The MESSENGER orbiter's January 2008 flyby of the planet Mercury was historic. The last time a spacecraft visited was 1975, and it only mapped half the planet. MESSENGER is now sending back a complete picture of Mercury, shedding light on its geological history. But the ongoing mission will return much more than images. Its data on the planet's core, magnetic field, composition, and other attributes will help scientists answer pressing questions about the evolution of the terrestrial planets and even the Solar System itself. In the feature video, watch the MESSENGER science team react as the orbiter's first images of Mercury roll in. To explore the images in detail, click on the slide show at left. Find out more on the mission by clicking on the essay "First Planet Finishes Last."
Bolivia’s diversity of animal and plant life is among the greatest in the world. Learn why the country has designated more than 17 percent of its land as protected areas.
How much can you reduce your carbon dioxide emissions? Is it worth it? Learn how simple choices multiplied by everyone in your community can make a big difference.
Curriculum Collection, Educator Guide
Humans, like all species, are a product of evolution. Help students understand the evolutionary story of our taxonomic family with this practical and printable exhibit guide.
Follow mermaids around the world and throughout history to see first-hand how cultures share and reinterpret mythic creatures.
Setting sail without a map wasn't the only concern facing European explorers. Their heads had also been filled with tales of monsters lurking in the oceans' depths.
The elusive giant squid was first described 500 years ago by Scandinavian sailors. Investigate what we've learned--and what still remains unknown--about this mysterious deep-ocean creature.