Astrophysics

Astrophysics

A colorful nebula with a bright center and symmetrical, wing-like clouds of gas and dust extends outward in space, as seen in a JWST reveal that uncovers stars and galaxies in the universe beyond.
Many facts are well-known to professionals, but are unappreciated or even rejected outright by the public. "How stars work" takes the cake.
Illustration of Earth overlaid with a grid and energy types from the Kardashev Scale: Type I, II, and III, representing planetary, stellar, and galactic energy usage.
The famous framework ranks civilizations by energy use — but ignores a critical factor that can halt their progress.
Image of a galaxy cluster with bright yellow galaxies at the center, surrounded by blue regions representing dark matter in deep space—a striking view often used for dark matter cosmic test MOND studies.
On cosmic scales, only dark matter (or something equivalent) gives us the Universe we observe. Now, the Sunyaev-Zel'dovich effect agrees.
Colorful nebula with bright stars ignite glowing gas clouds in space, featuring red, yellow, and blue hues against a dark background.
Although a star's "birth" is well-defined, it doesn't correspond to an ignition event in its core. Here's how stars are actually born.
A bright, circular object with concentric rings and a surrounding halo set against a dark background, resembling a gap-clearing planet or other astronomical phenomena.
One parameter, alone, sets the dividing line between rocky planets, gas giants, brown dwarfs, stars, and much more. Here's why mass matters.
A distorted galaxy with two bright, horizontal bands and scattered stars, seen against a dark background. Image credit: NASA/ESA/CSA.
By looking at a giant, remarkable, edge-on protoplanetary system, astronomers have found a proto-protoplanet for the first time.
Four people wearing black shirts and eclipse glasses look up at the camera indoors, their excitement echoing the spirit of the Artemis II distance record mission.
Human beings have now traveled farther from Earth than ever before with Artemis II's flyby of the lunar far side. Here's how it happened.
Known as the "past hypothesis" problem, the Universe's initially low entropy has long puzzled scientists. Now, cosmic inflation solves it.
A labeled illustration shows the Large Magellanic Cloud, astronomers' most pristine star (SDSS J0715-7334), and the Milky Way galaxy connected by a wispy trail.
The 1st generation of stars formed, lived, and died very early on. But 2nd generation stars could still persist today. Did we just find one?
A person’s silhouette looks out a spacecraft window at Earth—a blue and white sphere against the darkness of space—reflecting the hope inspired by Artemis II’s journey to the moon.
As humanity journeys to the Moon for the first time since 1972, can we rediscover our shared responsibilities: to the world and each other?
black hole merger
As light travels across the Universe, it's subject to cosmic expansion, changing fields, and relative motion. How about gravitational waves?
moon landing Apollo 11
Even though no human has stepped foot on the Moon's surface in 50 years, the evidence of our presence there remains unambiguous.
logarithmic history of universe
In a 13.8 billion year old Universe, a few seconds hardly seems like it matters. But these minuscule changes sure do add up over time.
Two peculiar galaxies collide in deep space, forming bright clusters and swirling dust clouds—a striking scene that reveals the beauty and violence of the cosmos against a dark background.
Most massive galaxies are spiral or elliptical shaped. But peculiar galaxies showcase the beautiful violence that helps explain our cosmos.
Illustration of multiple spiral galaxies and stars being pulled toward a central black hole in deep space, with blue and purple light streaks tracing the motion along a dark energy curve that shapes the universe.
Early on, the Universe needed near-perfect flatness, or atoms, stars, and galaxies couldn't form. What happens once dark energy takes over?
bok globule barnard 68 dust wavelength
The image you're seeing isn't a hole in the Universe, and the cosmic voids that do exist aren't hole-like at all.
A person sits on a chair against a white backdrop with abstract black dotted patterns, set against a yellow background.
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NASA astronomer Michelle Thaller makes the case that quantum entanglement may be the underlying fabric from which spacetime itself emerges. 
Looking up at the night sky gives us a glimpse of the Universe beyond our terrestrial concerns. Here's the science of what's out there.
No matter what physical system we consider, nature always obeys the same fundamental laws. Must it be this way, and if so, why?
color charge color anticolor
When what we predict and what we measure don't add up, that's a sign there's something new to learn. Could it be a new fundamental force?
travel straight line
In theory, the fabric of space could have been curved in any way imaginable. So why is the Universe flat when we measure it?
Binary black holes eventually inspiral and merge. That's why the OJ 287 system is destined for the most energetic event in history.
M81 Group
Over billions of years, fewer stars form, galaxies mutually recede, and the Universe becomes ever darker. Here's how fast it all happens.
wormholes
Nothing lives forever, at least, not in the known Universe. But relativity allows us to get closer than ever: from a physics perspective.
A satellite with large solar panels orbits above Earth against a colorful space background, where the cosmic clouds resemble the Hand of God carved by a dead star.
The path to exploring the high-energy Universe was clear and compelling. Here's how 2025's cuts are still causing NASA casualties in 2026.
Side-by-side images of a nebula in space, showing colorful, wispy gas and dust shells surrounding a bright central region with numerous stars in the background.
Resembling a cosmic brain, the Exposed Cranium Nebula instead shows a dying, massive star, as JWST reveals. Its fate remains uncertain.
warm-hot intergalactic medium sculptor wall
In traveling through the expanding Universe, particles slow down while light and gravitational waves redshift. What degrades and what won't?
A view of a star-filled night sky with numerous bright stars and distant galaxies, including Hubble-dark galaxy formations, scattered across a dark background.
The discovery of CDG-2, a galaxy that's more than 99.9% dark matter, could reveal a new population of ultra-faint galaxies. But is it real?
Voyager
No human has ever left the Solar System, and only six already-launched spacecraft will ever exit it. Will Voyager 1 remain the most distant?
black hole
Quantum entanglement links information between particles across space and time. So what happens when one of them falls into a black hole?