April Moon at Ascending Node

   Monday April 23rd the waxing gibbous 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.


   On Monday evening April 23rd the 8-day old waxing gibbous Moon will be within the boundaries of Leo the Lion and about 7o west (right) from the ‘Heart’ of the Lion, the star Regulus.

   Does our Moon actually go around the Earth as many graphics show? 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?”

   
   
   

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 Week of Moon Conjunctions


   Over the next 7 days (mornings) the Moon, as it wanes toward last quarter, will pass closely by several planets and brights stars in some close and some not so close conjunctions.
   Perhaps the best morning will be on April 7th when the near last quarter Moon will be 1-2o from Saturn and about 4o from Mars.
All three will easily fit within the field of view of binoculars.

   
   
   
   
   
   
   
   
   
   

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.

March Moon at Ascending Node

   Tuesday March 27th the waxing gibbous 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.


   On Tuesday evening March 27th the 10.5-day old waxing gibbous Moon will be within the boundaries of Leo the Lion and about 7o west (right) from the ‘Heart’ of the Lion, the star Regulus.

   Does our Moon actually go around the Earth as many graphics show? 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?”

   
   
   

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.

Jupiter Backs Up!

   Friday March 9th the outer ringed planet Jupiter stops its regular direct motion to the east and begins to move in retrograde toward the west. Retrograde motion for any planet further from the Sun then the Earth, that we observe from Earth, is an apparent motion of that planet caused by the faster moving Earth along its orbital path. As the Earth catches up and passes an outer planet that planet appears to move toward the west. Depending on the planet the retrograde motion may last a few weeks or months. Jupiter will be within the boundaries of the constellation Libra the Scales.

   Jupiter along with Mars and Saturn all rise before sunrise local time and the morning skies on March 9th the 21-day old last quarter Moon will be about 7o from the ‘red planet’ Mars.

   Follow the planet by way of its coordinates using just right ascension with the free equatorial star chart from Stephen F. Austin University.

Date Right Ascension
(Hours – Minutes)
June 5            14 52
June 15         14 48
June 25         14 46
July 5            14 45
July 15            14 44
July 25            14 46
August 4          14 48
August 14         14 51
August 24         14 55
September 3      15 00

   
   
   

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.

Mars Opposite Uranus

   Tuesday January 30th Mars and Uranus will reached their respective orbital positions that have them 180o apart. Mars will be located at approximately 207.6o and Uranus at approximately 27.6o of heliocentric longitude. This called heliocentric opposition.
   Interestingly at their last heliocentric opposition, February 26th 2016, Mars was located at approximately 200.0o and Uranus at approximately 20.0o of heliocentric longitude.
   
   
   

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.

Jupiter-Mars Close Conjunction

   If you were outside this morning you may have noticed over the southeastern horizon a bright star like object (Jupiter) just below a reddish star-like object (Mars). Both planets are moving eastward and Mars, as a faster orbiting planet, will gradually catch up and pass the planet Jupiter.
   Saturday and Sunday mornings January 6th-7th the planets Jupiter and Mars will be about 0.20′ (20 minutes) apart as Mars moves past Jupiter. With an apparent magnitude of -1.8 Jupiter far outshines Mars’s apparent magnitude of 1.40. This graphic is set for 7 am CST (12 UT) and the planets Mercury and Saturn are just above the eastern horizon. And further to the west higher over the southern horizon is the 20-day old waning gibbous Moon.
   This animated graphic is set to 1-day intervals starting with today, the 5th, and ending on the 7th. Both Mars and Jupiter are close enough to easily fit within the 25 mm eyepiece of a 6″ Reflector, and should make a great view with binoculars. I’m thinking that with the naked eye the two should almost merge into one, with Mars lost in the glare from Jupiter.

   
   
   

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.