Science pics of the week: Just what we need, gliding spiders

Friday, August 21, 2015, 2:55 PM - A new spider species glides to safety after a fall, an astronaut captures a "red sprite" from space and Cassini's awe-inspiring last look at Saturn's Dione. It's Science Pics of the Week!

Great! Just what we need! Gliding spiders!

Scientists searching through the treetops in Panama and Peru have discovered a previously unknown species of spider that is capable of gliding its way to safety after a fall.

The species, belonging to the genus Selenops, is now the only one researchers have ever found that has this ability.

"My guess is that many animals living in the trees are good at aerial gliding, from snakes and lizards to ants and now spiders," said Robert Dudley, co-author of the research and professor of integrative biology at UC Berkeley. "If a predator comes along, it frees the animal to jump if it has a time-tested way of gliding to the nearest tree rather than landing in the understory or in a stream."

According to UC Berkeley News:

Dudley and Stephen Yanoviak, a professor of biology at the University of Louisville in Kentucky, have been studying gliding insects in tropical forests for more than a decade, after discovering a group of ants that unfailingly land on a tree when accidentally brushed off a branch. This led them to toss from a tree every non-flying arthropod they could find to see which animals glided.
"As far as adult arthropods are concerned, only ants, bristletails and spiders use directed aerial descent," Yanoviak said. "However, the wingless immature stages of various insects that are winged as adults can also glide really well. These include cockroaches, mantids, katydids, stick insects and true bugs."
The 59 individual Selenops spiders they studied were all well-adapted to skydiving. They are "wafer thin," Dudley said, and flexible; they maneuver by spreading their legs wide in order to use lift and drag to steer themselves toward the tree trunk when they fall. If they fall upside down, they’re able to right themselves in midair. The biologists occasionally saw spiders bounce off the trunk, recover and maneuver back to the trunk a second time for a successful landing.

While this is certainly good for the spiders, and bad for anyone who seriously gets the creeps from our eight-legged fellow-denizens-of-Earth, the study of this kind of behaviour may help engineers design robots in the future that can use these methods to remain upright during a fall.

Sci-fi space squid? Astronaut captures "Sprite" from space

Lightning is pretty spectacular from here on the ground, but if you are able to capture these electrical discharges from above the clouds, sometimes you can see something entirely different pop up as well.

The image below was snapped from the International Space Station, as it passed over southern Mexico on August 10, 2015. To the far right in the image, a thunderstorm over the Gulf of Mexico glows from a lightning flash within the cloud, but hanging above is the tangled, red-tinged discharge known as a sprite.

Surface lights glow brightly and are stretched out in this long-exposure image, taken from the ISS. Credit: NASA. Inset added by author.

Although the exact cause of sprites still remains a mystery, they are known to last for only a very short time - on the order of milliseconds - so capturing not one, but two of them, within moments of one another, is incredible!

Cassini's incredible farewell to Dione

NASA's Cassini spacecraft made a close pass by Saturn's moon Dione on August 17, 2015, and it snapped images of the cratered surface that NASA are rightly calling "breathtaking."

This is just one of several "final flybys" that the spacecraft is performing in the last two years of the mission, leading up to it's Grand Finale, where it will orbit between the planet's upper atmosphere and its inner rings, making the closest passes over the planet ever performed.

Sources: UC Berkeley News | NASA | NASA