What We Learned So Far From The Total Solar Eclipse of 2017—And Why There's Much More to Come

In a composite photo, the International Space Station passes in front of the Sun during the total eclipse on August 21, 2017.
In a composite photo, the International Space Station passes in front of the Sun during the total eclipse on August 21, 2017.

Americans went mad for the total solar eclipse on August 21—and so did scientists. Earlier this month, researchers at the fall meeting of the American Geophysical Union in New Orleans teased out the first results of experiments performed during the eclipse.

"From a NASA perspective, there is no other single event that has informed so many scientific disciplines," Lika Guhathakurta, an astrophysicist at NASA Ames Research Center, said. Among the affected fields include solar dynamics, heliophysics, Earth science, astrobiology, and planetary science. "The eclipse provided an unprecedented opportunity for cross-disciplinary studies."

To that end, NASA grants and centers supported Sun-Moon-Earth alignment research during the eclipse that involved balloons, ground measurements, telescopes, planes that chased the eclipse, and a dozen spacecraft from the agency, as well as from the National Oceanic and Atmospheric Administration, the European Space Agency, and the Japanese Space Agency. In some regions, scientists meticulously mapped responses to the total eclipse by the land and the lower atmosphere. They measured ambient temperature, humidity, winds, and changes in carbon dioxide. These data were taken to find new insights into the celestial event, which occurs somewhere on the Earth every 18 months. (Calculate here how many you could potentially see in your lifetime.)


Of particular interest was how the eclipse affects the ionosphere, the barrier region between the atmosphere and what we think of as outer space; it is the altitude range where auroras occur, and where the International Space Station and low Earth orbit satellites are found. The ionosphere is affected by radiation from the Sun above and by weather systems below. The eclipse gave researchers the chance to study what happens to the ionosphere when solar radiation drops suddenly, as opposed to the gradual changes of the day-night cycle.

A total eclipse essentially creates a "hole" in the ionosphere. Greg Earle of Virginia Tech led a study on how radio waves would interact with the eclipse-altered ionosphere. Current models predicted that during the brief interval of the eclipse, the hole would cause waves to travel much farther and much faster than usual. The models, it turns out, are correct, and data collected during the eclipse supported their predictions. This facilitates a better understanding of what happens on non-eclipse days, and how variances in the ionosphere can affect signals used for navigation and communication.


"NASA's solar eclipse coverage was the agency's most watched and most followed event on social media to date," said Guhathakurta, with over 4 billion engagements. That sort of frenzied public interest for what amounted to a 90-minute celestial event over a thin strip of the United States, with around two minutes of totality for any given area, allowed scientists to engage "citizen scientists" to help with data collection.

Matt Penn of the National Solar Observatory led the Citizen CATE project (Continental-America Telescopic Eclipse), which deployed 68 small, identical telescopes to amateur astronomers across the eclipse path. "At all times, at least one CATE telescope was in the shadow looking at the [Sun's] corona," Penn said. "And sometimes we had five telescopes looking at the corona simultaneously." This resulted in a lot of data. "We got 45,000 images, and to go along with that, we got 50,000 calibration images."

girl in eclipse glasses looks up at the sun
Jeff Curry/Getty Images for Mastercard

They're still working on the data processing, but by combining images similar to the way smartphone cameras create HDR images in certain lighting conditions, scientists are able to view the Sun's corona—the shimmering halo of plasma that surrounds it—in stunning new detail. Image-processing techniques on the high-resolution data yielded surprising results. Specifically: There are interactions between the "cold" atmosphere of the Sun—the chromosphere, which is "only" 10,000°F—and the hot corona, which is 1,000,000°F. "We're hoping to analyze these data in more detail and come up with some publications in the near future," Penn said. The project's telescopes remain in the hands of the public, and new experiments are underway.

"Most of our volunteers were going see the eclipse anyway, and what we did was try to enable them to elevate their experience by participating in research. And that goes from collecting the data to publication," Penn tells Mental Floss. "We could have had 200 sites easily with the amount of interest we had." The public's keen interest in the eclipse will spur experiments of commensurate ambition in 2024, when North America again experiences a total solar eclipse.


Penn's project wasn't the only science conducted with a public-engagement aspect. The Eclipse Ballooning Project, led by Angela Des Jardins of Montana State University, enabled 55 teams of college and high school students to fly weather balloons to above 100,000 feet. There, they took measurements to see how the eclipse affects the weather-influencing lower atmosphere. The balloons also live-streamed the eclipse as it occurred across the continent. To give a sense of how long the project has been in development: When it was conceived, live-streaming as we experience it today had not yet been invented.

She tells Mental Floss that the project's success has spurred ideas for future large-team, long-term projects for the 2024 eclipse. "For me, the biggest lesson is, you have to have something that is really exciting and challenging in order to get students involved, and in order for the general public to be involved," she says.

Results from the Eclipse Ballooning Project are forthcoming, a common refrain by eclipse researchers. "We're really excited about taking this new type of data that no one has ever taken before, and now we are in the phase when we realize no one has ever tried to analyze data like this before," Penn says. "So we're inventing the analysis as well, and it's going to take time."

More results are sure to come in 2018.

Fossilized Fat Shows 550-Million-Year-Old Sea Creature May Have Been the World's First Animal

Ilya Bobrovskiy, the Australian National University
Ilya Bobrovskiy, the Australian National University

A bizarre sea creature whose fossils look like a cross between a leaf and a fingerprint may be Earth's oldest known animal, dating back 558 million years.

As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate find in a remote region of Russia: a Dickinsonia fossil with fat molecules still attached. These odd, oval-shaped creatures were soft-bodied, had rib structures running down their sides, and grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in the abstract of a new paper published in the journal Science.

Another variety of fossil
Ilya Bobrovskiy, the Australian National University

Although Dickinsonia fossils were first discovered in South Australia in 1946, researchers lacked the organic matter needed to classify this creature. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution, or the earliest animals on Earth,” senior author Jochen Brocks, an associate professor at ANU, said in a statement.

With the discovery of cholesterol molecules—which are found in almost all animals, but not in other organisms like bacteria and amoebas—scientists can say that Dickinsonia were animals. The creatures swam the seas during the Ediacaran Period, 635 million to 542 million years ago. More complex organisms like mollusks, worms, and sponges didn’t emerge until 20 million years later.

The fossil with fat molecules was found on cliffs near the White Sea in an area of northwest Russia that was so remote that researchers had to take a helicopter to get there. Collecting the samples was a death-defying feat, too.

“I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone, and repeat this process until I found the fossils I was after,” lead author Ilya Bobrovskiy of ANU said. Considering that this find could change our understanding of Earth’s earliest life forms, it seems the risk was worth it.

[h/t New Scientist]

The Weird, Disturbing World of Snail Sex


Romance is rare in the animal kingdom. Instead of wooing their partners before copulating, male ducks force themselves onto females, depositing genetic material with spiky, corkscrew penises. Then, there's tardigrade sex, which is less violent but not exactly heartwarming. Females lay eggs into a husk of dead skin. The male then ejaculates onto the eggs while stroking the female, and the whole process can take up to an hour.

But you can't talk about disturbing mating rituals in nature without mentioning snails. If you're unfamiliar with snail sexuality, you may assume that snail sex falls on the vanilla side: The mollusks, after all, are famous for being slow-moving and they don't even have limbs. But if you have the patience to watch a pair of snails going at it, you'll notice that things get interesting.

The first factor that complicates snail sex is their genitalia. Snails are hermaphrodites, meaning individuals have both a male set and female set of parts, and any two snails can reproduce with each other regardless of sex. But in order for a couple of snails to make little snail babies, one of them needs to take on the role of the female. That's where the love dart comes in.

The love dart, technically called a gypsobelum, isn't exactly the Cupid's arrow the name suggests. It's a nail-clipping-sized spike that snails jab into their partners about 30 minutes before the actual sex act takes place. The sliver is packed with hormones that prepare the receiving snail's body for sperm. Depending on the species, only one snail might release the dart, or they both might in an attempt to avoid becoming the female of the pair. You can watch the action in the video below.

For sex to be successful, both snails must insert their penises into the other's vaginal tracts at the same time. Both snails deposit sperm, and the strength of the love dart ultimately determines whether or not that sperm fertilizes their partner's eggs.

That's assuming the snail survives the little love-stab. In human proportions, the love dart is the equivalent of a 15-inch knife. Fortunately, snails are resilient creatures, and gastropod researcher Joris Koene tells KQED he's only ever seen one snail die from the transfer.

Snails also have a way of making it up to their partners after skewering them with a hormone stick. Their sperm deposit contains a dose of fortifying nutrients, something scientists refer to as a nuptial gift. It may not equal the energy expended during sex, but its enough to give them a small post-coital boost.