You are here: Home USNO News, Tours & Events Sky This Week The Sky This Week, 2017 March 7 - 14

The Sky This Week, 2017 March 7 - 14

It's time for Daylight Time!
Looking west at the Moon, Lost Gulch Overlook, 2017 March 1
imaged near Boulder, CO, with a Canon EOS Rebel T2i DSLR and 24mm lens

The Moon brightens the overnight hours this week, moving from the stars of the Great Winter Circle into the rising stars of spring. Full Moon occurs on the 12th at 10:54 am Eastern Daylight Time more on this below). The March Full Moon has a number of popular names, several of which reflect the easing of winter’s icy grip. Among these are the Worm Moon and the Sap Moon. It is also known as the Lenten Moon if it occurs in the period of fasting before Easter. Look for the Moon near the bright star Regulus in Leo on the evening of the 10th. They will be separated by just under two degrees. On the evening of the 13th you’ll find the Moon just one degree east of the second-magnitude star Porrima in the constellation of Virgo. On the following night Luna rises in the company of the bright planet Jupiter.

This is the week when we perform an annual ritual to adjust our clocks to give us the illusion of more daylight in the late afternoon and evening hours. At 2:00 am on the morning of Sunday, March 12 we must set our clocks ahead by one hour to observe Daylight Time, which will be in effect until November 5th. The idea of Daylight Time originated in Great Britain in the early 20th Century with a man named William Willett. He began advocating for advancing clocks in 1907 when he noticed the number of people who were still sleeping when the Sun was up in the morning. Various attempts to push Parliament to adopt the scheme were attempted over the next several years, but it was the outbreak of World War I that cast the die. Germany adopted the new scheme to allow factories to remain open longer in the afternoon under natural light, and Britain soon followed suit. Here in the U.S. the idea was promoted so that factory workers could have more time in the afternoons and evenings to tend their "victory gardens" after work. Standard Time and Daylight Time were finally codified into law by Congress in 1918, but almost immediately Daylight Time became very unpopular. The Daylight Time portion of the law was repealed in 1919, and regulations regarding it were left up to local jurisdictions. Daylight Time was again mandated by Federal decree in World War II, but it wasn’t until 1966 that it was again incorporated into Federal statute. The start and end dates were modified several times over the next four decades with the current period of Daylight Time codified in the Energy Policy Act of 2005.

You have probably noticed that Venus, which has been a fixture in the evening sky for the past few months, is now becoming less prominent in the early evening sky. If you want to catch a glimpse of her thinning crescent you need to get the telescope on her as soon as you can see her in evening twilight. She sets five to six minutes earlier each night this week as she overtakes the Earth on her inner orbit around the Sun. Her plunge from the sky becomes even more dramatic by the end of the week, and by the 25th she will move from the evening into the morning sky. She will soon greet early morning commuters and remain visible before the Sun for the rest of the year.

Mars is now left alone in the early evening sky where he continues to move eastward against the stars of the constellation Aires. Fortunately there aren’t many objects of similar brightness in this part of the sky, so he should be relatively easy to pick out in the southwestern sky as darkness falls. He sets at about the same time each evening as he manages to keep pace with the advancing Sun.

Jupiter rises with the Moon on the evening of the 14th, and before the switch to Daylight Time is well-placed for viewing by 11:00 pm. The Giant Planet is one of the most rewarding targets for the small telescope. Any instrument will show the four moons first documented by Galileo in 1610, and a four-inch aperture scope will show the planet’s dark equatorial cloud belts. On the evening of the 9th look for the planet’s famous Great Red Spot crossing his central meridian. You might also spot the shadow if the planet’s largest moon, Ganymede.

Saturn is approaching the celestial meridian in the southern sky as morning twilight begins to brighten the sky. The ringed planet will spend the year located between the summer constellations of Scorpius and Sagittarius. Your best view right now will be about an hour before sunrise, but you’ll also have all summer to check him out.


USNO Master Clock Time
Javascript must be Enabled