Excerpts from science, technology, environment and health reports from around the web.

Arafat and polonium-poisoning: A sort-of update

On Friday, the news network Al Jazeera made an announcement: the British medical journal, The Lancet, was now supporting the theory that the deceased Palestinian leader, Yasser Arafat, had died of polonium-210 poisoning.

According to the report, independent scientists had reviewed earlier findings by Swiss scientists and: “endorsed their work, which found high levels of the highly radioactive element in blood, urine, and saliva stains on the Palestinian leader’s clothes and toothbrush”.

Curiosity confirms origins of Martian meteorites

Earth’s most eminent emissary to Mars has just proven that those rare Martian visitors that sometimes drop in on Earth—a.k.a. Martian meteorites—really are from the Red Planet. A key new measurement of Mars’ atmosphere by NASA’s Curiosity rover provides the most definitive evidence yet of the origins of Mars meteorites while at the same time providing a way to rule out Martian origins of other meteorites.

The new measurement is a high-precision count of two forms of argon gas—Argon-36 and Argon-38–accomplished by the Sample Analysis at Mars (SAM) instrument on Curiosity. These lighter and heavier forms, or isotopes, of argon exist naturally throughout the solar system. But on Mars the ratio of light to heavy argon is skewed because a lot of that planet’s original atmosphere was lost to space, with the lighter form of argon being taken away more readily because it rises to the top of the atmosphere more easily and requires less energy to escape. That’s left the Martian atmosphere relatively enriched in the heavier Argon-38.

Stanford drones open way to new world of coral research

Like undiscovered groves of giant redwoods, centuries-old living corals remain unmapped and unmeasured. Scientists still know relatively little about the world’s biggest corals, where they are and how long they have lived.

The secret to unlocking these mysteries may lie with a shoebox-size flying robot.

New “magic number” inside atoms discovered

“Magic numbers” of protons and neutrons can make an atomic nucleus exceptionally stable—and a new one has just been added to the existing menagerie that helps sketch a fuller picture of the complicated inner workings of atoms. By smashing beams of nuclei together at high speeds, researchers have discovered that when a calcium atom has 34 neutrons in its nucleus, things stay pretty quiet—at least for a few milliseconds. The discovery overturns some of scientists’ previous notions about magic numbers and opens up a new line of inquiry for nuclear physics.

Jellyfish are taking over the seas, and it might be too late to stop them

Last week, Sweden’s Oskarshamn nuclear power plant, which supplies 10% of the country’s energy, had to shut down one of its three reactors after a jellyfish invasion clogged the piping of its cooling system. The invader, a creature called a moon jellyfish, is 95% water and has no brain. Not what you might call menacing if you only had to deal with one or two.

En masse, jellyfish are a bigger problem. “The [moon jellyfish swarm] phenomenon…occurs at regular intervals on Sweden’s three nuclear power plants,” says Torbjörn Larsson, a spokesperson for E.ON, which owns Oskarshamn. Larsson wouldn’t say how much revenue the shutdown cost his company, but noted that jellyfish also caused a shutdown in 2005.

DNA has a 521-year half-life

Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest — and putting an end to hopes of cloning a Tyrannosaurus rex.

After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.