Stories by Jonathan O'Callaghan

The possibility of the asteroid 2024 YR4 impacting our planet might not be ruled out until 2028, raising the prospect we’ll need to prepare for the worst

Peculiar bursts of energy called chorus waves have been detected in deep space far from our planet, suggesting they could pose problems for long-distance space travel

The Parker Solar Probe will swoop just 6.1 million kilometers above the sun’s surface on Christmas Eve. Scientists are thrilled at what we might learn

The nearby star Vega, featured in the 1997 movie Contact, appears to have a smooth disk devoid of giant planets for reasons we can’t explain

This blazingly fast star is shooting through the Milky Way with a planet in tow

Experiment shows that a nuclear explosion could save the planet from a deadly asteroid impact

Analyzing 1,504 supernovae into the distant universe, astronomers have shown the clearest evidence yet for cosmological time dilation as predicted by Einstein

Years of careful planning helped safeguard against last weekend’s severe space weather, but we still don’t know how we’d cope with a monster event

Facing budgetary pressure for its Mars Sample Return program, NASA has turned to private industry for ideas—perhaps with one specific company in mind

The Chandra X-ray Observatory faces a premature end under new funding cuts proposed by NASA—and astronomers aren’t happy

New analyses cast doubt on claims that a meteor witnessed over the South Pacific in 2014 came from another star system and raise questions about a high-profile expedition to recover the fireball’s fragments from the seafloor

The next year of science for the James Webb Space Telescope has been selected. It includes remote galaxy observations and, at last, a hunt for exomoons

Scientists have finally found the compact object at the heart of the famous supernova of 1987, and it’s not a black hole

The Laser Interferometer Space Antenna (LISA) will open a new era in astronomy that brings scientists to the brink of studying gravitational waves from the beginning of time

Rather than ripping up our fundamental models of the universe, the unexpectedly big and bright galaxies spied in the early universe by JWST probably have astrophysical explanations

Japan’s SLIM precision-landing spacecraft—a potential game-changer for upcoming lunar exploration—may expire on the moon before fulfilling its mission

A serendipitously discovered object nearly as massive as the Milky Way appears to be made of primordial gas that has formed almost no stars

Unique studies of gravity waves, atmospheric holes and dazzling coronal displays will accompany April’s total solar eclipse across the U.S., Mexico and Canada

Astronomers are moving ahead in planning NASA’s Habitable Worlds Observatory, a telescope designed to answer the ultimate question: Are we alone in the universe?

Amaterasu—the most powerful cosmic ray seen in three decades—seems to come from an empty point of the sky. New telescopes may solve the mystery of its origins

Scientists still can’t explain what is causing unusually bright explosions in space—but a surprising observation might offer clues

Images from each and every spacecraft now orbiting Mars have ruled out a meteorite strike as the cause of a 4.7-magnitude marsquake, the strongest temblor ever detected beyond Earth

NASA has reversed course on plans to curtail the New Horizons spacecraft’s planetary science studies following a rebellion among the mission’s leaders

250 million years from now, the emergence of a new supercontinent could render most of Earth’s surface uninhabitable for mammals