March Moon at Apogee

 Our Moon reaches apogee, (greatest distance from Earth), on Saturday March 18th. At that time the Moon will more or less be at a distance of 31.72 Earth diameters (404,640 km or 251,432 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 morning of the apogee Moon the 20-day old waning gibbous Moon rises a couple of hours before the Sun and is visible over the southern horizon.

   
   
   

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.

Moon Skips Past Stars and Planets

   Over the next several mornings, January 23rd to 25th the waning crescent Moon will pass by the star Antares, and the planets Saturn, and Mercury as these animated graphics are showing.

   
   
   

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.

2 Planets and 1 Star


   Wednesday evening August 24th the planet Mars will be within about 4o from the planet Saturn and 2o from the reddish star Antares in Scorpius the Scorpion. This is about the closest the three will be to each other this year.

   
   
   

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.

Mars Moves Forward

   Thursday June 30th Mars ends its apparent westward motion (retrograde motion) relative to the stars in the background and resumes its eastward or direct motion. The location of mars for this particular retrograde has the ‘Red Planet’ near a reddish star with a name suggestive of how similar it appears to Mars. This is the star Antares, the heart of Scorpius the Scorpion.
   Antares could be thought to literally translate to ‘anti-Ares’ suggesting that this reddish celestial object should not be confused with Ares, the Greek god of War. Many stars have several names originating several centuries ago and in different languages however many of the translations have Antares meaning ‘equal of Mars’.
   Right now Mars is just past its greatest apparent magnitude, its brightest. This typically happens at around Mars opposition, but Mars is even brighter if its opposition is around the time of its perihelion and the time when Earth is at aphelion.
   Mars is now again moving toward the east and it will gradually move closer to Antares coming within about 1o from Antares on August 24th. However the Earth is also revolving around the Sun so at the same time that Mars is closing in on Antares that part of the sky will be moving further west and setting earlier.

   This year Mars and Antares will still be above the horizon during August and by then local time for sunset will also be earlier.

   
   
   
   
   
   
   
   
   

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.net.

Follow the Moon

   Over the next several days the Moon, as it waxes toward full phase, will follow the ecliptic as it passes by some of its solar system colleagues. Starting on the 15th, a few degrees east from the blue-white star Spica in Virgo the Harvest Maiden, the waxing gibbous Moon will then pass a few degrees from Mars on the 16th and 17th. Then on the 18th the nearly full Moon will be about 3o from Saturn, and that night ending this month’s lunar sweep along the ecliptic and bright planets.
   This animated graphic shows an 'atlas' view of the area along the ecliptic and the the Moon's daily path from June 15th to the 20th. The celestial equator is the curved red line and the ecliptic is the green line.
   There are two distinct motions, and one subtle motion shown in this animation.

    -Planets are in motion with Saturn and Mars on the move with Mars moving toward the west as it retrogrades. On a day to day basis the subtle shift in the position of Saturn and Mars each day is relatively small. Saturn moves 0.033o each day (360o/10,755 Earth days), and Mars each day moves 0.52o (360o/687 Earth days) .
    -The Moon orbits from west to east so each day at the same time the Moon is further to the east, or rises (sets) later.
    -The daily shift in the sky from east to west due to the Earth’s revolution around the Sun. The sky shifts about 1 degree each day or celestial objects, like stars, rise (and set) about 4 minutes earlier each day.

   The graphics below are set for 10 pm CDT on the dates indicated.

This slideshow requires JavaScript.

   
   
   

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

Moon Passes Mars and Saturn

   This weekend the Moon will pass by the planets Mars and Saturn, both of which are located near the reddish star Antares in Scorpius the Scorpion. The Moon reaches its full phase on Saturday and while it is within a few degrees from Mars the planet Mars will be at opposition. The next evening, Sunday May 22nd the Moon, now at waning gibbous phase, will have moved further east and will be within a few degrees from Saturn.

   
   
   

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

Moon Sort of in Conunction with Mars and Saturn

click on graphic to see it full size
   Monday morning April 25th the 18 day old waning gibbous Moon will be within a few degrees from the planet Mars and a few more degrees from the planet Saturn. Not really a true conjunction but the trio will all fit within a 7×50 binocular field of view.

25apr-bino   
   
   
   
   
   The reddish star Antares, the ‘heart’ of Scorpius the Scorpion is 4-5o south from Mars and is just outside the binocular field of view.

   
   
   
   
   
   
   
   

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