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.

If all massive objects emit Hawking radiation, not just black holes alone, then everything is unstable, even the Universe. Can that be true?

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.

“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.”

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.

"We are all in orbit around the center of the Milky Way galaxy. How big is this collection of stars? Somewhere between 200 and 400 billion suns in the Milky Way galaxy, about 100,000 light years across."

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!

The fact that our Universe's expansion is accelerating implies that dark energy exists. But could it be even weirder than we've imagined?

The laws of physics obey certain symmetries and defy others. It's theoretically tempting to add new ones, but reality doesn't agree.

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.

The COSMOS-Web survey is now complete, combining JWST and Hubble infrared data. Its spectacular views show us the Universe as never before.

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?

Photons come in every wavelength you can imagine. But one particular quantum transition makes light at precisely 21 cm, and it's magical.

According to Stephen Hawking, spontaneously emitted radiation should cause all black holes to decay. But we've never seen it: not even once.

Empty space itself, the quantum vacuum, could be in either a true, stable state or a false, unstable state. Our fate depends on the answer.

Perhaps no existential question looms larger than that of our ultimate cosmic origins. At long last, science has provided the answers.

"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."

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?

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.

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.

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.

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?

"Many astronomers are really driven by the search for Earth twins because I think deep down the natural endpoint of this whole goal of looking for planets is to answer the question, are we alone?"

DESI, by mapping galaxies, has claimed they see evidence for dark energy evolving by getting weaker. But that's only one interpretation.

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?

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.

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?

The tiniest galaxies of all are the most susceptible to violence by their larger, bullying siblings. That's why we need them in isolation.