Mars at East Quadrature

orbital-positions   Saturday 19 July at 6 UT (1 CDT) the position of the planet Mars, with respect to the Earth and the Sun, places this planet at what is called eastern quadrature. At that orbital position Mars, and actually any outer planet, is at a 90 degree angle from the Earth as this graphic shows, and the banner graphic at the top of the page shows. Think first quarter Moon as that is a fair comparison of the relative positions of Earth, Sun, and Mars. At this position Mars follows the Sun across the sky from east to west as the Earth is rotating, meaning that Mars rises after the Sun and then sets after the Sun.

   This is a short video clip about Mars from a much longer video that I made as part of a live musical performance called “Orbit” at the Gottleib Planetarium in Kansas City Missouri during May 2011.

   
   
   
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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.

Split Decision ———//——— Venus at Dichotomy

Click on graphic to see it full size/

Click on graphic to see it full size.

   Today at 2 pm CDT (17 UT) the planet Venus will have reached what is described as its ‘theoretical dichotomy‘. From our perspective on Earth Venus will appear to be 50% illuminated as the banner graphic at the top of the page shows. Our Moon is on the west side of the Sun, and in its waning gibbous phases, so the Moon, for a couple of days, will resemble the phase appearance of Venus. Tomorrow, the 24th of March the last quarter Moon will most resemble the last-quarter appearing Venus.
   This animated graphic shows how the Earth, Sun, and Venus are arranged just one day after Venus had reached its greatest western elongation. It starts with an ecliptic perspective view of the Earth, Sun, and Venus from which you can see that Venus currently is north of the plane of the ecliptic. As the view switches to an overhead view you can see that the Earth, Sun, and Venus are more or less at at a right angle arrangement following yesterday’s greatest western elongation for Venus.

Click on graphic to see it full size.

Click on graphic to see it full size.

   Venus is currently in the eastern skies above the horizon and shining brightly in the hours before sunrise.
   
   
   
   
   
   
   
   
   
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 and Neptune

moon-neptune   This evening, if your skies are clear take a look at the near first quarter Moon. If you have binoculars aim them at the Moon but put the bottom curve of the Moon at the upper edge of the binocular field of view. Just above the lower part of the field of view will be the near 8th magnitude planet Neptune as the banner graphic at the top of the page shows. In this simulated view I have added the apparent magnitudes of some of the stars in the general area for magnitude comparison.

   The Moon this evening, and the planet Neptune are currently located near the water vessel carried by Aquarius the Water Bearer. As the animated graphic shows Aquarius pours the water into the mouth of Piscis Austrinus, the Southern Fish. The star Fomalhaut marks the fish’s mouth.

   Take a 1 minute tour of Neptune. This is part of a longer video tour of the solar system that was part of a live performance by Dark Matter.

   
   
   
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.

A Well Balanced Moon

Click on image to see full size

Click on image to see full size

   The first quarter Moon this evening lies nearly centered on the fulcrum for the constellation of Libra the Scales as the banner graphic at the top of the page shows. The image to the right shows a view toward the southwest about an hour after local sunset time. The planet Venus is low over the horizon and if you imagine an arc-shaped line curving upward toward the left, or east, along this arc is Spica, then Saturn, and then the first quarter Moon. The inset graphic shows the Moon within 1 degree of the third magnitude star Zubenelgenubi in Libra as would they would appear through 7×50 binoculars.
Click on image to see full size

Click on image to see full size

   With regard to the above written “arc-shaped line curving upward toward the left, or east” this arc-shaped imaginary line is in effect known as the ecliptic. The ecliptic in reality is the orbital path of the Earth around the Sun. However from our perspective we see the ecliptic as the apparent path the Sun follows against the stars in the background. It is the ecliptic that defines the constellations of the zodiac for example. Somewhere within a few degrees on either side of the ecliptic are where the 8 planets, Mercury – Neptune, are located as we view them from Earth. Our Moon also follows a monthly path that takes it above and below the ecliptic.
ecliptic.

   Click here to go to the Qué tal in the Current Skies web site for more observing information.

Moon and Spica Conjunction

   This evening, 15 July, the first quarter Moon will be about one-half degree away from the blue-white star Spica in the constellation Virgo the Harvest Maiden.

   
   Click here to go to the Qué tal in the Current Skies web site for more observing information.