The lowest Earth-observing satellite takes about _______ minutes to travel around the earth?

The correct answer is 90 minutes. Earth-observing satellites that are in low Earth orbit (LEO) typically revolve around the Earth at altitudes ranging from about 180 to 2,000 kilometers. At these altitudes, the satellites travel at high speeds, generally around 28,000 kilometers per hour (17,500 miles per hour), allowing them to complete an orbit of the Earth in approximately 90 minutes.

This relatively short orbital period enables these satellites to frequently cover the same geographic area, providing valuable data for various applications such as weather monitoring, environmental observation, and disaster response. The timing of the orbit also allows for capturing changes over time, as they revisit specific areas multiple times a day, depending on their orbit pattern.

Understanding the mechanics of low Earth orbit and the velocities involved clarifies why 90 minutes is the standard duration for completion of a full orbit around the planet.