Johan Hidding / Flickr

We know how much total matter is in the universe, including "normal" matter (things like stars, planets, you, me) and more mysterious "dark" matter. However, only about 10% of the normal matter has been accounted for in surveys of galaxies. Astronomers have long suspected the missing matter sits in threads of gas between galaxies, but it's hard to detect because it's very tenuous.

What's new: Researchers now report spotting about 30% of the missing matter by looking for its shadow in the cosmic microwave background — the afterglow of the big bang itself. The background light filters through the gas and gets bumped up to higher energies through collisions with the hot particles, leading to a subtly higher observed temperature between galaxies.

Why it matters: While it doesn't completely solve the mystery of the missing matter, the research may help us paint a fuller family portrait of the universe. By understanding what it's made of, we can learn more about its past and future evolution.

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As boycott grows, Facebook juggles rights groups and advertisers

Illustration: Aïda Amer/Axios

As an advertiser boycott of Facebook over its tolerance of hate speech continues to snowball, the company has begun making small, incremental changes to mollify activists while it tries to buy time to evolve its content policies.

Driving the news: Sources tell Axios that the product and policy changes sought by the #StopHateForProfit campaign were long under discussion both inside Facebook and with some external groups. Meanwhile, CEO Mark Zuckerberg has reportedly told employees that the boycotting advertisers will be back before long.

Replacing the nursing home

Illustration: Sarah Grillo/Axios

Nursing homes have been the epicenter of the coronavirus outbreak, prompting more urgent discussions about alternative housing situations for elderly Americans.

Why it matters: Deaths in nursing homes and residential care facilities account for 45% of COVID-19 related deaths, per the Foundation for Research on Equal Opportunity — but there are few other viable housing options for seniors.

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How Joe Biden would tackle the coronavirus

Illustration: Aïda Amer/Axios

If Joe Biden wins in November, his coronavirus response would feature a no-expenses-spared federal approach to mitigating the virus and a beefed-up safety net for those suffering its economic consequences.

Why it matters: It’s nearly inevitable that the U.S. will still be dealing with the pandemic come January 2021, meaning voters in America will choose between two very different options for dealing with it.