Moon Near Regulus

Click on graphic to see it full size.

Click on graphic to see it full size.

   Tuesday evening, 1 July, look toward the western horizon at around sunset for the thin 4.75 day old waxing crescent Moon to be a few degrees from Regulus, the ‘heart’ of Leo the Lion. The two will be separated by 6-7o so both will easily fit within the field of view of 7×50 binoculars as the banner graphic at the top of the page shows.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

June Apogee Moon #2

2june-apogee_mon    Our Moon orbits around the Sun with the Earth and 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*.
   The nearly 3.45-day day old waxing crescent Moon reaches apogee for the second time this month on Monday 30 June at 19 UT (2 pm CDT). At that time the Moon will more or less be at a distance of 31.75 Earth diameters (404,558 km or 251,396 miles) from the Earth.

   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Click on graphic to see it full size.

Click on graphic to see it full size.

   Monday evening the thin waxing crescent Moon will be setting about 1-2 hours after local time for sunset.

   
   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Moon – Venus Conjunction

Click on graphic to see it full size.

Click on graphic to see it full size.

   On Monday and Tuesday mornings before sunrise look toward the east to see the waning crescent Moon move past the planet Venus. On Monday morning, 23 June, the Moon will be up to the right from Venus. Then after 24 hours of Earth rotation combined with how far the Moon moves east during the same time period – Tuesday morning, 24 June – the two will form an striking conjunction less than 2o apart as this graphic set for Tuesday morning shows. With a pair of 7×50 binoculars you can easily see not only the Moon and Venus but a slight shift up to the left and the bright stars of the Pleiades will be in the field of view as well.
   The conjunction on Tuesday morning offers an opportunity for some ‘backyard’ astro-photography that could include the Moon, Venus, and the Pleiades — weather permitting!

Click on picture to see it full size.

Click on picture to see it full size.

Update: Tuesday 24 June – weather here finally cooperated with only a few clouds on the horizon and some wispy cirrus high overhead. This is a cropped portion from the original. Camera specs. f8; 1/13 sec.; ISO-800; 123 mm.

   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Sun Not In Cancer Today

21june-view-from-earth  According to the pseudoscience of astrology the Sun enters the constellation of Cancer the Crab on Saturday 21 June at 5:51 am CDT (10:51 UT). When in fact the actual position of the Sun today is still within the boundary of the constellation of Taurus the Bull, but by very little. The Sun is very close to the eastern boundary for Taurus and the western boundary for the Gemini Twins, as this graphic and the banner graphic at the top of the page shows.

   Read a little more about how astrology has the Sun incorrectly placed in a previous blog, and in another blog discussing the effects of precession.
   
   
   
   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Moon At Descending Node

21june-desc_node-ani   Saturday 21 June our Moon will be crossing the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path has with the ecliptic.

Click on graphic to see it full size.

Click on graphic to see it full size.

   At around sunrise or earlier Saturday morning look toward the east to see the thin 24-day old waning crescent Moon near the stars of the constellation Aries the Ram. This group of three stars fits nicely within the field of view of most binoculars. Further to the left or north are the stars making up the constellation Perseus the Hero. Of particular interest is the star Algol, an eclipsing binary star system. This star is actually a group of three stars with the second brightest of the trio orbiting in a nearly 3-day orbital period around the brightest star of the trio. When it passes in front of the brightest star the overall magnitude of the brightest star dims from 2nd to 3rd magnitude in about a 10 hour period.
   During the longer winter nights it is possible, if the timing is right, to see the entire magnitude change if one occurs after sunset. If this is early enough then there may be the chance to catch the opposite side of the stellar eclipse before the Sun rises the next morning. On the other if you live north of the Arctic Circle you have all night. Literally!!
   Down toward the northeastern horizon Venus shines brightly with the stars of the Pleiades just to the left from Venus.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

June Solstice

Sun's Apparent Motion Along the Ecliptic

Sun’s Apparent Motion Along the Ecliptic – from Taurus to Gemini

   Northern hemisphere spring comes to an end and its summer begins at 5:51 am CDT (10:51 UT) on Saturday 21 June as 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 still within the boundaries of the constellation Taurus the Bull – but just barely. Interestingly about 9 hours later, (3 pm CDT – 20 UT), the Sun ‘will move’ into the region of Gemini as it crosses the boundary between Gemini and Taurus.
   We know that it is the Earth’s orbital motion around the Sun that causes the sun’s apparent eastward motion amongst 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.

   Follow the seasons by observing how vegetation changes during 1 year. The video below was produced by an Earth orbiting satellite operated by the NASA/NOAA Suomi National Polar Orbiting Partnership (NPP). It is a really interesting narrated tour of the Earth from orbit over a variety of geographic features and landscapes.

Just had to include this!!

Just had to include this!!

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Mercury at Inferior Conjunction

orbital-positions   Thursday 19 June at 23 UT (6 pm CDT) the innermost planet Mercury reaches inferior conjunction. As the banner graphic at the top of the page shows, inferior conjunction of Mercury places Mercury between the Earth and the Sun – much like the position of the Moon at new phase. The graphic to the right shows the relative to the Earth and Sun position names for both inner planets and outer planets.

   The short video below, taken by the Mars Curiosity Rover, shows a transit of the Sun by Mercury as seen from the surface of Mars.

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Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

June Perigee Moon

jun15perigee    Our Moon orbits around the Sun with the Earth and 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*.
   The 17-day day old waning gibbous Moon reaches perigee this month on Sunday 15 June at 3:35 UT (Saturday 14 June at 10:35 pm CDT). At that time the Moon will more or less be at a distance of 28.385 Earth diameters (361,703 km or 224,752 miles) from the Earth.

   *Click here to read my 2006 Scope on the Sky column “The Real Shape of the Moon’s Orbit”. (PDF)

Click on graphic to see it full size.

Click on graphic to see it full size.

   Saturday evening, Sunday morning, the waning gibbous Moon will be located just east of the stars making the handle of the ‘Teapot’, the asterism for the constellation Sagittarius the Archer.

   
   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Mars Transits the Sun

saturn-mars-heliocentric_conjunction   Yes there will be a transit of the Sun by Mars, however you would have to be on the planet Saturn to see this transit as this graphic shows. This astronomical event is known as a heliocentric conjunction. It is determined by measuring, along the ecliptic, the angle between the Earth’s vernal equinox longitude, 0o, and a planet as would be seen if you were on the Sun.
   The Mars – Saturn heliocentric conjunction is on Saturday, 14 June, at 18 UT (1 pm CDT).
   While the short video below, taken by the Mars Curiosity Rover, is not a transit of the Sun by Mars it does show a transit of the Sun by Mercury as seen from the surface of Mars.

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Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.

Saturn Occultation

Click on graphic to see it full size.

Click on graphic to see it full size.

   During the course of the day on Tuesday 10 June the waxing gibbous Moon, as it moves eastward along its orbital path, will pass by the planet Saturn. The two will be their closest at 19 UT (2 pm CDT), which for my time zone and latitude is during the daylight hours as well as before the Moon rises. However as the two rise the Moon will be within a few degrees to the east from the planet Saturn making for a striking pair as this graphic is showing.

   saturn-occultationViewing this lunar-planet conjunction from other latitude locations will show the gap between the two to range from as it does from my latitude to no gap at all. The latter would be at latitudes where the viewing angle is such that the Moon occults, or passes in front of Saturn, which relative to the Moon is in the background. From the latitude of Queenstown South Africa (31o 54′ S : 26o 53′ E) observers will be able to see the Moon occult Saturn as this animated graphic is showing.

   
   
   
Caution: Objects viewed with an optical aid are further than they appear.
   Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.