By 2050, global average temperature could be between 1.4°C and 3°C warmer than it was just a couple of decades ago, according to a new study that seeks to address the largest sources of uncertainty in current climate models. That’s substantially higher than estimates produced by other climate analyses, suggesting that Earth’s climate could warm much more quickly than previously thought.

About 2 decades ago, scientists coined the term “snowball Earth” to describe a period about 700 million years ago when glaciers apparently smothered the planet even at latitudes near the equator. However, new evidence from ancient rocks bolsters the notion that some of the world’s seas remained unfrozen during this global deep freeze, striking a blow against the controversial idea that the planet was completely swaddled in ice at the time.

A centuries-old astronomical mystery may be finally solved. A scientist says she has figured out how Saturn’s spectacular rings formed. The dramatic process could help explain other solar system mysteries as well.