Just as the sun slips behind the Chilean Andes, it seemed to send up a tiny emerald flare. The photograph, taken from Cerro Pachón in Chile by NOIRLab Audiovisual Ambassador Petr Horálek, captures a classic but elusive atmospheric trick of the light: the green flash.
What is it?
Despite the dramatic name, a green flash isn’t an explosion or a burst of energy. It’s simply sunlight…
In the middle of Mauritania’s Sahara Desert, surrounded by an ocean of sand, lies a colossal stone spiral that seems almost too perfect to be natural. From orbit, in a recent image taken by the European Space Agency’s Copernicus Sentinel-2 satellite mission, it…
December's 'Cold Moon' rises: See breathtaking images of the final full moon of 2025
December 8, 2025
The final full moon of 2025 treated stargazers to a high-flying lunar spectacle as the “Cold Moon” glowed among the stars of the constellation Taurus on Dec. 4.
December’s full moon was the third in a string of “Supermoons” — full moons that…
A team of international researchers say they’ve uncovered new data on the world’s first recorded solar eclipse using a surprising source — ancient Chinese texts. These findings could help us understand more about the progression of the Earth’s rotation through the centuries.
The eclipse in question took place on July 17, 709 BCE, according to a chronicle titled “Spring…
See the metal guts of a satellite in this wild X-ray view | Space photo of the day for Dec. 4, 2025
December 5, 2025
In a hangar outside Zurich, a veteran of low Earth orbit lay under a kind of medical scanner no spacecraft was ever designed for. The patient was the European Retrievable Carrier mission, or EURECA, a 16.-4-foot-long (5 meters) European satellite that flew on the space…
Why is the universe made of matter? These 'ghost particle' experiments could help us find out
December 5, 2025
Scientists have inched a step closer to solving an enduring mystery in physics — why the universe contains any matter at all — thanks to a newly combined analysis from two of the world’s leading neutrino experiments.
By pooling nearly 16 years of measurements, the…
Don't miss the last full moon of 2025 as the 'Cold Supermoon' takes to the autumn sky on Dec. 4
December 5, 2025
Get ready stargazers, the final full moon of 2025 rises tonight! Here’s what to expect when the “Cold Supermoon” looms large over the eastern horizon at sunset on Dec. 4.
The exact moment of December’s full moon phase will take place at 8:13 p.m. EST (2313 UTC) on Dec. 4, at which time the lunar disk will appear fully illuminated opposite the sun in Earth’s sky…
A 'super-puff' exoplanet is losing its atmosphere, and the James Webb Space Telescope had a look
December 4, 2025
Astronomers have spotted a distant world “shedding” its atmosphere into space in real time, creating a giant companion cloud of gas that travels ahead of the planet as it orbits its star.
Observations from the James Webb Space Telescope (JWST) have revealed an…
Northern lights may be visible in 15 states tonight
December 4, 2025
The northern lights could light up skies across the U.S. tonight, as a high-speed solar wind stream from a coronal hole and an incoming coronal mass ejection (CME) are forecast to hit Earth, according to the National Oceanic and Atmospheric Administration’s (NOAA)…
NASA discovers 'space gum' and sugars 'crucial to life' in asteroid Bennu samples brought to Earth (video)
December 4, 2025
Scientists have detected several sugars essential for life in the samples brought back from asteroid Bennu, NASA announced on Tuesday (Dec. 2).
Analyzing pristine fragments of the asteroid delivered to Earth by NASA’s OSIRIS-REx spacecraft in 2023, a team led by Yoshihiro Furukawa of Tohoku University in Japan found ribose, a crucial building block of RNA, and glucose, an energy-rich sugar…
