A new NASA mission will capture images of Earth's invisible "halo," the faint light given off by our planet's outermost atmospheric layer, the exosphere, as it morphs and changes in response to the ...

Much as we may treasure and proclaim our independence, we actually live in a protective bubble called the heliosphere.

Every year, the moon, Earth's reliable celestial companion for 4.5 billion years, is getting 1.5 inches away. The distance to the moon is calculated by measuring the amount of time it takes for light ...