Scientists Who Sent Spiders To ISS Found Something Strange
If you think space is difficult for astronauts, then you should try being a spider spinning a web in pitch black weightlessness. OK, this sentence is kind of a Non Sequitur, but it accurately describes a fascinating, somewhat strange scientific experiment that was carried out on board the International Space Station (ISS).
You see, spiders on earth are pretty darn good at spinning webs. It turns out that gravity is an essential part of orienting spiders on webs. Spiders usually begin to spin their webs by falling from above and attaching anchor lines. The spider then usually sits in the top third of the web and points down at prey.
Scientists know exactly how important gravity is to spiders because they conducted (at least for a spider) incredibly annoying laboratory experiments that allowed spiders to start spinning a web on a frame before researchers invert the frame on a horizontal axis, to see how the arachnid reacts.
But what happens when you completely remove Earth’s gravity? This is what an international team of scientists wanted to test when they shot two spiders of the same species (Trichonephila clavipes) to the ISS to see how they would handle spinning webs in weightlessness.
“We have found that a spider in space that has no idea about gravity or light and has no idea what is going up and down looks in any direction when it is on the Internet,” says Samuel Zschokke. A research fellow at the University of Basel in Switzerland, whose research focus is spider webs, told Digital Trends. “As a result, the web is no longer asymmetrical, but rather symmetrical.”
See the light
Asymmetrical webs are a common feature of spider webs on Earth. Webs have a top-to-bottom asymmetry in size, so the bottom of the web’s coverage area is larger than the top. It is not surprising that this does not occur without gravitational guidance. Spiders will still spin webs, but they don’t look like the ones on earth.
However, Zschokke said that when the spiders were given a source of light, they replaced it with gravity, using the light as a proxy, building on it in the same way that they would normally steer towards gravity. Zschokke said the spiders’ ability to reconfigure their behavior is fascinating because they don’t need light to build webs on Earth. In essence, they traded one sensory response (when gravity counts as a sensory response) for another.
“You have this ability to make up for the loss of gravity through the use of light,” he said. “We didn’t expect that. After all, why should an animal that has always lived in a gravity environment like Earth be able to compensate for a lack of gravity with something else? “
Employee Stefanie Countryman, director of BioServe Space Technologies and research fellow in aerospace engineering at the University of Colorado Boulder, told Digital Trends that the results of the study provide valuable information on how living organisms adapt to a non-gravity environment can.
“As interest in long-term space exploration and off-planet life increases, studies like this can help show how living organisms stay healthy in space and how they can adapt to space,” said Countryman. “The next steps would be to repeat the experiment, but with larger habitats large enough for that particular type of spider to form a web that is closer to the ‘normal’ size that would be spun on Earth. It would also be of interest to take a closer look at how light affects the spider’s behavior without gravity. “
An article describing the research was recently published in The Science of Nature.