You Never See the Sun Where It Actually Is — Only Where It Was 8 Minutes Ago
Light takes time to travel, so every glance into space is a glance into the past. The night sky shows stars as they were years, even millennia, ago.
Cosmic Mysteries
Billions of Planets Are Drifting Through the Galaxy With No Star at All
Rogue planets wander interstellar space in permanent darkness, flung from their birth systems. There may be more of them than there are stars in the Milky Way.
The Andromeda Galaxy Is on a Collision Course With the Milky Way
Our galaxy and Andromeda are closing at 400,000 km/h and will merge in about 4.5 billion years. Yet not a single star is likely to collide.
A Photo of Sky the Size of a Sand Grain — Holding Thousands of Galaxies
Webb's first deep field captured galaxies as they were 13 billion years ago, in a patch of sky you could block with a sand grain held at arm's length.
Dark Energy: The Unknown Force That Owns 68% of the Universe
In 1998, astronomers found the universe's expansion is speeding up, driven by something nobody understands. It's the majority of everything, and it's a mystery.
Old TVs Could Pick Up the Big Bang — You May Have Watched It as Static
About 1% of analog TV static came from the cosmic microwave background: 13.8-billion-year-old light from the universe's infancy, still filling every cubic meter of space.
The Universe Is Expanding — but Our Two Best Measurements Disagree
Measured from the early universe, expansion runs at 67; measured from nearby stars, 73. The 'Hubble tension' hints our model of the cosmos is missing something.
The Boötes Void: A Hole in the Universe 330 Million Light-Years Wide
A region that should contain tens of thousands of galaxies holds barely 60. If the Milky Way sat at its center, we wouldn't have known other galaxies existed.
'Oumuamua: The Interstellar Object That Accelerated on Its Way Out
The first visitor from another star system was shaped like nothing we'd seen, had no comet tail — and sped up as it left. Scientists still argue about it.
Something Invisible Is Pulling Our Entire Galaxy Toward It at 2 Million km/h
The Milky Way and thousands of neighboring galaxies are streaming toward a mysterious region called the Great Attractor — hidden behind our own galaxy's disk.
The Pillars of Creation Are So Far Away They May Already Be Gone
One of the most famous space images shows towering columns of gas birthing stars — 6,500 light-years away, so their light shows us the distant past.
That Faint Band Across a Dark Sky Is You Looking Into Our Own Galaxy
The Milky Way's glowing arch is the combined light of hundreds of billions of stars — our galaxy seen from the inside. A third of humanity can no longer see it.
Something Is Sending Millisecond Radio Blasts From Across the Universe
Fast radio bursts release more energy in a millisecond than the Sun does in days — and some of them repeat on a schedule. We still don't know why.
85% of the Universe's Matter Is Missing — and We've Never Seen It
Every star, planet, and galaxy we can see is only a sliver of what exists. The rest is dark matter, and after 90 years we still don't know what it is.
The Wow! Signal: The 72-Second Radio Burst We've Never Heard Again
In 1977, a radio telescope in Ohio caught a signal so strange the astronomer on duty circled it and wrote 'Wow!'. Nearly 50 years later, it has never repeated.