1. Beam It Up! Sensing From a Distance Using Electromagnetic and Acoustic Energy Pulses

2. Animals Did It First o Bats emit pulses of ultrasonic acoustic energy (“clicks”). o The reflections (“echoes”) give them information about their environment.

3. Lunar Laser Ranging

4. Scary Details

5. Mapping Mars with Lasers

6. Echo Sounding o Mapping the ocean floor with pulses of acoustic energy. o The ocean absorbs electro- magnetic energy.

7. Side-Scan Sonar o Probes a line instead of a point.

8. Side-Scan Sonar Images o The S.S. Nedjan Before... And After.

9. A Different Kind Of Light o Radar uses radio frequency electro- magnetic energy.

10. Not Just For Air Anymore o Ground-penetrating radar is like a seismic survey, using electromagnetic rather than acoustic energy.

11. From Earth To Sky o Ground- penetrating radar could detect groundwater near the Martian surface.

12. From Sky Back To Earth

13. Global Positioning o Receivers on the surface get time and position data from multiple satellites. o A little bit of math gives a pinpoint planetary position.