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planetary science

planetary science

What Made the Moon? New Ideas Try to Rescue a Troubled Theory

Textbooks say that the moon was formed after a Mars-size mass smashed the young Earth. But new evidence has cast doubt on that story, leaving researchers to dream up new ways to get a giant rock into orbit.

Kuiper belt objects, planet nine
Abstractions blog

Planet Nine Is Put on Trial in Absentia

Breathless media coverage notwithstanding, the cases for and against a hypothetical Planet Nine in the outskirts of the solar system remain inconclusive.

Journey to the Birth of the Solar System
Multimedia

Journey to the Birth of the Solar System

Join David Kaplan on a virtual-reality tour showing how the sun, the Earth and the other planets came to be.

Earth scientists hope that their growing knowledge of the planet’s early history will shed light on poorly understood features seen today, from continents to geysers.
geophysics

Explorers Find Passage to Earth’s Dark Age

Geochemical signals from deep inside Earth are beginning to shed light on the planet’s first 50 million years, a formative period long viewed as inaccessible to science.

astrobiology

Scientists Debate Signatures of Alien Life

Searching for signs of life on faraway planets, astrobiologists must decide which telltale biosignature gases to target.