Our Neighbours Are Back

Though the shortest month of the year has no big surprises in store, the planets closest to Earth begin to rear their heads again. Observe them now and then watch how they evolve as the seasons go by. You can enjoy the show under the kind of crystal-clear sky that only winter provides.

Venus makes a quiet comeback

Invisible since early December, Venus slowly pulls away from the luminous Sun and gradually becomes the Evening Star. Still, the planet is hard to make out in the glow of twilight, especially in early February. Your best bet is to find an unobstructed west-southwest horizon and look for a tiny bright dot appearing 20 to 30 minutes after sunset. You must act fast because Venus quickly dips below the horizon. A good reference point on the 16th is a thin crescent Moon lying less than 2 degrees above Venus low on the horizon. Day by day, the challenge becomes easier as our neighbour rises higher and higher in the evening sky. The planet continues its ascension till the second half of May.

A red planet in the morning sky

Early birds will prefer to admire the return of Mars, which moves leisurely toward its opposition on July 27. Until then, Earth gradually catches up to the red planet on its orbit, reducing the distance separating the two. Mars’s diameter grows, and its glow finally begins to stand out above the south-southeast horizon around 4 a.m. The small red dot approaches the claws of Scorpius in early February and even passes less than 6 degrees north of the red supergiant star Antares from the 7th to the 16th. This is the perfect time to compare the colour and glow of the two bodies. Antares, after all, is the “rival of Ares,” the Greek god whose Roman equivalent is Mars. This early-morning scene gets even better on the 9th when a thin crescent Moon lies 4 degrees above the red planet. Thereafter, Mars strays into Ophiuchus and far outshines all the neighbouring stars.

Jupiter already rules the roost

In the second half of the night, once the winter constellations set and Sirius vanishes, Jupiter becomes the brightest object in the sky. Glowing a beautiful yellow-white, the planet lies about 10 degrees in front of the claws of Scorpius and forms with Arcturus and Spica a vast triangle easily observable even in the city. The biggest planet in the solar system also forms a subtler triangle with the two brightest stars in the constellation Libra, where Jupiter reigns throughout 2018. Incidentally, the common names of these two stars—Zubenelgenubi and Zubeneschamali—are the longest of any stars. Biggest, brightest, longest: what a superlative encounter! The Moon also occasionally visits Jupiter, notably on the 8th when the third quarter creates another triangle, this time with Mars.