Nov 5, 2019

Voyager 2's journey in interstellar space

Image: NASA/JPL-Caltech

The Voyager 1 and Voyager 2 probes — which launched in 1977 and are now traveling through interstellar space — may be complicating scientists' understanding of our solar system's structure.

Why it matters: Mapping the structure of our solar system places it in context with the rest of the galaxy, allowing scientists to learn more about the evolution and even future of our cosmic neighborhood.

Driving the news: A series of studies about Voyager 2 published in Nature Astronomy this week reveals contradicting information about the behavior of particles coming from the Sun and those in the interstellar medium.

  • Before Voyager 1 left the heliosphere — the part of space dominated by the influence of the solar wind — it detected particles from the interstellar medium leaking into the heliosphere.
  • Voyager 2, on the other hand, continued to detect solar particles leaking into interstellar space even after leaving the heliosphere, according to project scientist Ed Stone.
  • Voyager 1 also flew through what's now known as a stagnation region before reaching the heliopause — the boundary where the solar wind is overtaken by the interstellar medium. Voyager 2, however, didn't encounter that region.

Yes, but: Scientists still aren't sure what could account for these differences between Voyager 1 and Voyager 2, which are expected to have enough power to continue beaming back data for about five more years.

  • It's possible the differences could be the result of the Sun's 11-year solar cycle during which the star's activity increases and decreases, Voyager scientists have said.
  • Researchers will also need far more data points before being able to definitively understand the structure of the heliosphere, and there is talk of sending a spacecraft purposefully out to interstellar space to fill in the gaps.

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  • "Did I suffer? ... I've had some of my favorite employees leave," Karp told "Axios on HBO."

Michigan governor won't apologize for coronavirus lockdown

Michigan Gov. Gretchen Whitmer defended the strictness of her state's coronavirus lockdown in an interview with "Axios on HBO," saying it was necessary — despite the protests that have drawn national attention — because of how quickly the state's cases were rising.

The big picture: Whitmer, who has been a frequent target of President Trump, insisted that she had to act in the face of a lack of federal leadership — and that thousands more people in her state would have died without the lockdown.

World coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Axios Visuals

New Zealand now has only one novel coronavirus patient in hospital and just 22 active cases in the country, top health official Ashley Bloomfield confirmed at a briefing. He's "confident we have broken the chain of domestic transmission," with no new cases reported for most of May, he added.

By the numbers: Brazil on Monday recorded for the first time more deaths from the novel coronavirus in a single day than the United States, Reuters notes. Brazil reported 807 deaths from COVID-19 in the past 24 hours, compared to 620 in the U.S. for the same period.