SKY GUIDE: This map represents the night sky as it appears over Maine during March. The stars are shown as they appear at 10:30 p.m. early in the month, at 9:30 p.m. at midmonth, and at 8:30 p.m. at month’s end. Mars, Uranus, and Venus are shown at their midmonth positions. To use the map, hold it vertically and turn it so that the direction you are facing is at the bottom. Sky Chart prepared by Seth Lockman

The month of March always marks the beginning of spring in the northern hemisphere. Even though it has been a very mild winter, one of the warmest on record, it is always nice to welcome spring back officially along with the ever-lengthening days. That will happen at exactly 5:24 p.m. on Monday, March 20.

It should be much more inviting to go outside at night this month. The highlights include: a very close conjunction of our two brightest planets, Venus and Jupiter on March 1; a close conjunction of Jupiter and Mercury on March 27; Saturn returning to the morning sky; Comet C/2022 E3 (ZTF) still being visible as it passes through Taurus, Eridanus the River and Orion; an opposition of the dwarf planet Ceres and the second asteroid to be discovered, Pallas; and more chances to see the zodiacal light in the middle of this month near new moon.

Venus has been catching up with Jupiter at the rate of 1 degree per day in February. They will be just half a degree apart on the first of this month in Pisces the Fish, which is the width of the full moon. The moon appears to move eastward all the time against the fixed background of stars at the rate of half a degree per hour, which means that it is traveling around us at 2,000 miles per hour. That can only really be appreciated when the moon is occulting a star or planet or when the shadow of the moon races over you at that speed at the start of a total solar eclipse like the one I saw on Aug. 21, 2017. After that Venus will continue to climb higher even as Jupiter sinks lower, separating them at the rate of 1 degree per day for all of March.

A fairly close conjunction of our two brightest planets, Venus and Jupiter, occurs about every year. The last good one was on May 1, 2022, just before all seven of the planets lined up in order in the morning sky for most of the month of June. Notice that Venus is just under two magnitudes, or six times brighter, than Jupiter. Through a telescope you would also see that Venus is now 85% lit by the sun and getting less illuminated even as it is getting brighter because it is getting closer to Earth until June when it reaches inferior conjunction. They recently found another 13 small moons of Jupiter, so it is up to 92 while Saturn is up to 83. They will find many more since there are thousands of small objects in orbit around these two large planets because of their strong gravitational fields.

Watching this conjunction unfold all last month was similar to watching Saturn and Jupiter getting closer every day during November and December of 2020 leading up to their closest conjunction in 800 years happening right on the winter solstice that year. They were just 1/10 of a degree apart that day, easily visible in the same field of view in a telescope. Of course it was cloudy for us that day, but I did see and photograph them the next night when they were still less than a quarter of a degree apart. They get fairly close every 20 years.

Mercury returns to the western evening sky late this month and it will form a nice conjunction with Jupiter on March 27, half an hour after sunset. Uranus will be just over one degree to the left and above Venus, but you would need at least a pair of binoculars to see it.

Then Mars continues to get a little fainter and smaller each night since it is well past its opposition in December and has been tracking in its normal eastward motion since Jan. 12. We are leaving it a little farther behind each night in our respective orbits around the sun. Notice that the red planet will still shine brighter than the nearby orange star named Aldebaran, marking the eye of Taurus the Bull, at 0.9 magnitude. Mars will fade to match Aldebaran by the end of March.

Mars crosses eastward into Gemini on March 26. It will be just 1.1 degrees north of the nice open cluster M35 on March 29. That will be a nice view of that cluster and the conjunction in binoculars. There are two other open star clusters in Gemini nearby, visible in binoculars.

Saturn returns to our morning sky around the middle of this month and it will rise 75 minutes before dawn by March 31. Saturn has moved eastward into Aquarius after spending more than two years in Capricorn. It orbits the sun once every 29 years and is always moving at 6 miles per second around the sun, or more than three times slower than we are at 18.6 miles per second, just 10,000 times slower than the speed of light.

Comet C/2022 E3 (ZTF) is getting fainter but is still visible in binoculars or a telescope this month when the moon is not too bright, between March 10 and March 23. It passed right by Mars in Taurus on Feb. 10 and it will pass just to the right of a nice spiral galaxy called NGC 1637 on March 10. Then it continues through Eridanus the River and will approach Rigel in Orion by the end of the month. It will fade to 10th magnitude by then, or 100 times fainter than the brightest it reached at perigee last month on Groundhog Day. Then it may or may not return to our vicinity of the solar system for another 50,000 years, when it last visited us during the Stone Age.

The dwarf planet Ceres, the first asteroid to be discovered in 1801, will reach opposition on March 21 just after spring starts. Then Pallas, the second asteroid to be discovered and also officially a dwarf planet at 340 miles in diameter, or about the distance across Arizona, will be at its best near Sirius in Canis Major, the brightest star in our sky, on the first of March.

MARCH HIGHLIGHTS

March 1: Venus passes half a degree north of Jupiter.

March 3: The moon is at apogee or farthest from Earth today at 252,207 miles.

March 4: Sir Patrick Moore, a famous English astronomer, was born in 1923.

March 7: Full moon is at 7:40 a.m. This is also known as the Sap, Crow, Worm, or Lenten moon.

March 12: Daylight Saving Time begins at 2 a.m.

March 14: Albert Einstein was born in 1879. Last quarter moon is at 10:08 p.m.

March 16: Caroline Herschel was born in 1750. She worked well with her brother William and discovered eight comets. They were both accomplished musicians.

March 19: The moon passes 4 degrees south of Saturn this morning.

March 20: The vernal equinox is at 5:24 p.m.

March 21: The dwarf planet Ceres is at opposition this morning. New moon is at 1:23 p.m.

March 22: The moon passes half a degree south of Jupiter tonight.

March 24: The moon passes 0.1 degrees south of Venus tonight.

March 25: International Earth Hour occurs from 8:30 to 9:30 pm.

March 28: The moon passes 2 degrees north of Mars. Mercury passes 1.5 degrees north of Jupiter. First quarter moon is at 10:32 p.m.

March 31: Descartes was born in 1596.

Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.