5 Most Incredible Discoveries of the Week

Doctors crack a medical cold case, while scientists spot diamonds in an unexpected place:

• Revolutionary Robespierre Gets a Modern Diagnosis: The guillotine ended the life of French revolutionary Maximilien de Robespierre in 1794, but the 36-year-old might not have been long for this earth anyhow, a new study suggests.
• Antarctica May Hold a Stash of Diamonds: As a scramble for the Arctic's resources looms, scientists have spotted evidence of mineral riches at the planet's southern pole. An Australian-led team discovered rocks signaling large diamond deposits on the icy slopes of Mount Meredith—but there's one big problem.

• 1 in 200 Women Say They've Had a 'Virgin Pregnancy': An unbelievable-sounding new study finds that one in 200 young American women claims to have experienced a virgin pregnancy, à la the Virgin Mary. Bizarrely, the study found "virgin fathers" as well. Here's how researchers arrived at their findings.
• Rare Ritalin Side Effect: Painful Erections: Labels on Ritalin and other drugs used to treat ADHD will soon have a new warning: Beware long, painful erections. The problem is a chemical in the drugs called methylphenidate, and cases have been seen in kids as young as 8 years old.
• For Early Plague in Europe, Blame Halley's Comet? Halley's Comet provided more than just a light show for residents of planet Earth in the year 530 AD—a chunk of it may have slammed into Greenland, creating a massive dust storm and perhaps paving the way for the first recorded instance of the Black Death in Europe.

Click for more incredible discoveries, including an island that's behaving quite differently than scientists expected. (More discoveries stories.)