SUNSET: 
Hubble Images Reveal Dark Matter Problem
Astronomers studying Hubble Space Telescope images of massive galaxy clusters have uncovered a potential problem with dark matter.
Record-breaking Signal Reveals New Population of Black Holes
Gravitational-wave observatories have detected the most massive black hole merger yet, and it's challenging our ideas of black hole formation.
Hints of Young Solar Systems
By studying the images of small young star systems, astronomers expect to learn more about the formation of our solar system.
Our Unexpectedly Smooth Universe May Point to New Physics
The latest data release from a survey of 31 million galaxies reveals that our universe is even smoother than we thought it was.
New 3D Map of the Universe — and a Growing Cosmological Debate
The Sloan Digital Sky Survey has released a new map of the universe — and the results confirm ongoing tension over the expansion rate of the universe.
First All-sky Map from eRosita
The first all-sky X-ray map to be released in 30 years reveals new wonders of the hot and energetic universe.
A Mysterious X-ray Signal Has Gone Missing
The absence of a mysterious X-ray signal — which could have provided evidence of dark matter — is causing as much controversy as its detection did.
Astronomers Rein in Possibilities for Exotic Particle
Astronomers observing a distant galaxy have dramatically shrunk the range of possible properties of a long-predicted — but never-detected — subatomic particle.
White Dwarf’s Whirlwind Spin Drags Spacetime
Astronomers have used observations of a tight white dwarf-neutron star pair to confirm an aspect of Einstein's general theory of relativity.
Hubble Sheds Light on Dark Matter and Cosmic Expansion
The Hubble Space Telescope, which will celebrate its 30th birthday this April, has images cosmic mirages that yield two remarkable cosmological results.
Should We Blame Pulsars for Too Much Antimatter?
A new study suggests that pulsars are not the source of an unexpected surplus of antimatter particles detected by a space-based experiment. Dark matter remains a viable alternative explanation.
Best Image Yet of the Cosmic Web
Using the light cast by galaxies bursting with new stars, astronomers have mapped out a piece of the cosmic web 12 billion light-years from Earth.
Tension Over Hubble Constant Continues
A new measurement fuels an ongoing debate about the rate at which today’s universe is expanding.
Evidence for a Dark Matter Clump in the Milky Way
There are ghosts in our galaxy’s past. Now astronomers have found a way to detect them.
Astronomers Find Universe’s First Molecule
After decades of searching, astronomers have definitively detected helium hydride, the first molecule to form in the early universe.
What Quasars Can Teach Us About Dark Energy
Astronomers have found a way to turn quasars into standard candles, with potentially far-reaching implications for the nature of mysterious dark energy.
Starlight Tally Reveals Cosmic History of Star Formation
Nearly 11 billion years ago, the universe churned out stars at a rate 10 times greater than today. And yet all the starlight in the cosmos appears no brighter on the sky than a 60-watt light bulb seen from miles away.
Astronomy in Space with David Dickinson
HaloSat: A Small Satellite for a Big Question
HaloSat, a mini-satellite recently deployed from the International Space Station, is on the hunt for the universe's missing matter.
Best Test of General Relativity on Galaxy Scales
Astronomers have conducted the best, galaxy-scale test of general relativity yet, and it rules out some (but not all) theories of modified gravity.
Pulsar Limits “Fifth Force” Interactions with Dark Matter
A recent experiment to better understand the nature of dark matter constrains a possible "fifth force" of nature to almost zero.