September Moon at Perigee

   Our Moon reaches perigee, (closest to Earth), for this orbit, on Friday September 18st. At that time the Moon will be at a distance of 28.15 Earth diameters, 223,122 miles (359,081 km) from the Earth.

   On the day of the perigee Moon the 1.5-day old waxing crescent Moon will be over the western horizon near the innermost planet Mercury. Further to the east are Jupiter and Saturn.

   Does our Moon actually go around the Earth as this graphic shows? 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)

   
   
   
   
   
   

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.


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Sun Enters Virgo-2020

view_from_earth   Wednesday 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 few 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 return to bobs-spaces.


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Moon-Venus Conjunction + M44

   Monday morning September 14th look eastward in the pre-dawn skies for the 26-day old waning crescent Moon to be about 4-5o from the planet Venus and about the same distance from the open star cluster M-44, the Beehive Custer.

   The trio should make for an interesting view with binoculars.
   
   
   
   
   
   

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.


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Jupiter Corrects Its Reversal

jupiter-ani   On Saturday September 12th in a move that comes about annually, Jupiter will once again reverse its direction from moving toward the west to moving toward the east.
   For about the past 4 months Jupiter has appeared to be moving westward (toward the right) rather then toward the east. This happens as the faster moving Earth catches up with and then passes by Jupiter. This apparent westward motion of Jupiter is known as retrograde motion and for Jupiter it’s retrograde motion comes to an end on September 12th when Jupiter resumes its normal orbital motion toward the east, or to the left as we view Jupiter from the Earth.
   Since retrograde is a reference to motion and means backward or reverse motion, then the opposite of retrograde would be prograde motion. So it would be correct to describe Jupiter as having resumed prograde motion. However you would probably get a blank look from those you say this to! So stick with “direct motion” or just say that Jupiter orbits the Sun to the east as we see it from Earth.
   Jupiter is located over the southern horizon after sunset local time. It is about 7-8o to the west from Saturn.

   
   
   
   

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.


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September Apogee Moon

   Our Moon reaches apogee, (furthest from Earth), for this orbit, on Sunday September 6th. For this apogee the 19-day old waning gibbous Moon will be at a distance of 31.79 Earth diameters, 252,031 miles (405,606 km) from the Earth.

   On the date of the apogee the 19-day old waning gibbous Moon will be about 5o to the east from the planet Mars and both very visible through the night hours. Not visible to the naked-eye because of the bright Moonshine is the outer planet Uranus with a 5.8 apparent magnitude about 2-3o from the Moon.

   Does our Moon actually go around the Earth as this graphic shows? 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)

   
   
   
   
   
   
   
   
   

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.


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Moon-Mars Conjunction

   Saturday evening September 5th watch for the 18-day old waning gibbous Moon to be very close, about 0.5-1o, from the planet Mars. Both objects are bright with Mars having a -1.93 apparent magnitude compared with the Moon’s much brighter -12.0 apparent magnitude.
   For another apparent magnitude comparison look west for the planets Jupiter (-2.52) and Saturn (0.33).

   The two, Mars and the Moon, should make for a striking combination with binoculars or low-power telescope eyepiece.

   
   
   

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.


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Planetary Line-Up Ecliptic Style

   Look at the arrangement of the planets in the graphics below. One of the defining aspects of our solar system is the arrangement of the planets outward from the Sun. Not by size or distance but rather how their respective orbital paths around the Sun are all vertically arranged near the Earth’s orbital path, or as it is typically referred to as the Ecliptic or the Plane of the Ecliptic. The 8 classic planets all orbit the Sun with an orbital path that is up to about 8o from the ecliptic. This is called inclination. The table shows inclination relative the Earth’s orbit and also relative to the Sun’s center, its equator.
    Click on this link to read a previous posting (Tales Along the Ecliptic) about the ecliptic and inclination.
   During this week as the Moon moves eastward it will pass by the outer ringed planet Neptune Tuesday and Wednesday evenings September 1st and 2nd as the graphics show. However given the tremendous difference in apparent magnitude between the two (full Moon: -12.64 ; Neptune: 7.81) Neptune will not be visible, at least not while the Moon in nearby.


   Keep following the Moon as it orbits eastward toward the planet Mars when on September 5th Mars and the waning gibbous Moon will be less than 1o apart.
   
   
   

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.


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Moon on the Move

   Over the course of the next week or so the Moon will be moving eastward across the evening skies as it waxes from crescent toward full Phase on September 1st. This series of graphics shows the sky at 9:00 pm CDT daily until August 30th. Use the graphics as a guide to locating some of the stars near the path the Moon follows, as well as the evenings when the Moon is in conjunction with Jupiter, then Saturn.


   
   
   

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.


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Sun Is Not In Virgo

   According to the pseudoscience of astrology the Sun enters the constellation of Virgo the Harvest Maiden on Saturday 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.

   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 Perigee

   Our Moon reaches perigee, (closest to Earth), for this orbit, on Friday August 21st. At that time the Moon will be at a distance of 28.50 Earth diameters, 225,868 miles (363,500 km) from the Earth.

   On the day of the perigee Moon the 3-day old waxing crescent Moon will be over the western horizon setting about 3 hours after the Sun sets. Rising over the eastern horizon are two of the giant outer planets, Jupiter and Saturn.

   Does our Moon actually go around the Earth as this graphic shows? 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)

   
   
   
   
   
   

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.


Also Follow me and other great resources at Feedspot.