In the Sky This Month

The star Cursa represents the “footstool” of Orion, the hunter. During the evening hours it stands a little above Rigel, Orion’s brightest star, which is to the lower right of the hunter’s three-star belt.

The Moon is new today. It is crossing the imaginary line between Earth and the Sun, so it is hidden in the Sun’s intense glare. It will move into view in the west-southwest shortly after sunset tomorrow and Saturday, shining as a thin crescent.

Monoceros, the unicorn, is high in the south in mid-evening. Seen under dark skies, with the help of binoculars or a telescope, it yields some interesting sights. An example is the Rosette Nebula, a cloud of gas and dust that spans several light-years.

Andromeda descends the northeastern sky this evening. Among its wonders is Upsilon Andromedae, a system of two stars and at least four planets that are similar to Jupiter, the giant of our own solar system.

The planet Mercury is in conjunction, passing behind the Sun as seen from Earth. The Sun’s closest planet will peek into view in the east-southeast at dawn later this month, forming a tight triangle with Saturn and Jupiter.

The planet Mars stands high in the sky at nightfall. It looks like a bright orange star. Today is the vernal equinox in the planet’s northern hemisphere, marking the start of spring.

Draco, the dragon, is an ancient constellation. One of its stars, Thuban, marks one of its coils. Fifty centuries ago, Thuban stood at the north celestial pole. That made Thuban the North Star. But Earth’s axis shifts, so today the North Star is Polaris.

Antares will stand close to the lower right of the Moon at first light tomorrow. The bright orange star is at the heart of the celestial scorpion. It is classified as a red supergiant, one of the brightest and heaviest stars in our region of the galaxy.

The Moon is at last quarter today, which means it is three-fourths of the way through its month-long cycle of phases. It lines up at a right angle to the line from Earth to the Sun, so sunlight illuminates half of the lunar hemisphere that faces our way.

The Orion Nebula is a giant stellar nursery—a cocoon of gas and dust that has given birth to thousands of stars. It is in the south on winter evenings. The nebula is a faint smudge of light below the three bright stars that mark Orion’s Belt.