Sick Earth
Geologists studying mass extinctions in Earth's history have determined that the majority of extinction events were due to climate change rather than asteroid impacts.

Studying a Giant Planet
Eight years from now, the Juno spacecraft will arrive at Jupiter, with instruments to study its atmosphere. Research goals for the mission include determining how the giant planet formed, how much water it contains, and how its powerful auroras compare to Earth’s Northern Lights.

The Ions and Isotopes of Enceladus
Cassini will soon fly within 16 miles of Enceladus' surface to measure molecules in the Saturnian moon's environment. The data will provide insight into the early history of the solar system.

Animals Making Tracks
The fossilized trail of an aquatic creature suggests that animals walked using legs at least 30 million years earlier than had been thought. Scientists once thought that it was primarily microbes and simple multicellular animals that existed prior to the Cambrian, but studies like this may change that notion.

Measuring the Weight of Ancient Air
In the first study of its kind, researchers will measure the air pressure from nearly three billion years ago by using gas bubbles in lava and tiny craters made by raindrops. The results could indicate what sort of life may have existed on the ancient Earth.

The Little Bang
New research shows that a distant exploding star could have triggered the formation of our solar system. The study is helping astrobiologists understand the conditions in which habitable planets might form.

Short RNAs Have a Long History
MicroRNAs are tiny molecules used to fine-tune how genes are expressed. Now scientists are beginning to understand the early evolution of these important molecules and how they have affected the evolution of life on our planet.

Breathing Like a Bird
The remains of a unique dinosaur discovered in Argentina are helping scientists understand the connections between dinosaurs and birds. The study sheds light on an important moment in the evolution of life on our planet.

Digging up Ancient Microbes
Limestone from Namibia has biomarkers that indicate a community of microbes oxidized methane at least 300 million years ago. Such biomarkers can provide clues to the history of life on Earth, and could help scientists search for signs of life on other worlds.

Snow Falls on Mars
NASA's Phoenix lander has detected snow falling on Mars. Additional tests have revealed that liquid water once interacted with the planet's soils. The new revelations about the martian climate will help scientists understand if Mars was once habitable for life.