Old Moon below Mercury (Chris Vaughan, Starry Night Education)

This Week’s Sky: March 8 to 14, 2021

Mercury, Jupiter and Saturn crowd the pre-dawn sky for chances to meet with the old Moon this week.

Tuesday, March 9 – Old Moon meets Saturn (pre-dawn)

Old Moon meets Saturn (pre-dawn) (Chris Vaughan, Starry Night Education)

In the southeastern pre-dawn sky on Tuesday, March 9, the old crescent Moon will begin a trip past the bright planets gathered there. When the Moon rises it will be positioned less than a fist’s diameter to the right (or eight degrees to the celestial southwest) of magnitude 0.7 Saturn. By the time the sky begins to brighten at about 6 a.m., much brighter Jupiter, and then fainter Mercury, will have risen — forming a line to the lower left (east) of Saturn, and making a lovely photo opportunity when composed with some interesting landscape.

Wednesday, March 10 – Crescent Moon near Saturn and Jupiter (pre-dawn)

Crescent Moon near Saturn and Jupiter (Chris Vaughan, Starry Night Education)

The Moon’s visit with the bright morning planets will continue on Wednesday, March 10, when the slim crescent Moon will shift east to sit below and between bright, magnitude -2.0 Jupiter and fainter Saturn. Because the Moon will be riding 5 degrees south of the ecliptic, it will rise after Mercury joins the planet party. The scene will make another terrific photo opportunity (sorry Canada, but it’s especially so for observers viewing from more southerly latitudes, where the Sun will be farther below the horizon and the Moon will be higher).

Thursday, March 11 – Old Moon below Mercury (pre-dawn)

Old Moon below Mercury (Chris Vaughan, Starry Night Education)

Observers viewing from southern latitudes will be able to see the old crescent Moon complete its passage of the pre-dawn bright planets on Thursday, March 11. After the Moon rises over the east-southeastern horizon, it will shine a palm’s width below (or 6 degrees to the celestial southeast) of magnitude 0.0 Mercury – with much brighter Jupiter and slightly fainter Saturn forming a row to Mercury’s upper right (west).

Saturday, March 13 – New Moon (at 10:21 GMT)

At 5:21 a.m. EST, or 10:21 GMT, on Saturday, March 13, the Moon will officially reach its new Moon phase. While new, the Moon is travelling between Earth and the Sun. Since sunlight can only reach the far side of the Moon, and the Moon is in the same region of the sky as the Sun, the Moon becomes completely hidden from view for about a day. After the new Moon phase Earth’s celestial night-light will return to shine in the western evening sky. 

Sunday, March 14 – Daylight Saving Time begins (at 2 a.m.)

Daylight Saving Time begins (Chris Vaughan, Starry Night Education)

For jurisdictions that employ Daylight Saving Time (DST), clocks should be set forward by one hour at 2 a.m. local time on Sunday, March 14. For stargazers, the time change, plus the fact that sunset occurs one minute later each day near the March equinox, will mean that dark-sky observing cannot commence until much later in the evening — possibly after the bedtime of junior astronomers. The difference from local time to Greenwich Mean Time (GMT), or the astronomers’ Universal Time (UT), will be reduced by one hour when DST is in effect. Daylight Saving Time will end on November 7, 2021.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through to tour the universe together.