. Jupiter will reach opposition from the Sun this month, and be a great planet to view in a telescope all night long.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
April Evening Star Chart
The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. Note, Traverse City is located approximately 45 minutes behind our time meridian. (An hour 45 minutes behind our daylight saving time meridian. during EDT and 45 minutes behind our daylight standard time meridian. during EST). To duplicate the star positions on a planisphere you may have to set it to 1:45 or 0:45 earlier than the current time if you were near your time meridian.
April Morning Chart
For a list of constellation names to go with the abbreviations click here.
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star
- Follow the arc of the handle of the Big Dipper to the star Arcturus, and
- Straighten to a spike to Spica
- The Summer Triangle is in red
- The Lyrid meteor shower radiant is in yellow and marked LyrR
Evening nautical twilight ends at 9:17 p.m. EDT on the 1st, increasing to 10:01 p.m. EDT on the 30th.
Evening astronomical twilight ends at 9:54 p.m. EDT on the 1st, increasing to 10:45 p.m. EDT on the 30th.
Morning astronomical twilight starts at 5:46 a.m. EDT on the 1st, and increasing to 4:42 a.m. EDT on the 30th.
Morning nautical twilight starts at 6:23 a.m. EDT on the 1st, and Increasing to 5:26 a.m. EDT on the 30th.
NASA Calendar of Planetary Events
Credit: Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)
To generate your own calendar go to http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html
Times are Eastern Time and follow the time change dates.
Date Time Event Apr 01 Sa Venus: 13.4° W 01 Sa 04:49 Moon-Aldebaran: 0.3° S 01 Sa 05:59 Mercury Greatest Eastern Elongation: 19° 03 Mo 02:12 Moon North Dec.: 19° N 03 Mo 14:39 First Quarter 05 We 08:45 Moon-Beehive: 4° N 07 Fr 00:30 Moon-Regulus: 0.8° N 07 Fr 05:14 Moon Ascending Node 07 Fr 16:58 Jupiter Opposition from the Sun 10 Mo 17:20 Moon-Jupiter: 2.4° S 11 Tu 02:08 Full Moon 14 Fr 01:43 Uranus Conjunction with the Sun 15 Sa 06:05 Moon Apogee: 405500 km 16 Su 14:39 Moon-Saturn: 3.6° S 17 Mo 09:12 Moon South Dec.: 19.1° S 19 We 05:57 Last Quarter 20 Th 01:46 Mercury Inferior Conjunction with the Sun 21 Fr 04:16 Mars-Pleiades: 3.5° S 21 Fr 18:30 Moon Descending Node 22 Sa 07:40 Lyrid Meteor Shower: ZHR = 20 23 Su 13:59 Moon-Venus: 5.3° N 26 We 08:16 New Moon 27 Th 12:18 Moon Perigee: 359300 km 28 Fr 13:20 Moon-Aldebaran: 0.5° S 30 Su 09:33 Moon North Dec.: 19.2° N May 01 Mo Venus: 39.9° W
April 2017 Calendar
LU Ephemeris of Sky Events for Interlochen/TC April, 2017 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Sat 1| 07:23a 08:10p 12:47 | 09:15p 06:18a | Set 01:43a 30%| +------+-----------------------+----------------+-----------------------+ |Sun 2| 07:21a 08:12p 12:50 | 09:16p 06:16a | Set 02:44a 41%| |Mon 3| 07:19a 08:13p 12:53 | 09:18p 06:14a |F Qtr Set 03:38a 53%| |Tue 4| 07:17a 08:14p 12:56 | 09:19p 06:12a | Set 04:25a 63%| |Wed 5| 07:15a 08:15p 12:59 | 09:21p 06:10a | Set 05:05a 74%| |Thu 6| 07:14a 08:17p 13:02 | 09:22p 06:08a | Set 05:40a 82%| |Fri 7| 07:12a 08:18p 13:06 | 09:24p 06:06a | Set 06:11a 90%| |Sat 8| 07:10a 08:19p 13:09 | 09:25p 06:04a | Set 06:40a 95%| +------+-----------------------+----------------+-----------------------+ |Sun 9| 07:08a 08:20p 13:12 | 09:27p 06:02a | Set 07:08a 98%| |Mon 10| 07:06a 08:21p 13:15 | 09:28p 06:00a | Set 07:36a 100%| |Tue 11| 07:05a 08:23p 13:18 | 09:29p 05:58a |Full Rise 08:54p 99%| |Wed 12| 07:03a 08:24p 13:21 | 09:31p 05:56a | Rise 09:54p 97%| |Thu 13| 07:01a 08:25p 13:24 | 09:32p 05:54a | Rise 10:52p 93%| |Fri 14| 06:59a 08:26p 13:27 | 09:34p 05:52a | Rise 11:49p 87%| |Sat 15| 06:58a 08:28p 13:30 | 09:35p 05:50a | Rise 12:43a 80%| +------+-----------------------+----------------+-----------------------+ |Sun 16| 06:56a 08:29p 13:33 | 09:37p 05:48a | Rise 01:34a 72%| |Mon 17| 06:54a 08:30p 13:36 | 09:38p 05:46a | Rise 02:22a 64%| |Tue 18| 06:52a 08:31p 13:39 | 09:40p 05:44a | Rise 03:05a 54%| |Wed 19| 06:51a 08:33p 13:41 | 09:41p 05:42a |L Qtr Rise 03:45a 44%| |Thu 20| 06:49a 08:34p 13:44 | 09:43p 05:40a | Rise 04:21a 34%| |Fri 21| 06:47a 08:35p 13:47 | 09:44p 05:39a | Rise 04:55a 25%| |Sat 22| 06:46a 08:36p 13:50 | 09:46p 05:37a | Rise 05:27a 16%| +------+-----------------------+----------------+-----------------------+ |Sun 23| 06:44a 08:38p 13:53 | 09:48p 05:35a | Rise 05:59a 9%| |Mon 24| 06:43a 08:39p 13:56 | 09:49p 05:33a | Rise 06:33a 3%| |Tue 25| 06:41a 08:40p 13:59 | 09:51p 05:31a | Rise 07:08a 1%| |Wed 26| 06:39a 08:41p 14:01 | 09:52p 05:29a |New Set 09:01p 1%| |Thu 27| 06:38a 08:43p 14:04 | 09:54p 05:27a | Set 10:16p 4%| |Fri 28| 06:36a 08:44p 14:07 | 09:55p 05:25a | Set 11:29p 9%| |Sat 29| 06:35a 08:45p 14:10 | 09:57p 05:23a | Set 12:35a 17%| +------+-----------------------+----------------+-----------------------+ |Sun 30| 06:33a 08:46p 14:13 | 09:58p 05:22a | Set 01:34a 27%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunset and sunrise
03/30/2017 – Ephemeris – Have you ever seen zodiacal light?
Ephemeris for Thursday, March 30th. The Sun will rise at 7:26. It’ll be up for 12 hours and 41 minutes, setting at 8:07. The Moon, 3 days past new, will set at 11:23 this evening.
After you spot the moon tonight, hang around outside at the end of astronomical twilight, about 9:50 p.m. look to the west at Taurus the bull and Gemini, trying to block out the Moon. Then broaden your gaze. There will be a very faint triangular glow with broad base at the horizon leaning a bit to the left, with its apex near the V of the face of Taurus the bull and the bright star Aldebaran to the right of Orion. This glow is called Zodiacal Light, caused by the reflected sunlight off a cloud of dust located in the plane of the solar system. Most of the large bodies of the solar system orbit the sun close to a single plane. Zodiacal Light is best seen on spring evenings and autumn mornings where it tilts to the right.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
03/29/2017 – Ephemeris – It’s Wednesday, do you know where your bright planets are?
Ephemeris for Wednesday, March 29th. The Sun will rise at 7:28. It’ll be up for 12 hours and 38 minutes, setting at 8:06. The Moon, 2 days past new, will set at 10:10 this evening.
In the evening sky tonight, replacing Venus will be the elusive planet Mercury. This tiny planet might be seen to the upper right of the Sun’s setting point starting about 9 p.m. It will set at 9:49 p.m. Mars is still hanging on, in the west, and will set at 11:10 p.m. The thin sliver of a crescent Moon is seen left of and above Mercury and Below Mars tonight. This might be a good time to spot Earth shine on it’s night side. Jupiter will rise in the east at 8:47 p.m. a half hour before the star Spica, which it will be seen to hang out with this year. Jupiter will be still seen in the morning sky low in the southwest at 6 a.m. Saturn at the same time is in the south above the Teapot figure of Sagittarius. It will rise tomorrow at 2:33 a.m. in the east-southeast.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Mercury, Mars and the Moon low in the west at 9 p.m. March 29, 2017. Note the Moon as seen below is a thin crescent which cannot be displayed properly at this scale. Created using Stellarium.

The thin crescent Moon at 9 p.m. March 29, 2017. Created using Hallo Northern Sky. The program does not have the capability to show earth shine to fill out the rest of the sphere which may be detected with the naked eye or in binoculars.

Jupiter and Saturn with the morning constellations of summer at 6 a.m. tomorrow morning March 30, 2017. Created using Stellarium.
03/28/2017 – Ephemeris – Mercury is visible in the evening sky now
Ephemeris for Tuesday, March 28th. The Sun will rise at 7:30. It’ll be up for 12 hours and 35 minutes, setting at 8:05. The Moon, 1 day past new, will set at 8:56 this evening.
Mercury is in the evening sky now for it’s spring appearance. Mercury is best seen when it’s near its farthest from the Sun on spring evenings and autumn mornings. Mercury will reach its greatest elongation east of the Sun this coming Saturday with a 19 degree angle of separation from the Sun. This tiny planet is brighter before eastern elongating than after it. I find that the optimal time to look for Mercury is about 45 minutes after sunset. That makes it about 8:50 p.m. At that time Mercury will be low in the west only 9 degrees above the horizon. That’s a bit less than the width of a fist held at arm’s length above the lake or sea horizon, or the base of distant trees that are on your level. Mercury will be visible for about a week or so.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Mercury near the western horizon at 8:50 p.m. or 45 minutes after sunset. Also shown is its orbit as it appears tonight. The Moon and Uranus are not actually visible in the twilight glare. Mars will be visible a bit later. The Moon will appear between Mercury and Mars tomorrow night. Created using Stellarium.
03/27/2017 – Ephemeris – 5 more new moons before the Great American Total Solar Eclipse!
Ephemeris for Monday, March 27th. The Sun will rise at 7:32. It’ll be up for 12 hours and 31 minutes, setting at 8:04. The Moon is new today, and won’t be visible.
The Moon will be officially new at 10:57 this evening. Later this year there will occur at total solar eclipse visible from a narrow path the crosses the United States from Oregon to South Carolina. It will cross the cities of Casper Wyoming, Kansas City, just south of St Louis, Carbondale, Illinois; Nashville, Columbia and Charleston South Carolina. Carbondale is about the closest spot to us at about 600 miles. We will see about 75-80 percent of the Sun blocked by the Moon here in northern Michigan. The is generally a solar eclipse about every six new moons, the exception is an occasional solar eclipse on two consecutive new moons, except they will occur in opposite polar regions and are rarely total. The Moon’s orbit is tilted by 5° to the Sun’s path. This time the Moon is way south of the Sun.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

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.
The points are GE greatest eclipse, path width 71.27 miles (114.7 km); and GD greatest duration of totality, 2 minutes and 40.2 seconds.

An animation of the Moon’s shadow as it will cross the Earth’s surface August 21, 2017. Credit A.T. Sinclair/NASA
NASA’s Eclipse page: https://eclipse2017.nasa.gov/

The solar corona displayed during the July 10, 1072 total solar eclipse from Prince Edward Island. Credit Bob Moler.

Baily’s Beads – sunlight streaming through the valleys at the edge of the Moon at the end of totality, March 7, 1970, outside Bladenboro NC. Credit Bob Moler.
On May 5th, I’ll be giving a talk about the upcoming total solar eclipse. How to enjoy its partial phases here and along the path of totality.
03/24/2017 – Ephemeris – Finding Leo
Ephemeris for Friday, March 24th. The Sun will rise at 7:37. It’ll be up for 12 hours and 22 minutes, setting at 8:00. The Moon, 3 days before new, will rise at 6:24 tomorrow morning.
At 10 p.m. the spring constellation of Leo the lion will be high in the east-southeast. It can be found by locating the Big Dipper high in the northeast and imagining that a hole were drilled in the bowl to let the water leak out. It would drip on the back of this giant cat. The Lion is standing or lying facing westward. His head and mane are seen in the stars as a backwards question mark. This group of stars is also called the sickle. The bright star Regulus is at the bottom, the dot at the bottom of the question mark. A triangle of stars, to the left of Regulus, is the lion’s haunches. Leo contains some nice galaxies visible in moderate sized telescopes. The stars in Leo’s part of the sky are sparser than those in the winter sky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Add info on Mercury in the evening sky.
Addendum
03/23/2017 – Ephemeris – a single headed Hydra
Ephemeris for Thursday, March 23rd. The Sun will rise at 7:39. It’ll be up for 12 hours and 19 minutes, setting at 7:59. The Moon, 3 days past last quarter, will rise at 5:48 tomorrow morning.
In the southern evening sky can be found the constellation of Hydra the water snake. Unlike the mythical monster Hercules fought of the same name this Hydra has but one head, which is its most distinctive part. At 9 p.m. look to the south. The head of Hydra is located directly to the left of Procyon the bright star in Orion’s little dog Canis Minor, and to the right of the star Regulus in Leo. Hydra’s head is a small distinctive group of 6 stars that make a loop and the snake’s slightly drooping head. At that time the sinuous body of Hydra sinks below the horizon in the southeast. As it gets later in the evening the rest of Hydra’s body will slither to just above the southeastern horizon below the planet Jupiter this year and the bright star Spica in the constellation of Virgo.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
03/22/2017 – Ephemeris – Wednesday is bright planet day but we seem to be missing one of them
Ephemeris for Wednesday, March 22nd. The Sun will rise at 7:41. It’ll be up for 12 hours and 16 minutes, setting at 7:57. The Moon, 2 days past last quarter, will rise at 5:09 tomorrow morning.
It’s still dark enough to see the morning planets again during these Ephemeris play times. But it won’t last. Jupiter will be seen in the morning in the southwest above the star Spica. It will rise tonight at 9:19 p.m. in the East. Saturn can be glimpsed this morning above the Teapot figure of Sagittarius in the south. It will rise tomorrow at 3 a.m. in the east-southeast. The crescent Moon will be in the east-southeast. In the evening sky tonight Venus is essentially gone, just 3 days from passing inferior conjunction, it might be seen to the upper right of the Sun’s setting point. I once spotted it this close to conjunction in the bright twilight. It will set at 8:35 p.m. Mars is still hanging on, in the west, and will set at 11:11 p.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

Jupiter, Saturn and the crescent Moon at 7 a.m. this morning March 22, 2017. Created using Stellarium.

Venus at 15 minutes after sunset on a flat horizon 3 days before inferior conjunction from 45 degrees north latitude. Venus is seen at 3 degrees, 24 minutes above the horizon and practically invisible. Mercury is getting ready for its appearance in the west next week. We will visit it in more detail on Friday. Created using Stellarium.

Jupiter rising and the constellations of winter and spring at 10 p.m. this evening March 22, 2017. Created using Stellarium.

Jupiter and its moons at 7 a.m. and 10 p.m. today, March 22, 2017. orientation of Jupiter is as it appears on the sky at those times. Created using Cartes du Ciel (Sky Charts).

Saturn and its moons at 7 a.m. March 22, 2017. It is shown at the same scale as Jupiter above. 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 March 22, 2017. The night ends on the left with sunrise on March 23. Note that Venus is visible at both sunrise and sunset at least on these charts. Click on image to enlarge. Created using my LookingUp program.
03/21/2017 – Ephemeris – Let’s find Cancer the crab
Ephemeris for Tuesday, March 21st. The Sun will rise at 7:43. It’ll be up for 12 hours and 13 minutes, setting at 7:56. The Moon, 1 day past last quarter, will rise at 4:26 tomorrow morning.
At 10 this evening, the faint constellation, and member of the Zodiac, Cancer the crab is located in the south half way between the bright stars Castor and Pollux of the constellation Gemini, high in the south and the bright star Regulus in Leo the lion in the southeast. Cancer is very dim, looking like an upside-down Y if it’s stars can be made out. In the center of Cancer is a fuzzy spot to the unaided eye. In binoculars or a low power telescope this fuzzy spot becomes a cluster of stars. It is the Beehive cluster. At 577 light years away, according to the latest measurements, it is one of the closest star clusters, but more distant than the Pleiades and Hyades the face of Taurus the bull off in the west.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
03/20/2017 – Ephemeris – Spring starts today!
Ephemeris for Monday, March 20th. The Sun will rise at 7:45. It’ll be up for 12 hours and 10 minutes, setting at 7:55. The Moon, at last quarter today, will rise at 3:39 tomorrow morning.
This morning, at 6:29 (10:29 UT) the sun crosses overhead at the earth’s equator as it appears to head north, starting for us the season of spring. It’s the vernal equinox. As you can tell from my intro, we’re already above 12 hours of daylight, and we’ll add another 3 plus hours of daylight before summer begins in three months. We are already adding about 3 minutes a day of daylight to that goal now, the maximum rate. With the Sun out longer and its ascension higher in the sky each day, it is rapidly adding energy to the northern hemisphere. We don’t feel that immediately. While the land rapidly absorbs heat, the oceans and lakes, especially the Great Lakes are a big heat sink, taking a very long time to warm up.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
This March equinox also is the beginning of autumn for folks south of the equator.