June Moon at Ascending Node

   Thursday June 27th the waxing 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.

   On June 27th the 4-day old waxing crescent Moon will be with the constellation Leo the Lion, and the Moon will be located less than 1o from the heart of the Lion, the star Regulus. This should make for a great view with binoculars or through the eyepiece of a telescope.
   Just above the western horizon, possibly lost in the Sun’s glare, are two more planets – Mars and Mercury about 1o apart.

   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.

Mercury at Superior Conjunction

mercury at superior conjunction
   Wednesday June 21st the innermost planet Mercury reaches superior conjunction – on the opposite side of the Sun from the Earth. For those that are curious, Mercury at superior conjunction is approximately 1.324 AU (123,073,489 miles; 198,067,580 km) from the Earth – the combined distance of the Earth to Sun distance plus the radius of Mercury’s orbit.
   Mercury is not visible while in conjunction with the Sun but within the next week or so Mercury will reappear on the east side of the Sun and start becoming visible over the western horizon at sunset.

   
   
   

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.

Venus – Crescent Moon Conjunction


   Tuesday morning June 20th the 25-day old waning crescent Moon will be about 6o from the inner planet Venus. At -4.6 apparent magnitude Venus contrasts well with the Moon’s -11 apparent magnitude.

   
   
   

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.

Neptune Backs Up

Two days in a row! Like the song goes, “slow down you move too fast” – or proofread!!
   Friday June 16th the outermost of the 8 planets, Neptune, ends its westward retrograde motion around the Sun and will resume direct motion, moving eastward will come to an apparent halt in its eastward or direct motion and appear to start moving backward to the west in what is known as retrograde motion. In this graphic the location of the 21.5-day old waning gibbous Moon is shown to be about 2-3o from Neptune. Neptune has an apparent magnitude of nearly 8.0 making it all but only visible with telescopes – and certainly not on this date with -12th magnitude Moon nearby.

   Retrograde motion is an apparent motion that the outer planets, relative to the Earth, have. It is an apparent motion that looks as if the outer planet stops it normal direct motion to the east and reverses direction to the west. After a period of time the apparent westward motion ends and the planet resumes its normal orbital path to the east. Retrograde motion happens as the faster moving Earth catches up with and then passes by the outer planet. It is during this time that the backward apparent motion happens.

   The two inner planets also have retrograde motion but it is a result of their orbit around the Sun and not the Earth passing them by. For approximately one-half of their orbit they move east, from western elongation through superior conjunction to eastern elongation. Then at eastern elongation the inner planet starts moving westward through inferior conjunction to western elongation.

   Read a little more about retrograde motion in my February 2012 Scope on the Skies column, drawkcab planets, in Science Scope Magazine.

   
   
   

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.

Moon / Saturn Conjunction and Jupiter Pauses Briefly

   Friday June 9th one of the outer planets, Jupiter, becomes stationary in its retrograde westward orbital motion around the Sun. It will now begin moving in direct motion, its orbital direction around the Sun toward the east – as we view it from the Earth. Jupiter’s retrograde motion is something that occurs to varying amounts as the Earth passes by each outer planet.
   This animated graphic is set to show the motion of Jupiter from early May through the end of June. At the start the graphic shows where Jupiter is relative to the star Spica, and then it zooms in to make the retrograde loop for Jupiter easier to see.
   The Earth passing by an outer planet is a result of the Earth having a faster orbital speed, and as the angles between Earth and an outer planet change there is the appearance of the outer planet slowing down and stopping its regular eastward motion. Then for a time ranging from a week or so to several months the outer planet appears to be moving backward or toward the west. After a time the planet resumes its eastward motion.

   On Friday the 9th the just past full Moon, a 15-day old waning gibbous Moon, will be rising about an hour after local time for sunset. Between 2-3o to the right, or west, from the Moon is the planet Saturn as this graphic shows.

   
   
   

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.

June Moon at Apogee


   Our Moon reaches apogee, (greatest distance from Earth), on Thursday June 8th. At that time the Moon will more or less be at a distance of 31.85 Earth diameters (406,401 km or 252,526 miles) from the Earth.
   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?”


   On the day of the apogee Moon the 14-day old full Moon rises around local time for sunset and is 9-10o degrees from the reddish star Antares in Scorpius the Scorpion.

   
   
   

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.

Jupiter/Moon Conjunction

   Saturday evening June 3rd the 9.3-day old waxing gibbous Moon will be within 1-2o from the giant planet Jupiter. Both will very comfortably fit within the field of view of binoculars. Both rise in the east (except on Venus) at about 3 pm CDT and will be over the southern horizon a couple of hours before midnight local time.

   
   
   

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.