Several times a week, Mission Control at NASA's Johnson Space Center in Houston, TX, determines sighting opportunities for 4,600 locations worldwide. Register here.
Retracing Our Steps Although now a remote, dusty city at the southern edge of the Sahara Desert in present-day Mali, 700 years ago Timbuktu was a bustling commercial and academic center. Traders exchanged salt and gold, while Muslim scholars collected and wrote texts on Islam, medicine, astronomy, math, politics and more.