The enormous ring of light that appeared in the night sky on April 2 - above a thunderstorm in the Czech Republic - was a rare and fleeting lightning phenomenon.
Audubon website lets you enter your zip code to see a list of the best bird-friendly plants for your yard. Plus a free app to identify the birds you see.
The last remnant of a once-enormous ice sheet will be gone in about 300 years, according to a new study. Scientists say warming temperatures are the reason.
Considering both poles in February 2017, Earth essentially lost the equivalent of a chunk of sea ice larger than Mexico, in contrast to the average global minimum for 1981-2010.
Authors of a cover story in journal Nature this week called for immediate global action to reduce the magnitude of climate warming in order to secure a future for coral reefs.