Rockets, planes, balloons and countless observers on the ground will be studying the North American total solar eclipse on 8 April in unprecedented detail.
On Monday 8 April, millions of people across North America are set to witness one of the rarest of treats – a total solar eclipse.From the Pacific coastal city of Mazatlán in Mexico to the Eastern coast of Canada’s Newfoundland, the Moon will perfectly block the Sun and cast its shadow on the ground, turning day to near-night. But it’s not just the public set to be enthralled, as scientists race to prepare experiments to observe this magnificent event.Every 18 months, a total solar eclipse occurs somewhere on Earth, a fortuitous quirk of the Sun being 400 times further from Earth than the Moon and 400 times larger, making the disc of the Moon entirely cover the solar disc when it perfectly aligns between Earth and the Sun. This April eclipse is of particular note, however, because of the vast amount of populated land the eclipse will pass over, allowing many millions of people to watch.Locations in the path of totality will be plunged into darkness for no more than four minutes, but that is enough to perform some of the rarest of science experiments, with scientists hoping to observe the Sun’s atmosphere – its corona – as it dances around the Moon, the reaction of wildlife to the celestial event, and even launching rockets to observe how Earth’s atmosphere reacts.An estimated 31 million people will be in the path of the eclipse, double that of the last total solar eclipse that crossed the US on 21 August 2017. Totality is also longer this time around, up from two and a half minutes for most observers in 2017 because the Moon was further away from Earth. This eclipse path will also be almost twice as broad (nearly 200km wide [120 miles] versus just 110km [70 miles] in 2017).
Adam Hartstone-Rose from NC State University in North Carolina is leading a project to study how wildlife reacts to the eclipse. In 2017 he had teams of researchers stationed at different zoos in the path of totality to watch how animals behaved. Some were baffled – a group of gorillas trooped inside for their evening meal as darkness fell, but were left empty-handed as daylight returned. “The giraffes were my favourite,” says Hartstone-Rose. “Somebody had reported wild giraffes in Africa started galloping during a total eclipse. I was really sceptical because giraffes are pretty passive animals. Despite my scepticism, some of them started running around.”
The “most crazy behaviour”, says Hartstone-Rose, was a group of Galapagos tortoises. “As totality grew, they became more and more active,” he says. “Right at the peak of totality, they started mating, which we cannot explain. Maybe it was as one-time thing. We’re going to be watching more tortoises this time around.”
Hartstone-Rose will have researchers stationed at Fort Worth Zoo in Texas to monitor more than 20 species of animals during the eclipse, including gibbons, flamingos, orangutans, and, of course, tortoises. He is also asking members of the public to perform their own animal behaviour studies, either observing pets or nearby wildlife, and upload their observations online.
All animals are of interest, from dogs to farm animals. “There’s very little information about what farm animals do,” says Hartstone-Rose. “Are cows going to come towards the barn during totality? Shouldn’t roosters crow sometime during an eclipse?”
