Polar sea ice grows and shrinks dramatically each year, driven by seasonal cycles. Habitat for wildlife and harbinger of changing climate, sea ice offers scientists important clues about the state of our planet.

Lora Koenig, a remote-sensing glaciologist at NASA’s Goddard Space Flight Center, spent three dark, frigid months supporting research at the National Science Foundation’s Greenland Summit Camp. Near the end of her stay, Koenig emailed the Earth Observatory answers to a few questions…

Searching for alternative sources of energy for his country, one student turned to a NASA satellite to assess the feasibility of offshore wind power in Southeast Brazil.

Earth’s temperature depends on how much sunlight the land, oceans, and atmosphere absorb, and how much heat the planet radiates back to space. This fact sheet describes the net flow of energy through different parts of the Earth system, and explains how the planetary energy budget stays in…