November Moon at Apogee

   Our Moon reaches apogee, (greatest distance from Earth), on Tuesday November 21st. At that time the Moon will more or less be at a distance of 31.84 Earth diameters (406,132 km or 252,359 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 3.5-day old waxing crescent Moon will be over the southwestern horizon at sunset local time. Were it not so bright the glow of the Milky Way in the background might have been visible. Saturn is visible, but it is low above the horizon.

*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.

Waxing Crescent Moon Conjunctions with Mercury and Saturn

   Over the next two evenings, November 19th and 20th the waxing crescent Moon will be passing by the innermost planet Mercury and then one of the outer planets, Saturn. The thin 1.5-day old waxing crescent Moon will be near Mercury on Sunday the 19th, and then the 2.5-day old thin waxing crescent Moon will be near Saturn on Monday the 20th.

   
   
   

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 Superior Conjunction

mercury at superior conjunction
   Sunday October 8th the innermost planet Mercury reaches superior conjunction – on the opposite side of the Sun from the Earth. For those that are curious, Mercury at superior conjunction is approximately 1.408 AU (130,881,776 miles; 210,633,801 km) from the Earth – the combined distance of the Earth to Sun distance plus the radius of Mercury’s orbit.
   Mercury is not visible while in conjunction with the Sun but within the next week or so Mercury will reappear on the east side of the Sun and start becoming visible over the western horizon at sunset.

   
   
   

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 – 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.