Articles by Rafi Letzter, Contributor

Rafi wrote for Live Science from 2017 until 2021, when he became a technical writer for IBM Quantum. He has a bachelor's degree in journalism from Northwestern University’s Medill School of journalism. You can find his past science reporting at Inverse, Business Insider and Popular Science, and his past photojournalism on the Flash90 wire service and in the pages of The Courier Post of southern New Jersey.

Articles by: Rafi Letzter

A Hubble Space Telescope image shows the Lagoon Nebula, part of the small portion of matter in the Milky Way that isn't made of dark matter.

A huge cloud of invisible particles seems to be missing from the Milky Way

By Rafi Letzter published 14 April 20

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.

A Hubble Space Telescope image shows RS Puppis, one of the cepheids used to measure the expansion of the universe.

We might be living in a gigantic, intergalactic bubble

By Rafi Letzter published 25 March 20

The bubble concept could explain one of the strangest mysteries plaguing astrophysics: Why can't we tell how fast the universe is expanding?

This radio image shows two jets shooting out of the center of Cygnus A, a galaxy not too far from our own. A new paper reports discovering a similar object in a much more distant, ancient galaxy. That galaxy has a bright, relatavistic jet emanating from its central supermassive black hole pointed at Earth, making it a blazar.

The universe may have been filled with supermassive black holes at the dawn of time

By Rafi Letzter published 15 March 20

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.

A long-exposure image shows stars appearing to whirl around Polaris, the north star, which appears fixed in the sky.

Something strange is going on with the North Star

By Rafi Letzter published 12 March 20

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.

A map shows the sharp decline in emissions over China between early January and late February as parts of the country went on lockdown in an attempt to contain the COVID-19 coronavirus.

Dramatic effect of coronavirus lockdowns seen from space

By Rafi Letzter published 3 March 20

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.

american physical society aps conference cancelled coronavirus

Huge physics conference canceled at the last minute due to coronavirus fears

By Rafi Letzter published 3 March 20

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

By Rafi Letzter published 2 March 20

The bubbling, raucous quantum vacuum distorts the shape of every hydrogen atom in the universe, and it distorts antimatter "antihydrogen" too.

Physicist Freeman J. Dyson at The Church Center for the United Nations in New York on March 22, 2000.

Freeman Dyson, quantum physicist who imagined alien megastructures, has died at 96

By Rafi Letzter published 28 February 20

Physicist Freeman Dyson was known for his work on quantum physics and mathematics, as well as his big ideas about the far future.

An illustration shows a rocket approaching an asteroid that's drifted too close to Earth. A scout probe orbits nearby.

What should we do if a 'planet-killer' asteroid takes aim at Earth?

By Rafi Letzter published 22 February 20

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.

An image from NASA's Cassini probe, taken Sept. 23, 2006, shows a pair of hydrocarbon lakes on Titan.

Saturn's weird, Earth-like moon just failed a key test for alien life

By Rafi Letzter published 18 February 20

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.

A photo shows the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project at night.

Mysterious 'fast radio bursts' from deep space repeat themselves every 16 days

By Rafi Letzter published 11 February 20

For the first time, astrophysicists have detected a pattern in fast radio bursts, one of the most mysterious phenomena in the universe.

A single frame Rosetta navigation camera image of Comet 67P/Churyumov-Gerasimenko.

Rosetta's 'rubber ducky' comet changed color as it neared the sun. Here's why.

By Rafi Letzter published 8 February 20

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.

An illustration shows what the interior of IceCube might look like without the ice.

A super-rare 'Zee burst' in Antarctica could one day unlock a key mystery of ghostly neutrinos

By Rafi Letzter published 7 February 20

Watch out for the Zee burst!

Photons could reveal 'massive gravity,' new theory suggests

By Rafi Letzter published 6 February 20

This is a radical new design compared to the world's most sensitive gravitational wave detectors.

Black holes are infinitely dense objects surrounded by smooth event horizons.

Black holes shouldn't echo, but this one might. Score 1 for Stephen Hawking?

By Rafi Letzter published 2 February 20

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.