October Moon at Perigee


   Our Moon reaches perigee, (closest distance from Earth), for this orbit on Monday October 9th. At that time the Moon will be at a distance of 28.76 Earth diameters (366,855 km or 227,953 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*


   On the day of the perigee Moon the 20-day old waning gibbous Moon is above the east to southeastern horizon around midnight 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.

When the Moon Hits You In The Eye!


   Tuesday September 12th the 18-day old waning gibbous Moon will be once again poking Taurus the Bull in the eye! Actually the Moon will be within about 0.5o from the reddish star Aldebaran, the ‘angry eye’ of Taurus.
   
   
   
some extra Bob’s Space
   
   
   


   With binoculars the view of the Moon this close to Aldebaran and the rest of the v-shaped group of stars making up the open star cluster the Hyades should be as good as this graphic shows. But minus the blue lines!

   
   
   
   
   

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.

Dance of the Planets: 9 Sep. – Mercury & Regulus Conjunction

   This morning I set up my camera looking eastward along Highway 50. With city lights behind me, ‘Auto Row’ down the road, and a 19-day old waning gibbous Moon high over my right shoulder the sky was not really that dark. However pictures of visible planets and stars do not always have to be under dark skies or good seeing conditions. Adding to that were the low clouds along the horizon.
   This graphic shows the sky I had plans for imaging this morning, including Dwarf Planet Ceres near Pollux in the Gemini Twins. Plans had been to capture Mercury in conjunction with the star Regulus (check), and also Mars which this morning was closer to the horizon below Mercury (no check!). In the next few days Mars will be higher and easier to include in the group picture. Higher above the horizon and very bright with a -3.95 apparent magnitude was Venus.

   
   
   

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.

August Moon at Descending Node

   Tuesday August 8th the just past full Moon, a waning gibbous 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 17-day old waning gibbous Moon will be over the east-southeast horizon an hour or so after sunset local time. The Moon will be about 10o from the outermost, (8th), planet Neptune.
   
   
   
   

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.

2017 Perseid Meteor Shower – Not A Good Year

   In reality this year’s annual Perseid Meteor shower will be affected by the Moon. The waning gibbous Moon will rise at about the same time as the constellation Perseus – the location for the meteors. With the bright reflected light from the Moon it will be nearly impossible to see any meteors.
   Also keep in mind that the numbers quoted for meteors per hour, the ‘ZHR’ or Zenith Hourly Rate, is an average not a guarantee that you will see that many. On a good peak night in some years I have seen 30 or 40 bright meteors per hour from dark skies. The best time is the few hours before sunrise as the Earth rotates your location into the direction the Earth is moving and sort of puts you face-on into the meteors.
(graphic source from Facebook with this URL: http://sci-techuniverse.com/) — link takes you to a non-existent web site, or to a Go-Daddy advertisement
Update: I did a search for the web site and found that the correct address is http://www.sci-techuniverse.com/, and after searching the web site I could not find this graphic. There is, however a write-up from last year about the Perseids.

   The peak time for the Perseids is August 12th and 13th but more specifically during the predawn hours of the 13th as the constellation Perseus is rising.
   
   
   
   
   
   
   

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 Gets An Eyeful!

   Thursday July 13th morning in the couple of hours before sunrise local time the inner planet Venus will be within about 3o from the reddish star Aldebaran in Taurus the Bull. Aldebaran is often described as the “red, angry eye” of Taurus. It is located at the end of the v-shaped open star cluster the Hyades, a ‘loose’ grouping of several hundred stars of which the brightest form the v-shape of the Bull’s face.
   On the 13th Venus becomes the other eye of the Bull. The apparent brightness or magnitude difference between Venus (-4.07) and Aldebaran (0.84) is quite striking.

Venus passing Aldebaran July 12th-17th   Over the next few days Venus will steadily move away, toward the east, from Aldebaran as this animated graphic is showing. It is a simulated view through 10×50 binoculars and runs from July 12th to July 17th.

   
   
   
   
   

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.

July Moon at Descending Node

   Wednesday July 12th the 18-day old waning gibbous 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 18-day old waning gibbous Moon will be over the south-southeast horizon an hour or so after sunset local time. The Moon will be in conjunction, and within about 2o from the outermost, (8th), planet Neptune.
   
   
   
   

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.