Expedition 47 Flight Engineer Tim Kopra of NASA (@astro_tim) shared this May 15, 2016 photograph taken from the International Space Station to social media, writing, "Water etchings in western @Mexico sands. @Space_Station #Explore"

This week, the space station reached its 100,000th orbit, since its first component, the Zarya cargo module, launched Nov. 20, 1998. The International Space Station's trajectory passes over more than 90 percent of Earth's population. NASA's Spot the Station service provides notifications of where and when to see the orbital laboratory flying overhead - including a widget that organizations can easily embed on their websites. NASA's Johnson Space Center in Houston calculates the sighting information several times a week for more than 4,700 locations worldwide.