Deane Morrison, University of Minnesota
With two full moons and the spring equinox, what's not to love about March?
With a new moon on the 15th, February's darkest skies come in mid-month. Use the moonless evenings to enjoy the bright winter constellations, which dominate the southern sky after nightfall. Grab a star chart and look low in the south for lovely Sirius, the brightest of stars. It radiates from Canis Major, the big dog, and can be imagined as a jewel in the dog's collar. Sirius — also called the Dog Star — owes its status to its proximity. Not quite nine light-years away, it's one of our closest neighbors.
January starts and ends with full "supermoons" – one on New Year's Day and one on the 31st. On New Year's Day we get the closest full moon of the year – a mere 221,700 miles away. Perfect fullness comes at 8:24 p.m. – less than five hours after both moonrise and perigee, the moon's closest approach to Earth in a lunar cycle. In other words, 2018 starts with a rising moon that scores way up on the size, brightness and roundness scales. During the night of Jan. 1 and 2, it travels the sky in Gemini.
December wastes no time in giving us its best gift: a supermoon.
The Milky Way arches high across the mid-evening sky from east to west in November. At its eastern end, winter constellations Orion, the hunter; the Gemini twins; Taurus, the bull; and Auriga, the charioteer, enter the sky. At its western end, the Summer Triangle of bright stars wheels toward the horizon. Face north to see scraggly Perseus just to the right of M-shaped Cassiopeia. Below them the Little Dipper hangs from its anchor — Polaris, the North Star — and the Big Dipper hugs the horizon.
October is known for its clear, crisp weather, so let's hope the pattern holds. Mars joined Venus in the morning sky about a month ago. The red planet is climbing as Earth starts to catch up to it in the orbital race, while Venus is slowly dropping as it gets ready to sail behind the sun. On Oct. 5, the planets slip by each other, coming within half a moon's width. Look low in the east about an hour before sunrise; Venus will be the slightly higher and brighter object.
In August, Jupiter heads for the sunset. Every evening it sinks lower, along with its longtime companion Spica, the brightest star in Virgo. Saturn comes out in the south, between the Teapot of Sagittarius to the east and Scorpius to the west.
Venus reigns over the morning sky this month. The queen of planets rises two and a half hours ahead of the sun on July 1, with its lead growing to three hours by July 31, thanks almost entirely to the sun rising about half an hour later by the end of the month.
After nightfall this month, we can compare two giants: Saturn and Jupiter. Jupiter comes out as a beacon in the southwest and sets in the west a few hours later. Trailing it is Spica, the brightest star in Virgo. Below Spica and Jupiter is the skewed, four-sided form of Corvus, the crow. Saturn rises in the east around sunset and travels the night sky between Scorpius and its red heart, Antares, to the west and the Teapot of Sagittarius to the east. On June 15, Earth laps the ringed planet in the orbital race and it will be at its brightest for the year.
Saturn has been moving toward center stage as much speedier Earth gains on the ringed planet. In May Saturn starts rising before midnight. It first appears low in the southeast, to the left of the red star Antares in Scorpius; by dawn Saturn and Antares have moved to the south or southwest.