March is the perfect time to learn more about one of the few constellations that actually looks like the creature it represents: Leo the Lion.
This beautiful spring constellation is located south of the Big Dipper, which itself can be found near the zenith in the evening at this time of year. Use the famous Big Dipper asterism to help you find Leo: Start by drawing an imaginary line between the bowl’s two outer stars (on the same side as the handle) and extending it toward the horizon. Along the way, slightly to the right of that line, you’ll see a group of stars shaped like a large sickle, similar to a backwards question mark.
The Sickle represents the celestial Lion’s head and mane. Located at the base of this mirror-image question mark is Regulus, which is the brightest star in the constellation and is meant to be the noble animal’s heart. This star is located very close to the ecliptic, the imaginary line that the Sun appears to travel over the course of a year. It’s also the region of sky along which the planets and the Moon move. That means the Moon passes close to Regulus on a regular basis, as will be the case on the evening of March 5, when the gibbous Moon will lie less than 4 degrees to the upper left of Regulus.
Regulus means “little king” in Latin. It’s actually a quadruple star system, roughly 80 light-years away from us. This main sequence star is four times more massive and 350 times brighter than the Sun.
A triangle of stars to the left of the Sickle represents the Lion’s hindquarters and tail. The brightest star at the tip of the triangle is named Denebola, which comes from Arabic meaning “the Lion’s tail.”
The constellation Leo is home to many galaxies. An instrument of at least 100 mm in diameter is all a seasoned stargazer needs to observe these far-away celestial islands.
Venus and Jupiter in the evening sky
The bright planets Venus and Jupiter put on a show at twilight this month. On the evening of March 1, they will be in conjunction above the west-southwestern horizon. Venus is the brighter of the two; a mere half a degree to its left is Jupiter, slightly less luminous but still impressive. With each passing day, Jupiter draws ever closer to the horizon, making it increasingly difficult to see. Venus follows the opposite path and climbs higher during the month.
The Moon joins the planetary duo from March 22 to 24. On the 22nd, look for the thin crescent Moon above the western horizon about 45 minutes after sunset; you should also be able to spot Jupiter to the lower right of the Moon. The lunar crescent will appear below Venus on the evening of March 23 and above the brilliant planet the following evening.
Mars and the Moon ride high in the sky
Mars is visible all evening long throughout the month and is easily recognizable by its red hue. At nightfall, the Red Planet stands very high in the sky, at more than 65 degrees in altitude in the west-southwest, and sets in the northwest around 2 a.m. (EST). The Moon will draw close on March 27 and 28: On the 27th, the lunar crescent will hang below and slightly to the right of the Red Planet; the next day, the Moon will glide to the upper left of Mars.
Here’s a small viewing challenge: On the evening of March 27, try to spot Jupiter and Mercury, a mere 1½ degrees apart, in the twilight glow. The slightly brighter Jupiter will sit to the left of Mercury. However, the viewing window will be very short: The duo will shine less than 4 degrees above the western horizon, about 30 minutes after sunset, before disappearing below the horizon shortly thereafter. Binoculars will help you locate the two planets in the still-bright sky.
Lastly, remember to move clocks and watches forward for Eastern Daylight Time on the night of March 11-12. Astronomical spring begins on March 20 at 5:23 p.m. EDT.