(Washington) Strange animal behaviors, a rarely observable solar corona, and even possible effects on humans: scientists will be hard at work on April 8 to collect valuable data during the solar eclipse which will cross the United States.
Total eclipses are “rare” and represent an “incredible scientific opportunity,” Pam Melroy, associate administrator at NASA, said at a press conference. The American space agency will be at the forefront, notably with the launch of sounding rockets.
Here’s an overview of what the researchers plan to study.
Solar crown
When the Moon completely covers the Sun’s central disk, the outer layer of its atmosphere, called the solar corona, will be visible “in a very special way,” Pam Melroy said. However, this is an area “that we do not yet fully understand”.
The heat of the corona increases with distance from the Sun’s surface, a counterintuitive phenomenon that scientists struggle to explain.
It is also in this upper region that solar flares occur, or the prominences of immense plasma structures.
During an eclipse, the lowest part of the corona is better visible than using a specific instrument called a coronagraph, says Shannon Schmoll, an astronomer at Michigan State University. So this is a golden opportunity to study it.
One thing particularly excites scientists: the Sun is currently close to its peak activity, which returns every 11 years.
Thus, “the chances of observing something incredible are very high,” rejoiced Pam Melroy.
Earth’s atmosphere
Scientists will also study changes in the upper part of Earth’s atmosphere, the ionosphere.
This is where a large part of communications signals pass. “Disruptions in this layer can cause problems for our GPS and communications,” said NASA manager Kelly Korreck.
However, the ionosphere is affected by the Sun: its particles are charged with electricity under its radiation during the day.
Three small sounding rockets will be launched before, during and just after the eclipse from Virginia, in the eastern United States, in order to measure these changes.
The drop in light caused by the eclipse, more rapid and localized than a sunset, should make it possible to learn more about how light affects the ionosphere – in order to be able to better predict potential future problematic disturbances.
Animal behaviors
Eclipses cause surprising behaviors in animals: for example, giraffes have been seen galloping, or roosters and locusts starting to crow.
In addition to light, temperatures and winds can also drop, to which animals are sensitive.
Andrew Farnsworth, a researcher at Cornell University’s Ornithology Laboratory, studies the effect on birds. It uses weather radars to detect animals in flight.
During the previous eclipse in the United States, in August 2017, researchers observed “a drop in the number of flying animals,” he explains.
This eclipse had caused the cessation of daytime behavior (with insects or birds landing), but without causing nocturnal behavior such as the flight of bats or migratory birds, he explains. This year, in April, these birds may be further pushed to migrate.
These studies are “important for understanding the way in which animals perceive the world”, underlines the expert.
Human wonder
“Eclipses have a special power. They touch people, who feel a kind of reverence for the beauty of our Universe,” NASA boss Bill Nelson said this week.
It is this feeling of wonder that researchers studied in 2017, based on data from just under 3 million users of the social network Twitter.
The result: Those in the eclipse’s path were more likely to use the pronoun “we” (as opposed to “I”) and to be concerned about others, according to Paul Piff, a psychology researcher at UC Irvine. An experience of wonder seems to “connect us to each other,” he summarized.
This year he plans to study whether such an experiment could have an impact on political divisions.
Citizen science
Some 40 participatory science projects are also planned. “We encourage you to help NASA by observing what you see and hear around you,” called Bill Nelson.
Participating citizens will be able, for example, to record the sound environment around them, or even the temperature and cloud cover using a phone application.