hiker looks at starry winter sky

Eyes on the skies – March

Welcome to the Ontario Parks “Eyes on the Skies” series. This space (see what we did there?) will cover a wide range of astronomy topics with a focus on what can be seen from the pristine skies found in our provincial parks.

March is one of the most glorious months to be camping, or even just spend time outdoors enjoying our parks.

On March 20, the earth passes through Spring Equinox. This is the day that formally marks the beginning of spring, and affords equal hours of sunlight and darkness.

Here are our astronomical highlights for March:

The sun

Sunrise

The sun reaches the Spring Equinox on March 20. Equinox can mean “equal” and “night”. Therefore this is a time when we have equal amounts of day and night.

The earth’s many motions combine wonderfully to provide us with fascinating observations. We rotate along our axis, of which north is currently pointed towards Polaris, the North Star. We orbit around the sun in 365 and ¼ days, and the sun orbits around the center of our galaxy in just under 250 million years.

For the purposes of discussing the position of the sun in March and the Spring Equinox, let’s just focus on two of these motions: the rotation and orbit of the earth.

Diagram showing seasonal rotation of earth around sun

The diagram above shows the earth’s motion around the sun, as well as its rotation around its axis. Even though the earth moves continuously around the sun, the direction the axis points does not change, at least not over the course of a few years.

For observers in the northern hemisphere, we see the axis of the earth pointed towards Polaris the North Star. Light from the sun (represented by the orange arrows in the diagram above) hits the earth, and results in warming the whole planet. There is more focused heating in the area directly under the sun’s rays.

During the summer, because the northern hemisphere is pointed towards the sun at noon, there is more daylight hours and more direct heat for those in the north. In the winter, the situation is reversed, as the sun’s direct light is more focused on the southern hemisphere at noon, leaving the north with less light and less heat.

During the spring and fall equinoxes, the earth is positioned such that the sun’s direct light is over the equator, right in between the northern and southern hemispheres. During this time, we have equal amount of light and darkness, and moderate temperatures. The equinoxes are important markers of seasonal change.

Here are our sunset and sunrise times for March:

March 1 March 15 March 31
Sunrise 7:03 7:39 EDT* 7:08 EDT*
Midday 12:38 13:35 EDT* 13:30 EDT*
Sunset 18:13 19:31 EDT* 19:53 EDT*

*We begin daylight savings time on the morning of Sunday, March 10.

The moon

The moon and a star

The phases of the moon for March occur on almost the exact same dates as they did in February because the duration of February is about the same length as the time it takes for the moon to orbit the earth.

March’s Lunar Phases are as follows:

Many people have commented on shapes they see on the face of the moon. One of the clearer figures is that of a lady in the moon. An astronomy presenter was showing the lady in the moon to an audience, and a younger participant commented that she looked an awful lot like Wilma Flintstone.

Once you see Wilma, you will never forget her again:

the shape of a woman's face in the moon

The planets

The planets present little change from last month. Mars is still up in the western sky at sunset and the planets  Jupiter, Saturn and Venus all rise (in that order) in the early hours before sunrise.

Mercury, the closest planet to the sun and, therefore, never far away from the sun’s light, is actually relatively high on March 1, but difficult to see low in the western sky just after sunset.

March constellations

Constellation diagram

In last month’s blog, we discussed Gemini the Twins, as well as two other prominent constellations seen in the winter.

This month’s post will focus on three constellations that mark the transition from winter to spring: Leo the Lion, Cancer the Crab, and Coma Berenices.

March’s night sky phenomena

The importance of having dark sky preserves cannot be understated.

In addition to the many benefits already described previously in our blog, you can see many things that others can’t from the light-polluted skies of our urban and, increasingly, our rural locations.

Gegenschein
Photo: ESO/Y. Beletsky – ESO CC BY 4.0

The zodiacal light and the gegenschein are two phenomena known for centuries, but only visible in dark skies with a good western or eastern horizon.

This completes our review of March skies

Remember to bundle up and enjoy the view from our parks. The stars await those who make the effort to enjoy them!