Gif Courtesy NOAA
Gif Courtesy NOAA

Will the plume from the Saraha help or hurt us?

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By Victoria Jaggard, SCIENCE Executive Editor

Neatnik that I am, I think of dust as a constant foe. Keeping bookshelves and gaming consoles clean is hard enough in a normal week, so my attention was instantly piqued when news broke of a huge dust plume bearing down on North America.

In this case, the dust in question (pictured above) comes from more than 5,000 miles across the sea, blown off the Sahara desert and carried by trade winds across the Atlantic. It’s actually a common occurrence, as our Alejandra Borunda reports. Winds sweep millions of tons of mineral-rich dust out of the Sahara every year. This event is only unusual because the plume is riding lower than normal, carrying denser amounts of dust into the air layers where we live and breathe.

On a planetary scale, dust is a blessing and a curse. The Sahara plume is full of nutrients such as iron and phosphorus, and annual sprinklings help support photosynthetic creatures on land and in water. Some scientists even think dust plumes from Africa can play a role in regulating hurricane formation. On the flip side, fine-grained dust can wreak havoc on human health; studies suggest that long-term exposure to dense amounts of dust can affect newborn survival rates, among other consequences.

While dust storms are largely natural events, the health effects echo larger issues of air pollution from clearly human-driven actions, such as ocean shipping and vehicle emissions. And that’s where things get worrisome, since climate change and land development threaten to dry out even more places, possibly leading to increases in the world’s dust plumes. The potential effects of more dust in the atmosphere are still being examined, but I, for one, will feel better if we treat our home planet well and make serious efforts to keep the place tidy.

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Your Instagram photo of the day

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Everything is illuminated: Photographer Stephen Wilkes says his first trip to China came in 1979, when the major type of transportation there was the bicycle. “There was only a handful of automobiles,” he says, “mostly for diplomats, and most were Soviet and from the 1950s. About 33 years later, I took this photo of the Yan’an Elevated Road, in Shanghai.” As of 2018 the number of registered vehicles in China was 369 million.

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Today in a minute

Please, no: An H1N1 swine flu strain with the potential to make humans sick has been found in Chinese pigs, Science reports. A study released Monday focused on the influenza variant, dubbed G4, which is spreading silently in workers on pig farms in China, although it is not yet making anyone ill. A team of scientists says the virus should be “urgently” controlled to avoid a potential pandemic, the New York Times reports. A variant of the H1N1 virus spread worldwide in 2009, killing about 285,000 people.

After a COVID-19 vaccine is developed: How will the vaccine be rolled out? More precisely, with more than 140 potential vaccines in development, how will we know when one is good enough and safe enough to counsel people to take it? “Parsing what makes a COVID-19 vaccine good enough for mass rollout is the primary challenge for scientists and policymakers in the coming months,” Roxanne Khamsi writes for Nat Geo. Khamsi relates as a warning the hasty 1976 roll-out of a not-ready flu vaccine blamed for 25 deaths and 500 cases of paralysis. Today’s authorities will need “to ensure appropriate safety checks—or risk repeating the mistakes of 1976 and losing public confidence,” she writes.

Harm reduction: Could nations hard-hit by the pandemic adopt a few common-sensical procedures that have helped New Zealand, South Korea, and even New York State beat back the coronavirus? That means scenarios such as convincing people to wear masks for the riskiest situations, such as crowded spaces, but relaxing those guidelines in more spacious settings, such as parks. “We were stuck, maybe six weeks ago, in this false binary between staying at home indefinitely and going back to business as usual,” epidemiologist Julia Marcus tells Nat Geo’s Nsikan Akpan. Instead, greater understanding of the pandemic, of social distancing, and of mask use have opened this more flexible ground, particularly where guidance from authorities is consistent.

: Where U.S. COVID-19 cases are increasing—and decreasing

The week in the night sky

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Thunder Moon: Keen sky-watchers may notice that the July full moon, known traditionally as the thunder moon, will lose just a bit of its silvery luster this weekend, as part of its northern limb gradually dims. That’s because Earth's outer, paler shadow will fall on the outer edge of the lunar disk. The celestial phenomenon, known officially as a penumbral lunar eclipse, may be a bit tricky to catch with the naked eye, however, since the shading effect will be quite subtle. The deepest part of the eclipse will occur at 12:30 a.m. ET on Sunday, with best views across the Americas, Western Europe, and most of Africa. On Sunday evening, look for the full moon to also be posing with Jupiter and Saturn, creating an eye-catching triangular formation in the constellation Sagittarius. Jupiter is the brighter white star-like object, while Saturn shines dimmer with a golden-yellow coloration. —Andrew Fazekas

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The big takeaway

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Trying to reason with wildfire season: If it were just about the fires this year, it would be enough. California’s state fire department had nearly twice the fire calls at midyear than it did in 2019. But as Nat Geo’s Sarah Gibbens reports, firefighters in 2020 face the added challenge of COVID-19, and some of the most fire-prone states are dealing with record cases of the pandemic as the nation enters what may be the hottest summer on record. “None of us have had to do this before,” says Cal Fire Battalion Chief Amy Head. “None of us have had to deal with a major pandemic during wildfire season.” Pictured above, a firefighter lighting a backfire in early June to stop the Quail Fire from spreading near Winters, California.

In a few words

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On Thursday, Rachael Bale covers the latest in animal news. If you’re not a subscriber, sign up here to also get Whitney Johnson on photography, Debra Adams Simmons on history, and George Stone on travel.

The last glimpse

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The good news about volcanoes: Deaths and extinctions have gone hand in hand in most reporting about volcanic eruptions. But new models show that at least one bout of volcanic activity could have helped warm the planet after years of catastrophic darkness and cold. Studying the dino-killing asteroid that hit Earth 66 million years ago, researchers noted that a series of massive volcanic eruptions may have helped some life on our planet survive and bounce back, Nat Geo’s Michael Greshko reports.

This newsletter has been curated and edited by David Beard, with photo selections by Jen Tse. Have an idea or a link? We'd love to hear from you at . Thanks for reading, and have a good week ahead.