Jupiter Backs Up!

   Friday March 9th the outer ringed planet Jupiter stops its regular direct motion to the east and begins to move in retrograde toward the west. Retrograde motion for any planet further from the Sun then the Earth, that we observe from Earth, is an apparent motion of that planet caused by the faster moving Earth along its orbital path. As the Earth catches up and passes an outer planet that planet appears to move toward the west. Depending on the planet the retrograde motion may last a few weeks or months. Jupiter will be within the boundaries of the constellation Libra the Scales.

   Jupiter along with Mars and Saturn all rise before sunrise local time and the morning skies on March 9th the 21-day old last quarter Moon will be about 7o from the ‘red planet’ Mars.

   Follow the planet by way of its coordinates using just right ascension with the free equatorial star chart from Stephen F. Austin University.

Date Right Ascension
(Hours – Minutes)
June 5            14 52
June 15         14 48
June 25         14 46
July 5            14 45
July 15            14 44
July 25            14 46
August 4          14 48
August 14         14 51
August 24         14 55
September 3      15 00

   
   
   

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 Libra

310ct-view-from-earth   Sunday October 30th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Virgo the Harvest Maiden and into the constellation of Libra the Scales. 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 return to bobs-spaces.

2016 September Equinox

   On Thursday September 22nd at 14:21 UT, (9:21 am 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.

Saturn at East Quadrature-2015

   Friday August 21st the position of the planet Saturn with respect to the Earth and the Sun places this ringed planet at what is called eastern quadrature. Saturn is at a 90 degree angle from us as this graphic shows. Think first quarter Moon as that is a fair comparison of the relative positions. At this position Saturn follows the Sun across the sky from east to west as the Earth is rotating, meaning that Saturn rises after the Sun and sets after the Sun.

   Where is Saturn now? Saturn is west (to the right) from the planet Saturn and near the eastern side of the constellation Libra the Scales.

Learn a little (or a lot) more about Saturn by visiting the Cassini at Saturn mission web site.
Click here to go to the Cassini Mission web site.
Click here to go to the Cassini Mission Flyby web page to see when the next Saturn satellite flyby will be.

   This is a short 5 minute video I made as part of a live musical performance called “Orbit” that I was part of in May 2011. This is a piece from the much longer tour of the solar system performance and video and shows Saturn and some of its moons as viewed from the Cassini spacecraft that month.

   
   
   
   

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.

Another Balanced Moon

   Wednesday morning, February 11th the 22-day old, nearly last quarter, Moon will be 1-2o from Zubenelgenubi, a 5th magnitude star in Libra the Scales.
    Down to the left, or east from the Moon are the stars of Scorpius and Sagittarius. Just above the reddish star Antares, the heart of the scorpion, is the planet Saturn. And just above the eastern horizon is the innermost planet Mercury.
11feb-bino   With an apparent 5th magnitude Zubenelgenubi is just barely visible to the naked-eye. However with binoculars the star is visible, and with the near last quarter Moon ‘next door’ the two will make for an interesting view through binoculars or a wide-field eyepiece in a telescope.

   
   
   
[centup]
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 Scorpius

23nov-view-from-earth   Sunday November 23rd at 11 UT (5 am CST) the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Libra the Scales and into the constellation of Scorpius the Scorpion. 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.
   
   
   

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 Libra

310ct-view-from-earth   Friday October 31st at 6 UT (1 am CDT) the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Virgo the Harvest Maiden and into the constellation of Libra the Scales. 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.
   
   
   
[centup]
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.