2017 September Equinox

   On Friday September 22nd at 20:02 UT, (3:02 pm CDT) the Sun will have reached the astronomical coordinates of 0 degrees declination and 12 hours of right ascension, or RA. This places the Sun within the boundaries of the constellation Virgo the Maiden, or as some would say, “the Sun is in Virgo.” This is the actual position of the Astronomical Sun as opposed to the pseudoscience of astrology which has the astrological Sun entering the constellation of Libra the Scales.
   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   Declination is the astronomical equivalent to latitude measuring from 0 degrees at the equator to 90 degrees at either pole. Right ascension, or RA, is like longitude except that there is only east RA. The globe is divided into 24 sections, and like meridians of longitude, these hour circles are 15 degrees wide at the celestial equator and taper to a ‘point’ at the north and south pole respectively. In RA the ‘hour’ circles are counted from 0 hours to 23 hours. The 0 hour circle is at the intersection of the ecliptic and the celestial equator in the constellation of Pisces the Fishes.
   In a class lesson about seasons today would be one of the two days during the year when the Sun would be described as being over the Earth’s equator. If you were at the Earth’s equator the Sun would have an altitude of 90 degrees, or straight up in your sky at your local time for midday. At that moment there would not be a shadow. However at any other latitude, north or south at midday, the Sun would be at an angle less than 90 degrees and there would be a midday shadow. (Midday is the local time when the Sun is halfway between local rising time and local setting time. At any midday the Sun is at its maximum altitude above the southern horizon in the northern hemisphere, or is at its maximum altitude above the northern horizon in the southern hemisphere.)
   What is often noted about an equinox day is the reminder that equinox means equal night as a reference to there being equal amounts of daylight, and night. Also on an equinox day the Sun would rise due east and set due west for virtually everywhere on the globe. The times for sunrise and sunset would be approximately 12 hours apart, and the rising time would be around 6 am local time, and the setting time would be around 6 pm local time.

Hola Moon doh

Hola ‘Moo’ndo! Think Globally.

   So why “September Equinox” instead of using the more familiar “Fall Equinox”. Primarily because the southern hemisphere is also changing seasons on this day however for the southern hemisphere this is the start of their spring season. Despite the opposite seasons it is somewhat of a northern hemisphere bias that traditionally we would call this day the “Autumnal or Fall Equinox”, and in March we would say the “Spring” or “Vernal Equinox”. I favor the use of the name of the month so that regardless of which hemisphere it is just simply the March equinox or the September equinox, and by extension we would also have the June solstice and the December solstice..
   
   This short video shows students at Colegio Menor San Francisco de Quito, a school in Quito Ecuador, measuring the altitude of the sun hourly on the day of the 2004 September Equinox. They were taking part in Project SunShIP, Sun Shadow Investigation Project. There are also some pictures showing a local midday shadow from other participating schools in the United States and U.K.

   
   
   

Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Sun Enters Virgo-2017

view_from_earth
   Saturday September 16th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation of Leo the Lion and into the constellation of Virgo the Harvest Maiden. This is the true or actual position of the Sun as opposed to the pseudoscience of astrology which usually has the astrological Sun one constellation ahead or east from the Astronomical Sun’s position.
   In a couple of days the Sun, according to astrology, will cross the ecliptic moving southward crossing from Virgo into the constellation of Libra the Scales. We know this day as the September equinox, which this year is on the 22nd.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

Mercury at Inferior Conjunction

orbital-positions   Saturday August 26th the innermost planet Mercury reaches inferior conjunction. At inferior conjunction Mercury will move between the Earth and the Sun – much like the position of the Moon at new phase. The graphic to the right shows the planet positions relative to the Earth and Sun for both inner planets and outer planets.

   While at this inferior conjunction Mercury will not be directly in line with the Earth and the Sun – on the ecliptic. Mercury has an orbital inclination of 7o with respect to the ecliptic. So like our Moon, Mercury during each complete orbit, will cross the plane of the ecliptic moving north (ascending node) and also moving south (descending node).

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Solar Eclipse Follow-Up

   Fearing for massive traffic jams we (wife Susan and granddaughter Keeley) left for Briarcliff Elementary School in North Kansas City around 8 am. Virtually no traffic as we went around the city and went across the Missouri River and river valley on Highway 169 and then up the bluff on the other side to the school. Lightning was to the north and southwest and thunder was rumbling – but the Sun was sort of shining through broken clouds.

   The sky remained partly cloudy as I set up and students were coming outside to practice how to use their eclipse glasses. The sky stayed partly cloudy until about 10 minutes before totality as the leading edge of what would soon be rain approached from the northwest as broken cumulus type clouds.

   Leading up to totality there were two distinct sunspot groups visible as this picture shows. We were fortunate that the sky stayed relatively clear leading up to totality. However the broken clouds started clumping together but the clouds did part several times allowing for us to see totality each time there was a break in the clouds.
   No post totality pictures because within a few seconds after totality ended the last of the broken clouds passed and the sky was completely overcast. As we left the school it was raining. Got home a few minutes before the eclipse ended – skies were partly cloudy – so we had one last look with eclipse glasses.


   A big shout-out to Mrs. Kate Place, her staff and students, at Briarcliff Elementary School for hosting the Eclipse on the Cliff event.
   Click here to see 360o pictures and videos. Be sure to select HD at the highest resolution possible.
   
   
   

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Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Sun Not In Virgo

   
According to the pseudoscience of astrology the Sun enters the constellation of Virgo the Maiden on Tuesday August 22nd. When in fact the actual position of the Sun on this date is toward the west and still within the boundaries of the constellation of Leo the Lion.
   And if you were viewing the solar eclipse you were seeing the Sun in Leo with the heart of the Lion, the star Regulus, just to the left of the Sun.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.

August Moon at Ascending Node – and Oh Yeah, A Total Solar Eclipse!

   Monday August 21st the new Moon will be crossing the plane of the ecliptic moving north relative to the ecliptic. This is known as the ascending node, one of two intersections the Moon’s orbital path has with the ecliptic. The ecliptic is actually the Earth’s orbit and the Moon’s orbit is inclined about 6o from the ecliptic. So there are two node intersections, the ascending and descending nodes.

   On August 21st the new Moon will be crossing the plane of the ecliptic at 10:34 UT (5:34 am CDT) within the constellation Leo the Lion. 8 hours later, at 18:30 UT (1:30 pm CDT), the Moon will reach new phase. This close timing between the new Moon phase and a node crossing means only one thing – eclipse!!

   My eclipse viewing area will be at an Elementary School in the North Kansas City School District. From that location totality will be approximately 80 seconds. This short video showing totality for 80 seconds, was clipped and edited from a video shot during the November 2012 total solar eclipse viewed from Australia.

   Read a bit more about this eclipse from a previous post.

      Does our Moon actually go around the Earth as many graphics show? From our perspective on the Earth the Moon appears to circle around the Earth. However, in reality, the Moon orbits the Sun together with the Earth*

   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

   Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”

   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.

Sun Enters Leo

10aug-view_from-earth
   Thursday August 10th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Cancer the Crab and into the constellation of Leo the Lion. This is the true or actual position of the Sun as opposed to the pseudoscience of astrology which usually has the astrological Sun one constellation ahead or east from the Astronomical Sun’s position.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   

Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to go to bobs-spaces.