Scorpius Grabs the Moon!

scorpius-moon-ani   Monday September 1st the nearly first quarter Moon will be rising within the clutches of Scorpius the Scorpion as the banner graphic shows.
   When looking for or recognizing the star pattern for Scorpius most look for what could be described as the English letter J, or as I tell my younger students a ‘lazy J’.

Click on graphic to see it full size.

Click on graphic to see it full size.

   This part of the northern hemisphere late summer skies is always a treat to observe especially if the skies are dark enough to see the Milky Way. If you can find the teapot-shaped asterism for Sagittarius then look for the pour spot on the right side. Under dark skies the Milky Way looks like steam rising from the teapot. Look just off to the right, west, from the pour spout and you are looking toward the center of our galaxy, some 27,000 light years away. Here is an infrared image of the galaxy center from NASA’s 2MASS mission.

   
   
   

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.

Saturn, Mars, and the Moon

Click on graphic to see it full size.

Click on graphic to see it full size.

   Sunday evening August 31st the 6.5 day young waxing crescent Moon will be close to the planets Mars and Saturn. All three objects of this triple conjunction will easily fit within the field of view of binoculars. Closest will be at 19 UT (2 pm CDT) but there will be parts of the world that may be able to see the Moon occult (pass in front of) Saturn.

   
   
   

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.

Moon At ascending Node

29aug-ascen-node   Saturday Friday the 29th of August at 13:15 UT (8:15 am CDT) our 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 (dark green line) has with the ecliptic. Note the ecliptic is the line with ‘Oct’ however that is a reference to when the Sun will be at that point along the ecliptic and not the date for this node crossing.

Click on graphic to see it full size.

Click on graphic to see it full size.

   That evening look for the waxing crescent Moon to be close to the bluish-white star Spica in Virgo.

   
   
   

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.

The Moon Traverses Virgo

   For the next few days the Moon will travel eastward across the length of the constellation Virgo the Maiden. During those few days the Moon will be waxing from a thin crescent toward first quarter phase on September 2nd. Along the way it will be near the planet Mercury on Wednesday evening August 27th, then, Porrima a 3rd magnitude star, then Virgo’s alpha star the 1st magnitude Spica. Then as an added bonus the Moon will near the 9th magnitude Dwarf Planet Ceres.
   But wait!! There is more. On the 31st the Moon will be close to Mars and Saturn. Depending on your location The Moon will occult the planet Saturn.

This slideshow requires JavaScript.

   
   
   

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.

Mars Meets Saturn

Click on graphic to see it full size.

Click on graphic to see it full size.

   Monday evening the 25th of August Mars and Saturn will be at their closest to one another as they are separated by less than 1o. This occurs at 18 UT, 1 pm CDT. Both planets are moving eastward along their respective orbits with Mars (0.519o per day) being closer to the Sun moving faster than Saturn (0.0334o per day). For my time zone the closest approach will occur during the afternoon but by sunset the separation will not have increased by that much.

   Using binoculars, or just your eyes, compare the apparent magnitude of Mars (0.59), Saturn (0.59), and Zubenelgenubi (2.75). This is a good example of how distance is the key to apparent magnitude. For solar system objects, (planets, moons, asteroids, comets), how much sunlight is reflected is determined by the overall apparent size of the object’s disk. In the case of Saturn its ring system spans around 200,000 miles and with an apparent size like that Saturn is able to reflect enough sunlight so that despite its greater distance from the Sun Saturn, at varying times during its orbit around the Sun, may appear as bright or brighter than Mars.

   
   
   

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.

August Apogee Moon

24aug-apogee-moon    Our Moon orbits around the Sun with the Earth and 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 on graphic to see it full size.

Click on graphic to see it full size.

   This very thin 28.5-day old waning crescent Moon shows only about 1% of its disk and rises just before sunrise local time. Given its thin crescent shape plus daylight it more than likely will not be noticed. New Moon is about 24 hours later. So despite it being ‘invisible’ this waning crescent Moon reaches apogee this month on Monday 25 August at 1 am CDT (6 UT). At that time the Moon will more or less be at a distance of 31.87 Earth diameters (406,523 km or 243,914 miles) from the Earth. For those keeping track, this is the 2nd greatest apogee distance for this year.

   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

   
   
   
   

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.

Sun Not In Virgo Today

Click on graphic to see it full size.

Click on graphic to see it full size.

  According to the pseudoscience of astrology the Sun enters the constellation of Virgo the Maiden on Saturday August 23rd at 5 UT (12 am CDT August 22nd). When in fact the actual position of the Sun today is still within the boundaries of the constellation of Leo the Lion.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   

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.