In the latest edition of our Scientific Chicago series with University of Chicago paleontologist Neil Shubin, a new spacecraft takes the closest pictures ever taken of the sun’s surface; researchers begin to unravel the mystery of how sea turtles navigate across thousands of ocean miles; and it turns out the so-called “bystander effect” is not just a human trait.
Here’s a closer look at each of those stories:
Closest ever images of the sun
The Solar Orbiter spacecraft, a joint mission between NASA and the European Space Agency, has beamed back its first close-up images of the sun. The images were taken 48 million miles above the solar surface between the orbits of Mercury and Venus, and they reveal what researchers have termed “campfires” — miniature versions of the solar flares that can be seen from Earth. Researchers believe the miniature flares could explain a decadeslong mystery of why the sun’s atmosphere is so much hotter than its surface. The temperature of the sun’s corona is more than a million degrees Celsius while the sun’s surface is a relatively cool 5,500 degrees.
“The sun might look quiet at first glance, but when we look in detail, we can see those miniature flares everywhere we look,” said David Berghmans of the Royal Observatory of Belgium, a principal investigator on the mission.
The orbiter will eventually move even closer to the sun. To protect its camera and instruments from the intense heat they’re housed behind a titanium heat shield coated in a special substance called SolarBlack, made from charred animal bones.
Green turtle navigation
Researchers since the time of Charles Darwin have long puzzled over how sea turtles are able to navigate across thousands of miles of open ocean. Now researchers reporting in the July edition of Current Biology believe they may have the answer.
“By satellite tracking turtles traveling to small, isolated oceanic islands, we show that turtles do not arrive at their targets with pinpoint accuracy,” said Graeme Hays of Australia’s Deakin University. “While their navigation is not perfect, we showed that turtles can make course corrections in the open ocean when they are heading off-route. These findings support the suggestion, from previous laboratory work, that turtles use a crude true navigation system in the open ocean, possibly using the Earth’s geomagnetic field.”
“Bystander Effect” not just a human trait
The so-called “bystander effect,” a theory that individuals are less likely to offer help to a victim when there are other people present, is not just a human trait — rats do it too!
Peggy Mason, professor of neurobiology at the University of Chicago and senior author of the study and her team of researchers found previously that rats consistently freed trapped companions, even saving a bit of chocolate for them, and this behavior was driven by a rat version of empathy.
But in this new study using the same trapped rat test, researchers observed the behavior of rats to see if they still helped the trapped rat when some of the rats were treated with an anti-anxiety medication to make them less likely to free a trapped peer because they do not feel its anxiety. The rats treated with the anti-anxiety medicine were dubbed “confederates” by the researchers.
The team found that rats tested with confederates were less likely to help than those tested alone — a bystander effect in rats.
“It’s worse to have a non-responsive audience than to be alone,” Mason said. “The rats try helping, but it’s just not a rewarding experience because the other rats don’t appear to care. It’s as though the rat was saying to himself, ‘I helped yesterday and no one cared. Not doing that again.’”