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 7:04 7:38 EDT 7:07 EDT
Midday 12:38 13:34 EDT 13:30 EDT
Sunset 18:12 19:32 EDT 19:53 EDT

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.

While February had no full moon, both January and March enjoy two full moons. The second full moon is known as the “Blue Moon”. The term has nothing to do with the colour of the moon, but is used to refer to the 4th full moon in a 3-month season, or the 2nd full moon in any given month.

March’s Lunar Phases are as follows:

March lunar phases

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

Planet diagram
Photo: SkySafari 6 Pro.

Jupiter, Mars, and Saturn continue to rise earlier and earlier in the morning sky. Jupiter is now rising just before midnight, and is well up at sunrise by month’s end. On the morning of March 8, the Moon will join the three planets, forming a nearly evenly spaced line.

Venus, named for the Roman goddess of beauty, is one of the most beautiful objects that can be seen without a telescope in the night sky. It sometimes appears in the evening sky, and sometimes in the morning sky. Interestingly, many ancient cultures did not connect these two appearances as being the same object, and referred to them as morning star and evening star.

venus-phasingThis photo shows Venus as seen through a telescope at the Killarney Provincial Park Observatory. No detail can be seen because Venus is completely shrouded in clouds. This photo illustrates how Venus goes through phases as it orbits the sun. Galileo first discovered this in the early 1600s using his very primitive optic tube.

Venus is remarkably similar to Earth in many ways: it comes closer to the earth then any other planet, it is about the same size as the earth, and it is a rocky world that has a thick atmosphere.

However, Venus’ thick atmosphere is made of over 90% carbon dioxide (CO2). This well-known greenhouse gas permits light from the sun to reach the surface of Venus and warm it up. But very little of the warmth is able to escape back out into space because the CO2 traps it, like panes of glass preserve heat in a greenhouse. As a result, Venus, not Mercury, is the hottest planet in our solar system, with average temperatures around 460 degrees Celsius.

In fact, it was the discovery of this “greenhouse effect” on Venus by Carl Sagan that first alerted the scientific community to the potential dangers of climate change on our own planet.

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.

Click here to read more.

Meteor showers

There are no major meteor showers this month. However, there are always sporadic meteors to be see. Sporadic meteors are meteors that do not seem to have an identified common location in the sky.

Did you know…

…the Northern Lights are caused by charged particles from the sun?

Aurora Borealis at Greenwater PP

The spring and fall equinoxes tend to be good times to view the Northern Lights, also known as the Arsaniit in Inuktitut.

This magical glow occurs when charged particles emanating from the sun along the solar wind interact with the earth’s magnetic field. When a large amount of charged particles are involved, the earth’s magnetic field can become so compressed on its sunward side that it is no longer capable of deflecting all the material away from our atmosphere. Instead, the material can collide into our atmosphere, charging up the molecules of air much like a neon sign.

For more on the Northern Lights, check out this post.

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!