A bittersweet evening under the stars

Dave Lane is seen at Burke-gaffney Observatory at Saint mary’s University in April 2022. It was his last day at SMU where he worked as system administrator in the astronomy and physics department for over 30 years. He died in march 2024. - photo by tiffany fields

A first-quarter Moon, slightly hazed by wildfire smoke from afar, hangs conveniently low in the sky over Portland Hills on this spring evening.

As usual when there’s a “good” Moon out there, I’m on the balcony with a telescope and camera. We have a nice view of the southern horizon, which comes in handy at this time of year when the summer constellations rise into view.

I do have to contend with the light pollution that increasingly blights our night sky. The plaza next door is a particular challenge as it comes equipped with an array of security lights that would fit right in on the East German border when the wall still existed. 

As a result, I’ve erected my own wall of artificial trees in the corner of the balcony. If I adjust my viewing chair appropriately, I can block most of the glare and enjoy the stars bright enough to penetrate the suburban sky glow. 

Much of astronomical observing has been limited to my “balcony sessions” in recent years as the result of ill health. So I’ve been doing a lot of lunar and planetary observing, although a newly purchased light pollution filter provides decent views of the bright deep sky objects such as the Lagoon and Orion nebulae. 

My go-to scope these evenings is also a new purchase, at least new to me. It’s the definition of a bittersweet experience. The sweet: The TeleVue Pronto is a lovely scope. The bitter: It belonged to Dave Lane. 

this pronto refractor telescope, which now stands celestial watch on my balcony, belonged to the late dave lane. - john mcphee

Dave, who died in March 2024, was a dedicated member of the Royal Astronomical Society of Canada.  Beginning in the 1980s, he served in many roles, including national and local president, despite a busy work schedule as system administrator in the astronomy and physics department at Saint Mary’s University. 

 He automated SMU’s Burke-Gaffney Observatory so it could be used remotely from around the world, and he created Earth Centered Universe, a planetarium and telescope-control program that allows institutes the ability to operate their own educational astronomy platforms. 

On top of all that and more (his resume would fill pages), Dave was instrumental in the design and construction of the Halifax Centre’s St. Croix Observatory, which opened for members’ use in 1997. 

Among several endowment and legacy funds in Dave’s memory, partly supported by an auction last year of his astronomical equipment, his wife Michelle has created the St.Croix Observatory Property Endowment (SCOPE) Fund. There are $10,000 worth of matching funds available thanks to Michelle and Tony Schellinck.

You can find details on how to support this project on the Halifax RASC website.

As I put Dave’s scope on the tripod, I try to put the bitter aside. He was only 60 when he died from an aggressive brain cancer. In a just universe, Dave would be still using this scope.

But as a scientist he’d likely agree with one of my favourite writers, Iain M. Banks, who also died too young of cancer. 

“The universe does not have our own best interests at heart, and to assume for a moment that it does, ever did or ever might is to make the most calamitous and hubristic of mistakes.”

I point the Pronto toward the first-quarter Moon. There’s an interesting terminator region to explore and the clear sky may not last that long.

Something's crooked about our home planet

The sun sets on the bay of Fundy in August 2024. - john mcphee

When we lived in the Annapolis Valley, I often dreaded the drive home from the Herald newsroom in Halifax this time of year.

People who regularly use Highway 101 know what I’m talking about. The open fields on both sides of the highway are perfect for creating whiteouts.

But winter driving has its challenges even on a clear day. 

The low-lying Sun is a constant irritation on an east-west highway like the 101. Driving west, it’s either directly in your eyes or slightly to the left, so you have to keep moving your visor around. Driving east, it's ideally positioned for optimum blinding potential between the rearview mirror and the passenger side visor. 

Darn you orbital motion and planetary axial tilt!

Tilted worlds

Most planets don’t spin completely upright in space. Their rotations were knocked askew in the early years of the solar system billions of years ago when planets, asteroids and other celestial bodies regularly whacked into one another. 

The only exception is Mercury, the closest planet to the Sun. Mercury’s rotation is almost perfectly upright, only two degrees off the perpendicular, likely due to its proximity to the Sun’s huge tidal effect. 

At the other extreme are planets such as Uranus, which has an axial tilt of about 98 degrees, creating an almost sideways rotation. 

If Earth wasn’t tilted, there would be about 12 hours of sunlight everywhere all year long. Here in Nova Scotia, the temperature would hover around 7 C, give or take a couple of degrees. So yay, no short winter days or icy sidewalks! But boo, no forests! The lack of seasonal temperature spikes would create a tundra environment in the 40 to 50 latitude zones, British meteorologist Robin Smith postulates.

But odds are there wouldn’t be any people around to bemoan the lack of trees anyway. The climate on a non-tilted Earth would have limited human development to scattered settlements, according to Don Attwood, an ecological anthropologist at McGill University.

While Earth’s tilt of 23.4 degrees is comparatively minor, it’s enough to create seasonal changes throughout the year. Beginning in the fall, Earth's northern hemisphere begins to turn away from the Sun. As a result, the Sun gradually appears lower in the sky and terrestrial temperatures take a hit from the more indirect sunlight.

When the Sun’s path hits bottom, sometime between Dec. 20 and Dec. 23, we've reached the winter solstice. Ironically this occurs at the point in Earth's orbit when we're closest to the Sun (known as the perihelion). 

Latin for “standing still of the Sun,” solstice refers to the point where the Sun reaches its most northerly (summer) or southerly (winter) point relative to the celestial equator. As a result, in summer the Sun rises in the northeast in Nova Scotia and in the southeast in winter. 

In 2024, the winter solstice will occur Dec. 21 at 09:20 Universal Time (5:20 a.m. Atlantic). Since the Sun is at its lowest angle, this will be the shortest day of the year at only eight hours, 48 minutes and 35 seconds, according to timeanddate.com. 

Compare that to the summer solstice when the Sun is in the sky between 15 and 16 hours. And - yippee - it’s also way higher in the sky and out of our eyes on those long drives west.

A meteor streaks through the orion/taurus region in may 2023. The green dot above the meteor is the comet 46p/Wirtanen.- john mcphee

Solstice stars

The winter solstice has been marked by festivals and other celebrations since ancient times across the world. As usual, the Caribbean folks have the coolest sounding name for their event. During Junkanoo, people dress up in flamboyant costumes and hit the streets.

After your solstice party, be sure to check out the gems of the winter sky that decorate the southeast at this frigid time of year. This region is packed with stellar show-offs — the red, blue and yellow giants that make up the winter constellations of Auriga, Taurus and Orion.

There’s no constellation like Orion for bright stars and sheer presence.The Hunter dominates the eastern horizon in December and January. You’ll likely first notice its “belt” of three stars (from left Alnitak, Alnilam and Mintaka) or the bright blue supergiant Rigel to the lower right. 

Above the Hunter is its quarry, Taurus the Bull. Its most luminous star, Aldebaran, is the only member of this constellation that really stands out. This red giant shines about 360 times brighter than the Sun.

That’s dim compared to the luminosity of other giant and supergiant stars, but Aldebaran is relatively close at 67 light-years.

Aldebaran appears to be a part of an arrow-shaped cluster called the Hyades. But that’s an optical illusion caused by our perspective on Earth. The rest of the Hyades group lies on the same line of sight as Aldebaran but they’re about twice as far away.

Escaping the light

THERE'S no doubt, the farther you are from the city lights, the better your stargazing will be. Light pollution robs us of the subtle beauties to be found in the night sky, whether it's the ribbon of stars and glowing gases of the Milky Way or the faint constellations of spring.

For instance, if you're in the city, you'd be hard-pressed to pick out groups like Virgo, low in the east, or Hydra's sprawling ladder of stars that now stretches from the southeast to the high southwest.

There are plenty of places in my province, Nova Scotia, where you can find dark skies. In fact, some of them rank among the best in Canada. But there's good news for urban observers: light pollution doesn't affect planet observation. The sun does a great job of lighting up these objects for our enjoyment and even small details in planets' atmospheres and surfaces make it through the glare.

Of course, sometimes nearby lights that shine directly into your eyes can make even planet watching difficult. In that case, you have to do some creative positioning to use trees or structures to block these offending photons.

even distinctive constellations like ursa major can be hard to find in light-polluted skies. In dark sky preserves like kejimkujik national park, it’s a cinch to scoop up the big dipper. - john mcphee

I usually drape an old blanket over deck rails or a high deck chair and sit on a lower chair in my attempts to shut out neighbours' porch lights or street illumination.

The most interesting planets to observe in a telescope, I think most observers would agree, would be Saturn and Jupiter.

While you need a telescope to enjoy Saturn's rings and surface features, a good pair of binoculars are enough to keep you coming back to Jupiter night after night. That's because its four brightest moons - Ganymede, Io, Callisto and Europa - are easily visible with just 10x power, although as tiny specks. You can detect changes in their positions over a matter of hours as they orbit around Jupiter.

This moon dance is obvious when you take another look on the following night - the lineup will likely be quite different.

If you're more ambitious and have your eye on objects a lot farther down the cosmic road than our solar system, such as galaxies, you must flee the light and seek out a nice dark spot in the country.

In Nova Scotia, it doesn't take too much of a drive to escape light blight,  even if you live in Halifax or Sydney. But you should get at least an hour's drive away from the city, since it doesn't take much sky glow to wash away detail in deep-sky objects.

Some of the province's dark sky areas are described on cleardarksky.com, a website that mainly focuses on weather and sky conditions for amateur astronomers. I say some because the website gets its light pollution information from the World Atlas of Artificial Night Sky Brightness, which oddly enough doesn't include Cape Breton and other parts of the province.

However, cleardarksky does indicate that areas such as Kejimkujik Natinoal Park in Queens County and the Argyle area near Yarmouth are little affected by light pollution. The Milky Way, the central region of our galaxy best visible in the summer, is so bright in these areas that it can cast shadows.

find a dark sky and point a telescope toward the coma berenices region of the night sky. You’ll find dozens of smudges of light, which are galaxies that contain billions of stars. - john mcphee

If you look at the entire light pollution map of North America, it's clear that this kind of observing is to be treasured.

While the Liscombe Game Sanctuary area on the Eastern Shore is one of those areas left out of the light pollution grading, it's well known among local amateur astronomers as an excellent dark-sky site.

As for Cape Breton, the skies over the East Bay and Bras d'Or area first tweaked my interest in stargazing, way back when. I can remember being more interested in the satellites and airplanes zooming across the sky, but I was also captivated by the glittering blanket of stars over the island hills. 

If you do find yourself a dark, safe place, and you have even a small telescope, you can observe many galaxies in April and May. Hundreds of galaxies are visible with a larger telescope in the Leo-Virgo region.

Two of the brightest in April, M65 and M66, can be found in the isosceles group that makes up the Lion's hindquarters. Find the star at the right bottom corner of the triangle, and look slightly below and to the left for M65 and M66. These two are so close together that they both fit into the viewing field of a small telescope.

It's worth escaping the city lights to marvel at these star cities so many light-years away. ​