September Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Saturday September 28th. At that time the Moon will be at a distance of 28.05 Earth diameters, 222,328 miles (357,803 km) from the Earth.

   On the day of the perigee Moon the 29-day old very thin waning crescent Moon will be over the eastern horizon rising within about 30 minutes ahead of the Sun. This puts the Moon too close to the Sun to be seen. The waning crescent Moon becomes new Moon about 12 hours after the Sun and Moon rise.

   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)

   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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

A Black Moon

   What is a “Black Moon”? According to a commonly used definition a “Black Moon” is any month during which there are 2 new Moons, or even more rare a month with no new Moons. Obviously the Moon at new phase is in the direction of the Sun and therefore is not visible at all, perhaps given rise to the name “Black Moon” because the illuminated side of the Moon is toward the Sun, and the unilluminated, dark, side of the Moon is toward the Earth.
   On Thursday August 1st the first of two new Moons this month will rise about 30 minutes after the Sun rises and will not be visible as it follows the Sun across the sky to moonset about 1 hour after sunset local time. On August 30th the second new Moon of the month will follow a similar pattern as the new Moon on August 1st in that this new Moon also will not be visible as it too follows the Sun, setting within an hour after the Sun sets. Graphics below are set for the time when the new Moon transits, or is due south, and is mid-way between rising and setting.
   What makes the term “Black Moon”, in this instance, interesting is that depending on your time zone the “Black Moon” may have been either July or August depending on your local time zone for the new Moon of July 31st or August 1st.

 
New Moon Dates and Times (using UT)
July 2          19:16 UT
August 1         3:12 UT  (July 31 10:12 pm CDT)
August 30       10:37 UT


   
   
   

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.


Also Follow me and other great resources at Feedspot.

June Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Monday May 13th. At that time the Moon will be at a distance of 28.89 Earth diameters, 228,977 miles (368,504 km) from the Earth.

   The 4.68-day old waxing crescent, Moon rises is over the southwestern horizon at sunset local time and sets around midnight. About 12o east from the Moon is the ‘Heart of the Lion’, the star Regulus in Leo the Lion. Between this time and and the same time tomorrow the Moon will have passed Regulus and be a few degrees away from the star, but on the east side.

   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)

   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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

May Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Monday May 13th. At that time the Moon will be at a distance of 28.93 Earth diameters 229,296 miles (369,017 km) from the Earth.

   The 9-day old waxing gibbous, Moon rises around mid-afternoon and sets the following day, and is visible all night.

   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)

   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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

April Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Tuesday April 16th. At that time the Moon will be at a distance of 28.55 Earth diameters 226,308 miles (364,209 km) from the Earth.

   The 12-day old waxing gibbous, Moon rises shortly after sunset local time is visible all night. Over the southwestern horizon, but not shown, is the planet Mars which sets around midnight.

   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)

   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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

March Moon at Perigee

   Our Moon reaches perigee, (closest distance to Earth), for this orbit, on Tuesday March 19th. At that time the Moon will be at a distance of 28.17 Earth diameters (223,309 miles – 359,381 km) from the Earth.

   The 13-day old nearly full, waxing gibbous, Moon rises shortly after sunset local time is visible all night. Over the southwestern horizon, as the Moon is rising,is the planet Mars which sets around midnight.

   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)

   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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

December Moon at Perigee and Ascending Node

   Our Moon reaches perigee, (closest distance to Earth), for this orbit on Monday December 24th. At that time the Moon will be at a distance of 28.30 Earth diameters 224,352 miles (361,060 km) from the Earth.

   Monday December 24th the waning gibbous 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 Monday December 24th the 18-day old waning gibbous Moon rises around 7:30 pm local time.

   *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 go to bobs-spaces.


Also Follow me and other great resources at Feedspot.

October Moon at Ascending Node, and at Perigee

   Wednesday October 31st the 22-day old last quarter Moon will be crossing the ecliptic moving north. This is known as the ascending node, one of two intersections the Moon’s orbital path has with the ecliptic. (see animated graphic below)
   Also on that same day, Wednesday October 31st, the last quarter Moon reaches perigee, (closest distance from Earth). At that time the Moon will more or less be at a distance of 29.025 Earth diameters, (230,032 miles 370,201 km), from the Earth.


On the day of perigee and ascending node the first quarter Moon rises at around midnight and is only a few degrees away from the open star cluster M-44, the Beehive Cluster.

   
   
   

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.


Also Follow me and other great resources at Feedspot.

August Perigee Moon at Ascending Node, and a Partial Solar Eclipse

   Friday August 10th the 28.5 day old waning crescent 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.

   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?”

Perigee Moon
   Our Moon reaches perigee, (closest distance to Earth), for this orbit on Friday August 10th. At that time the Moon will be at a distance of 28.07 Earth diameters (358,100 km or 222,513 miles) from the Earth. The Moon will also be 28.5 days old, and only 15.8 hours from new Moon Phase.
    When the time of perigee is close to a node crossing there will be either a lunar or solar eclipse. In this case less then 24 hours after the node crossing there will be a partial solar eclipse. This solar eclipse is only visible from Arctic, Greenland and parts of Asia.

   
   
   

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.


Also Follow me and other great resources at Feedspot.

Circumstances for a Solar Eclipse


   Friday July 13th and Saturday the 14th circumstances are such that there will be a partial solar eclipse that will be best viewed from along the northern coast of Antarctica. (hey! every Antarctic coast is a northern coast!!
Specifically the partial solar eclipse will be visible at around 129o E near the Claire Coast.

   Circumstances for a solar eclipse, like for a lunar eclipse, require the Moon to be at either its ascending node or its descending node and be at or close to either new or full Moon phase. A node crossing occurs when the Moon with an orbit tilted 6o from the ecliptic (the Earth’s orbit) intersects the ecliptic.


   The Moon has an elliptically shaped orbit so if the timing for lunar apogee (furthest from Earth) or perigee (closest to the Earth) happens around a new Moon at a node crossing then the apparent size of the Moon will be anywhere from smaller to larger than the Sun’s apparent size. Smaller means a longer eclipse including the length of totality.


   
   
   However the bottom line is the timing between the node crossing and new Moon. This time the Moon crosses the ecliptic moving north, ascending node, approximately 24 hours after new Moon phase setting up a partial solar eclipse.

So what are the circumstances?
Times are in Universal Time (CDT = UT-5)
   July 13th
   1:48 UT – Partial Solar Eclipse Begins
   2:48 UT – New Moon — Partial Solar Eclipse
   3:01 UT – Mid-Eclipse (maximum Sun covered)
   4:13 UT – Partial Solar Eclipse Ends
   8:27 UT – Moon at Perigee – 357, 432 km (222,098 miles)
   July 14th
   2:52 UT – Moon at Ascending 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.


Also Follow me and other great resources at Feedspot.