Polling shows that nearly half of Americans now believe aliens have visited this planet—and that the number who aren't sure has dropped by two-thirds. The reasons why, experts say, are complicated.

The new dataset, published in Earth System Science Data by 16 scientists, shows a significantly cooler Earth from the late 1700s through 1849 compared with 1850-1900 — the latter being what scientists have defined as the “preindustrial” baseline period used to assess the planet’s temperature change.

Particles that escaped Earth’s atmosphere accumulated on the lunar surface over billions of years. Here’s what you’ll learn when you read this story: It used to be thought that there were more volatiles than expected in lunar soil because they escaped Earth before it had a stable magnetic field.

China shipped 13% more rare-earth products in November than in the preceding month, a sign that a more relaxed export regime is restoring flows of the critical minerals used in electric vehicles, weapons and high-tech manufacturing.

The 38-foot-wide space rock is projected to come to within just 123,000 miles of our planet, according to NASA.