Aug 13, 2019

Interstellar dust found in Antarctica may reveal details of solar system's journey

Miriam Kramer, author of Space

The remnant of a supernova. Photo: NASA/CXC/F. Vogt et al./ESO/VLT/MUSE/STScI

Radioactive dust sent out by ancient supernovas has been found in Antarctica, according to a new study in the journal Physical Review Letters.

The big picture: Researchers behind the study suggest that our solar system is currently flying through a cloud of cosmic material thought to be shaped by supernovas.

  • Those stellar explosions may leave behind traces of the radioactive isotope iron-60, which the scientists found in Antarctic snow.
  • This study and future work could help explain more about our solar system’s past and its movements through the Milky Way, according to a synopsis published by the American Physical Society.

What they found: The team behind the study thinks that the iron-60 atoms found in the region were delivered to Earth in the last 20 years.

  • "I think Earth essentially picked [the element] up during the movement through the cloud, not like a real injection as you would expect from a very near supernova," Dominik Koll, an author of the study, tells Axios by email.
  • The scientists had been concerned that the isotope might have been created by nuclear weapons, but the team ruled that out when the other concentrations of bomb-created isotopes didn't match what they found in Antarctica.

What's next: Koll and his colleagues are hoping to get a look at older Antarctic snow in order to compare concentrations of iron-60 in the past to those found today.

  • Older samples may reveal exactly when our solar system traveled into the supernova-enriched cloud it appears to find itself within now.

Go deeper

Updates: George Floyd protests enter 12th day

Protesters in Washington, D.C. on June 6. Photo: Samuel Corum/Getty Images

Thousands of demonstrators are gathering in cities across the U.S. and around the world to protest the killing of George Floyd. Huge crowds have assembled in Washington, D.C., Philadelphia and Chicago for full-day events.

Why it matters: Twelve days of nationwide protest in the U.S. has built pressure for states to make new changes on what kind of force law enforcement can use on civilians and prompted officials to review police conduct.

Updated 57 mins ago - World

In photos: People around the world rally against racism

Despite a ban on large gatherings implemented in response to the coronavirus pandemic, protesters rally against racism in front of the American Embassy in Paris on June 6. Photo: Julien Mattia/Anadolu Agency via Getty Images

Tens of thousands of people have continued to rally in cities across the world against racism and show their support this week for U.S. demonstrators protesting the death in police custody of George Floyd.

Why it matters: The tense situation in the U.S. has brought the discussion of racism and discrimination onto the global stage at a time when most of the world is consumed by the novel coronavirus.

Updated 2 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 7:30 p.m. ET: 6,852,810 — Total deaths: 398,211 — Total recoveries — 3,071,142Map.
  2. U.S.: Total confirmed cases as of 7:30 p.m. ET: 1,917,080 — Total deaths: 109,702 — Total recoveries: 500,849 — Total tested: 19,778,873Map.
  3. Public health: Why the pandemic is hitting minorities harder — Coronavirus curve rises in FloridaHow racism threatens the response to the pandemic Some people are drinking and inhaling cleaning products in attempt to fight the virus.
  4. Tech: The pandemic is accelerating next-generation disease diagnostics — Robotics looks to copy software-as-a-service model.
  5. Business: Budgets busted by coronavirus make it harder for cities to address inequality Sports, film production in California to resume June 12 after 3-month hiatus.
  6. Education: Students and teachers flunked remote learning.