The International Space Station is going to be a familiar sight in Toronto skies over the next two weeks, as it makes as many as 17 visible passes above the city between tonight and October 18. During many of these fly-overs, it will be one of the brightest objects in the sky.

Having the ISS pass overhead isn't entirely rare, but having so many opportunities to see it fly overhead is certainly a treat, especially at the magnitude of brightness that's been predicted. For tonight's pass, which will take place in the northwestern sky, the space station will be just a little dimmer than the brightest star in the Earth's sky, Sirius.

On other passes to come over the next 12 days, it will be far brighter. Sirius has an apparent magnitude of −1.47, while the ISS will appear as bright as −2.8 on October 15. The lower the number on the apparent magnitude scale, the brighter an object is. For reference, the maximum brightness of Mars is −2.91.

When picking a time to view the ISS, you'll want to account for a number of factors. Weather is the most obvious. Cloud cover will ruin any sighting opportunities. Beyond that, you'll want to check how long the fly-over will be (upcoming ones will range from less than a minute to five minutes), how bright the station will appear, and what part of the sky it will cross.

Fortunately, a number of websites provide the key information that you need. Heavens Above has good info pertaining to brightness, while Spot the Station is a bit easier to read in terms of the duration of each event. You can also use the European Space Agency site to track the current location of the ISS.

When you do a little bit of research, you'll find that on some upcoming nights we'll be treated to two fly-bys, generally separated by about an hour and half, which is the time it takes the ISS to orbit the Earth. This period is one of the best chances you'll get to see the station pass by Toronto, so make sure you get out there.

Photo via NASA.