Night sky by a forest

Eyes on the skies — November

Welcome to the Ontario Parks “Eyes on the Skies” series. This 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.

November usually brings our first snows and the opportunity for some great outdoor adventures.

The early sunset and later sunrise provides us with almost 15 hours of darkness in which to observe nighttime splendors.

Here are our astronomical highlights for November 2019:

The sun

The sun continues its southerly drop in altitude throughout November. This makes for a later sunrise and earlier sunset.

Don’t forget to fall back to Eastern Standard Time (from Eastern Daylight Time) on the morning of November 3!

French River sunset

Here are the sunrise and sunset times for November:

November 1 November 15 November 30
Sunrise 8:05 am 7:25 am 7:45 am
Midday 1:10 pm 12:10 pm 12:14 pm
Sunset 6:14 pm 4:56 pm 4:43 pm

The moon

The moon has long captivated observers of all ages. Even a pair of small binoculars will reveal the craters of the moon.

November’s lunar phases of the moon occur as follows:

  • Waxing cresent on November 1
  • First quarter on November 5
  • Waxing gibbous on November 9
  • Full moon on November 12
  • Waning gibbous on November 15
  • Last quarter on November 19
  • Waning cresent on November 22
  • New moon on November 26

The planets

The planets Jupiter and Saturn are now becoming fairly low in the southwest sky at sunset, but are still quite noticeable. Venus, the brightest of all the planets (as seen from Earth), is now starting to become visible just after sunset.

By month’s end, Venus will be better placed than Jupiter, which means that both are somewhat difficult to see low in the southwest just after sunset.

The most exciting and relatively rare planet viewing this month is of the planet Mercury, crossing the face of the sun! On November 11, Mercury will pass directly between us and the sun, and will “transit” across the sun’s disk. People who are properly equipped will enjoy the sight of Mercury, which will appear as a small dot slowly crossing the sun.

Photo of Mercury in front of the Sun.
Goddard Space Flight. Photo: NASA

Warning: observing the sun without proper protection can damage your eyesight. Please consult with knowledgeable authorities before looking at this magnificent sight.

Places to either see the transit or to learn more are: the Royal Astronomical Society of Canada, Ontario Science Centre, Science North and the Canada Science and Technology Museum

Observing transits was of great interest historically, as they helped determine the distances of the planets. Back in the early 16th century, the astronomer Nicolaus Copernicus (Mikolaz Kopernik in Polish) had mathematically calculated the distances to the planets in terms of Earth’s distance to the sun (known as an Astronomical Unit or 1 AU) using simple trigonometry and the periods of the planet’s orbits (he had already assumed all the planets circled the sun and not the earth).

The problem that remained was to determine the actual distance of Earth to the sun in miles or kilometres. Once that was accomplished, we would know the distances to the other planets. Scientists, always being fascinated with how to solve seemingly unsolvable problems, came up with a possible solution.

The planets Venus and Mercury sometimes transit the sun. If two observers, stationed at opposite sides of the earth, were to observe the transit and note the difference in the times in which the planet first “touched” the side of the sun, they could actually calculate the distance to the sun from trigonometry. Since the observers knew their distances apart (the diameter of the earth had been calculated by Eratosthenes over 2,000 years ago), they could solve, mathematically, for the the distance to the sun.

Today, the study of transits helps us tune our ability at discovering exoplanets, planets orbiting other stars. Some of the latest technology used in exoplanet research is based on models that have been built up over the years by looking at the transits of Mercury and Venus.

For example, we know that some of the exoplanets we have discovered cause a small drop in brightness of their host stars when they transit. In addition, it is predicted that planets that have a thick atmosphere don’t just appear/disappear but have a more gradual appearance/disappearance due to their atmospheres playing optical tricks with the light of their host stars.

The more we discover and learn about our own natural environment close to home, the more we can predict and study about those things that are too far away to observe directly.

November meteor showers

The annual Leonid meteor shower will peak on the morning of November 18. Unfortunately, as the moon is nearly full, its light will block out all but the brightest meteors.

Meteor shower from space.
Leonids as viewed from Space. Photo: NASA

For a detailed explanation of meteor showers, check out this link.

Featured constellations: the epic of Andromeda and Perseus

In this month’s edition, we trace an ancient Greek myth across six constellations.

Find this story of heroes, princesses and sea monsters here.

Diagram of constellations

This completes our review of the November skies…

Check back next month to learn more about the winter solstice, the Geminid meteor shower, and Monoceros the Unicorn.