June Moon at Ascending Node

   Thursday June 27th the waxing 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 June 27th the 4-day old waxing crescent Moon will be with the constellation Leo the Lion, and the Moon will be located less than 1o from the heart of the Lion, the star Regulus. This should make for a great view with binoculars or through the eyepiece of a telescope.
   Just above the western horizon, possibly lost in the Sun’s glare, are two more planets – Mars and Mercury about 1o apart.

   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.

Mercury at Superior Conjunction

mercury at superior conjunction
   Wednesday June 21st 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 1.324 AU (123,073,489 miles; 198,067,580 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.

2017 June Solstice

21june-ecliptic   Northern hemisphere spring comes to an end and its summer begins on Wednesday day June 21st at 4:24 UT (11:24 pm CDT Tuesday June 20th) 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 latitude 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 11 hours later, June 21st at 15 UT (10 am CDT) the Sun will actually be entering the region of the Gemini Twins as it crosses the boundary between Gemini and Taurus.
Just had to include this!!
   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.

   
   
   

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.

Saturn at 2017 Opposition

saturn-opposition-ani
   Thursday June 15th the outer planet Saturn reaches its orbital position known as opposition. This is a position which has the faster moving Earth passing Saturn and at opposition is centered between the outer planet and the Sun. Picture the arrangement with the Moon at full phase; Sun – Earth – Moon, and that is similar to the arrangement for Saturn at opposition.

   When an outer planet, like Saturn, reaches opposition that planet rises around local time for sunset and is visible all night.

   
   
   
   
   

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.

ISS Followed the Arc

   Last evening, Sunday June 11th the ISS, International Space Station orbited over my part of the world. The ISS appeared about 45o above the west-northwest horizon and followed a path that went below the bowl of the Big Dipper and in a straight line ‘followed the arc to Arcturus’ in the constellation Bootes the Herdsman. At its peak the ISS reached nearly the zenith and at its brightest had to be at least -3.0 in apparent magnitude. After a several minutes the ISS moved out of sunlight and faded from view above the southeastern horizon.
Camera settings were 18mm; ISO 800; F4.0; 2 sec.
   One dependable and accurate source of viewing information for the ISS is at NASA’s ISS Sightings web site. Here you may learn the time and direction the ISS will appear, its duration of visibility, and its time and direction it will stop being visible.

   In a similar manner the Heavens Above web site will also provide viewing information for the ISS but in addition it will display a star map showing the path across the sky. This sample graphic shows the ISS path for June 12th.

   Want to see what the Earth looks like from the ISS? Click on this link to go to the ISS HD Earth Viewing web site for a view from one of several cameras mounted on the ISS as this screen capture shows. There are two additional maps that show the current position and orbital path of the ISS.
   
   
   

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.

June Moon at Apogee


   Our Moon reaches apogee, (greatest distance from Earth), on Thursday June 8th. At that time the Moon will more or less be at a distance of 31.85 Earth diameters (406,401 km or 252,526 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*

*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?”


   On the day of the apogee Moon the 14-day old full Moon rises around local time for sunset and is 9-10o degrees from the reddish star Antares in Scorpius the Scorpion.

   
   
   

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.

Neptune at Western Quadrature

orbital-positions   On Sunday June 4th the position of the planet Neptune with respect to the Earth and the Sun places this ringed planet at what is called western quadrature. At that orbital position Neptune, and actually any outer planet, is at a 90 degree angle from us as this graphic shows. Think third quarter Moon as that is a fair comparison of the relative positions. At this position Neptune leads the Sun across the sky from east to west as the Earth is rotating, meaning that Neptune rises before the Sun and also sets before the Sun.

click on graphic to see it larger   Neptune currently is within the boundaries of the constellation Aquarius the Water Bearer. At around 7th magnitude Neptune is too dim to see with the naked-eye but easily seen with a telescope or binoculars. In 7×50 binoculars Neptune may be visible near the 4th magnitude Lambda Aquarii, and just below the point of a small triangle arrangement of 6th magnitude stars.

   This is a short video clip from a much longer video that I made as part of a live musical performance called “Orbit” at the Gottleib Planetarium in Kansas City Missouri during May 2011.

   
   
   

Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.