Mars and M22


Mars and M22 Cluster

Mars shines near the globular star cluster Messier 22 in Sagittarius.

This week Mars has been passing near one of the brightest globular star clusters, M22. I caught the pair tonight, November 8, as they sank into the southwestern sky.

The two form a contrasting pair, with red Mars now 260 million kilometres away, far enough that its light takes 13 minutes to reach Earth. However, blue M22 lies so far away, toward the galactic core, that its light take 10,000 years to reach Earth.

Mars appeared closer to M22 earlier this week but tonight was the first night with a narrow window of dark sky between twilight and moonrise, allowing me to shoot the pair.

I shot the image through a telescope with a short focal length of 400mm, taking in a field of about 5 by 3 degrees, the field of high-power binoculars. The image is a stack of eight 2-minute exposures at f/4.5 with the TMB 92mm refractor and Canon 6D at ISO 800.

– Alan, November 8, 2014 / © 2014 Alan Dyer

Goodness Gracious! A Great Ball of Stars!


This is what half a million stars look like when packed into one big ball. 

This is the globular star cluster called Messier 22, in Sagittarius. It’s the biggest and best such object visible from Canadian latitudes, though it always sits low in our summer sky. M22 is one of 150 or so such spherical clusters of stars that orbit our Milky Way. This one sits 10,000 light years away from us, toward the centre of the Galaxy. Those half million stars are packed into a sphere 100 light years across. In our sky it appears as big as the Full Moon, though not as bright of course. But just imagine the sky if you can view it from the centre of M22. The heavens would be ablaze with stars. 

I shot this with the 130mm refractor at f/6. It’s a stack of just three 4-minute exposures with the Canon 7D. Though M22 was low above the southern horizon from the Cypress Hills where I shot this, the final image turned out pretty well. 

– Alan, August 30, 2012 / © 2012 Alan Dyer