The trans-Neptunian object Altjira, 44 times farther from the Sun than Earth is, could be the second known trinary, confirming a theory about the formation of our solar system.
Matthew R. Francis
A Dragonfly for Titan
A new eight-rotor robotic probe will head to the solar system’s most Earth-like moon. Here’s what its team is doing to prepare.
Greenland Ice Sheet Stores Hidden Water Throughout the Melt Season
A new method uses stations around Greenland’s coast to measure how much meltwater weighs down the bedrock beneath the ice, improving our understanding of its contribution to sea level rise.
The Relatively Messy Problem with Lunar Clocks
Using Einstein’s theory of general relativity, physicists found that clocks on the Moon would run 56 microseconds faster than clocks on Earth. That finding will help future lunar missions navigate.
Kepler’s Drawings Might Reveal When the Sunspots Disappeared
Johannes Kepler’s landmark 1607 sunspot observations may have been made at the end of the solar cycle, helping constrain the start of the Maunder Minimum.
Saving the Planet with Radar Astronomy
Once the largest telescope in the world, Arecibo kept watch for dangerous asteroids using radar. With it gone, the world is preparing the next generation of radar observatories.
Spiral Waves May Explain the Sun’s Baffling Rotation
New observations and models show a connection between high-latitude waves in the Sun’s interior and the different rates of spin between the solar equator and poles.
Did a Cosmic Explosion Make the Ionosphere Dance?
Researchers have linked a 2022 gamma ray burst to a disturbance in the upper atmosphere, but proving the connection highlights the problems with this kind of measurement.
Five Martian Mysteries That Have Scientists Scratching Their Heads
Despite centuries of study and many spacecraft visits, the Red Planet still holds secrets. Here are just a few.
Essential Ingredient for Life Found on Enceladus
Icy plumes from Saturn’s moon Enceladus contain phosphorus, part of the biochemistry of life—the first time the element has been found in a liquid environment beyond Earth.