Red planet redux

From top, Saturn, Mars and the star antares are seen in August 2016. - John mcphee

IT'S CAPTURED the imagination since the time of the Egyptians, who called the wandering "star" Har decher, the Red One. The Greeks and Romans, inspired by that distinctive bloody hue, named it after their gods of war.
As with most of the planets' names, the Romans had their way.

While Mars is perhaps the most intriguing planet, mostly thanks to  its prominence in fiction and movies, it's not usually an impressive object to the naked eye.

While its rusty orange colour is eye-catching, it's a small world and must be relatively close to the Earth to be bright enough to really stand out .At about 6,800 kilometres in diameter, the rocky planet is only half the size of Earth. So even during close approaches, you need a good-sized telescope to make out specific features.

Unlike Venus or the gas giants Jupiter and Saturn,  Mars doesn't have clouds in its atmosphere to reflect light back to observers on Earth.

But when it does get close enough, like right now, it's a a beautifully eerie sight in the late evening in the southeast.  Mars will makes its closest approach, about 57 million kilometres, on July 31. At its farthest point, Mars is about 400 million kilometres from Earth. 

 While it will be at its brightest since 2003, Mars won't get very high in the high during this apparition. It will rise into more favourable viewing during its next opposition on Oct. 6, 2020. 

Spring ahead to the vernal equinox

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THE SUN SETS OVER KEJIMKUJIK LAKE IN NOVA SCOTIA. THE SUN WILL CROSS THE CELESTIAL EQUATOR INTO THE NORTHERN HEMISPHERE ON MARCH 20 AT 1:30 A.M., MARKING THE BEGINNING OF SPRING. (JOHN MCPHEE)

While the bright constellations of winter depart the celestial stage, the star that gives us life will also make a noteworthy transition this month. 

The sun will cross the celestial equator from the southern hemisphere to the northern half on March 20 at 1:30 a.m. ADT - the vernal equinox. 

Of course, the sun isn't actually moving - we are. As the Earth zips around our home star, different parts of the planet get more or less sunlight at various points in that orbit.

That's because the Earth's spin is a little crooked - it's tilted 23.5 degrees compared to the plane of our orbit. 

From late March onward, we northerners get the benefit of the tilt, while the sunlight begins to fall more directly on the southern hemisphere in September. 

Earth isn't the only off-kilter planet in our system. On the extreme end is the cold gas giant Uranus, which rotates virtually sideways in space at 82 degrees, according to NASA's website on weather in the solar system. 

But another gas giant, Jupiter, is tilted only three degrees. And Jupiter's spin isn't only super straight, it's super fast.  The planet whirls around so quickly that its poles are slightly flattened.

Jupiter has moved into prime viewing position in the evening sky this month, after being part of the planetary party at dawn last month. It's high in the southeast by 10 p.m. in Nova Scotia in the constellation Leo.

Even a small telescope will reveal the faint cloud bands that wrap around this gas giant. You’ll also notice dots of light around the planet, which are Jupiter’s largest moons. 

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I took this (Not great) photo on Feb. 23, 2016, when all four of Jupiter's Galilean moons were visible.

You’ll often see all four of the “Galilean” moons Callisto, Io, Europa and Ganymede, which are named after the Italian astronomer who first saw them in his newly upgraded 20x telescope on Jan. 7, 1610.

Turning our gaze out beyond our solar system, we see the changing of the guard from the winter showpieces of Orion, Canis Major and Taurus to the more subtle spring constellations.

Leo the Lion leads the charge in the east ‐ this rather faint constellation is easier to locate than usual. As noted above, this month it encompasses the planet Jupiter, the third brightest object in the night sky after the moon and Venus.   Above Jupiter is the brightest star in Leo, the blue‐white Regulus, which marks the bottom of the constellation's trademark reverse question‐mark.

The much brighter Arcturus marks the otherwise dim constellation Bootes (buh‐OH‐teez) to the east of Leo. When you see this striking rusty star rise in the evening, you know winter's days are numbered. 

King of the planets rising

There’s lots to admire about the planet Jupiter, which rises in the evening in late January into February.

It’s the largest body in the solar system, besides the sun of course. About 1,321 Earths could fit within its sphere.

A celestial body this size creates huge gravitational field in space. Its effects reach all the way to our planet from 778 million kilometres away, which can be a good thing. Asteroids and comets headed for the Earth can be deflected out of harm’s way.

On the other hand, this immense gravitational slingshot can fling objects toward us. It all depends from what part of the solar system the comet or asteroid originates. 

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Mars at top left, Jupiter below with nicely arrayed line of moons (bottom up) Callisto, Ganymede, Europe and Io. The star to the far left is HIP54057. I shot this in 2015 through my old Meade refractor. (JOHN MCPHEE)

Besides the grandeur of the planet itself, Jupiter’s array of moons is unparalleled in our system. At last count, 67 bodies were known to orbit the planet.

The four largest  - Callisto, Io, Europa and Ganymede - are known as the Galilean moons, after the Italian astronomer who first documented them using his rudimentary telescope.

Over 400 years later, they remain a favourite target of astronomical observers. In typical backyard telescopes and good quality binoculars, they appear as specks of light lined up on one or both sides of the planet. Sometimes  the moons and/or their shadows can be seen slowly crossing Jupiter's disc, known as transits.  You’ll need a telescope that has a lens or mirror at least 90 millimetres in diameter to observe these events. 

Usually only one moon or one shadow can be seen at a time but occasionally two are visible. Much rarer, usually only once or twice a decade, is a triple transit. Check out Sky and Telescope's calendar of Jovian moon events here. 

Jupiter is the only planet that's prominent in the evening this month. But early birds can catch the sight of all five naked eye planets. From east to west, Mercury, Venus, Saturn, Mars and Jupiter will span the sky at dawn. Mercury will be the toughest to spot low in the east because it's relatively dim and closest to the sun. But this plenitude of planets hasn't happened for a decade so get up early and enjoy the show. 

Springing into the night sky

I'm dreaming of the mountains, where the children learn the stars.

Rexroth's Daughter, Greg Brown

The planet mars - at left - rises with the Milky Way in PEI. - John McPhee

IN THIS light-polluted, screen-obsessed time, learning the stars probably doesn't rank high on many to-do lists. That's too bad. It's really not that difficult to develop at least a passing acquaintance with the universe around us.

And it's free, at least before you get hooked enough to start buying equipment. Once you get a feel for the patterns and motions of the stars, you get a new appreciation for how our planet fits into the scheme of things.

There's a lot of talk about reality this and reality that, these days. Well, turn off the TV, step outside on a clear night and there's a beautiful reality for you. It's home. We're hitching a ride on a hunk of rock circling a huge nuclear furnace, our sun, which is a pretty ordinary star among the 400 billion or so that make up our Milky Way galaxy alone.

This is a good time of year for getting to know our cosmic neighbourhood - at some point, surely, we'll enjoy real spring temperatures, before the invasion of the insect world has yet to begin.

Celestial guidebooks

Before you venture out under the stars, make sure you spend some time indoors with some good guidebooks. I have sung the praises of Nightwatch (Firefly Books) before in this space, and I may as well repeat the chorus. Canadian astronomer Terence Dickinson offers an appealing, informative source of information for the beginning and intermediate stargazer.

A couple of other Firefly publications may help as well. These are lower-cost alternatives to larger format tomes such as Nightwatch. Practical astronomy: A Beginner's Guide to the Night Sky, by Storm Dunlop, covers the whole gamut of amateur astronomy, while the title of the Moon Observer's Guide, by Peter Grego, explains its purpose.

Both publications have their good points, which I'll get to, but let's get the quibbles over with first. With any guidebook, I want to know the background and expertise of the author. Strangely, the books offer no information at all about Dunlop or Grego. Both are based in Britain, and a Google search revealed they are prolific writers and members of the astronomical community.

Dunlop's book calls itself a beginner's guide but doesn't pitch itself to the younger reader, and that's probably a smart move.

Only young adults and older readers who have a serious interest in the hobby would likely get through this book: Dunlop offers a lot of information here.

But it's almost too much of a good thing. This compact volume is stuffed with graphics, sidebars and illustrations. There are no obvious divisions of content, so everything tends to run together.

But if you are intent on absorbing as much as possible about this hobby, this is a reasonably priced, valuable volume. I particularly like Practical Astronomy's mini-tables of contents that direct the reader to pages within a section that refer to more specific observing topics.

I'm also impressed with the Moon Observer's Guide. Like many such volumes, it's organized by lunar days - that is, the first day after new moon, Day 2 and so on. Each section includes a map of that particular slice of moon, accompanied by descriptions of the craters, "seas" and other lunar sights to be seen during that phase.

Grego also gives tips on instruments best suited for observing the moon, as well as pointers on photography, videography and drawing your observations. The final chapters offer a glossary of terms and information on eclipses and exploration programs such as Apollo.

Star trails are seen in this stack of long exposures of the Milky Way. - John McPhee

Under the dome

If you've yet to delve into the bookstore, buy a magazine such as the Canadian publication Sky News or Sky and Telescope from the United States. These magazines have simple star charts so you can begin orienting yourself under the celestial bowl.

Hold the star chart at about chest level and face south. Turn the chart so that south is at bottom - this way the chart accurately reflects the orientation of the stars when you look up.

As I've mentioned before, star charts can be tricky and take a bit of mental gymnastics. For example, the southern horizon as represented on our chart may look like it should be behind you, when that direction is oriented at bottom. But remember that's the direction you're facing - the sky is like an inverted bowl, so the usual terrestrial map orientations don't work.

So give it a try on the next clear night. Look south. If you have a clear view of the horizon, you will see the star Spica (SPIKE-uh). As your chart should indicate, this star is in the faint constellation Virgo. Spica stands out, because it's one of our brightest stars and it's located in a sparse section of sky.

Look higher in the sky and to the left for another bright star, Arcturus (arc-TOUR-us), in the kite-shaped constellation Bootes (buh-OH-teez), the Herdsman. 

The most recent maps also should include the planets, at least the ones visible at about 10 p.m. You'll have plenty of opportunity to spot a planet this summer.

Let's start with the ringed jewel of the solar system, Saturn, which will put on a great show this summer as it climbs higher in the sky.  Go back to Spica in the south.  Look below it and to the left for Saturn, a pale yellowish orb that is slightly brighter than the blue Spica. 

Turn your gaze above and slightly right of Spica to find a closer solar system neighbour, Mars. The Red Planet, which has more of a subdued rusty hue to the naked eye, is making one of its closer approaches to Earth. 

Now turn around and face the west. You’ll find Jupiter, the largest planet, closing out its winter apparition in the west. Later this month in the west after sunset, tiny Mercury (it's only slightly larger than our moon) will put on a good show.  This sun-hugging planet is always relatively low in the west at dusk or in the east at dawn. But this time around it will climb high enough for a good view, particularly on May 30-31 when a very thin crescent moon will appear to the left of this little rocky world. 

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. ​