Water bears go where no animal has gone before

A water bear (OMG, they're so cool!)

Timeline, 2008: They say that in space, no one can hear you scream (or at least that Alien movie said it). The reason for that is that sound waves require matter to be propagated, and in the vacuum of space, there is no matter. Hard as your vocal cords may push, they can’t make the sound travel through nothing.

That vacuum carries other complications for people beyond an inability to chat unprotected. Space is cold—temperatures run close to absolute zero, or -272 Celsius. With the vacuum, there is no oxygen and no pressure. And let’s not forget the bombardment with deadly cosmic rays and, if you’re hanging around just above Earth, UV rays 1000 times more powerful than those we experience on terra firma.

Boiling saliva and bubbling blood. Ewww.

Thus, if you send person or a dog or an ape unprotected into space, within minutes, the lack of pressure would lead to an uncomfortable death involving boiling saliva and bubbling blood. Yet, there are organisms known to survive the environment of space, primarily some bacteria and lichen, the symbiotic combination of algae and fungus. Now, we’ve learned that a little critter that lives on lichen also can be quite the intrepid space traveler.

Water bears–not even remotely like bears

The space animals—the first animals, in fact, known to pull off unprotected space travel—are representatives of two species of tardigrades. There are up to 1000 species of these little animals, more familiarly known as “water bears” because of their rotund, bear-like appearance. Researchers had noted their hardiness under earthbound conditions, observing that although the animals thrive in a damp environment, when conditions go dry, they can shut down for as long as 10 years until the environment moistens up again. Some accounts have compared the water bears to “Sea Monkeys,” the brine shrimp of comics advertisements that come to you dried up in a little packet, only to “miraculously” come to life when you add water.

On a September 2007 European Space Agency mission, scientists decided to test the tardigrades in the most hostile environment available—in space just above planet Earth. They tested two species of water bear, Richtersius coronifer and Milnesium tardigradum, both entering space as dried out versions of their usual selves. The 120 animals from each species were divided into four groups, one that remained on Earth as a control, two that were exposed to the vacuum of space and different combinations of UV rays, and a fourth that experienced only the vacuum of space without the radiation.

Vacuum OK, UV bad

The animals spent 10 days traveling unprotected far above the earth before returning to Earth, where they were hydrated in the lab. Amazingly enough, all three groups of space-traveling tardigrades initially perked right up and lived for a few days. After that, however, only the vacuum-alone group maintained that rate of survival. In the UV-exposed groups, animals that had experienced the vacuum of space and exposure to UV-A and UV-B survived at rates between 10% and 15%. Animals that had been exposed to all three types of UV—A, B, and C—all died.

Nevertheless, the animals that did survive appeared to thrive, reproducing heartily and generally living the usual life of the unusual water bear. Researchers find their ability to withstand radiation particularly intriguing, given that the bombardment would normally shred the DNA of most organisms. Investigators hope to find out more about how the bears  resist the perils of space, seeking perhaps to co-opt some of the tardigrade’s techniques to use in protecting astronauts.

Space, schmace. How about 4000 m deep?

Tardigrades didn’t really need to travel into outer space—or really, inner space—to prove their toughness. They are known to live as high as 6000 meters up in the Himalayas and as deep as 4000 meters down in ocean trenches. Water bears have also been found living in apparent ease in hot springs above boiling temperature.

Mystery spot in the night sky baffles astronomers

The mystery light that baffled astronomers

In 2006, astronomers working on the Supernova Cosmology Project, which scans the universe for supernovae, or exploding stars, noted something no one had ever seen before. An unidentified light appeared, grew increasingly brighter for about 100 days, and then over the next 100 days faded away completely.

Not a supernova

Sure, there are other things in the night sky that behave that way, including supernovae themselves, but this particular burst of brightness carried completely unrecognizable features. The light came to our attention thanks to the Hubble Space Telescope, which wanders the universe sending back pictures of very cool things for us to investigate. In this case, Hubble was trained on a cluster of galaxies in a constellation known as Bootes, which is home to Arcturus, said to be the fourth brightest star in the night sky. But this mystery light in 2006 briefly gave Arcturus more competition than a supernova.

A supernova gives off an intense amount of light that can actually outshine a galaxy during its relatively brief period of existence. But supernovae do not last longer than 70 days, and usually are radiant for only about three weeks. The mystery light, on the other hand, burned for 200 days. Another example of light changes in the night sky is microlensing, in which light from a distant object bends around something of enormous mass, such as a cluster of galaxies, thanks to gravitational pull. This light didn’t fit that description, either.

No signature matches

In fact, when astronomers compared its atomic spectra signature with all known signatures in their databases, they found nothing that matched. Spectral signature analysis is one way we determine the elemental makeup of something that is light years away. The signature results from a pattern of light wave frequencies, which begin thanks to the vibrations of electrons. Electrons within an atom can vibrate at different frequencies, so atoms emit light waves at different frequencies. We see those differences as bands of color when we look at them through a device that separates the wavelengths, and different elements exhibit different banding patterns: hydrogen, for example, has a different color banding pattern than helium. Thus, we can look at light traveling from billions of miles away and determine the elemental makeup of its source based on the banding patterns of these emissions.

But the banding signature of the mystery light didn’t match that of any known cosmic object. What also remained mysterious was exactly how far away the light was. Astronomers could roughly say that it was no closer than 130 light years because it lacked parallax motion, which diminishes with distance. For a good example of how parallax motion changes with distance, close one eye and hold your thumb up close to your face. Now, switch eyes, closing one and opening the other. Switch back. You’ll see that your thumb appears to shift position. That’s parallax motion. Now, hold your thumb at arm’s length and do the same thing. You’ll see that the shift is considerably less. At a predictable distance—130 light years—such a shift on a cosmic scale would be undetectable. But all astronomers can really say is that it’s no closer than that and no farther away than 11 billion light years, based on the lack of a hydrogen signature.

Destined to remain an engima

So right now, the Mystery Light (otherwise known as SCP 06F6) that’s not too close and, in cosmic terms, not that far away, remains an enigma. Some have suggested that it was the radiant remnant of an enormous interstellar collision, perhaps between a white dwarf, an incredibly dense star at the end of its life, and a black hole. But the signs—from the spectral signature to the lack of microlensing—don’t really fit that scenario. Whatever it was, this light that grew in brightness by 120 times before fading away completely will remain a mystery for the foreseeable future.

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