Mars at Ascending Node

click on graphic to see it larger   Two or three times each month I post information about the location of our Moon as it crosses the ecliptic, the Earth’s orbital path around the Sun. These are known as nodes and there is an ascending node and a descending node representing the location where the Moon crosses the ecliptic moving north or south.

   The ecliptic is used as the reference for all solar orbiting objects and with regard to the planets each of them is tilted or inclined from the ecliptic. So each planet, like our Moon, has an ascending and descending node.

   On Wednesday December 2nd the planet Mars crosses the ecliptic moving north, it’s ascending node.

   Click here to learn a little more about the ecliptic. This was a previous post from December 2019, but it still illustrates the ecliptic and the planets respective orbits relative to the ecliptic.

   This table shows the inclination of planets relative to the ecliptic as well as the Sun’s equator extended outward.

   
   
   
   
   
   
   

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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December Moon at Ascending Node

   Tuesday December 1st the 17-day old waning gibbous Moon will be crossing the plane of the ecliptic moving north. 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 the day of the node crossing the 17-day old waning gibbous Moon will be over the eastern horizon around sunset local time. Mars is higher over the southeastern horizon while Jupiter and Saturn are low over the western horizon.

   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 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 return to bobs-spaces.


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Sun Enters Ophiuchus-2020

ophiuchus   Sunday, November 29th the Sun in its apparent eastward motion along the ecliptic, moves out of the constellation Scorpius the Scorpion and into the constellation of Ophiuchus the Healer. 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.

ophiuchus-scorpion   Ophiuchus is the 13th constellation of the zodiac (Astronomical) but does not appear in the astrological zodiac nor in the astrology column found in many newspapers. A constellation of either zodiac is defined the same way, using the ecliptic path. If the ecliptic passes through a constellation boundary then that constellation is a zodiac constellation. In the graphics I use the ecliptic path clearly crosses across the boundary for the constellation Ophiuchus the Healer.

   Ophiuchus is described in a mythology story as a healer. In one story following a mortal fight between Orion and Scorpius the Scorpion Ophiuchus kills the scorpion by stepping on it; extracts the venom from the scorpion; and then uses it to bring Orion back to life.
cadeuces   In Ophiuchus’s hands he is holding a long snake, the 2-part constellation of Serpens – Serpens Cauda (tail of the snake) and Serpens Caput (head of the snake). There are many stories about Ophiuchus and the snake including one where this is the origin of the symbol for medicine, the caduceus. However the caduceus is used primarily in the United States as the symbol for medicine, and is depicted as 2 snakes wrapped around a staff with wings. rodIf there is a connection with a medical symbol then it should be with the Rod of Asclepius, a staff with one snake.


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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November Moon at Apogee – And the Ecliptic

click on graphic to see it larger   Our Moon reaches apogee, (furthest from Earth), for this orbit, on Thursday November 26th. For this apogee the 12-day old waxing gibbous Moon will be at a distance of 31.82 Earth diameters, 252,211 miles (405,894 km) from the Earth.

   On the date of the apogee the 12-day old waxing gibbous Moon will be about 12o to the east from the planet Mars. The Moon will also be about 11o west from the outer planet Uranus. Currently Uranus has an apparent magnitude of around 5.7 meaning that it could be seen with the unaided in dark enough skies, or with telescopes and even binoculars – as long as the Moon is not in that part of the sky.

   Along the Ecliptic
   You may notice the arrangement of the planets spread across the horizon as shown in the graphic. Many objects in our solar system orbit the Sun in a path that is somewhat parallel with the Earth’s orbit, the ecliptic. All of the orbits are tilted or inclined away from the ecliptic however the 8 classical planets all have orbits that are inclined less than 7o from the ecliptic. Dwarf planets, asteroids, comets, for example, have orbital inclinations greater than 7o.
   The ecliptic also defines the Sun’s apparent path against the background of stars throughout the year. The planets are also in motion as they orbit the Sun as the video below illustrates.
   Take a short cruise along the ecliptic with the Sun!


   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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Waxing Gibbous Moon – Mars Conjunction


   Wednesday evening November 25th the 11-day old waxing gibbous Moon will be about 3-4o from the planet Mars.

   
   
   

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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Outer Planets on the Move – Heading for a Grand Conjunction

   During much of this past year I have been following Jupiter and Saturn as they move toward a very close conjunction on December 21st. I started observing and taking pictures of the two outer planets while they were in the morning skies last spring. Over the course of the ensuing months the pair of planets gradually shifted to the evening skies (due to Earth revolution) and also drew closer together.
   Jupiter is closer to the Sun than Saturn so it moves about 0.082o each day compared with the 0.0340o that Saturn moves each day. As a result Jupiter will catch up with Saturn and put the two in a planetary conjunction, actually a ‘Grand Conjunction’ happening only once every 18-19 years.
   Click here to learn more about this Grand Conjunction.

   The pictures below were taken from a variety of locations near my house, U.S. Highway 50, and a local athletics park, Legacy Park.

To be continued…
More pictures will be added as I take them.

   
   
   

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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Inner Planets on the Move

   This past month, November, the inner planets Mercury and Venus were very visible in the early morning skies before sunrise. Both of the planets were at or near their respective western elongation. Venus was there during August and Mercury reached its western elongation on November 10th.
   What I wanted to capture was the daily change in the position of Venus as it passed the star Spica in Virgo the Harvest Maiden. Venus moves about 1.6o each day so its eastward motion should be obvious after a day or so. It was – it is!. Mercury, if you are wondering, moves about 4o each day.
   Both inner planets were somewhere around their maximum separation from the Sun – as we see it the inner planet is to the right side of the Sun, or toward the west.
   The series of pictures were taken from two locations near my house. One is from an empty lot near U.S. Highway 50 looking east. The other pictures are from somewhere along the street I live on! The first picture was taken at Legacy Park and includes the ISS orbiting over my location.


   
   
   

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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Waxing Crescent Moon Passes Jupiter and Saturn

   Wednesday and Thursday evenings November 18th and 19th at sunset local time look westward for our Moon and two planets. The 4-day old waxing crescent Moon will be about 6o to the west, right from Jupiter and about 9o from Saturn.

   During the 24-hours between the two evenings our Moon will have aged 1 day and will have moved approximately 15o toward the east. And by Friday the Moon will be about 5o to the east, left from Saturn and about 7o from Jupiter.

   
   
   

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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November Moon at Descending Node


   Tuesday November 17th the nearly 3-day old waxing crescent Moon crosses the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path (dark green line) has with the ecliptic.


   On the date of the descending node the waxing crescent Moon will be over the southwestern horizon at sunset local time. Spread across the horizon from west to east are Jupiter, Saturn, Dwarf Planet Ceres, Neptune, and Mars.

   
   
   
   
   

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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Venus – Spica Conjunction


   Over the next few days the inner planet Venus will be moving eastward as it passes the blue-white star Spica in Virgo the Harvest Maiden. This animated graphic is set to 1-day intervals and shows the morning sky from November 16th to the 20th.


   On Monday morning November 16th Venus will be the closest to Spica for a conjunction that has the two separated by about 3-4o. A few degrees, 13o, further east (lower) is the other inner planet Mercury.

   
   
   

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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