It's not just Niagara Falls. Many states in the US have impressive waterfalls. Some require a hike, but others are easy to ...

The sounding rockets released vapor tracers and pressure sensors at different altitudes across central and northern Alaska during a sudden auroral substorm.

See photos of Alaska submitted to National Geographic by users like you. 1 of 26 This photo was submitted to Your Shot, our photo community on Instagram. Follow us on Instagram at @natgeoyourshot ...