Dance of the Planets – 20 Sep. Venus / Regulus Conjunction

   This morning the inner planet Venus and the ‘heart of the lion’, the star Regulus were about 0.5o from each other. Lower near the horizon and emerging from the mornning cloud layer is the other inner planet Mercury, and just above and fainter the planet Mars.
   Camera particulars: Canon Rebel T7i; 27 mm; ISO-800; f/5.6; 8 sec.

   
   
   

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.

Dance of the Planets-Sep. 18

   The ‘dancing’ continues.
   Monday morning September 18th there will be a ‘solar system cluster’ (for lack of another term!), in the hour or so before the Sun rises.
   Look eastward for three planets (Venus, Mars, Mercury), the 27.5-day old thin waning crescent Moon, and the star Regulus in the constellation Leo the Lion.
   The Moon is situated between Venus and Mars and Mercury such that you are able to see the Moon and Venus within one field of view with binoculars, and by shifting your view lower then be able to see the Moon with Mars and Mercury within that field of view.

   
   
   

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.

September Moon at Ascending Node

   Sunday September 17th the waning crescent 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 September 17th the thin 26.5-day old waning crescent Moon will be within the constellation of Leo the Lion. The Moon will be located about 6o from Venus, and about 9o from the heart of the Lion, the star Regulus. A few more degrees further east from Venus and Regulus (below, as they rise in the morning), is the ‘Red Planet’ Mars, and nearby is the innermost planet Mercury.
   These two planets are close enough for both to be seen in the field of view of binoculars.

   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.

Moon – Dwarf Planet Ceres Conjunction

   Friday morning September 15th the waning crescent Moon will be within about 6o from the dwarf planet Ceres. Ceres should be just visible with binoculars with an apparent magnitude of between 7th and 8th. Within the binocular field of view, about 3o above Ceres is 3rd magnitude kappa Geminorum. And about 5o from Ceres is the star Pollux, one of the ‘Twin’ stars in Gemini the Twins.

   
   
   

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 Tuesday September 12th Mercury, the innermost planet, will reach its orbital position known as greatest western elongation at 17.9o. 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, Venus, and the star Regulus 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.

Dance of the Planets: 9 Sep. – Mercury & Regulus Conjunction

   This morning I set up my camera looking eastward along Highway 50. With city lights behind me, ‘Auto Row’ down the road, and a 19-day old waning gibbous Moon high over my right shoulder the sky was not really that dark. However pictures of visible planets and stars do not always have to be under dark skies or good seeing conditions. Adding to that were the low clouds along the horizon.
   This graphic shows the sky I had plans for imaging this morning, including Dwarf Planet Ceres near Pollux in the Gemini Twins. Plans had been to capture Mercury in conjunction with the star Regulus (check), and also Mars which this morning was closer to the horizon below Mercury (no check!). In the next few days Mars will be higher and easier to include in the group picture. Higher above the horizon and very bright with a -3.95 apparent magnitude was Venus.

   
   
   

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.

Dance of the Planets

   This month the excitement (speaking for myself!) with planet watching shifts to the morning skies. The two inner planets Mercury and Venus and one outer planet, Mars, have several conjunctions with one another and the star Regulus in Leo the Lion throughout this month.
   This animated graphic is set for 1-day intervals starting with September 8th and ending on the 30th.

   
   
   

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.