Space & Astrophysics
Did the Milky Way form by slowly accreting matter or by devouring its neighboring galaxies? At last, we’re uncovering our own history.
Forget billions and billions. When it comes to the number of galaxies in the Universe, both theorists’ and observers’ estimates are too low.
Known as orphaned planets, rogue planets, or planets without parent stars, these “outliers” might be the most common type of planet overall.
Our galactic home in the cosmos — the Milky Way — is only one of trillions of galaxies within our Universe. Is one of them truly our “twin?”
Electromagnetism, both nuclear forces, and even the Higgs force are mediated by known bosons. What about gravity? Does it require gravitons?
When three wise men gifted baby Jesus with gold, frankincense, and myrrh, they had no idea one was made from colliding neutron stars.
Carl Sagan was far from the first to declare we are the children of ancient stars.
There was a lot of hype and a lot of nonsense, but also some profoundly major advances. Here are the biggest ones you may have missed.
The Firefly Sparkle galaxy was only spotted because of gravitational lensing’s effects. Yet galaxies like these brought us a visible cosmos.
Sixty years ago, the Soviet Union was way ahead of the USA in the space race. Then one critical event changed everything.
The problem for galactic-scale civilizations comes down to two numbers.
From a hot, dense, uniform state in its earliest moments, our entire known Universe arose. These unavoidable steps made it all possible.
It was barely a century ago that we thought the Milky Way encompassed the entirety of the Universe. Now? We’re not even a special galaxy.
Even with just a momentary view of our galaxy right now, the data we collect enables us to reconstruct so much of our past history.
50 years ago, Stephen Hawking showed that black holes emit radiation and eventually decay away. That fate may now apply to everything.
The closest known star that will soon undergo a core-collapse supernova is Betelgeuse, just 640 light-years away. Here’s what we’ll observe.
Most waves need a medium to travel through. But the way that light and gravitational waves travel shows that space can’t be a medium at all.
The Sombrero is the closest bright, massive, edge-on galaxy to us. JWST’s new image, taken with MIRI, finally shows what’s under its hat.
Gravitational waves are the last signatures that are emitted by merging black holes. What happens when these two phenomena meet in space?
DESI has allowed astronomers to create an unprecedented 3D map of the Universe representing 20% of the entire sky.
For nearly 60 years, the hot Big Bang has been accepted as the best story of our cosmic origin. Could the Steady-State theory be possible?
In November 1974, astronomers used the radio telescope at Puerto Rico’s Arecibo Observatory to send a hello to the universe.
Two parts of our Universe that seem to be unavoidable are dark matter and dark energy. Could they really be two aspects of the same thing?
“I was stunned. Here in front of me was the original apparatus through which a new vision of the world was slowly and painfully brought to light.”
Scalars, vectors, and tensors come up all the time in physics. They’re more than mathematical structures. They help describe the Universe.
Since the mid-1960s, the CMB has been identified with the Big Bang’s leftover glow. Could any alternative explanations still work?
The most massive early galaxies grew up faster, and have more stars, than astronomers expected, according to JWST. What does it all mean?
There are a few small cosmic details that, if things were just a little different, wouldn’t have allowed our existence to be possible.
Recent controversies bode ill for the effort to detect life on other planets by analyzing the gases in their atmospheres.
Astronomer Adam Frank asks: With so many extraordinary claims, why can’t anybody produce the proof?