Scientists find deep-sea bacteria that are invisible to the human immune system

Silent MRSA carriers have twice the mortality rate of adults without the bacteria

Hoards of purple sea urchins have decimated kelp forests off the coast of northern California. In the past they were kept in check by predators like the sunflower sea star. But there have been some big ecological shifts, exacerbated by climate change, that have led to an urchin explosion.

Previously thought to be science fiction, a planet in a triple-star system has been discovered