A revolutionary set of star-seeking telescopes is taking precision to the next level.

What does it take to plot a Universe's worth of galaxies, clusters, quasars, nebulae, stars, dwarfs, and supernovae?

Most asteroids and comets don't pass anywhere near Earth. Meet the astronomers on wary watch for the ones that do.

Gravity may seem elementary. But proving Einstein’s theories about it is quite hard. Now scientists are struggling to capture gravity’s most elusive hallmark: the gravitational wave.

Learn the origins of our Moon.

Life on Earth depends on light and heat from the Sun. But the Sun emits more than just light and heat. Tiny particles—mostly protons and electrons—stream away from the Sun in a "solar wind" that can reach speeds of more than a million kilometers an hour. See how scientists are modeling interactions between solar winds and Earth's magnetosphere, the magnetic shield generated by our planet's rotation and molten core, which protects us from the full impact of these supersonic particles.

Because a star's brightness does not indicate its distance, scientists have begun using a novel method of tracking stellar motion to learn which stars are truly "local."

Nowhere else are primates as diverse...or as endangered.

Lessons learned from one of the world's oldest marine parks may help set the stage for restoration of our global oceans.

Roads, development, and other consequences of haphazard urban and suburban growth are causing a bumpy ecological ride for many species of animals and plants—ours included.

One of the most abundant forms of ocean life is gelatinous goo that, until recently, was all but invisible to science.

Using satellites to map land cover helps scientists understand life on Earth and how humans alter ecosystems. When sunlight hits the Earth’s surface, some of the light bounces back into space. Different land surfaces, such as forests, bare ground, roads, and water, reflect different wavelengths of the sunlight differently. Satellites measure the reflected radiation to image distinct land features, as illustrated in the August 2004 Bio Viz Congo Land Cover.

Fires are an important agent of change in ecosystems around the world. Natural fires, such as those set by lightning strikes, have historically been so frequent that many plants have evolved in response to regional fire regimes. Many fire-adapted plants have reproductive strategies that actually use fire to stimulate their seeds to drop and/or sprout on newly burnt soil. Fires release the nutrients bound up in living vegetation, thus fertilizing new growth. By removing standing vegetation, fires make space for new vegetation to grow. Humans have used fire for thousands of years to clear land and prepare soil for crops. By changing the frequency, intensity, and patterns of fire around the world, human activity has changed, and continues to change, the face of our planet.

Three of the most catastrophic volcanic eruptions in geologic history occurred at a place now visited by over three million people a year.

How tsunami researchers are trying to get ahead of the next big wave.

Follow a team of glaciologists racing to core the world's largest tropical ice cap--before global warming melts it away.

The North Atlantic Oscillation may pale against El Niño’s press. But this climate pattern can kick up a commotion all over the Northern Hemisphere. Lately, scientists have been discovering why.

Oxygen gas is key to Earth's biological diversity, but it wasn't always so. Find out how scientists are studying oxygen's origins by tracing its footprints in ancient rocks.

During the winter months, a layer of ice forms across vast expanses of the Arctic Ocean. Each summer, more than half of that ice vanishes.

Ozone gas (O3) in the upper atmosphere shields Earth from the Sun's dangerous ultraviolet radiation. Since the early 1980s, scientists have been aware that manmade chlorofluorocarbons (CFCs) destroy atmospheric ozone worldwide. The greatest losses have occurred at the poles; the Antarctic ozone "hole" is most extreme in October.

Water temperatures at the ocean surface are constantly changing. These changes affect—and are influenced by—weather and climate worldwide. By studying satellite measurements of sea-surface temperatures, scientists are learning to detect and predict recurring weather patterns such as El Niño events, which can cause devastating droughts and floods around the world.