Universe Expansion

Universe Expansion

A view of deep space showing numerous galaxies of various shapes and sizes scattered across a dark background.
To learn how our Universe grew up, we have to look at large numbers of galaxies at all distances to find out. Good thing we have JWST!
A colorful, irregular galaxy with bright clusters of stars, some possibly from a generation stars before sun, and nebulae against a dark background scattered with distant stars.
Our Sun only arose after 9.2 billion years of cosmic history: with many stars living and dying first. How many prior generations were there?
Since the time of Galileo, Saturn's rings have remained an unexplained mystery. A new idea may have finally solved the longstanding puzzle.
A split image shows a star field on the left and a COSMOS-Web survey area diagram on the right, with labeled NIRCam and MIRI footprints alongside the moon for scale, highlighting galaxies explored by JWST science.
By deeply imaging a large volume of space, COSMOS-Web provides JWST's widest cosmic views. Its gravitational lenses reveal a big surprise.
As the Universe ages, it continues to gravitate, form stars, and expand. And yet, all this will someday end. Do we finally understand how?
From here on Earth, looking farther away in space means looking farther back in time. So what are distant Earth-watchers seeing right now?
A diagram illustrating one of the biggest mysteries: the origin of the universe, from the Big Bang and inflation to today, showing the formation of atoms, stars, galaxies, and the ongoing expansion of space.
From the Big Bang to a prior period of cosmic inflation, our cosmic origins are clearer than ever. Yet these 5 big mysteries still remain.
A circular diagram illustrating the observable universe, showing planets, stars, galaxies, and cosmic background radiation layers—revealing where Big Bang echoes still linger.
If you think of the Big Bang as an explosion, we can trace it back to a single point-of-origin. But what if it happened everywhere at once?
black hole
All of the matter that we measure today originated in the hot Big Bang. But even before that, and far into the future, it'll never be empty.
planck temperature polarization
The hot Big Bang is often touted as the beginning of the Universe. But there's one piece of evidence we can't ignore that shows otherwise.
As we gain new knowledge, our scientific picture of how the Universe works must evolve. This is a feature of the Big Bang, not a bug.
most distant
The universe is filled with unlikely events, but it is also full of ways to fool ourselves.
ESO milky way
Questions about our origins, biologically, chemically, and cosmically, are the most profound ones we can ask. Here are today's best answers.
A dense star field with dark, irregular dust clouds—where cosmic dust come from—obscures parts of the glowing stars in the Milky Way.
Dust is ubiquitous in the modern Universe, appearing in nearly all galaxies. But our cosmos was born dust-free. So where does it originate?
It's the origin of our entire observable Universe, but it's still not the very beginning of everything.
Book cover for "Facing Infinity: Black Holes and Our Place on Earth" by Jonas Enander, featuring a starry night sky, a swirling black hole graphic, and a faint silhouette of a priest gazing into the cosmic abyss.
In this excerpt from "Facing Infinity," Jonas Enander examines how John Michell conceived of "dark stars," or massive bodies with enough gravity to trap light, all the way back in 1783.
A bright, circular blue and white object is centered against a black background, with a smaller red object to the lower left.
Going back to 1990, we hadn't even found one planet outside of our Solar System. As we close in on 6000, we now see many of them directly.
Abstract 3D geometric surface with intersecting translucent orange and brown planes, inspired by the amplituhedron theory of everything, set against a blurred orange background with white network lines.
Since even before Einstein, physicists have sought a theory of everything to explain the Universe. Can positive geometry lead us there?
An artist's impression of a cluster of stars.
With several seemingly incompatible observations, cosmology faces many puzzles. Could early, supermassive stars be the unified solution?
As we look to larger cosmic scales, we get a broader view of the expansive cosmic forest, eventually revealing the grandest views of all.
An abstract animation of white, textured patterns symmetrically forming on a blue and black background evokes the mysterious dance of dark energy, subtly hinting at its weakening presence as if guided by the precision of DESI.
The Universe isn't just expanding; the expansion is accelerating. If different methods yield incompatible results, is dark energy evolving?
A chart titled "Masses in the Stellar Graveyard" shows the black holes and neutron stars detected by LIGO-Virgo-KAGRA, plotted on a logarithmic scale in solar masses, highlighting how LIGO triples black hole haul with each new discovery.
10 years ago, LIGO saw its first gravitational wave. After 218 detections, our view of black holes has changed forever. Can this era endure?
A grainy black and white image shows SPHEREx comet 3I/ATLAS gleaming at the center, surrounded by stars appearing as streaks due to long exposure.
Designed to map galaxies, the SPHEREx mission's first science result is instead about interstellar interloper 3I/ATLAS. No, it's not aliens.
Four images of a nebula, sculpted by a dead star, are shown side by side in radio, optical, and X-ray wavelengths; the fourth composite image reveals the so-called "Hand of God." Each is labeled at the bottom.
In our own Milky Way, a recently deceased star creates a ghostly, hand-like shape in X-rays some 150 light-years wide. Here's how it's made.
A 3D potential energy surface with a central peak and surrounding valley illustrates zero-point energy power; two blue spheres indicate positions atop the peak and within the valley. Axes labeled Re(φ), Im(φ), and V(φ).
Throughout history, "free energy" has been a scammer's game, such as perpetual motion. But with zero-point energy, is it actually possible?
The Universe was born incredibly hot, and has expanded and cooled ever since. Could life have begun back when space was "room temperature?"
space expanding
Just 13.8 billion years after the hot Big Bang, we can see 46.1 billion light-years away in all directions. Doesn't that violate...something?
An image of an ancient black hole
At the center of Hubble's famous "cosmic horseshoe," a very heavy supermassive black hole has been robustly measured. How is it possible?
parallel universe
Parallel universes are among the most profound notions in all of quantum physics. It's a compelling and fascinating idea, but is it true?
A hexagonal telescope with a gold exterior and an open, black interior is shown against a black background, highlighting NASA habitable worlds observatory science.
At the end of July, hundreds of scientists convened to plan NASA's upcoming astrophysics flagship mission. Will the US allow it to happen?