For humans to be intimately involved in many interconnected processes at a planetary scale carries huge risks.

ECONOMIST: The geology of the planet

Its atmosphere is escaping like a comet but on a planetary scale.

NPR: NASA Sends Spacecraft to Pluto

And we also believe that Mars had planetary-scale oceans in the northern hemisphere.

NPR: Revisiting the Viking Missions to Mars

In trying to bring these views up to date, Kaplan plunges into a planetary review that is often thrilling in its sheer scale, its encyclopedic breeziness.

NEWYORKER: Faces, Places, Spaces