Early Monday morning October 21st the last Quarter Moon will be high over the southeastern horizon and more or less lined up with the ‘Twin Stars’ of Gemini, Pollux and Castor. The Moon will be about 4-5o from Pollux and about 9-10o from Castor.
Tuesday August 27th the 26-day old thin 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.
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*
Read this very informative article about the Earth-Moon system and their orbital motions, written by Joe Hanson. “Do We Orbit the Moon?”
Northern hemisphere spring comes to an end and the summer season begins on Tuesday June 21st at 8 UT (3 am CDT) when the Sun ‘reaches’ the celestial coordinates of 23.5o north declination and 6 hours right ascension. With respect to the Earth’s surface the Sun is described as over the Tropic of Cancer, 23.5o, north of the Earth’s equator. At this same time the Sun is just entering the boundaries of the astrological constellation Cancer the Crab. Interestingly about 19 hours later, Wednesday June 22nd at 3 UT (10 pm CDT June 21st) the Sun will actually be entering the region of the Gemini Twins as it crosses the boundary between Gemini and Taurus.
According to the pseudoscience of astrology the Sun, at this date, would be entering the astrological sign of Cancer the Crab.
We know that it is the Earth’s orbital motion around the Sun that causes the sun’s apparent eastward motion among the stars in the background. This is how the Sun ‘reaches’ a celestial coordinate, how it ‘crosses’ the boundaries between constellations, or how it is ‘in’ a constellation.
With respect to the southern hemisphere this is the end of their summer and start of their fall season. So thinking globally my preference has been to use the name of the month to designate the season change. Hence the use of the term June Solstice rather than summer solstice.
Friday April 12th the first quarter Moon will be within 6-7o from the star Pollux in the constellation of the Gemini Twins and will more or less fit within the field of view of 7X50 binoculars.
Over the next couple of nights the 15 to 16 day old waning gibbous Moon will move past Pollux and Castor, the twin stars of Gemini, and Procyon the alpha star in Canis Minor, the Little Dog. With a little imagination or the animated graphic it’s not hard to picture Pollux kicking the Moon. Ok a lot of imagination, or the animated graphic!
Animated graphic shows the sky for December 15th and 16th a couple of hours after sunset.
Happy 4th of July!!
Saturday July 4th the United States of America celebrates its Independence Day. Regardless of your location that evening take a look at the skies for not only fireworks but also for three of the brightest planets. Off to the east is the planet Saturn rising just ahead of the Scorpion’s claws. Over the the western horizon are Jupiter and Venus, still close enough to see in the field of view of binoculars. Nearby is the heart of Leo the lion, the star Regulus.
And if you have a level and low enough horizon there is a chance that you could see Comet PANSTAARS (C/2014 Q1). The comet is a few days away from it perihelion, closest to the Sun, and is estimated to have an apparent magnitude of 5-6 making it just bright enough to be seen with the naked-eye under good dark sky conditions. With binoculars it may resolve into showing a tail. This graphic is from the Sky Live web site and it shows the comet near the ‘Twin Stars’, however note how close this is to the Sun. Once the sky gets dark enough the comet and the ‘Twin Stars’ may be too low to be visible.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.