Moon Near Antares

   Wednesday morning May 2nd the waning gibbous Moon will be about 8-9o from the heart of Scorpius the Scorpion, the reddish star Antares. Joining the Moon is Jupiter to the west, and Saturn and Mars to the east.

   
   
   

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.

Saturn at Western Quadrature

saturn-west-quadrature   Thursay March 29th, the position of the planet Saturn with respect to the Earth and the Sun places this ringed planet at what is called western quadrature. Saturn is at a 90 degree angle from us as this graphic shows. Think third quarter Moon as that is a fair comparison of the relative positions. At this position Saturn leads the Sun across the sky from east to west as the Earth is rotating, meaning that Saturn rises before the Sun and also sets before the Sun.

Saturn currently is within the constellation of Sagittarius the Archer as this graphic shows. From the northern hemisphere, looking toward the southern horizon, you can find Saturn to the east, left, from the reddish star Antares. Between Saturn and Antares is Mars, about 2-3o from Saturn. To the right from Antares is the planet Jupiter.

Learn a little (or a lot) about Saturn by visiting the Cassini at Saturn mission web site.
Click here to go to the Cassini Mission web site.

   This is a short 5 minute video I made as part of a live musical performance called “Orbit”. This is a piece from the much longer tour of the solar system performance and video and shows Saturn and some of its moons as viewed from the Cassini spacecraft that month.

   
   
   


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.

February Moon at Apogee

   Our Moon reaches apogee, (greatest distance from Earth), on Sunday February 11th. At that time the Moon will more or less be at a distance of 31.80 Earth diameters (405,700 km or 252,090 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 apogee the 25.6-day old very thin waning crescent Moon will be over the eastern horizon at around sunrise local time and within about 2o from the ringed planet Saturn.

   Since the Moon and Saturn are in the area of the Milky Way this should make for interesting viewing with Binoculars and pictures,

*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.

Moon – Spica Conjunction

click on graphic to see it larger
   Monday morning February 5th the 19-day old waning gibbous Moon will be within 6-7o from the blue-white star Spica in Virgo the Harvest Maiden.

   
   
   

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 – Regulus Conjunction


   Thursday morning February 1st the waning gibbous Moon will be in conjunction with the star Regulus in Leo the Lion. Depending on your location the two will be anywhere from around 1o to at least 5.5o as is the separation from my location.


   And while outside remember to turn toward the south and east to see Jupiter, Mars, and Saturn stretched out above the horizon. The brighter stars, Spica in Virgo the Harvest Maiden and Antares in Scorpius the Scorpion are also arranged along the same ‘line’ as the three planets.

   
   
   

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.

A Lunar ‘4-fer’ Plus Planets: Perigee; Ascending Node; Blue Moon; and a Total Lunar Eclipse!!

   Our Moon reaches full phase for the second time this month on Wednesday January 31st at 13:27 UT (7:27 am CST). According to the popular definition for a ‘Blue Moon’ the second full Moon in a month is known as the ‘Blue Moon’. This happens about every 2.5 years with this year being a little more different in that there will be a second Blue Moon month in March.

   Our Moon reaches perigee, (closest distance from Earth), for this orbit on Wednesday January 30st at 9:48 UT (3:38 am CST). At that time the Moon will be at a distance of 28.14 Earth diameters (358,994 km or 221,204 miles) from the Earth.

      On Wednesday January 31st the full 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.
      
   What do you get when you have the full Moon at a node crossing? An eclipse – in this case a total lunar eclipse. Timing for this eclipse favors viewing from the western half of the continental United States. Here is a link to download a lunar eclipse page information page (PDF) from the NASA eclipse web site
   Mid-eclipse has the darkened Moon a few degrees away from the open star cluster, M-44, commonly known as the Beehive Cluster. Both the Moon and tM-44 will fit within the field of view of binoculars.
   Here is a summary of the eclipse event starting times from the NASA Eclipse web site. My local time, CST, is UT-6 hours. An important time will be local sunrise-moonset time. For me local sunrise and Moon set time is 7:26 am CST meaning that totality will be in progress as the Moon sets. Here is a link to the Sun and Moon Data calculator web page at the U.S.N. Observatory so you may determine your local sunrise/moon set time. Here is a link to the Hermit Eclipse web site for more information about the eclipse and an interactive map showing eclipse event particulars.
P1 = 10:51 UT 4:51 CST
U1 = 11:48 UT 11:48 CST
U2 = 12:51:47 UT 6:51 CST
U3 = 14:07:51 UT 8:07 CST
U4 = 15:11:11 UT 9:11 CST
P4 = 16:08:27 UT 10:08 CST

   As the eclipsed Moon is setting in the west turn toward the south and east to see Jupiter, Mars, and Saturn plus the bright stars Spica and Antares.

   
   
   
   
   
   

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 Western Elongation

19jan-mercury-east-elongation
   On Monday January 1st Mercury, the innermost planet, will reach its orbital position known as greatest western elongation at 22.7o. At that moment Mercury, the Sun, and the Earth, would be arranged in something close to approximating a right angle as this graphic shows. Even though it sounds confusing at western elongation for either Mercury or Venus the inner planet will be to the right of the Sun as we view them, meaning that at western elongation an inner planet rises in the east before the Sun rises. And at eastern elongation with the inner planet on the left side of the Sun the inner planet follows the Sun across the sky setting after the Sun sets.
orbital-positions
   From our perspective the orbits of Mercury and Venus appear to move from one side of the Sun to the other – out to the left (east) from the Sun to eastern elongation, then reverse and move westward (inferior conjunction) between the Earth and the Sun to western elongation. From there the inner planet moves eastward going behind the Sun (superior conjunction) and eventually reappearing on the eastern side of the Sun for an eastern elongation. Repeat over and over – do not stop!


   Mercury is visible in the morning skies before sunrise along with Mars, Jupiter, and the stars Spica and Antares, 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.