For the last dozen years, humanity has had a continual presence in space. During that time, the International Space Station has grown considerably, to the point where it's now the third-brightest object in the sky, meaning that you don't have to have any sort of equipment to view it—you simply have to know when to look up.

Now, NASA is making knowing when to look up a bit easier. If you go to its Spot the Station site, you can register to have e-mail alerts sent to you whenever the facility is due to pass overhead in your area. Since the Station crosses near something like 90 percent of the Earth's population, nearly everyone should have the chance to see it.

NASA's system lets you specify your country and region, so that it can calculate when an alert is due. You get the choice of asking for morning or evening viewing opportunities (or both), and NASA only sends the notifications when the station is going to be high enough in the sky that trees and buildings are less likely to block the view. In the US, the system also has instructions for sending the e-mail to your cellular carrier, which will convert the contents to a text.

A sample of one of these alerts looks like this:

SpotTheStation! Time: Wed Apr 25 7:45 PM, Visible: 4 min, Max Height: 66 degrees, Appears: WSW, Disappears NE.

Having seen it myself, I will verify that it moves pretty quickly. As such, it's more important to be able to pick out something moving against a starry background than to have a precise sense of direction. And, even if you don't get a chance to see it, it might not be a bad thing to get an occasional reminder that humanity has occupied an outpost in space for well over a decade now.