Astronomers have counted up the number of galaxy clusters in the cosmos and found a problem: the number is much lower than they expected. What's going on?
A rare alignment of a quasar’s “flashlight” beam and a filament of the cosmic web illuminates the universe’s large-scale structure.
A new image of the Lagoon Nebula from the Paranal Observatory in Chile provides a stunning view the iconic object, which lies 5,000 light-years from Earth in Sagittarius.
Evidence from observations and computer simulations supports a picture of galaxy growth that isn't dominated by the rough-and-tumble crashes of big galaxies. Instead, most of the universe's stellar metropolises appear to feed themselves with nibbles instead of feasts.
Astronomers have used the Hubble Space Telescope to peek into the universe's early eras using the light from galaxies that existed several hundred million years after the Big Bang.
A contentious yet gifted astronomer, Arp challenged a key underpinning of the Big Bang throughout the 1970s and 1980s and ultimately fell into disfavor among his colleagues.
Imagine a three-star system with two white dwarfs and a wildly spinning, superdense neutron star, all packed within a space no bigger than Earth's orbit.
Gaia launched flawlessly Thursday morning at 9:12 UTC (4:12 a.m. Eastern Standard Time). This long-awaited mission will precisely map the distances and motions of 1 billion stars in our galaxy.
A complex of three bright, star-forming clumps called Himiko is merging in the early universe. With its light reaching us from when the universe was only 800 million years old, this primordial galaxy could yield insight into the elusive process of early galaxy formation.
Two recent experiments limit physicists’ favorite candidate for the elusive and invisible matter lurking in the universe.
Astronomers have confirmed that light from a distant galaxy is reaching us from about 700 million years after the Big Bang. The galaxy's emission hints that star formation during that era might have proceeded at a much faster rate than previously thought.
After four years of exquisite observations, the latest mission to study the universe's earliest light has been shuttered. But this end is a happy one and comes with a significant cosmological legacy.
Astronomers have finally detected a much-hoped-for pattern in the afterglow of the Big Bang, and it might help reveal inflation's signature.
Four powerful radio bursts have left astronomers scratching their heads. The bursts appear to come from several billion light-years away and could provide a whole new look at the universe — but observers aren't sure what they are.
Studies of primitive stars suggest the universe has far too little of one form of lithium and far too much of another. But new work shows that the second problem might be nonexistent.
A massive neutron star and its lightweight sidekick provide a unique space laboratory to test general relativity. So far, gravity keeps behaving as it's supposed to.
Three potential detections from deep underground could be from dark matter particles. While still uncertain, the result suggests a particle mass in keeping with hints from several other experiments.
Scientists using an instrument aboard the International Space Station have measured a signal that might come from dark matter — or might not.
Planck mission scientists have released the first half of their observations of the cosmic microwave background. The results are a stunning confirmation of today's standard model for how the universe formed and grew. But they also raise some head-scratchers.
Nearing the end of its mission, ESA's Herschel Space Observatory has delivered a highly detailed map of extremely cold gas and dust in the iconic Andromeda Galaxy.
Our Milky Way ranks near the top in the pecking order of spiral galaxies, but it's no match for an enormous "island universe" in the constellation Pavo that is more than 500,000 light-years across.
Scientists keep trying to disprove the Standard Model that governs modern physics. And they keep failing.
New observations by the Hubble Space Telescope reveal some of the earliest galaxies in the universe.
Astronomers have discovered an unexpected explanation for why they can only find a small fraction of the satellite galaxies the Milky Way is supposed to have.
An international team has used the disappearance of high-energy photons to narrow in on the origin of the light suffusing the cosmos.