Gold nugget. Photo: studiocasper / iStock

The Earth formed over 4 billion years ago with a ready supply of heavy elements like gold and platinum, but the source of those elements has been somewhat of a mystery.

Stars like our sun fuse hydrogen into helium, and at the end of their lives go on to create carbon and oxygen before exhausting themselves. Bigger stars are capable of the intense pressures needed to make silicon, magnesium, nickel and iron before exploding in ferocious supernova detonations that can make even heavier stuff.

What's next: The recent observation of merging neutron stars puts an interesting twist on the game of elements: three Earth masses worth of gold was found in the remnants of that explosion. This means that, like supernovas, these energetic mergers are capable of forming heavy elements. Which process dominates in the universe? We're still not sure.

Go deeper: More on the neutron star collision.

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Updated 27 mins ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 8 a.m. ET: 19,401,935 — Total deaths: 721,906 — Total recoveries — 11,767,805Map.
  2. U.S.: Total confirmed cases as of 8 a.m. ET: 4,942,747 — Total deaths: 161,367 — Total recoveries: 1,623,870 — Total tests: 60,415,558Map.
  3. Politics: Trump says he's prepared to sign executive orders on coronavirus aid.
  4. Education: Cuomo says all New York schools can reopen for in-person learning.
  5. Public health: Surgeon general urges flu shots to prevent "double whammy" with coronavirus — Massachusetts pauses reopening after uptick in coronavirus cases.
  6. World: Africa records over 1 million coronavirus cases — Gates Foundation puts $150 million behind coronavirus vaccine production.

The silver linings of online school

Illustration: Annelise Capossela/Axios

Online learning can be frustrating for students, teachers and parents, but some methods are working.

The big picture: Just as companies are using this era of telework to try new things, some principals, teachers and education startups are treating remote learning as a period of experimentation, too.

Warren and Clinton to speak on same night of Democratic convention

(Photos: Abdulhamid Hosbas/Anadolu Agency via Getty Images, Sean Rayford/Getty Images)

Sen. Elizabeth Warren and Hillary Clinton both are slated to speak on the Wednesday of the Democratic convention — Aug. 19 — four sources familiar with the planning told Axios.

Why it matters: That's the same night Joe Biden's running mate (to be revealed next week) will address the nation. Clinton and Warren represent two of the most influential wise-women of Democratic politics with the potential to turn out millions of establishment and progressive voters in November.