Why sunsets on Mars glow blue instead of red
Mars flips the colours of an Earth sunset. NASA's Curiosity rover photographed a cool blue glow around the setting Sun, and Martian dust explains why.
Boston’s deadliest wave in 1919 was made of molasses
In January 1919 a burst tank sent a wave of molasses through Boston's North End, killing 21 people. Physicists later worked out why it proved so deadly.
The first webcam was built to watch a coffee pot
Cambridge researchers pointed a camera at their coffee pot in 1991 to avoid wasted trips. In 1993 it went on the web and became the world's first webcam.
Your body gives off visible light, just too faint to see
Humans emit a faint visible glow, about 1,000 times too weak for our eyes to detect. Japanese researchers imaged it and found it peaks in late afternoon.
The Sahara sends the Amazon about 22,000 tonnes of phosphorus a year
Wind carries Saharan dust across the Atlantic to the Amazon, delivering about 22,000 tonnes of phosphorus a year. How NASA measured this unlikely link.
A five-month-old godwit flew from Alaska to Tasmania nonstop
In 2022 a young bar-tailed godwit flew at least 13,560 km from Alaska to Tasmania in 11 days without landing once. Here is how scientists tracked it.
Yoruba talking drums really do copy the patterns of speech
Acoustic analysis shows the Yoruba dùndún drum closely mirrors the timing, pitch and loudness of spoken Yoruba. Here is how the talking drum really talks.
The kilogram was a metal cylinder in a Paris vault until 2019
For 130 years, the world's kilogram was one metal cylinder kept near Paris. Here is why scientists retired it in 2019 and tied mass to the Planck constant.
Point Nemo: the place on Earth farthest from any land
Point Nemo in the South Pacific sits about 2,688 km from the nearest land. Here is how it was found and why space agencies aim old spacecraft there.
How a 12-year-old on Réunion made vanilla a global crop
Vanilla rarely fruited outside Mexico until 1841, when Edmond Albius, a 12-year-old enslaved boy on Réunion, found a way to pollinate its flowers by hand.