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.
NASA

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.
NASA

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.)

PEERING THROUGH THE "HOLE" IN THE IONOSPHERE

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.

FINDING UNEXPECTED INTERACTIONS

"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.

ATTEMPTING TO ANALYZE DATA NO ONE HAS EVER SEEN BEFORE

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.

nextArticle.image_alt|e
In a composite photo, the International Space Station passes in front of the Sun during the total eclipse on August 21, 2017.
Apeel
arrow
Food
New Plant-Based Coating Can Keep Your Avocados Fresh for Twice as Long
Apeel
Apeel

Thanks to a food technology startup called Apeel Sciences, eating fresh avocados will soon be a lot easier. The Bill Gates–backed company has developed a coating designed to keep avocados fresh for up to twice as long as traditional fruit, Bloomberg reports, and these long-lasting avocados will soon be available at 100 grocery stores across the Midwestern U.S. Thirty or so of the grocery stores involved in the limited rollout of the Apeel avocado will be Costcos, so feel free to buy in bulk.

Getting an avocado to a U.S. grocery store is more complicated than it sounds; the majority of avocados sold in the U.S. come from California or Mexico, making it tricky to get fruit to the Midwest or New England at just the right moment in an avocado’s life cycle.

Apeel’s coating is made of plant material—lipids and glycerolipids derived from peels, seeds, and pulp—that acts as an extra layer of protective peel on the fruit, keeping water in and oxygen out, and thus reducing spoilage. (Oxidation is the reason that your sliced avocados and apples brown after they’ve been exposed to the air for a while.) The tasteless coating comes in a powder that fruit producers mix with water and then dip their fruit into.

A side-by-side comparison of a coated and uncoated avocado after 30 days, with the uncoated avocado looking spoiled and the coated one looking fresh
Apeel

According to Apeel, coating a piece of produce in this way can keep it fresh for two to three times longer than normal without any sort of refrigeration of preservatives. This not only allows consumers a few more days to make use of their produce before it goes bad, reducing food waste, but can allow producers to ship their goods to farther-away markets without refrigeration.

Avocados are the first of Apeel's fruits to make it to market, but there are plans to debut other Apeel-coated produce varieties in the future. The company has tested its technology on apples, artichokes, mangos, and several other fruits and vegetables.

[h/t Bloomberg]

nextArticle.image_alt|e
In a composite photo, the International Space Station passes in front of the Sun during the total eclipse on August 21, 2017.
iStock
arrow
Lists
15 Facts About the Summer Solstice
iStock
iStock

It's the longest day of the year in the Northern Hemisphere, so soak up some of those direct sunrays (safely, of course) and celebrate the start of summer with these solstice facts.

1. THIS YEAR IT'S JUNE 21.

June 21 date against a yellow background
iStock

The summer solstice always occurs between June 20 and June 22, but because the calendar doesn't exactly reflect the Earth's rotation, the precise time shifts slightly each year. For 2018, the sun will reach its greatest height in the sky for the Northern Hemisphere on June 21 at 6:07 a.m. Eastern Time.

2. THE SUN WILL BE DIRECTLY OVERHEAD AT THE TROPIC OF CANCER.

A vintage mapped globe showing the Tropic of Cancer
iStock

While the entire Northern Hemisphere will see its longest day of the year on the summer solstice, the sun is only directly overhead at the Tropic of Cancer (23 degrees 27 minutes north latitude).

3. THE NAME COMES FROM THE FACT THAT THE SUN APPEARS TO STAND STILL.

Stonehenge at sunrise.
CARL DE SOUZA, AFP/Getty Images

The term "solstice" is derived from the Latin words sol (sun) and sistere (to stand still), because the sun's relative position in the sky at noon does not appear to change much during the solstice and its surrounding days. The rest of the year, the Earth's tilt on its axis—roughly 23.5 degrees—causes the sun's path in the sky to rise and fall from one day to the next.

4. THE WORLD'S BIGGEST BONFIRE WAS PART OF A SOLSTICE CELEBRATION.

A large bonfire
iStock

Celebrations have been held in conjunction with the solstice in cultures around the world for hundreds of years. Among these is Sankthans, or "Midsummer," which is celebrated on June 24 in Scandinavian countries. In 2016, the people of Ålesund, Norway, set a world record for the tallest bonfire with their 155.5-foot celebratory bonfire.

5. THE HOT WEATHER FOLLOWS THE SUN BY A FEW WEEKS.

Colorful picture of the sun hitting ocean waves.
iStock

You may wonder why, if the solstice is the longest day of the year—and thus gets the most sunlight—the temperature usually doesn't reach its annual peak until a month or two later. It's because water, which makes up most of the Earth's surface, has a high specific heat, meaning it takes a while to both heat up and cool down. Because of this, the Earth's temperature takes about six weeks to catch up to the sun.

6. THOUSANDS OF PEOPLE GATHER AT STONEHENGE TO CELEBRATE.

Rollo Maughfling, the Archdruid of Glastonbury and Stonehenge, conducts a Solstice celebration service for revelers as they wait for the midsummer sunrise at Stonehenge on June 21, 2012, near Salisbury, England.
Rollo Maughfling, the Archdruid of Glastonbury and Stonehenge, conducts a Solstice celebration service for revelers as they wait for the midsummer sunrise at Stonehenge on June 21, 2012, near Salisbury, England.
Matt Cardy, Getty Images

People have long believed that Stonehenge was the site of ancient druid solstice celebrations because of the way the sun lines up with the stones on the winter and summer solstices. While there's no proven connection between Celtic solstice celebrations and Stonehenge, these days, thousands of modern pagans gather at the landmark to watch the sunrise on the solstice.

7. PAGANS CELEBRATE THE SOLSTICE WITH SYMBOLS OF FIRE AND WATER.

Arty image of fire and water colliding.
iStock

In Paganism and Wicca, Midsummer is celebrated with a festival known as Litha. In ancient Europe, the festival involved rolling giant wheels lit on fire into bodies of water to symbolize the balance between fire and water.

8. IN ANCIENT EGYPT, THE SOLSTICE HERALDED THE NEW YEAR.

Stars in the night sky.
iStock

In Ancient Egypt, the summer solstice preceded the appearance of the Sirius star, which the Egyptians believed was responsible for the annual flooding of the Nile that they relied upon for agriculture. Because of this, the Egyptian calendar was set so that the start of the year coincided with the appearance of Sirius, just after the solstice.

9. THE ANCIENT CHINESE HONORED THE YIN ON THE SOLSTICE.

Yin and yang symbol on textured sand.
iStock

In ancient China, the summer solstice was the yin to the winter solstice's yang—literally. Throughout the year, the Chinese believed, the powers of yin and yang waxed and waned in reverse proportion to each other. At the summer solstice, the influence of yang was at its height, but the celebration centered on the impending switch to yin. At the winter solstice, the opposite switch was honored.

10. IN ALASKA, THE SOLSTICE IS CELEBRATED WITH A MIDNIGHT BASEBALL GAME.

Silhouette of a baseball player.
iStock

Each year on the summer solstice, the Alaska Goldpanners of Fairbanks celebrate their status as the most northerly baseball team on the planet with a game that starts at 10:00 p.m. and stretches well into the following morning—without the need for artificial light—known as the Midnight Sun Game. The tradition originated in 1906 and was taken over by the Goldpanners in their first year of existence, 1960.

11. THE EARTH IS ACTUALLY AT ITS FARTHEST FROM THE SUN DURING THE SOLSTICE.

The Earth tilted on its axis.
iStock

You might think that because the solstice occurs in summer that it means the Earth is closest to the sun in its elliptical revolution. However, the Earth is actually closest to the sun when the Northern Hemisphere experiences winter and is farthest away during the summer solstice. The warmth of summer comes exclusively from the tilt of the Earth's axis, and not from how close it is to the sun at any given time. 

12. IRONICALLY, THE SOLSTICE MARKS A DARK TIME IN SCIENCE HISTORY.

Galileo working on a book.
Hulton Archive, Getty Images

Legend has it that it was on the summer solstice in 1633 that Galileo was forced to recant his declaration that the Earth revolves around the Sun; even with doing so, he still spent the rest of his life under house arrest.

13. AN ALTERNATIVE CALENDAR HAD AN EXTRA MONTH NAMED AFTER THE SOLSTICE.

Pages of a calendar
iStock

In 1902, a British railway system employee named Moses B. Cotsworth attempted to institute a new calendar system that would standardize the months into even four-week segments. To do so, he needed to add an extra month to the year. The additional month was inserted between June and July and named Sol because the summer solstice would always fall during this time. Despite Cotsworth's traveling campaign to promote his new calendar, it failed to catch on.

14. IN ANCIENT GREECE, THE SOLSTICE FESTIVAL MARKED A TIME OF SOCIAL EQUALITY.

Ancient Greek sculpture in stone.
iStock

The Greek festival of Kronia, which honored Cronus, the god of agriculture, coincided with the solstice. The festival was distinguished from other annual feasts and celebrations in that slaves and freemen participated in the festivities as equals.

15. ANCIENT ROME HONORED THE GODDESS VESTA ON THE SOLSTICE.

Roman statue of a vestal virgin
iStock

In Rome, midsummer coincided with the festival of Vestalia, which honored Vesta, the Roman goddess who guarded virginity and was considered the patron of the domestic sphere. On the first day of this festival, married women were allowed to enter the temple of the Vestal virgins, from which they were barred the rest of the year.

A version of this list originally ran in 2015.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios