Astrophysics

Astrophysics

A colored pixelated grid with rectangular outlines; a legend in the top right labels blue as F115W, green as F200W, and red as F277W—capturing data from the JWST to record a distant galaxy.
Coming from just 280 million years after the Big Bang, or 98% of cosmic history ago, this new, massive galaxy is a puzzle, but not a mirage.
entanglement across space
If all massive objects emit Hawking radiation, not just black holes alone, then everything is unstable, even the Universe. Can that be true?
Two bright, irregularly shaped nebula clouds with blue, purple, and pink gases dominate the dark space background, where dazzling stars twinkle—reminding us that in space, appearances can deceive.
There's an old saying that "what you see is what you get." When it comes to the Universe, however, there's often more to the full story.
A person sits on a chair with hands clasped, facing forward. Blue waveforms and dots form a digital backdrop behind them.
1hr 19mins
“We don't have enough knowledge to precisely calculate what is going to happen, and so we assign probabilities to it, which reflects our ignorance of the situation.”
Scatter plot with dark blue data points and black dashed elliptical contours centered on the origin, with axes labeled ξ (') horizontally and vertically—similar to plots used by astronomers in studies of the smallest galaxy ever discovered.
With stars, gas, and dark matter, galaxies come in a great array of sizes. This new one, Ursa Major III/UNIONS 1, is the smallest by far.
Astro2020
NASA astrophysics, which gave us Hubble, JWST, and so much more, faces its greatest budget cut in history. All future missions are at risk.
Diagram of the solar system with gravitational waves emanating from a distant bright source, and a triangular spacecraft array detecting the waves in space.
Just 10 years ago, humanity had never directly detected a single gravitational wave. We're closing in on 300 now, with so much more to come!
dark energy accelerated expansion
The fact that our Universe's expansion is accelerating implies that dark energy exists. But could it be even weirder than we've imagined?
baryon acoustic oscillations
It took nearly 400,000 years, after the Big Bang, to first form neutral atoms. The imprints from that early time can now be seen everywhere.
A dense field of stars and galaxies is visible against a black background, with some bright stars showing lens flares.
The COSMOS-Web survey is now complete, combining JWST and Hubble infrared data. Its spectacular views show us the Universe as never before.
Visualization of a section through the large-scale structure of the universe highlighting cosmic web patterns and distributions.
Since 1998, we've known our Universe isn't just expanding, but the expansion is accelerating. Could the Big Bang itself be the reason why?
Illustration of a large particle accelerator facility underground, with scientists working and a city landscape above ground.
The laws of nature are almost perfectly symmetric between matter and antimatter, and yet our Universe is made ~100% of matter only. But why?
A repeating pattern of wireframe 3D geometric shapes intersected by diagonal yellow lines on a black background, evoking a physics break down of forms at the Planck scale.
There are limits to where physics makes meaningful predictions: beyond the Planck length, time, or energy. Here's why we can't go further.
Bright star at the center of a blue nebula radiates mass energy, surrounded by numerous smaller stars, with diffraction spikes visible from the brightest stars.
All stars shine due to an internal source of energy. Usually, it's nuclear fusion: converting mass into energy. What makes them most bright?
Photons come in every wavelength you can imagine. But one particular quantum transition makes light at precisely 21 cm, and it's magical.
An artist's rendering of an alien planet and a red star.
A Cambridge-based team claims to find molecules on an exoplanet that are only produced by life on Earth. Don't fall for the unfounded hype.
According to Stephen Hawking, spontaneously emitted radiation should cause all black holes to decay. But we've never seen it: not even once.
Book cover of "Target Earth" by Govert Schilling, featuring a meteor streaking toward Earth—a striking visual of cosmic catastrophe—set against space, clouds below, and an orange background.
If an asteroid hadn't killed off the dinosaurs, humans would almost certainly have never walked the Earth.
An astronaut stands proudly on the moon's surface near scientific equipment and a lunar lander, as the American flag waves in the background, symbolizing a pioneering USA nation.
After drastic cuts to the NIH, the FDA, the NSF, and the DOE, NASA science faces down its smallest budget ever. All of society will suffer.
black hole baby universe
Perhaps no existential question looms larger than that of our ultimate cosmic origins. At long last, science has provided the answers.
A vast view of deep space, captured in one of NASA's most important images, displays numerous galaxies of varying shapes and colors against a dark backdrop scattered with distant stars.
The Hubble Space Telescope, launched in 1990, was originally seen as a colossal mistake. This one image, taken in 1995, changed everything.
A person sits in front of a white backdrop, surrounded by a cosmic map with galaxies and celestial objects.
2hr 18mins
"Asking the question of, "Where did the entire universe come from?" is no longer a question for poets and theologians and philosophers. This is a question for scientists, and we have some amazing scientific answers to this question."
uranium oxide oklo nuclear reactor
Planets can create nuclear power on their own, naturally, without any intelligence or technology. Earth already did: 1.7 billion years ago.
The spiral galaxy, surrounded by dim stars and interstellar dust, stands out against a dark background, shining brighter than astronomers once imagined.
The most famous Hubble images show glittering stars and galaxies amidst the black backdrop of space. But more was captured than we realized.
Diagram of the universe's expansion with grid patterns and cosmic elements, framed by "Consensus or Crisis?" in white text on black background. This visual encapsulates how cosmology changed from 2000 to 2025, highlighting key theories and discoveries.
25 years ago, our concordance picture of cosmology, also known as ΛCDM, came into focus. 25 years later, are we about to break that model?
planetary nebulae
In around 7 billion years, we expect the Sun to run out of fuel, dying in a planetary nebula/white dwarf combination. Is that for certain?
A glowing orange planet casts a shadow in space amid a backdrop of stars.
Exoplanets can exist anywhere around their parent stars, even so close that they evaporate or disintegrate. Even the rocky ones.
Two visualizations map the cosmos, displaying color-coded cosmic microwave background radiation. Blue and orange patches indicate temperature variations across a spherical and an oval projection.
It's difficult to project a sphere onto a flat, two-dimensional surface. All maps of the Earth have flaws; the same is true for the cosmos.
Two colorful spiral galaxies interacting in space, with bright centers and swirling arms of red, blue, and white hues, set against a backdrop of stars.
The Kalam cosmological argument asserts that everything that exists must have a cause, and the "first" cause must be God. Is that valid?
We understand many things about our Universe, and our home within it, extremely well. The number of stars in the Milky Way isn't among them.