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Archive for the ‘Equinox’ Category

03/20/2017 – Ephemeris – Spring starts today!

March 20, 2017 Comments off

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.

Earth near equinox

Image from the DISCOVR satellite in halo orbit at the Earth-Sun L1 point, nearly a million miles (1.6 million km) sunward of the Earth. as of March 17, 2017. As usual Michigan is covered by a cloud.  Credit NOAA/NASA.

11/24/2016 – Ephemeris – The little constellation that used to start the seasonal year

November 24, 2016 Comments off

Ephemeris for Thanksgiving Day, Thursday, November 24th.  The Sun will rise at 7:52.  It’ll be up for 9 hours and 14 minutes, setting at 5:06.  The Moon, 3 days past last quarter, will rise at 3:54 tomorrow morning.

From antiquity, the first constellation of the Zodiac has been Aries the ram.  That’s the constellation the Sun entered on the first day of spring, or the vernal equinox.  Well that was a couple of thousand years ago.  Currently the vernal equinox point is in western Pisces.  This is due to the wobbling of the Earth’s axis called precession.  The spinning Earth like and top or gyroscope wobbles when force is applied to it.  In this case the Sun and Moon.  One wobble takes 26,000 years to complete.  Anyway, Aries is a small constellation of four stars in a bent line, below the triangular constellation of Triangulum, which is itself below Andromeda.  It’s a bit west or right of the Pleiades or Seven Sisters star cluster.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Aries the ram

Aries the ram animated finder chart for 9 p.m. November 24, 2016. Created using Stellarium and GIMP.

The vernal equinox today

The vernal equinox today, where the blue line, the celestial equator and the orange line, the ecliptic or path of the Sun cross. The Sun is where these lines cross on the first day of spring (March 20th around here). Note that the vernal equinox is now in western Pisces. Created using Stellarium.

The vernal equinox in AD 100

The vernal equinox back in AD 100, where the blue line, the celestial equator and the orange line, the ecliptic or path of the Sun cross. The Sun is where these lines cross on the first day of spring. Note that the vernal equinox was at the east edge of Pisces. Created using Stellarium.

09/22/2016 – Ephemeris – Autumn will begin this morning

September 22, 2016 Comments off

Ephemeris for Thursday, September 22nd.  The Sun will rise at 7:30.  It’ll be up for 12 hours and 8 minutes, setting at 7:39.  The Moon, 1 day before last quarter, will rise at 12:06 tomorrow morning.

Fall is about to a, well… fall upon us and in a few weeks so will the leaves.  At 10:21 (14:21 UT) this morning the Sun will cross the celestial equator heading south.  The celestial equator is an imaginary line in the sky above the earth’s equator.  At that point the sun will theoretically set at the north pole and rise at the south pole.  The day is called the autumnal equinox and the daylight hours today is 12 hours and 8 minutes instead of 12 hours exactly.  That’s due to our atmosphere and our definition of sunrise and sunset.  The reason for the cooler weather now and the cold weather this winter is that the length of daylight is shortening, and the Sun rides lower in the sky, spreading its heat over a larger area, thus diluting its intensity.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Earth near the autumnal equinox

The Earth as seen a couple of days ago from NOAA,s DSCOVR satellite located near the Sun-Earth L-1 point 1 million miles sunward from the Earth. Credit NOAA/NASA.

Sun's path through the sky on the equinox

The Sun’s path through the sky on the equinox day from Traverse City, MI. Created using my LookingUp program.

 

09/16/2016 – Ephemeris – The Harvest Moon is slightly eclipsed for everyone but the Americas

September 16, 2016 Comments off

Ephemeris for Friday, September 16th.  The Sun will rise at 7:23.  It’ll be up for 12 hours and 27 minutes, setting at 7:50.  The Moon, at full today, will rise at 7:59 this evening.

Tonight’s full Moon is the Harvest Moon, the nearest full Moon to the autumnal equinox.  For the next few nights the Moon will rise later each night by much less than the average 50 minutes later each night effectively lengthening twilight for those gathering in crops.  Also this afternoon there will be a penumbral lunar eclipse visible, well not here in Michigan… because the Moon won’t be up.   Actually just about the whole world except North America and most of South America will be able to see the eclipse.  A penumbral eclipse is what I call a 5 o’clock shadow eclipse.  You wouldn’t know it unless someone pointed it out to you, when the Moon dips into the Earth’s outer shadow and the sunlight falling part of it is diminished by a little bit.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Moonlight on the bay

The not so full Moon of Monday night and its reflection on the waters of Suttons Bay after the schooner Inland Seas docked after an evening sail. Credit: the author.

Penumbral eclipse 9/16/2016

The penumbral eclipse of the Moon centered on 2:25 p.m. Eastern time, 18:54 UT, for an hour and a half before and after. Only near the middle of the eclipse will anything be visible of the effect. I find that wearing sunglasses reduces the brightness of the moon and enhances the penumbral shadow. Credit: NASA/GSFC/ Fred Espenak.

For the full-page pdf of the above click here: http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2016Sep16N.pdf

09/13/2016 – Ephemeris

September 13, 2016 Comments off

Ephemeris for Tuesday, September 13th.  The Sun will rise at 7:19.  It’ll be up for 12 hours and 36 minutes, setting at 7:56.  The Moon, 3 days before full, will set at 4:40 tomorrow morning.

Last Thursday evening an Atlas V rocket lifted off with NASA’s only interplanetary mission this year.  The spacecraft called by one of NASA’s tortured acronyms OSIRIS-Rex is on its way to the asteroid Bennu, which was discovered in 1999, and named by a 3rd grader in a contest.  Bennu is an Egyptian deity resembling a heron and also resembling the spacecraft.  OSIRIS-Rex will take two years to reach the small asteroid, orbit it for two years mapping it in great detail and will approach to retrieve a sample.  It will take 3 years to return the sample to the Earth in 2023.  Bennu is interesting because it contains organic compounds from the origin of the solar system and because of the tiny chance it could hit the Earth in 200 years or so.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

OSIRIS-REXx

The OSIRIS-REx spacecraft with its sampler boom extended.

Categories: Asteroid, Equinox, NASA

09/22/2015 – Ephemeris – Equinox tomorrow and September 27th Moon’s triple whammy

September 22, 2015 Comments off

Ephemeris for Tuesday, September 22nd.  The Sun will rise at 7:29.  It’ll be up for 12 hours and 11 minutes, setting at 7:40.   The Moon, 1 day past first quarter, will set at 2:02 tomorrow morning.

Tomorrow at 4:20 a.m. before most of us wake up summer will officially end and Autumn will start.  That’s the exact time of the autumnal equinox.  We are noticing that the days or rather daylight hours are getting noticeably shorter day by day.  Autumn will end when the days will stop getting shorter on the first day of winter, December 21st.  The full moon this Sunday is triply important.  Most important is that a total lunar eclipse will happen.  Second, it is the Harvest Moon, the nearest full moon to the autumnal equinox, more on that next week.  Also it is the closest the Moon gets to the Earth all year.  Yup it’s a so-called supermoon.  If the Moon were a 2 inch ball it would be 20 feet from an 8 inch Earth.  The supermoon is a foot closer.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

That last bit about the Moon being a two-inch ball will come in handy if you come to the Girl Scout Badge Bash at ECCO in Traverse City Thursday night.

08/31/2015 – Ephemeris – Previewing the skies of September – Part 1

August 31, 2015 Comments off

Ephemeris for Monday, August 31st.  The Sun will rise at 7:03.  It’ll be up for 13 hours and 18 minutes, setting at 8:21.   The Moon, 2 days past full, will rise at 9:31 this evening.

Let’s look forward to the skies of September. The sun will moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 15 minutes tomorrow the 1st. to 11 hours 46 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 54 degrees tomorrow, and will descend to 42 degrees on the 30th. The Straits area will see the sun a degree lower.  The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 4:20 a.m. on September 23rd.  Saturn is setting before midnight now, but Venus and Mars are appearing in the morning sky soon.  Tomorrow we’ll look at September’s lunar eclipse.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location

Addendum

Star Chart for September 2015

Star Chart for September 2015. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 p.m. EDT.  That is chart time.  Note, Traverse City is located 1 hour 45 minutes behind our time meridian.  To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

Evening astronomical twilight ends at 10:04 p.m. EDT on August 1st, decreasing to 9:02 p.m. EDT on the 30th..

Morning astronomical twilight starts at 5:19 a.m. EDT on August 1st, and increasing to 6:01 a.m. EDT on the 30th.

Add a half hour to the chart time every week before the 15th and subtract and hour for every week after the 15th.

For a list of constellation names to go with the abbreviations click here.

The green pointer from the Big Dipper is:

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
  • Follow the arc of the Big Dipper’s handle to Arcturus.
  • The Summer Triangle is shown in red.

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 Daylight Time on a 24 hour clock.  Some additions made to aid clarity.

Conjunctions like the Mars-Regulus: 0.8° N means Regulus will appear 0.8° north of Mars.

Sep 01 Tu Venus: 25° W
04 Fr 05:59 Mercury Elongation: 27.1° E
05 Sa 01:09 Moon-Aldebaran: 0.6° S Occultation?*
05 Sa 05:54 Last Quarter
06 Su 13:06 Moon North Dec.: 18.2° N
10 Th 01:53 Moon-Venus: 2.9° S
13 Su 02:41 New Moon
13 Su 02:55 Partial Solar Eclipse (Southern tip of Africa to Antarctica)
14 Mo 00:38 Moon Ascending Node
14 Mo 07:28 Moon Apogee: 406500 km
18 Fr 22:54 Moon-Saturn: 3.1° S
21 Mo 04:59 First Quarter
21 Mo 08:02 Moon South Dec.: 18.1° S
23 We 04:20 Autumnal Equinox
24 Th 15:38 Mars-Regulus: 0.8° N
27 Su 17:04 Moon Descending Node
  27  Su 21:46 Moon Perigee: 356900 km – Super moon
27  Su 22:48 Total Lunar Eclipse
27 Su 22:50 Full Moon – Harvest Moon
30 We 10:36 Mercury Inferior Conjunction with the Sun
Oct 01 Th Venus: 43.6° W

* For the Grand Traverse Region the Moon will rise at 12:10 a.m. occulting Aldebaran.  Aldebaran will appear at the Moon’s unilluminated top right edge at approximately 12:40 a.m.

Note:  All lunar conjunctions in the table above are geocentric.  Double check with a program like Stellarium to check on the position of the body with respect to the moon for your location.