Astrophysics

Astrophysics

flight through universe CEERS JWST NASA
Wavelengths stretch, distances grow, and temperatures cool as the Universe expands with time. How are the various cosmic parameters related?
A jellyfish galaxy with a bright white and yellow core is surrounded by red clouds of gas, set against a dark background filled with stars.
Weird-looking galaxies, with tentacle-like tails or prominent dual streams, appear like jellyfish or bunny ears. But that’s just the start.
A vast starry sky showcases a spinning galaxy, a relic from 12 billion years ago, among countless stars of varying brightness on a dark background.
For over 10 billion years, the cosmic star-formation rate has been dropping and dropping. Someday, the final star in the Universe will die.
gravity probe b
We first measured G, the gravitational constant, back in the 18th century. As the least well-known fundamental constant, can it be improved?
In 2017, a kilonova sent light and gravitational waves across the Universe. Here on Earth, there was a 1.7 second signal arrival delay. Why?
A cylindrical space habitat with green landscapes and rivers, viewed from inside; two moons and a bright sun-like object are visible through large windowed sections.
NASA’s Caleb Scharf talks with Big Think about life’s long experiment in expansion.
Four people work at consoles surrounded by monitors and control panels in a dimly lit NASA mission control room, with large display boards overhead.
What if the first search for life beyond Earth actually succeeded?
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.
Planets grow from protostellar material in disks, leading to full-grown planetary systems in time. At last, the final gap has been filled.
A wavy line, one meter long, transitions from dark red to bright yellow above a ruler, set against a magenta oval with a blue background featuring drawn human figures.
Until the late 20th century, there wasn't a truly universal standard. Under our current definition, everyone agrees on what "one meter" is.
Book cover of "Do Aliens Speak Physics?" by Daniel Whiteson and Andy Warner, featuring a blue background, yellow and white text, and an illustration of a robot and people interacting.
Do aliens speak the same physics that we do, with similar laws, observables, and underlying mathematics. Maybe not, argues Daniel Whiteson.
gravitational wave effects on spacetime
We've now detected hundreds of gravitational waves with LIGO, Virgo, and KAGRA. What if we tried Weber's original method in the modern day?
terraforming
The first world beyond Earth for human habitability should be the Moon, not Mars. This is why we should terraform our lunar neighbor first.
two particles different wavelength speed of light
Times dilate and lengths contract near the speed of light. Bizarre and confusing? Sure. But under relativity, it can't be any other way.
A field of galaxies in deep space, featuring a bright spiral galaxy at the lower right with a stellar stream escaping the galaxy, and a large, bright red star at the upper left.
Stellar streams are faint trails of stars that appear to "stream" out of galaxies. A new one, escaping galaxy M61, may point to many others.
Three side-by-side images show different views of the Red Spider Nebula in space, captured by JWST, with a bright center and colorful gases in orange, green, and blue against a backdrop of stars.
When dying, Sun-like stars have binary companions, spectacular sights arise from the ionization. JWST spots the Red Spider Nebula in action!
big crunch
There's some, but not overwhelming, evidence that dark energy is evolving. What would it take for a "Big Crunch" to be our cosmic fate?
solar system model
Scientists are notoriously resistant to new ideas. Are they falling prey to groupthink? Or are our current theories just that successful?
ufo lights liverpool
Physicist Daniel Whiteson challenges the notion that all intelligent species would eventually uncover the same laws of nature. Do you agree?
DUNE neutrino detectors
Nearly 100 years after being theorized, the strange behavior of the neutrino still mystifies us. They could be even stranger than we know.
An image of El Gordo, a massive galaxy cluster captured by Hubble
The planet, the Solar System, and the galaxy aren't expanding. But the whole Universe is. So where does the dividing line begin?
big bang
For 13.8 billion years, the Universe has been expanding. But that couldn't have been the case for an eternity, and science has proven it.
dark matter
Dark matter has never been directly detected, but the astronomical evidence for its existence is overwhelming. Here's what to know.
A dense cluster of differently sized red, blue, and green spheres overlaps against a black background, evoking the biggest mysteries surrounding the origin of the universe.
We've long known we can't go back to infinite temperatures and densities. But the hottest part of the hot Big Bang remains a cosmic mystery.
quasar-galaxy hybrid
Found by Hubble before JWST's launch, GNz7q looked like a mix of a galaxy and a quasar. Was it actually our first known "little red dot"?
Illustration of the universe's large-scale structure with colorful concentric circles, representing cosmic structure distribution, against a black background.
Observations with the Hubble space telescope helped cement dark energy and reveal the Hubble tension. How are these two things so different?
A spacecraft with bright engine exhaust approaches Mars, depicted with its reddish surface and a large crater visible.
"Think of it like a transcontinental railroad — not the fastest way to move a lot of mass, but certainly the most efficient,” Jared Isaacman said about nuclear electric propulsion.
A series of solar sail spacecraft harvest solar power at night, floating above Earth's atmosphere with the sun shining in the background.
Solar power has the disadvantage that there's no Sun at night. Satellite startup Reflect Orbital wants to change that, but at what cost?
Artistic illustration depicting one of the biggest mysteries of the origin of the universe, showing entangled particles connected by curved paths in space, inspired by concepts from quantum physics and wormholes.
Inflation's two main criticisms, that it can predict anything and that the "measure problem" remains unsolved, can't erase its successes.
The Orion Nebula surrounded by stars, with a bright green meteor streaking diagonally across the image, evokes the wonder of shooting stars illuminating the night sky.
The Orionids meteor shower peaks October 20th/21st here in 2025, coinciding with a new Moon. See the brightest shooting stars of the year!
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!