Comparative Planetology

Some exoplanets have a direct line of sight to observe Earth’s biological qualities from far, far away.

Venus may have had an Earth-like environment billions of years ago, with water and a thin atmosphere. Yet testing such theories is difficult without geological samples to examine.

A new study is helping scientists piece together the ancient climate of Mars by revealing how much rainfall and snowmelt filled its lake beds and river valleys 3.5 billion to 4 billion years ago.

An upcoming NASA mission could find that there are more rogue planets – planets that float in space without orbiting a sun – than there are stars in the Milky Way.

Brines may still be percolating up to the surface on Ceres today as the result of an impact that created the Occator crater 20 million years ago.

The first helicopter attempting to fly on another planet is a marvel of engineering. Get up to speed with these key facts about its plans.

The trigger for “Snowball Earth” global ice ages may have been drops in incoming sunlight that happened quickly, in geological terms, according to an MIT study.

Using advanced techniques, scientists have detected organic compounds containing nitrogen in Martian meteorites which were ejected from Mars' surface ~ 15 million years ago, proving that evidence for early life can be preserved and detected today

Every rock tells a story, and so does each fatty acid called a lipid. Your cholesterol, which is part lipid and part protein, could last for billions of years, and contains the information that you are a mammal. Could we find lipids beyond Earth? NASA

To study the history of life on Earth and look for it beyond our planet, scientists in the field of astrobiology look for signs called “biosignatures". By looking at what life on Earth was like millions and even billions of years ago, astrobiologists can make