Stonehenge is carefully aligned on a sight-line that points to the winter solstice sunset, but, this year as in most recent years, the revelry began before sunrise.
Eric Verlinde's new theory of gravity - an alternative to Einstein's theory - eliminates the need for dark matter. To test it, astronomers measured gravity around 33,000 galaxies.
Mars' atmospheric pressure is less than 1% that of Earth, so spacecraft come down hard. Europe has been trying for a Mars' soft landing since 2003. How they plan to succeed.
Lucy lived 3.18 million years ago in what's now Ethiopia. An analysis of high-resolution CT scans of her fossilized skeleton shows she was equipped for climbing trees.
Like most life on Earth, our gut microbes have their own circadian rhythm. Disrupting that daily routine can be bad - and keeping it in balance can be good - for whole body.