What’s Up In the Sky - April 2010

Fred Barrett | Apr 01, 2010

By Fred Barrett

We still have the winter constellations gathered around Orion in the South and Southwest during the evening. Fifteen degrees left of the sullen red eye of Betelgeuse on the right shoulder of Orion, you encounter the bright star Procyon in the constellation Canis Minor. Procyon is less than 12 light years away and is one of our nearest stellar neighbours. It has a white dwarf companion that is very difficult to find next to the brilliance of Procyon.

Looking about 15 degrees higher, you will see Mars between the constellation Cancer on the left and Gemini on the right. Mars’ brightness has faded since opposition at the end of January but even with the loss of almost a magnitude of brightness and a decrease of 25% in disk size, surface features can still be made out in a modest telescope. It helps that the planet is very high and therefore there is less atmosphere to interfere with good ‘seeing’. The atmosphere is like a lens. The more turbulence in the atmosphere, the more it changes the shape of the lens. Imagine wearing a pair of glasses that constantly shift in and out of focus. When there is a minimum of atmosphere and the air is calm, that is called good ‘seeing’.

Cancer the Crab is one of the faintest constellations and you will need to let your eyes get adapted to the dark by going outside away from lights for about 20 minutes. This will give your pupils a chance to dilate to allow more light to enter. Once you’re adapted, Messier 44, the Beehive cluster, will pop right out near the centre of the propeller shape of the constellation. It’s an easy naked eye object and spectacular in binoculars or a wide field telescope. The other object, Messier 67, is one of the very oldest known galactic clusters. A typical cluster is eventually shoved around and dispersed by passing stars but this cluster is almost 1,500 light years above the crowded region of the galactic plane. This sparsely populated region has allowed it to keep its identity.

Let’s have a look at the rest of the planets. Mercury is lost in the glare of the Sun until the last few days of March when, and you can’t miss this, it pairs up with Venus in the western horizon just after sunset. It’s a beautiful sight to see, especially with binoculars.

Jupiter is in conjunction (it’s on the other side of the Sun from us) at the end of February and won’t be seen again until the end of March.

Saturn makes up for that loss. In early March it can be found low in the East just after twilight. It rises to the southeast at the head of the constellation Virgo by late evening (Leo is east of Cancer and Virgo is east of Leo). It is in opposition on March 21st, which means that it is at its maximum brightness and size. Its rings will be tilted about 4 degrees in early March, decreasing to about 3 degrees by the end of the month.

New Moon is on the 15th. Watch for a very thin crescent new Moon on the right of Venus after sunset on the 16th. On the 20th, the Moon will occult some of the stars on the left side of the Pleiades cluster. Full Moon is March 29th and some call it the Full Worm Moon. The reasoning goes that as temperatures rise and the ground warms in March, worm casts appear. Since I make my own maple syrup, I’m happy to call it, as early settlers did, the Full Sap Moon.

Remember that Daylight Saving Time begins at 2AM EDT, March 14th. Adjust your clocks ahead one hour. If only our internal clocks adjusted as easily as bedside alarm clocks!

Watch for the Zodiacal light. The best time for viewing the Zodiacal light in the western sky begins about the 3rd of March and lasts for roughly two weeks. It is a triangular, hazy cone of light made up of particles of dust orbiting the Sun. These fine dust motes betray their presence by scattering light and this is what we see. It’s best seen in March because the tiny particles are in the plane of the ecliptic and the ecliptic is at its steepest angle to the horizon at this time of year. Be careful not to confuse the Zodiacal light with twilight, which occurs in the same part of the sky. The Zodiacal light will still be there long after twilight. Don’t use any visual aids like binoculars. It’s best seen by naked eye.

Note that the SPRING or VERNAL equinox occurs at 1.32PM DST on the 20th.

If you have questions or suggestions, Fred Barrett may be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it.

The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..