Latest articles by Rafi Letzter
These lava tubes could be the safest place for explorers to live on Mars
The Martian surface is a radiation hot zone. But ancient lava tubes might offer explorers safety from the cosmic bombardment
Massive piece of Chinese space junk slams uncontrolled into Earth's atmosphere
The 19.6 ton (17,800 kilogram) body of a Chinese rocket slammed into the planet's atmosphere today (May 11). It was the biggest such incident since 1991.
Renowned string theorist proposes new way to hunt our solar system's mysterious 'Planet 9'
A new paper by physicist Edward Witten proposes hunting Planet 9 using a fleet of laser-launched probes like Breakthrough Starshots'.
A long-lost type of dark matter may resolve the biggest disagreement in physics
Right now, key measurements of the universe's expansion are contradicting each other. A lost form of dark matter could help them agree.
A huge cloud of invisible particles seems to be missing from the Milky Way
A key signal for a certain kind of dark matter failed to turn up in a search throughout the Milky Way. Now scientists are disagreeing about what that means.
We might be living in a gigantic, intergalactic bubble
The bubble concept could explain one of the strangest mysteries plaguing astrophysics: Why can't we tell how fast the universe is expanding?
The universe may have been filled with supermassive black holes at the dawn of time
As the universe cooled in the era after the Big Bang, a supermassive black hole had already formed in the center of a galaxy, forming a giant engine of energy we can still see today.
Something strange is going on with the North Star
Something's up with the North Star, a cepheid. Its distance, mass and age should be easy to measure. But new calculations keep disagreeing with one another and failing to make sense.
Dramatic effect of coronavirus lockdowns seen from space
There's been a sharp drop in air pollution over China since the acceleration of the COVID-19 coronavirus outbreak, and satellites can see it from space.
Huge physics conference canceled at the last minute due to coronavirus fears
Organizers of the American Physical Society's March conference made the decision to cancel due to coronavirus concerns less than two days before the conference was set to begin.
Mysterious 'antihydrogen' particles reveal uncanny quantum effect
The bubbling, raucous quantum vacuum distorts the shape of every hydrogen atom in the universe, and it distorts antimatter "antihydrogen" too.
Freeman Dyson, quantum physicist who imagined alien megastructures, has died at 96
Physicist Freeman Dyson was known for his work on quantum physics and mathematics, as well as his big ideas about the far future.
What should we do if a 'planet-killer' asteroid takes aim at Earth?
If a giant object looks like it's going to slam into Earth, humanity has a few options. A new guide could help NASA decide which one is best.
Saturn's weird, Earth-like moon just failed a key test for alien life
Life on Earth likely began with the bubble-like membranes that surround our cells. Similar membranes probably wouldn't form on Titan, according to quantum mechanics.
Mysterious 'fast radio bursts' from deep space repeat themselves every 16 days
For the first time, astrophysicists have detected a pattern in fast radio bursts, one of the most mysterious phenomena in the universe.
Rosetta's 'rubber ducky' comet changed color as it neared the sun. Here's why.
As Rosetta's comet got near enough to the sun for frost to evaporate off its surface, a color-changing water and dust cycle began that shuffled its colors around.
A super-rare 'Zee burst' in Antarctica could one day unlock a key mystery of ghostly neutrinos
Watch out for the Zee burst!
Photons could reveal 'massive gravity,' new theory suggests
This is a radical new design compared to the world's most sensitive gravitational wave detectors.
Black holes shouldn't echo, but this one might. Score 1 for Stephen Hawking?
When two neutron stars slammed together far off in space, they created a powerful shaking in the universe — and their echoes could violate Einstein's theory of relativity.
Physicists: Ancient life might have escaped Earth and journeyed to alien stars
A pair of researchers presented a wild new theory in a new paper.
2 satellites will narrowly avoid colliding at 32,800 mph over Pittsburgh on Wednesday
A collision would create a debris belt that would endanger spacecraft worldwide.
Mysterious particles spewing from Antarctica defy physics
What's making these things fly out of the frozen continent?
Ancient Australian crystals unlock history of Earth's first magnetic field
It was a lot more powerful than anyone believed.
