Truly dark skies are becoming less common worldwide due to light pollution. Light pollution is the illumination of the night sky by artificial light sources on the ground. As well as making it difficult to see the stars, light pollution also can affect the biology and ecology of species around the world.

From tomorrow through March 16, you can join in a global campaign to address light pollution locally and globally. The “;Globe at Night”; project invites people to record the brightness of the night sky by matching the appearance of the constellation Orion with star maps of progressively fainter stars. After the observing period, “;Globe at Night”; will release a map of light-pollution levels worldwide. For more information about light pollution and to participate in this citizen scientist project, visit www.globeatnight.org.

Saturn at Opposition

On March 22, Saturn will be opposite the sun in the sky. The ringed planet will be visible all night, rising at sunset and setting at sunrise. Unfortunately, Saturn's rings will appear almost edge-on this year, so they will be difficult to see through a telescope. Saturn is in the constellation Virgo right now. Since Virgo is a difficult constellation to see, try finding Leo, then look for Saturn below the lion's haunches.

Constellation Spotlight: Leo

The zodiac constellation Leo the Lion is easily identifiable by the Sickle, an asterism that looks like a backward question mark. The bright star Regulus makes up the point on the question mark and represents the lion's heart. Regulus, which means “;little king,”; is actually a multiple-star system that can be seen with binoculars or through a telescope. Imagine that the Sickle is the lion's head and mane, then look behind it for a triangle of stars that make up the lion's haunches. The brightest star of this triad is Denebola, meaning “;the lion's tail.”; Leo is visible in the eastern sky after sunset, then travels through the zenith and sets in the west just before sunset.

This group of stars has been seen as a lion for centuries, starting with the ancient Babylonians. The ancient Greeks saw Leo as the Nemean Lion that Heracles killed as part of his Labors. The lion is included in a zodiac map found in the Temple of Isis at Dendera, Egypt.

Spring Forward

The vernal equinox occurs in Hawaii at 7:32 a.m. March 20, marking the start of spring. An unrelated but also important event is the start of daylight saving time at 2 a.m. March 14, when most of the mainland sets clocks one hour later. The full moon occurs March 29. Traditionally, French champagne was bottled on the day of the March full moon since it was believed that the springtime moon would lend extra effervescence to the wine.