Kevin Moloney for The New York Times
A sawfish at the Denver aquarium. The visually-arresting fish is disappearing at alarming rates in places where it once prospered.
Pluto, the un-planet, continues to make news without lifting a finger: Last week two of its moons got new names, Kerberos and Styx, with an Internet poll helping to determine the winner. For some people, the latter name may have evoked nostalgia (the theme of our cover this week), either for the big-hair band that sang "Too Much Time on My Hands" (1981) or perhaps for high school days spent trying to translate the underworld passages of Virgil's "Aeneid." (O.K., maybe that was just me.)
Geophysics
Shock Round the World (Twice)
The 56-foot meteor that streaked across the sky and crash-landed on Feb. 15 in Chelyabinsk, Russia, produced shock waves that circled the earth twice, according to a newly published article. Its seismic waves were detected at 20 stations around the world that listen to the earth to monitor compliance with the Comprehensive Nuclear Test Ban Treaty, the article said, adding that the meteor's explosion was "among the most energetic events ever instrumentally recorded." After the 10,000-ton rock blew up 14 miles above the earth, it fell in fragments of up to half a ton and injured more than 1,200 people. Its explosion had the force of 460,000 tons of TNT, the "equivalent to about 30 atomic bombs dropped on Hiroshima during World War II," as National Geographic put it.
Marine Conservation
Toothy and Scarce
Consider the sawfish: It looks like a cartoon character, can grow up to 23 feet long and served as a symbol of the German submarine U-96, featured in "Das Boot." (This was not the sawfish's fault.) It is also disappearing at alarming rates, becoming nearly extinct in places where it once prospered, like the coast of Florida. "Sawfish populations have dropped 90 to 99 percent over the past few decades," according to a Scientific American blog post, which cites "coastal development in sawfish habitat and people's willingness to pay top dollar for the animal's striking toothed snouts," which get tangled easily in fishing nets. In terms of protecting the creatures, taxonomy had also been a problem, with confusion over whether there are actually five or seven species. Last week the National Oceanic and Atmospheric Administration aimed to straighten things out and give full protection to all sawfish under the United States Endangered Species Act. The proposed rule, published in the Federal Register, is open to comments until Aug. 5.
Space
Name That Moon (Twice)
Four billion miles from the sun, there are at least five moons orbiting Pluto. The two smallest, discovered in 2011 and 2012 and each about 20 miles in diameter, have officially been named Kerberos and Styx by the International Astronomical Union. Mark Showalter of the SETI Institute, who led the team that found the wee moons, invited people to vote online for names, a contest that drew 500,000 entries. The ground rules were that the names had to come from underworld characters from Greek and Roman mythology, but many people did not care and submitted names like "Potato and Potahto," Dr. Showalter told The New York Times. Alas, while Ira Gershwin would have been honored, those names would not have gone well with those of the other moons, Nix, Charon and Hydra. The popular vote went to the name Vulcan — and let's be honest, "Star Trek" fans, that was probably not an homage to the Greek god of fire — but it was vetoed by the astronomical union.
Genetics
Resisting Cholera
The human genome may be even smarter than we think: In the Ganges Delta in South Asia, where cholera has long been a big killer, the population's genetic wiring has evolved in a way that protects against the disease, researchers reported last week. Scientists studying residents found variations in about 300 genes that together produced a natural resistance to cholera; they concluded that those variations had very likely developed within the last 5,000 to 30,000 years. "Pinpointing the genes responsible for natural resistance to cholera will help the development of better vaccines," The Times reported.
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