SKY HIGHLIGHTS provides information about things happening in the sky for the upcoming month.
The information here is a rough transcript of information covered on the popular CBC Radio
One Calgary Eyeopener "Eye on the Night Sky"
segment presented by Calgary Centre member Don Hladiuk and heard on the CBC radio morning show
the first Tuesday of each month at 6:22 AM. Don is a life member of the Royal Astronomical Society
of Canada and was twice President of the Calgary Centre. Since June 1984, Don has had a regular radio spot on
the Eyeopener describing monthly Sky Highlights to southern Albertans.
For additional sources of sky information see the list of links below this month's article.
For information about the Calgary Centre of the RASC, please
visit our web site at http://calgary.rasc.ca/ or contact one of
the Calgary Centre Executives.
ASTRONOMICAL HIGHLIGHTS
May 2012
(Broadcast Date May 1, 2012)
Partial Solar Eclipse for Albertans
On the evening of May 20, Albertans will be able to witness a partial solar eclipse (weather permitting). A partial eclipse occurs at new moon when the moon and the sun line up. From southern Alberta one will see the silhouette of the moon slowly move across the face of the sun until about 2/3 of the sun is obscured around 7:14pm MDT.
The times of the major events are as follows for Calgary:
Eclipse Begins: 6:04 pm MDT
Maximum Eclipse: 7:14 pm MDT (Sun's altitude will be 190 at an azimuth of 280°
Eclipse Ends: 8:18 pm MDT
As with any eclipse, observing the sun is extremely dangerous. NEVER look at the sun (even when it is 2/3 covered) without using an approved solar filter or a safe projection method.
One of the safest methods to observe the partial phases of a solar eclipse is to use a projection method. First locate a large piece of cardboard (e.g. 0.5m X 0.5m). Next cut a 5 cm hole in the middle. Cover the hole with a piece of aluminum foil. Using a sharp pencil, poke a small hole into the aluminum foil. Next go outside and hold the cardboard sheet up to block the sun. DO NOT LOOK through the pinhole. Look at the projected image on the ground (inside the shadow of the cardboard sheet). The greater the distance from the ground, the larger the projected image will be. Shorter distances to the ground yield smaller but brighter and crisper images. One can experiment to determine what distance works best for your setup. Hint: use a piece of white paper/cardboard to act as a projection screen on the ground.
On the left, one can see plans on how to construct a solar telescope from a long cardboard box. It uses a pin hole at one end and a viewing hole cut out in the other so you can observe the eclipse. You can balance the box on your shoulder with your back to the sun while peering into the viewing hole.
There are also safe methods to directly view the partial phases of a solar eclipse by using approved solar filters. There are cool looking special aluminized mylars that look like crazy sunglasses but only let in a fraction of sunlight. One can also use a Number 14 welder's glass. Most welder's glass are made of a lower density, so make sure you have a Number 14! If you are not sure what type of welder's glass you have, don't use it. Do not take any unnecessary risks when it comes to your eyes.
This is the first widespread solar eclipse for North America in nearly a decade (last one was June 10, 2002). If you are down in the SW USA on May 20 you will be near the center line for this eclipse and experience a rare annular solar eclipse. This type of an eclipse occurs when the moon is further away from the earth (in its slightly elliptical orbit), therefore the moon's disk is just not quite big enough to cover the solar disk completely. Observers along the center-line will observe the black lunar disk with an annulus of sunlight blazing around it. Again, everyone must use solar filters or a safe projection method to observe all phases of this eclipse.
There is another more sophisticated method that requires projecting the sun through a small telescope or binoculars onto a sheet of paper. This method can be dangerous as the internal structure within a telescope or binoculars can become very hot and even soften the glue that holds the optics in place. There are also special filters that mount on the front end of the telescope or binoculars (filtering the light before it enters the optical assembly) and provides a more magnified view.
Please remember this is not as exciting or life changing as a total solar eclipse. But it is an opportunity to see astronomy in motion. In real time, you will be able to observe the silhouette of the moon pass in front of the sun in a little over 2 hours.
If you are still not sure if your method is safe or not, just drive down to the new TELUS Spark* Science Centre (north of the zoo) or the Rothney Astrophysical Observatory (near Priddis) on May 20 at 6:00pm. Safe solar filtered telescopes will provide superb views of this solar eclipse and also of another solar event on June 5. Check websites for more info.
Venus Transit - June 5, 2012
The safe solar viewing methods described above can also be used to observe the rare Venus Transit on June 5, 2012. I will describe why this is so rare next month. If you miss this date, you will have to wait over 105 years to see it again.
What's Up in May Skies:
The night sky is becoming shorter and shorter (as we approach the summer solstice), but we can still enjoy the spring constellations and 3 bright planets. Venus is the brightest at sunset shining brilliantly in the western sky. Over the next month it will drop quickly towards the sun and will be in conjunction on June 5 as it transits in front of the sun. Mars is still high in the SW at sunset below Leo the Lion. And last but not least, the beautiful ringed planet Saturn is located just above the bright star Spica in Virgo (in the SE after sunset).
Dates to Remember:
May 3: Telescope viewing at the TELUS Spark* Science Centre until 10:00pm.
May 4: Moon near Mars
May 4: Hawkwood School Star Night
May 11: Vulcan Star Night - at the Trek Station at 7:30 pm MDT.
May 17: Free public lecture at the TELUS Spark* Science Centre by Alan Dyer. Talk is entitled "Tales of the Transits of Venus". This will be a superb presentation and should not be missed.
May 20: Partial Solar Eclipse - Safe viewing opportunities provided at the TELUS Spark* Science Centre
May 20: The Rothney Astrophysical Observatory (near Priddis) will have another public open house from 6:00 -8:30pm. Safely view the partial solar eclipse with astronomers from the University of Calgary. Go to: http://www.ucalgary.ca/rao/
May 22: Thin crescent moon below Venus low in the sky at sunset.
May 29: Moon near Mars
May 31: Moon near Saturn
June 5 - the last Transit of Venus until 2117 (see above).
Join Don next month (June 5) as he will provide information on observing the last Venus Transit until 2117.
For more astronomy info go to: http://calgary.rasc.ca/
or follow Don on Twitter at: www.twitter.com/astrogeo
Sky Chart for May 15 ~11:00pm MDT
Previous Sky Highlights:
Other Sources of Current Sky Information:
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