Stories by Alexandra Witze

Swarms of satellites launched by SpaceX and other companies are disrupting astronomical observations. Here's how scientists are coping

The intriguing chemistry of a rock collected by the Perseverance rover could trace to microbial activity—or not

Top advisers in NASA’s Office of the Chief Scientist are among the first to go amid a government-wide downsizing effort

Scientists and supporters rallied in cities across the U.S. and Europe to protest dramatic funding cuts and other attacks from the Trump administration

The Trump administration has acted fast to attack science with a range of funding and policy tactics

Space scientists within NASA and outside it feel betrayed by the Trump administration’s changes at the agency, which was known for promoting inclusion in science

Earth’s core is transforming, which could affect the length of our 24-hour day, Earth’s magnetic field, and more

The Thirty Meter Telescope and Giant Magellan Telescope might need to compete for survival in the face of federal spending limits

Fresh investigations find that the Red Planet’s liquid-metal core is smaller than scientists thought

The Greenland Ice Sheet could experience runaway melting if the world overshoots climate targets, but even then quick action could stabilize it

Thirty years ago, astronomer Carl Sagan convinced NASA to turn a passing space probe’s instruments on Earth to look for life — with results that still reverberate today

NASA’s Perseverance rover has collected valuable samples, but a new report says the plan to fetch them is unworkable

Observations from the James Webb Space Telescope suggest that TRAPPIST-1 c, the second world in a seven-planet system, lacks an atmosphere

The huge watery cloud spurting from Enceladus could carry the ingredients for life farther into space than previously known

TRAPPIST-1b is probably an airless rock, but the same may not be true for its six Earth-sized siblings

New studies have revealed the spacecraft’s final moments and the remarkable aftermath of its impact

SETI, the search for extraterrestrial intelligence, is deploying machine-learning algorithms that filter out earthly interference and spot signals humans might miss

An investigation by agency historian finds no evidence explicitly linking former director James Webb with anti-LGBT+ actions

As the InSight lander reports the largest-ever meteorite strikes on Mars, scientists wish it a fond farewell

Revised calibrations for the James Webb Space Telescope’s instruments are bedeviling researchers studying the distant universe

The celestial crash between NASA’s DART spacecraft and the asteroid Dimorphos is yielding spectacular pictures and data

NASA’s Perseverance rover has collected four rock samples from an ancient river delta where organisms might have thrived

Smoke from burning cities would engulf Earth after a nuclear war, causing worldwide crop failures and starvation, models show

Rolling up an ancient river delta in Jezero Crater, the rover starts crucial rock sampling.