Archive
05/05/2022 – Ephemeris – Halley’s Comet returns… in pieces
This is Ephemeris for Cinco de Mayo, Thursday, May 5th. Today the Sun will be up for 14 hours and 25 minutes, setting at 8:52, and it will rise tomorrow at 6:25. The Moon, 3 days before first quarter, will set at 1:53 tomorrow morning.
The Eta Aquariid meteor shower will reach peak at about 4 am, tomorrow morning. However, the radiant, the apparent source of the meteor streaks, doesn’t rise until 3:15 am. If you’re waiting to see the return of Halley’s Comet, you needn’t wait until the main body of the comet returns in 2061. Halley’s Comet has made many passes of the inner solar system in recorded history, and more before that, returning to the inner solar system every 76 years or so, before returning to its frigid home beyond Neptune. It’s closest pass to the Sun, called perihelion, is inside Venus’ orbit. On the way in and out, it passes close to the Earth’s orbit. It has left a trail of debris, which we pass through in May and again in October.
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 Eta Aquariid meteor shower radiant as it will be apparent tomorrow morning at 4:30 or at the beginning of nautical twilight. The radiant isn’t a ting that can be seen, but the point from which all the meteors of this shower can be traced back to. The funny looking lower case “n” is the Greek letter eta. The shower is named for the star seen just above the radiant, which is in the center of a small triangle of stars that make up Aquarius’ water jar. Click on the image to enlarge it. Created using Stellarium.
05/04/2021 – Ephemeris – We cross Halley’s Comet debris this week
This is Bob Moler with Ephemeris for Tuesday, May 4th. Today the Sun will be up for 14 hours and 23 minutes, setting at 8:51, and it will rise tomorrow at 6:26. The Moon, 1 day past last quarter, will rise at 4:20 tomorrow morning.
The Eta Aquariid meteor shower will reach their peak for us Thursday morning the 6th. The Eta Aquariids are caused by bits of Halley’s Comet, passing the Earth’s orbit heading out from the Sun. The Orionids of late October are debris of Halley’s comet passing the Earth’s orbit heading in toward the Sun. The Eta Aquariids are named for the star nearest the radiant of the meteor shower. The constellation of Aquarius has many shower radiants, which is why the shower is named for a star in Aquarius. The radiant rises shortly before 3:30am and astronomical twilight begins an hour later. There’s perhaps another half hour of visibility after that. The peak will occur Thursday morning where 20 meteors per hour or more might be seen.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
two other minor meteor showers are active then with only a handful of meteors an hour
compared to the Eta Aquariids’ somewhat higher rates. The funny looking “n” character
next to Aquariid is the Greek letter Eta. Chart created using Stellarium.
the inner solar system, and the Eta Aquariids when it’s leaving.
Credit my LookingUp program.
05/01/2017 – Ephemeris – Previewing May 2017 Skies
Ephemeris for Monday, May 1st. The Sun rises at 6:32. It’ll be up for 14 hours and 15 minutes, setting at 8:47. The Moon, 1 day before first quarter, will set at 2:24 tomorrow morning.
Today starts the month of May when the promise of spring is finally fulfilled. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes today to 15 hours 19 minutes on the 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 61 degrees now to 67 degrees at month’s end. The altitude of the sun in the Straits area will be a degree lower than that but your daylight hours will be a few minutes longer. Local apparent noon this month, when the sun passes due south, will be about 1:38 p.m.
This is the month of the Eta Aquariid meteor shower which will reach its peak this Thursday and Friday. There will be dark skies around 5 a.m. to see the meteors coming from the southeast.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
May Evening Star Chart
Evening Star Chart for May 2017 (11 p.m. May 15, 2017). Created using my LookingUp program. Click on image to enlarge.
The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. Note that 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 hour 45 minutes (Daylight Time) or 45 minutes (Standard Time) earlier than the current time if you are near your time meridian.
Note the chart times of 11 p.m. and 5 a.m. are for the 15th. For each week before the 15th add ½ hour. For each week after the 15th subtract ½ hour. The planet positions are updated each Wednesday on this blog.
May Morning Star Chart
Star Chart for May 2017 mornings based on 5 a.m. May 15th. Created using my LookingUp program. Click on image to enlarge.
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
- The Summer Triangle is in red
- The Eta Aquariid meteor shower radiant is in yellow and marked EAqR is active from April 19th to May 28th and peaks May 6th. Zenithal Hourly Rate at peak is expected to be 50, though considerably less than that is expected due to its radiant’s low position in our skies. Data from the International Meteor Organization 2017 calendar.
Evening nautical twilight ends at 10:02 p.m. EDT on the 1st, increasing to 10:46 p.m. EDT on the 31st.
Evening astronomical twilight ends at 10:47 p.m. EDT on the 1st, increasing to 11:44 p.m. EDT on the 31st.
Morning astronomical twilight starts at 4:40 a.m. EDT on the 1st, and increasing to 3:44 a.m. EDT on the 31st.
Morning nautical twilight starts at 5:24 a.m. EDT on the 1st, and Increasing to 4:42 a.m. EDT on the 31st.
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 for Michigan, US
Date Time Event May 01 Mo Venus: 39.9° W 02 Tu 2:23 pm Moon-Beehive: 3.7° N 02 Tu 10:47 pm First Quarter 04 Th 5:49 am Moon-Regulus: 0.6° N 04 Th 6:42 am Moon Ascending Node 04 Th 10:54 pm Eta Aquariid Shower: ZHR = 60 05 Fr 9:51 am Mars-Aldebaran: 6.2° N 07 Su 5:24 pm Moon-Jupiter: 2.3° S 10 We 5:43 pm Full Moon 12 Fr 3:51 pm Moon Apogee: 406200 km 13 Sa 7:07 pm Moon-Saturn: 3.4° S 14 Su 4:29 pm Moon South Dec.: 19.3° S 17 We 6:59 pm Mercury Elongation: 25.8° W 18 Th 8:33 pm Last Quarter 18 Th 9:30 pm Moon Descending Node 22 Mo 8:32 am Moon-Venus: 2.4° N 23 Tu 9:20 pm Moon-Mercury: 1.6° N 25 Th 3:44 pm New Moon 25 Th 9:23 pm Moon Perigee: 357200 km 27 Sa 7:36 pm Moon North Dec.: 19.4° N 29 Mo 9:50 pm Moon-Beehive: 3.4° N 31 We 7:56 am Moon Ascending Node 31 We 12:08 pm Moon-Regulus: 0.3° N Jun 01 Th Venus: 45.8° W
May 2017 Calendar
LU Ephemeris of Sky Events for Interlochen/TC May, 2017 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Mon 1| 06:32a 08:48p 14:15 | 10:00p 05:20a | Set 02:24a 38%| |Tue 2| 06:30a 08:49p 14:18 | 10:02p 05:18a |F Qtr Set 03:07a 49%| |Wed 3| 06:29a 08:50p 14:21 | 10:03p 05:16a | Set 03:43a 59%| |Thu 4| 06:28a 08:51p 14:23 | 10:05p 05:15a | Set 04:16a 70%| |Fri 5| 06:26a 08:52p 14:26 | 10:06p 05:13a | Set 04:45a 78%| |Sat 6| 06:25a 08:54p 14:28 | 10:08p 05:11a | Set 05:12a 86%| +------+-----------------------+----------------+-----------------------+ |Sun 7| 06:24a 08:55p 14:31 | 10:09p 05:09a | Set 05:39a 92%| |Mon 8| 06:22a 08:56p 14:33 | 10:11p 05:08a | Set 06:07a 97%| |Tue 9| 06:21a 08:57p 14:36 | 10:13p 05:06a | Set 06:36a 99%| |Wed 10| 06:20a 08:58p 14:38 | 10:14p 05:04a |Full Rise 08:45p 100%| |Thu 11| 06:18a 09:00p 14:41 | 10:16p 05:03a | Rise 09:42p 99%| |Fri 12| 06:17a 09:01p 14:43 | 10:17p 05:01a | Rise 10:38p 96%| |Sat 13| 06:16a 09:02p 14:45 | 10:19p 05:00a | Rise 11:30p 91%| +------+-----------------------+----------------+-----------------------+ |Sun 14| 06:15a 09:03p 14:48 | 10:20p 04:58a | Rise 12:19a 85%| |Mon 15| 06:14a 09:04p 14:50 | 10:22p 04:57a | Rise 01:03a 78%| |Tue 16| 06:13a 09:05p 14:52 | 10:23p 04:55a | Rise 01:44a 70%| |Wed 17| 06:12a 09:06p 14:54 | 10:25p 04:54a | Rise 02:21a 60%| |Thu 18| 06:11a 09:08p 14:56 | 10:26p 04:52a |L Qtr Rise 02:54a 50%| |Fri 19| 06:10a 09:09p 14:58 | 10:28p 04:51a | Rise 03:26a 40%| |Sat 20| 06:09a 09:10p 15:00 | 10:29p 04:50a | Rise 03:57a 30%| +------+-----------------------+----------------+-----------------------+ |Sun 21| 06:08a 09:11p 15:02 | 10:30p 04:48a | Rise 04:28a 20%| |Mon 22| 06:07a 09:12p 15:04 | 10:32p 04:47a | Rise 05:02a 12%| |Tue 23| 06:06a 09:13p 15:06 | 10:33p 04:46a | Rise 05:38a 5%| |Wed 24| 06:05a 09:14p 15:08 | 10:35p 04:45a | Rise 06:20a 1%| |Thu 25| 06:04a 09:15p 15:10 | 10:36p 04:44a |New Set 09:04p 0%| |Fri 26| 06:04a 09:16p 15:12 | 10:37p 04:42a | Set 10:16p 2%| |Sat 27| 06:03a 09:17p 15:13 | 10:39p 04:41a | Set 11:21p 7%| +------+-----------------------+----------------+-----------------------+ |Sun 28| 06:02a 09:18p 15:15 | 10:40p 04:40a | Set 12:18a 15%| |Mon 29| 06:02a 09:19p 15:17 | 10:41p 04:39a | Set 01:05a 24%| |Tue 30| 06:01a 09:19p 15:18 | 10:42p 04:38a | Set 01:45a 34%| |Wed 31| 06:00a 09:20p 15:19 | 10:43p 04:38a | Set 02:19a 44%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunset and sunrise
05/03/2016 – Ephemeris – Halley’s Comet is back… In little bitty pieces
Ephemeris for Tuesday, May 3rd. The Sun rises at 6:29. It’ll be up for 14 hours and 21 minutes, setting at 8:50. The Moon, 3 days before new, will rise at 5:23 tomorrow morning.
There’s a meteor shower happening this week that’s a tough one for observers as far north as we are. It’s the Eta Aquariids: seeming to come from the Water Jar asterism of the constellation Aquarius the water bearer. It will reach peak on Thursday the 5th, however the radiant point rises around 3:30 a.m., and twilight starts an hour and a half later. The radiant is also low in the southeastern part of the sky. The meteors are fast-moving and many of them are bright. They are bits shed by Halley’s Comet and left in its orbit. The Earth passes close to Halley’s orbit twice a year: In late October as the particles come in from the outer solar system, and again in early May as they head back out again. We’ll see souvenirs of Halley’s Comet before it returns in 2061.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Eta Aquarid radiant at the peak of the shower. The radiant moves slowly to the east with time. Credit: Bob Moler’s LookingUp program.
This meteor shower is low for us in the Northern Hemisphere, but it will be great for those Down Under. The Moon is even cooperating this year, by getting out of the way. The active dates for the shower are April 19th to May 28th. The velocity of the meteoroids that strike the atmosphere is 66 km/s. Halley’s Comet, and thus its debris is traveling in a retrograde orbit, going the wrong way in a one way solar system, which is why the speed of the particles is so high.
05/05/2015 – Ephemeris – Eta Aquariids, an early visit of Halley’s Comet
Ephemeris for Tuesday, May 5th. Today the Sun will be up for 14 hours and 24 minutes, setting at 8:52. The Moon, 2 days past full, will rise at 10:29 this evening. Tomorrow the Sun will rise at 6:26.
The Eta Aquariid meteor shower will reach peak tomorrow morning. But the Moon will be bright, so only the brightest of them will be seen. However if you’re waiting to see the return of Halley’s Comet, you needn’t wait until the main body of the comet returns in 2061. Halley’s Comet has made many passes of the inner solar system in recorded history, and many more before that, returning to the inner solar system every 76 years or so, before returning to its frigid home beyond Neptune. It’s closest to the Sun, called perihelion is inside Venus’ orbit. On the way in and out it passes close to the Earth’s orbit. It has left a trail of debris, which we pass through in May and again in October.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Eta Aquariid radiant at 5 a.m. The radiant moves slowly to the east with time. Credit: My LookingUp program.
We get two meteor showers from Halley’s Comet. The Orionids, when Halley is approaching the inner solar system, and the Eta Aquariids when it’s leaving. Credit: My LookingUp program.
Bob Moler's Ephemeris Blog 