King penguin with chick.
Three squawks for conservation! After New Zealand businessman Joseph Hatch boiled down 3 million Macquarie Island king penguins for their blubber, public outrage helped make the island a wildlife sanctuary in 1933. The king penguins then flourished undisturbed, growing from the decimated population of 3,400 to half a million today. Those raw numbers look good, but to gauge the population’s viability, scientists needed to find out a little more. A new study has found that the population has also recovered to pre-slaughter levels of genetic diversity, just 80 years after their near-extinction.
Population bottlenecks like the one caused by Hatch’s steam digester mean not only fewer individuals but also less diversity in the gene pool. This makes it difficult for the population to adapt to any stresses—a disease, for example, that can wipe out the remaining population if everyone has the same immune system.
To compare pre- and post-bottleneck genetic diversity, the researchers sequenced DNA from 1,000-year-old penguin bones on the island. The ancient DNA samples had similar levels of diversity as modern samples from the foot of living penguins. The researchers were surprised by how the population had recovered and saw this as a testament to conservation efforts.
The peripatetic magnetic south pole.
A hundred years after Robert Scott‘s disastrous mission to the South Pole, a pair of Kiwi scientists are traveling to his observation hut today to continue the work he began there: tracking the Earth’s magnetic field. Since 1957, New Zealand has measured the field at Scott’s base every five years, accruing data that, along with measurements from other, more comfortable sites around the world, helps maintain the model used by NATO and nations’ defense departments for navigation.
The planet’s magnetic field needs tracking because it is shifting: the magnetic south pole has been traveling northwestward at a rate of 6 to 9 miles a year for the past century. (The geographic South Pole is somewhere altogether different.) This shift occurs because the mass of molten metal that makes up the Earth’s outer core is in a constant state of turmoil, and the the poles could veer off in another direction at any time. Intriguing, the magnetic field has also been getting weaker since the 1800s. But whether that means the poles will flip at some point in the future—it’s happened before!—or whether it will start getting stronger again very soon is a mystery.
Water, water, everywhere! Radar results from a lunar probe have revealed that the moon’s north pole could be holding millions of tons of water in the form of thick ice, raising the possibility that human life could be sustained on Earth’s silvery satellite, NASA scientists said.
A NASA radar aboard India’s Chandrayaan-I lunar orbiter found 40 craters, ranging in size from 1 to 9 miles across, with pockets of ice. Scientists estimate at least 600 million tons of ice could be entombed in these craters [Wired].
Scientists estimate that this amount of water could easily sustain a moon base, or, if the oxygen in the ice was converted to fuel, could fire one space shuttle per day for 2,200 years. Last year, scientists found almost 26 gallons of water ice on the moon’s south pole, by crashing a rocket hull into a cold, dark crater. The crash produced a plume of material that provided evidence of water ice on the moon’s surface.