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The Sky This Week, 2020 March 3 - 10

Time for Daylight Time
Crescent Moon, 2020 March 2, 02:51 UT imaged from Alexandria, Virginia.
Crescent Moon, 2020 March 2, 02:51 UT
Imaged from Alexandria, Virginia with a 10.2-cm (4-inch) f/6.5
Explore Scientific AR102 refrractor and a ZWO ASI224MC color imager.

The Moon brightens the overnight hours this week, waxing to her full phase as she passes into the stars of the springtime sky.  Full Moon occurs on the 9th at 1:48 pm Eastern Daylight Time.  March’s full Moon is popularly known as the Worm Moon or Sap Moon, both indicators of the inevitable arrival of spring.  On the evening of the 6th, look just below and to the right of the Moon with binoculars to see the scattered stars of the “Beehive” star cluster.

March 8th is the second Sunday in March, and that means that it’s time to set our clocks forward by one hour to observe Daylight Time.  Technically this should be done at 2:00 am EST on the morning of the 8th, but most of us will make the change before we go to bed on the night of the 7th.  This annual ritual is mandated by Act of Congress and enforced by the Department of Transportation, and it has a very rocky history.  This annual ritual affects everyone in the country except for residents of Arizona and Hawai’i.  In Hawai’i’s case it’s because the state is located in the tropics where the annual excursion of day/night change is relatively small.  Arizona is excepted because the residents there never adopted Daylight Time when it was regulated by state statutes.  The Federal law governing time zones and Daylight Time rule wasn’t codified until 1966 under the Uniform Standard Time Act, but Arizona and certain western counties in Indiana were excepted.  Since then the law has been modified twice, with the most recent bill passing Congress in 2005.  Under this Act all of Indiana now observes Daylight Time, but Arizona still stays on Mountain Standard Time.  Whether you like Daylight Time or not, the U.S. Naval Observatory has nothing to do with it.  Regulations regarding enforcement of standard time laws falls under the purview of the Department of Transportation.  We provide the time-scale on which civil time is based, but we don’t tell you what to do with it!  We will remain on Daylight Time until November 1st.

Setting the clocks ahead gives the winter’s bright constellations a bit of a reprieve for evening skywatchers.  Orion and the surrounding stars of the Great Winter Circle cross the meridian an hour later than they do on Standard Time.  Even with the nearly full Moon scattering her light around the sky these winter luminaries are easy to spot and identify.  One particular star to keep an eye on is Betelgeuse, the star at the upper right of the constellation’s familiar outline.  Betelgeuse is a gigantic star, one that is nearing the end of its evolution, and it has shown fluctuations in brightness for centuries.  However, this past year has seen the star fade to an unprecedented minimum brightness, one that made it comparable to the constellation’s three “Belt Stars”.  Betelgeuse’s size and instability make it a likely candidate for a supernova, the cataclysmic explosion that marks the end of a massive star’s life, but the recent fading probably won’t be a harbinger of such an event.  Astronomers now believe that a coincidence of several long-term variability cycles led to the star’s deep minimum, and it now appears that Betelgeuse is brightening again.  You can follow the progress of the star’s rebound from your yard.  At its brightest it is comparable to the blue star Rigel, Orion’s brightest star.

Venus dominates the early evening sky, beaming down from the stars of the diminutive constellation of Aires, the Ram.  The dazzling planet is moving steadily eastward along the ecliptic, keeping her on pace with the advancing Sun.  She will continue to be a fixture in the springtime sky until May, when she will seem to drop out of the sky like a free-falling stone.

The pre-dawn sky plays host to three bright planets, which can all be found in the southeast as morning twilight begins to brighten the sky.  Of the three, Mars is the first to rise, followed by Jupiter and Saturn.  As the week begins the span between Mars and Saturn spans just under 20 degrees, but by the week’s end the group tightens up considerably.  Watch Mars close the gap with Jupiter over the next few weeks.  By the time of the equinox the red planet will approach and pass Old Jove before setting his sights on Saturn.