Big Picture: Lighter than air

Fill a lightweight material with hot air, helium or hydrogen, and you have a vessel that floats in the air. People around the world use balloons, blimps and airships for transportation, to conduct research, to deliver messages, to protest, and - mostly - for having fun. Collected here are recent photographs of balloons of all shapes, sizes and purposes - ranging from a child's toy to a football-field-sized research instrument, and much in between. (31 photos total)

Click the image above to see the full collection.