Signs of Life? Why Astronomers Are Excited About Carbon Dioxide and Methane in the Atmosphere of an Alien World

Exoplanet K2-18b.

Are we alone? This question is nearly as old as humanity itself. (Image: J. Olmsted (STScI) / Science: N. Madhusudhan (Cambridge University) via NASA / CSA / ESA)

Is This Nearly Pure Aluminum Artifact 300 Million Years Old?

A pile of scrap aluminum waiting to be recycled.

The modern method for the production of aluminum was developed in 1886, so aluminum artifacts older than that are shocking to discover. (Image: Sportmoments via Dreamstime)