Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

The LIGO detector in Louisiana. Photo: Caltech/MIT/LIGO Lab

Astronomers think they've detected the ripples in space and time sent out by a black hole and neutron star colliding.

The big picture: Scientists have detected gravitational waves sent out by 2 black holes merging and 2 neutron stars merging, but if confirmed, this will be the first detection of a black hole and neutron star colliding.

Why it matters: Astronomers hope that the Aug. 14 detection will help them learn more about both black holes and neutron stars, the super dense remnants of dead stars.

Details: Researchers aren't yet sure of the exact size of the black hole or neutron star that sent out the gravitational waves, but further analysis could help determine the masses of the two objects.

  • "[W]e're very confident that we've just detected a black hole gobbling up a neutron star," physicist Susan Scott, of Australian National University, said in a statement.
  • “However, there is the slight but intriguing possibility that the swallowed object was a very light black hole — much lighter than any other black hole we know about in the universe. That would be a truly awesome consolation prize.”

How it works: The two LIGO detectors in Washington state and Louisiana and the Virgo detector in Italy are responsible for listening for gravitational waves emitted by cosmic crashes as they move through our part of space.

  • The sensitive L-shaped observatories use lasers to pick up the moment that the ripples pass through Earth, slightly warping everything they pass through as they go.

Go deeper

Fed chair says low interest rates aren't driving stock market prices

Jerome Powell. Photo: ANDREW CABALLERO-REYNOLDS / Getty Images

Federal Reserve chairman Jerome Powell told reporters on Wednesday that rock-bottom interest rates aren't playing a role in driving stock prices higher, while noting that vulnerabilities to the financial system are "moderate."

Why it matters: The statement comes amid unshakeable stock prices and a Reddit-fueled market frenzy — prompting widespread fears of a bubble and the role monetary policy has played in that.

2 hours ago - World

Biden freezes U.S. arms deals with Saudi Arabia and UAE

Trump struck several large arms deals with Mohammed bin Salman (L) and Saudi Arabia. Photo: Kevin Dietsch-Pool/Getty Images

The Biden administration has put on hold two big arms deals with Saudi Arabia and the United Arab Emirates which were approved in the final weeks of the Trump administration, a State Department official tells Axios.

Why it matters: The sales of F-35 jets and attack drones to the UAE and a large supply of munitions to Saudi Arabia will be paused pending a review. That signals a major policy shift from the Trump era, and may herald sharp tensions with both Gulf countries.

Dan Primack, author of Pro Rata
2 hours ago - Podcasts

Robert Downey Jr. launches VC funds to help save the planet

Robert Downey Jr. on Wednesday announced the launch of two venture capital funds focused on startups in the sustainability sector, the latest evolution of a project he launched two years ago called Footprint Coalition.

Between the lines: This is a bit of life imitating art, as Downey Jr. spent 11 films portraying a character who sought to save the planet (or, in some cases, the universe).