Greater Toronto Area Space Station Flyovers for the week of October 17th, 2021

As shown above, on Monday, October 18, 2021 from 8:02 pm to 8:04 pm EDT, the Chinese Tiangong Space Station will be visible from the GTA, rising from the southwestern horizon near Venus, and then entering Earth’s shadow above the southern horizon near Jupiter. 

Artificial satellites are visible because they are high enough to be bathed in sunlight while the sun is below the horizon for earthbound observers. When the geometry is just right, brilliant beams of sunlight are reflected to Earth from flat, shiny surfaces on the spacecraft – which we see as a steady point of light that crosses the night sky in mere minutes.

Low Earth orbiting satellites (LEOs) like the space station can only be seen within an hour or two of dusk and dawn (even though they are passing overhead at all hours of the day and night). Satellites with higher orbits can be seen throughout the night. Geostationary satellites such as telecom and satellite television transmitters need to broadcast toward specific regions of the Earth, so they are placed in very remote orbits that hold them fixed at a specific altitude and azimuth in the sky.

Engineers do not bother attaching lights to satellites. If you see a night sky object that has flickering or flashing lights, it’s an aircraft. Decommissioned satellites and space “junk”, such as spent rocket boosters, can smoothly vary in brightness if they are tumbling.

A very good website for satellite predictions is www.heavens-above.com. Click on the Location link and enter your geographic location – manually, or by dropping a pin on the provided map. Then return to the main page and select from the provided list of object types, such as “ISS”. Apps such as Sputnik!, free ISS Detector, and Orbitrack will put satellite predictions in your pocket, alert you of imminent passes, and even show you where in the sky to look. The SkySafari 6 app also includes an extensive satellite database.

The ISS (or International Space Station) won’t be visible over the GTA this week – but the Chinese Tiangong station will be. Here are the passes.

(Note: The more negative the Mag. number, the brighter it will look. The larger the Max Alt. number, the higher up in the sky it will be!) The higher and brighter passes are highlighted with “!!”. (Data adapted from www.Heavens-above.com. If you enter your location in their website, you will get a list of the passes for your location.) All the times below are expressed in Eastern Time.

Chinese Tiangong Pass…

My Insider’s Guide to the Galaxy session about satellites is on YouTube here.

Keep looking up, and enjoy the sky when you do. I love questions and requests. Send me some!