Readers weigh in on ET and the meaning of life

All about aliensNew telescopes and spacecraft will soon help researchers scour our galaxy for signs of extraterrestrial life. But what might aliens look like? And if they do exist, why haven’t they returned our calls? These are just some of the questions addressed in the Science News special report “In Search of Aliens” (SN: 4/30/16, p. 24).

Readers enjoyed Tina Hesman Saey’s feature “Will we know ET when we see it?” (SN: 4/30/16, p. 28) and described what they think aliens might look like.

“The search for extraterrestrials is a subject which needs to be taken more seriously by mainstream science. Thanks for looking at it and please have more on the topic,” Wade Carmen wrote. He suggested aliens might look similar to creatures that dwell in the deep ocean. “H.G. Wells did it right by envisioning Martians as cephalopods in War of the Worlds,” he added. “The first extraterrestrial forms of life likely to be encountered are microbes or even something amorphous like the Blob.”

Other readers thought the search for ET might require new definitions for life: “Maybe ribose is ET,” said Cabell Smith, drawing a connection between the special issue and Christopher Crockett’s “Ribose could have formed in space” (SN: 4/30/16, p. 18), which reported that the key sugar in RNA can form in lab-made “interstellar” ice. Annselm Morpurgo took the idea a step further. “I am still waiting for some astrophysicist to declare that there may even be life on the surface of the sun,” she wrote. “Forget biology. Information exchange between self-replicating structures of any kind, such as electromagnetic ‘bumps’ in a chaotic ‘soup,’ might also qualify.”

Great Plains shake-upEarthquakes are no longer just a natural hazard. For the first time, the U.S. Geological Survey included human-made earthquakes from activities such as wastewater injection in its annual hazard forecast, Thomas Sumner reported in “Quake risk high in parts of central United States” (SN: 4/30/16, p. 20).

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Online reader Pro-Marx wondered if more frequent small, human-made earthquakes could relieve built up stress and prevent the occassional massive quake.

Smaller earthquakes can relieve stress on a fault but not enough to reduce the intensity of big quakes, Sumner says. As earthquakes’ magnitudes increase, the energies they release rise drastically. A magnitude 6 earthquake, for instance, releases nearly 32 times as much energy as a magnitude 5 quake and about 32,000 times as much energy as a magnitude 3 earthquake, according to the USGS. Scientists do not consider triggering artificial quakes a good prevention strategy. “Accumulating all of those smaller quakes would be a tall task, especially when you run the risk of accidentally triggering a damaging quake,” Sumner says.

Salamander insightsEurope’s spookily pale and blind cave salamanders, called olms, include a dark form with what look like functional eyes, Susan Milius reported in “What’s odd about a dark, big-eyed salamander” (SN: 4/30/16, p. 4).

Online reader John Turner wondered why dark olms evolved those traits. “Maybe every few generations, every few tries, a pigmented and sighted salamander makes it across open ground from one cave system to another cave system to spread the species,” he wrote. “That would be the reward for keeping a few black sheep in the family, no?”

The evolution of dark skin and vision likely resulted from olms spending more time in shallow caves where it’s lighter, says olm researcher Stanley Sessions of Hartwick College in Oneonta, N.Y. Their evolution, of course, “does not have a ‘purpose’ such as allowing [olms] to migrate over the surface,” he says. Although spring floods occasionally wash both dark and light olms aboveground, “they are all thoroughly aquatic with delicate gills, and die very quickly if they are exposed to air for long,” he says.

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