What you will see on a clear night in
Constellations: The Big Dipper (part of the Great Bear), Bootes, Perseus, Cassiopeia, Scorpius and Saggitarius.
Double Stars: Alcor & Mizar
Shower, August 12.
Warm summer evenings will make it ideal to view the Big Dipper, Saturn, the Moon, meteors, the Summer Triangle and other star groups.
Have you ever seen a meteor shower? If you're on vacation August 12 at a cottage or a camp, look up and you'll be treated to a rare celestial event: the PERSEID METEOR SHOWER. Or, if you’re home those two nights, have your parents drive you a few kilometres into the country—away from city lights—to see the special nighttime event.
The best way to observe the meteors
is from a lounge chair as binoculars or a telescope is not required.
will likely originate in the northeast, in the area of the
constellations PERSEUS (the Hero) and CASSIOPEIA (the
Some observers refer to a meteor shower as "shooting stars." In fact, the shooting stars are not stars at all, but comet debris (dust and sand) that burns up in the Earth's atmosphere. A handful of meteors can usually be seen any summer night, as long as you are clear from light pollution.
The seven-star BIG DIPPER--the most well-known star configuration--is a circumpolar grouping, meaning we see it year-round because it is close to the North Star. The Dipper is part of the constellation Big Bear.
Locate the Dipper's bowl. If you draw an imaginary line beyond the two end stars of the bowl, you will find the NORTH STAR. Many people believe the North Star is the brightest star in the night sky. Not true; it's actually quite dim. However, it is in the same spot every night because it is above the Earth's axis.
The North Star is the lead star of the seven-star LITTLE DIPPER, which pours into the bowl of the Big Dipper. But you have to be at a very dark site, like a farm or a cottage far away from city lights, to be able to make out the Little Dipper (see Vacation Sightings). There is something unique about one of the seven stars of the Big Dipper. Look carefully at the second star from the end of the Dipper's handle and you'll see a double star, ALCOR & MIZAR. The star duo is more definitive with binoculars or a telescope.
You can use the Big Dipper to find ARCTURUS, the brightest star in the summer. If you draw another imaginary line, this one in the shape of an arc beyond the handle of the Big Dipper's handle, you will locate Arcturus. That's why some astronomers say, "Let's arc to Arcturus." Continue your imaginary line beyond Arcturus and you will spot another star, Spica. Thus the expression, "Speed on to Spica."
In early July, JUPITER appeared high in the south as a large “star” –even brighter than the star Arcturus. By the end of July it will have dropped to the southwest. If trees, homes or buildings are obstructing your southwest view, ask your parents to drive you to Wilmot Line, a road that branches off Erb St., just past the Waterloo landfill. A good place to park on Wilmot Line is on a hill 2.2 km from Erb St., near a 60 km/h road sign.
Even though Jupiter looks like a star, it has a diameter 11 times than of Earth--the giant of the solar system. It takes 12 years to orbit the Sun--about the same time you've been on the Earth! The fifth planet from the Sun is a huge gas ball of helium and hydrogen so big that its volume would contain 1,300 Earths.
Note: The Jupiter video shown here includes its four largest moons, called Galilean moons. Look closely and you will see the moons actually move around the planet! Even though they look like tiny stars through a good quality telescope, most of them are larger than our Moon.
Just as the constellation Orion took centre stage in winter, the SUMMER TRIANGLE takes the spotlight this summer. Even though this bright triangle is technically not a constellation, its three stars become easier to spot overhead as the summer progresses.
Leading the western march is VEGA, the brightest of the
three stars. The remaining two stars comprise DENEB in the north and
ALTAIR in the south.
The three stars are in three constellations: Vega is in LYRA (the Lyre), Altair is in AQUILA (the Eagle) and Deneb is in CYGNUS (the Swan). Unfortunately, because of light pollution, we can't make out the rest of these constellations from our backyards.
The star Deneb serves as the swan's tail while the star ALBIREO at the far end is the swan's head. Albireo is inside the Summer Triangle. The swan's wings are at right angles to the body.
Cygnus is also known as the NORTHERN CROSS due to its shape. The swan's wings double as the arms of the cross while the swan's body doubles as the cross's shaft.
Albireo at the south end of the swan (or the cross) within the Summer Triangle is a double star. You will need binoculars or a telescope to pick out two stars of different colours; one is blue (hotter than the Sun) and the other is orange (similar to the Sun, although somewhat cooler).
Amateur astronomers use a special trick with their telescope to accentuate the colour of a star; they adjust their focus knob so that the goes out of focus. Vega is a prime example; by putting it out of focus, you will see that it is a bluish-white star.
Star groups such as the Summer Triangle and constellations like ORION THE HUNTER--which are far from the NORTH STAR-- rise above the eastern horizon and then disappear below the western horizon during a portion of the year.
During July and August, you will see the Summer Triangle move from the eastern sector of the sky to the western sector. Most constellations relocate from east to west as the Earth rotates around the Sun. Star groups (such as the Summer Triangle) and constellations such as ORION, which are well below the NORTH STAR, rise above the eastern horizon and then disappear below the western horizon during a portion of the year. Orion will return next winter at which time The Summer Triangle will disappear.
Some astronomers say the most rewarding object in the
night sky is the MOON. Between July 9-30 and August 7-to-29, the
Moon will display it's early evening phases:
- July 9 and Aug. 7: full Moon
- July 27 and Aug. 26: crescent Moon
- July 30 and Aug. 29: first quarter Moon
This photo shows the Moon between crescent and first quarter.
Craters and "seas" (the grey areas of the Moon) can be
easily picked out with binoculars or a low power telescope. The secret
to viewing the night sky with binoculars is to keep them as steady as
possible: either mount them on a tripod or sit back in a lawn chair
that has a tilted back.
Where to look for the Moon? The crescent phase will
appear in the west, the quarter phase in the south and the full Moon in
Did you know that the Moon's craters are the result of
our closest celestial object being pummelled and battered by giant
space rocks or asteroids? If the Moon had an atmosphere, the craters
would have long eroded away from wind and water erosion like what
happened here on Earth. But because there is no atmosphere on the Moon,
the craters have not changed ever since they were formed.
The Moon's craters and mountains are most dramatic if you
look near the terminator, the line that separates the dark side from
the sunlit side. That's because the shadows created by the Sun are the
longest. If you look through a telescope, you can even spot crater
walls disappearing into the shadows.
Have you ever been to a cottage or a camp in the summer
and gazed at a band of stars that snakes across the sky? That is the
MILKY WAY-- our home galaxy. You were seeing the galaxy edge-on,
similar to looking edge-on at a dinner plate.
Since it is impossible to view the Milky Way in such a
dramatic way in the city because of light pollution, make sure you have
a look at it while you are on vacation with your family. (Technically
speaking, the handfuls of stars you see year-round in your backyard are
part of the Milky Way, but they pale in comparison to what you'll see
at the cottage or camp).
The best way to scan the Milky Way is to lie on the
grass, the beach or the boat dock and look straight up. With your naked
eye you will see thousands of stars; using binoculars, you can view
thousands more. Note how the Milky Way cuts right across the Summer
Triangle. To the north the Milky Way passes through the W-shaped
constellation CASSIOPEIA (the Queen). As you count the seven stars of
the Big Dipper, see if you can locate all seven stars of the Little
Dipper as it pours into the big one.
Professional astronomers estimate that our galaxy
consists of more than 200 billion stars. Some of you may ask, "If there
are that many stars in the Milky Way - and each star is a sun--how come
we're not blinded by the bright light of so many suns?" That's because
99% of the light is hidden by dust and gas in the Milky Way.
All astronomy books contain overhead illustrations of the
Milky Way, showing it as a spiral galaxy. Granted, it's impossible to
make out the galaxy's 200 billion stars. But here's an easy way to
grasp that number: if you represent just one star with a single grain
of sand, then a heaping wheelbarrow of sand would represent 200 billion
If you have your star finder that you got in class, you
will see that the largest portion of the Milky Way appears at
the southern horizon in summer. If you rotate the planisphere all the
way around, the galaxy will change position in the sky. That's because
we see the Milky Way in different parts of the sky as the Earth travels
around the Sun.
The star Arcturus is the main star in the constellation
Bootes. From your backyard this star is big, but all by itself. From
the cottage, however, the five remaining stars of Bootes pop out.
If you can find a hill that overlooks the southern horizon, you'll be able to spot two constellations that make up the widest part of the Milky Way, SCORPIUS (the Scorpion) and SAGITTARIUS (the Archer). Between these two constellations is the galaxy's centre.