From time to time, the International Space Station (ISS) becomes noticeable in the night sky. While on Earth, it's like a radiant star moving rapidly above the skyline. It is so shiny and can be seen from the middle of a city. But it appears for a while and disappears after.

NASA has made a Spot the Station program where people worldwide can sign up to acquire alarms when the ISS will be visible from their places. These alarms can be in form of email or text message. Usually, alarms are directed a few times each month when the ISS is close to your area. People can also visit the Spot the Station Web site to sign up and see a record of approaching sighting chances.

The notice you will receive varies on where your area is as these notices will only be sent if the ISS is noticeable in your area. You can also use an app to look for the ISS. It is called the ISS Detector Satellite Tracker that helps you by telling when and where to look for the ISS or Iridium flares. Like the program, you also get an alarm a few minutes before it passes in your area.

These notices include details on where to view the ISS in the night sky. Take note where the sun sets because it is a big help in knowing the direction on where to look for the station. The altitude at which the ISS will be seen is in degrees. For example, 90 degrees means it is located over your head. It is easier way to estimate the degrees, you can put your fist at arm's length toward the horizon and this is equal to around 10 degrees.

Currently, there is about more than half a million people who signed up in the NASA'S Spot the Station program and ISS Detector Satellite Tracker. The ISS fulfills as both an orbiting lab and place for international spacecraft. The U.S., Canada, Europe, Japan and Russia are the main partnering countries taking part in running the ISS.

The ISS circles at nearly 220 miles above the Earth at it moves at an average speed of 27,724 kilometers (17,227 miles) per hour. Today, the ISS has roamed more than 1.5 billion miles through space.