Astrophysics

Astrophysics

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.
Map highlighting an area in Europe, centered on the Netherlands and surrounding countries, with a red overlay labeled "PDF.
Common knowledge says the maximum size of a PDF is as big as 40% of Germany — but that’s a gross underestimate.
branching parallel universes
The Multiverse isn't just a staple of science fiction; there's real-life science behind it, too. Here are 10 facts to expand your mind.
A colorful, spinning galaxy with a bright orange core, existing for 12 billion years, is surrounded by smaller galaxies and star clusters against a black space background.
Large, massive, rotating galaxies like the Milky Way are common today. So how could one form a mere ~2 billion years after the Big Bang?
Over a century after we first unlocked the secrets of the quantum universe, people find it more puzzling than ever. Can we make sense of it?
globular cluster terzan 5
For centuries, even after we knew the Sun was a star like any other, we still didn't know what it was made of. Cecilia Payne changed that.
A cartoon of three cosmic phenomena (CMB, Baryon Acoustic Oscillations, Supernovae) pulling on a triangle. Text below reads: "Something has to give...
DESI, by mapping galaxies, has claimed they see evidence for dark energy evolving by getting weaker. But that's only one interpretation.
From the vastness of space, Earth at night reveals its exo-earth beauty, with illuminated continents showcasing a tapestry of lights across North and South America. Major cities and regions emerge from the glowing darkness, painting a vivid picture against the backdrop of oceans.
Even from a single pixel, multiwavelength data taken over time can reveal clouds, icecaps, oceans, continents, and even signs of life.
Colorful galaxy with dark dust lanes and bright stars, set against a deep space background.
Someday, we'll look back and see a young galaxy forming stars for the first time. JADES-GS-z14-0, the farthest ever, isn't early enough.
Einstein's general relativity has reigned supreme as our theory of gravity for over a century. Could we reduce it back down to Newton's law?
Two side-by-side images of the Pillars of Creation in the Eagle Nebula showcase different views with vibrant colors and star-filled backgrounds, embodying the great paradox of beauty within science.
Our scientific instruments are constantly improving, revealing nature's workings as never before. Without them, we'll remain in the dark.
round Earth messenger
All scientific theories are limited in scope, power, and application, being mere approximations of reality. That's why consensus is vital.
A grid of six Hubble Space Telescope images showcases different types of colorful nebulae with intricate shapes against a starry backdrop.
Some nebulae emit their own light, some reflect the light from stars around them, and some only absorb light. But that's just the beginning.
A tilted spiral galaxy gracefully tipped towards the viewer reveals a bright core and dark, dusty rings, set against the infinity of deep blue space.
When we see spiral galaxies, some are face-on, others are edge-on, but most are tipped at an angle. But which side is closest to us?
Composite image of spiral galaxy NGC 300. Left: wide view with area highlighted. Right: close-up of highlighted area. Bottom: magnified star field view. NASA and the Hubble Heritage Team.
The tiniest galaxies of all are the most susceptible to violence by their larger, bullying siblings. That's why we need them in isolation.
A vivid image of a bright, colorful galaxy with swirling red, blue, and white clouds of gas and dust, where galaxies collide amid distant stars in the dark, expanding universe.
The Universe is expanding, and individual, bound structures are all receding away from one another. How, then, are galaxies still colliding?
A red star is at the center, with five orbiting paths marked by yellow dots, resembling exoplanets around the nearest single star, set against a starry night backdrop that illustrates a planetary system.
Barnard's star, the closest singlet star system to ours, has long been a target for planet-hunters. We've finally confirmed it: they exist!
A group of five men in suits pose with model rockets, showcasing their commitment to fundamental research. Beside them, an illustration depicts a space station orbiting Earth and the Moon, highlighting their visionary investment in space exploration.
Back in 1970, Sister Mary Jucunda wrote NASA, decrying large investments in science. A former Nazi's legendary response is still relevant.
Text "Cosmic Origins" over a bright, colorful explosion effect with star-like patterns in the background.
Since the dawn of history, humans have pondered our ultimate cosmic origins. Now in the 21st century, science has gone beyond the Big Bang.
Illustration shows a supermassive black hole with a captured star and hypervelocity star, near the Large Magellanic Cloud, with double star orbits labeled. Earth is visible in the foreground.
Just 165,000 light-years away, the Large Magellanic Cloud is suspected to house a supermassive black hole. At last, evidence has arrived.
Illustration of a comet from an old manuscript on the left, and a black and white image of a comet in space on the right.
Fears of celestial collisions — and calculations of their likelihood — go back to the very origins of modern science itself.
Green glowing orbs and funnel-shaped structures with light patterns floating in a vibrant green misty background.
There are some 26 fundamental constants in nature, and their values enable our Universe to exist as it does. But where do they come from?
Two images of the Sombrero Galaxy reveal its beauty: one with a bluish hue showcasing visible details, and the other with a reddish hue highlighting a different spectrum. Captured by JWST, these images offer an unmatched view of this spiral galaxy's complex structure.
One of the most promising dark matter candidates is light particles, like axions. With JWST, we can rule out many of those options already.
Laser guide star
Astronomers see spiral and elliptical nebulae nearly everywhere, except by the Milky Way's plane. We didn't know why until the 20th century.
warp field stars
Perhaps the most well-known equation in all of physics is Einstein's E = mc². Does mass or energy increase, then, near the speed of light?