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. 20

   The ‘dancing’ continues.
   Wednesday morning September 20th the inner planet Venus and the star Regulus will be about 0.5 o from each other in a very close conjunction. Venus is shining at an apparent magnitude of 3.9 while Regulus, the ‘heart of the lion’ has an apparent magnitude of 1.4. Both will fit within the field of view of binoculars as well as a low power or wide-field telescope eyepiece.
   Look a bit lower toward the horizon for two more planets, the innermost planet Mercury, and the ‘Red Planet’ Mars.

   
   
   

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.

Dance of the Planets Continues

   In a previous post I described how the two inner planets, Mercury and Venus, and an outer planet, Mars, will be visible over the eastern horizon in the hour or so before the Sun rises. Given their respective orbital speeds the three planets will interact with one another in a series of conjunctions that at times will include the star Regulus in Leo the Lion.
   Once again facing east along 50 Highway at around 6 am CDT with early morning traffic just starting to increase. Still dealing with haze and low clouds, some of which are remnants of Hurricane Irma.

   
   
   

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.