Spring Skies: Martian Fever

Photo by Sky Xe, via Wikimedia Commons.

If you plan to go stargazing just once this spring, you should find the planet Mars. You cannot have missed how missions to Mars have been in the news recently, with three missions arriving at the planet in mid-February. The orbits of Mars and Earth line up every two years, creating a window of favorable conditions to send spacecrafts. During the last window which opened in July 2020, three separate spacecraft were launched: the “Hope” spacecraft from the United Arab Emirates (UAE), China’s Tianwen-1 spacecraft, and a mission from NASA which includes both a robotic rover “Perseverance” and a helicopter called “Ingenuity.” That’s right, a helicopter is (hopefully) going to fly on another planet, and this spring you can see Mars in the evening sky while it’s there.

To find Mars, look for a reddish orange point of light in the west after sunset; if you are on campus, stand on the far side of the Observatory with your back to the building. Over the course of the spring, Mars will pass in front of two of the most easily identifiable Zodiac constellations—Taurus and Gemini—which you might also enjoy finding. It will spend some time close to the beautiful star cluster known as the Pleiades (or the Seven Sisters), which you can use to do the traditional eye sight test (how many sisters can you see?);  finishing up the view will be the iconic Orion constellation to the left.

The included screenshot from Stellarium, a free planetarium software, shows the view at 9.00pm on Saturday April 17th, when the crescent Moon will be close on the sky to Mars, but any evening this semester will work just fine to see all of this.

A screenshot of the night skies above the Western horizon at 9.00pm on Saturday April 17th. Via Stellarium.org (free planetarium software). 

The spring can be a challenging time for stargazing, as it’s not yet warming up and the hours of darkness are shortening. Marking this change of the seasons is the Spring Equinox, when the hours of daylight equal those of nighttime all over the world. This year, the equinox will happen early in the morning of March 20th; the exact date varies around March 21st because of leap days and the slightly elliptical shape of the Earth’s orbit around the Sun. This changing length of daylight is why we change our clocks in the spring, moving them forward one hour on a Sunday (this year Sunday March 14th). The downside is having to get up an hour earlier to make our classes on time, but the benefit (unless you want to see the stars) is extended daylight hours in the evenings. 

However, the spring also reminds us of the many different cultural connections to astronomy, particularly the Moon. The Lunar New Year is always celebrated on a New Moon in January or February; this year it was February 12th. Later in the spring, the Christian festival of Easter is also set by the lunar cycle: the festival happens on the first Sunday following the first Full Moon after the Spring Equinox, falling this year on April 4th. For Muslims, the dates of Ramadan are also set by the Moon. Observance begins with the first crescent Moon sighting in the evening after the April 11th New Moon, and the end is marked by the crescent Moon sighting after the May 11th New Moon. If you want to see the Full Moon this semester, look out for it in the west in evenings around the end of the month (February 27th, March 28th, or April and May 26th). A personal favourite of mine is the “morning Moon,” the time around the first quarter phase when the crescent Moon is visible to the east in the morning. Try looking for this around February 19th, March 21st, April 20th or May 19th. 

Happy Stargazing, and keep looking up.

Spring 2021 Astronomy Calendar


9th: expected arrival to Mars of the UAE spacecraft “Hope”

10th: expected arrival to Mars of China’s Tianwen-1 spacecraft

11th: Conjunction of Venus and Jupiter (pre-dawn event) 

12th: New Moon and the Lunar New Year

15th: Galileo born 1664

18th: expected arrival to Mars of NASA’s “Ingenuity” helicopter

19th: Copernicus born 1473; First quarter Moon

19th: Mercury retrograde ends

27th: Full Moon


5th: Last quarter Moon

13th: New Moon

14th: Daylight savings starts (clocks “Spring forward” an hour)

20th: Spring Equinox (5.37am ET); Venus in the morning sky

21st: First quarter Moon

28th: Full Moon; 


4th: Last quarter Moon; Easter Sunday

11th New Moon

20th: First quarter Moon

22-23rd: Lyrids Meteor shower

26th: Full Moon


3rd: Last quarter Moon 

6-7th: Eta Aquarids Meteor Shower

11th: New Moon

19th: First quarter Moon

26th: Full Moon and Lunar Eclipse (5.45-8.43am ET)

This article was edited by Lydia Guertin and Nora Reidy.