The Sky This Week, 2014 June 10 - 17
|The Moon, Mars, and Spica over the Washington Monument
Imaged at the 5th annual Astronomy Festival on the Mall,
2014 June 6
The Moon descends to the southern reaches of the ecliptic this week, brightening up the rising southern summer constellations. Full Moon occurs on the 13th at 12:11 am Eastern Daylight Time. June’s Full Moon is variously known as the Mead Moon, Rose Moon, Strawberry Moon, or Honey Moon. All of these names reflect Luna’s appearance at her low southerly declination, since the haze and humidity of the midsummer air tends to give a warmer tint to her otherwise silvery face. On the evening of the 10th you’ll find her just east of golden Saturn. On the following night look for the ruddy star Antares just over seven degrees south of the Moon. By the end of the week she sets off for the long climb through the rising autumnal stars.
Those of you who are not “morning people” (and I count myself among you) can take heart as this week finds the earliest sunrises of the year. On June 14th Old Sol breaks the Washington horizon at 5:42 am EDT, and as the week ends his rise time begins to slowly creep back toward a more civilized hour. However, due to the elliptical nature of the Earth’s orbit we won’t see the latest sunset until the 28th, when the Sun retires at 8:38 pm. In between we find the summer solstice falling on the 21st. This is the day with the longest duration of daylight as the Sun stays above the DC horizon for 14 hours and 54 minutes.
The bright Moon and the year’s shortest nights limit our nighttime skywatching to the brightest objects in the sky. Fortunately, besides the planets, there are other objects that we can pick out without having to stay up all night long. The first or these is the bright star Arcturus, which stands high on the meridian at around 10:00 pm. Arcturus is the brightest star in the northern hemisphere sky and the fourth brightest in the entire heavens. Its rosy tint tells us that it is a star that has evolved into its early giant stage, fusing hydrogen is a shell around an inert helium core. It is the closest star of this type to the Sun, located just under 37 light-years away. Its light was used to open the 1933 Chicago World’s Fair; at the time it was thought to be 40 light-years distant, and it had been 40 years since the World Columbian Exposition was staged in Chicago in 1893.
By midnight you should see the signature stars of summer high in the eastern sky. Vega, Deneb, and Altair form the distinctive asterism known as the Summer Triangle, and the area around these stars will provide you with hours of delightful views through binoculars, especially once the Moon pulls away. Some of the densest star clouds of the Milky Way are contained in the Triangle’s environs with a host of small asterisms and loose star clusters sprinkled along the way.
Jupiter can still be seen shortly after sunset in the western sky, but you have to act fast to get a quick glimpse of him in the telescope. By the 15th he sets at the end of evening twilight, so if you do catch a glimpse of him it will be against a bright sky background. In another month he’ll slip behind the Sun, then we’ll have to wait until the winter to see him in the evening sky again.
Mars still shines with his distinctive ruddy glow as the evening twilight deepens. The red planet now spends his evenings on the west side of the meridian to the west of the bright star Spica in the constellation of Virgo. Mars is picking up speed as he begins to move eastward along the ecliptic, and by mid-July he’ll race past the blue-tinted star. Mars’ disc continues to shrink in the telescope eyepiece, so sighting detail on his ruddy surface requires lots of patience and a steady atmosphere.
Saturn is now well-placed for viewing as evening twilight fades to darkness. The ringed planet now crosses the meridian at around 11:00 pm, so you’ll have several hours to enjoy telescopic views of him. Despite his low declination, in steady air you should be able to spot the Cassini Division in the planet’s icy rings in a four-inch or larger telescope, and the more aperture you can command the more of his bevy of moons will reveal themselves.
Venus continues to play cat-and-mouse with the rising Sun, visible low in the east in gathering morning twilight. This week she moves from the constellation of Aires into Taurus, and next week she will glide to the south of the Pleiades star cluster.