The Geminids-2017

   A few hours after sunset local time, on Wednesday December 13th, look toward the west for ‘shooting stars’, or meteors coming from the area around the constellation the Gemini Twins. These are the annual Geminid Meteor Shower – one of the best meteor showers each year, and at times rivaling the August Perseid Meteor Shower. The calculated peak time for the meteors is December 14th at 7 UT (2 am CST), but this does not mean that is the only time to view them. The Geminid Meteor Shower is named for the constellation that the meteors radiate outward from. This is the same for all meteor showers, and the ‘spot’ in the sky is known as the radiant. The Geminid radiant is just above the ‘twin’ star Castor, and under ideal viewing conditions an average of about 70 meteors per hour could possibly be seen. This year without the interference of moonlight will increase the chances of seeing the meteors.
   Meteor showers result from the Earth’s orbital path intersecting areas of comet debris. Comets, as they orbit the Sun, leave behind pieces of their icy, dirty, selves. If these debris clouds happen to be along the Earth’s orbital path then the Earth will regularly pass through the comet debris cloud. As this happens the small comet pieces hit our outer atmosphere and vaporize from the friction generated heat. We then see these as the shooting stars that make up meteor showers.
   There are, however, two exceptions to this. The January Quadrantid Meteors and the Geminids each come from their own respective asteroid rather than a comet. The source for the Geminids is Asteroid 3200 Phaethon

   
   
   
   

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

December Moon at Ascending Node

   Friday December 8th 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 December 8th the 21-day old waning gibbous Moon will be within the boundaries of Leo the Lion and about 3o east from the ‘Heart’ of the Lion, the star Regulus.

   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.

December Moon at Perigee


   Our Moon reaches perigee, (closest distance from Earth), for this orbit on Monday November 4th. At that time the Moon will be at a distance of 28.025 Earth diameters (367,492 km or 222,135 miles) from the Earth. This is approximately 17 hours after full Moon making this full Moon the year’s Super 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*


   On the day of the perigee Moon the 16.5-day old waning gibbous Moon is above the eastern horizon about 1 hour after sunset local time. The Moon is located just east of Orion’s club and Orion appears to be swinging his club as if it were a baseball bat toward the Moon – but missed. Strike One!!.

   *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.

Neptune at Eastern Quadrature

1dec-neptune-east-quadrature   Sunday December 3rd the position of the planet Neptune with respect to the Earth and the Sun places this ringed planet at what is called Eastern Quadrature. Neptune is at a 90 degree angle from the Earth – think first quarter Moon as that is a fair comparison of the relative positions. At this position Neptune follows the Sun across the sky from east to west as the Earth is rotating, meaning that Neptune rises after the Sun and sets after the Sun.

   Where is Neptune now? The 8th planet from the Sun is currently within the constellation of Aquarius the Water Bearer and has recently completed its retrograde motion (November 22th).

   
   
   
   
   
   This is a 1 minute clip from a video I made showing Neptune and some of its moons as viewed from the Voyager 2 spacecraft. This clip is from a longer video of a tour of the solar system and was part of a live musical performance called “Orbit”. The performances were done at the Gottleib Planetarium in Science City at Union Station in Kansas City MO.

   

   
   
   

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.

Taurus Sniffs the Moon!

   Saturday evening November 2nd the 14.5-day old waxing gibbous Moon (full Moon tomorrow) will be a couple of degrees from the reddish star Aldebaran in Taurus the Bull. Aldebaran is at one end of a v-shaped open star cluster, the Hyades, that makes up the face of Taurus. Because of its reddish color it has been described as the angry eye of the bull.
   Normally the Hyades are a great view with binoculars as is the Pleiades, another open star cluster that is often described as a ‘baby dipper’.

   
   
   

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 Ophiuchus

ophiuchus   Thursday, November 30th 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.

November Moon at Descending Node


   Saturday November 25th the waxing crescent Moon will be crossing 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 day of the node crossing the 7.5-day old waxing crescent Moon will be over the southwestern horizon an hour or so after sunset local time.
   
   
   
   

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.