Water found on the moon and Earth came from small meteorites called carbonaceous chondrites in the first 100 million years or so after the solar system formed, according to researchers who found evidence in samples of moon dust returned by lunar crews of Apollo 15 and 17.

Comets did not deliver the molecules, they conclude in their Science Express article.

The discovery's telltale sign is found in the ratio of an isotopic form of hydrogen, deuterium, to standard hydrogen. The ratio in the Earth's water and in water from specks of volcanic glass trapped in crystals within moon dust match the ratio found in the chondrites. The proportions are far different from those in comet water. 

In a previous article, I demonstrate how to build an alcohol burner for a home chemistry set. In my article, I mention that "second-hand stores like Goodwill, Salvation Army, and local mom&pop shops are treasure troves of things to hack or repurpose."

I would like to mention too that close-out stores like Dollar General are also fertile ground for modding.

While school-age models of atomic nuclei show them as being spherical, like a basketball, they are more like the shape of a football. 

Yet for some particular combinations of protons and neutrons, nuclei can also assume very asymmetric shapes, like a pear, where there is more mass at one end of the nucleus than the other. 

Men who experience sexual harassment are far more likely than women to induce vomiting and take laxatives and diuretics - purging - in an attempt to control their weight, according to a new psychology paper.

Two days ago I wrote a quick post to stimulate non-flat-EEG readers to consider an apparently trivial question, which in fact hid many subtleties. The general question I wanted to address was whether an estimate missing an uncertainty was more or less useful than a quoted uncertainty on the same parameter when the estimate itself was missing.

The African clawed frog (Xenopus laevis) and Budgett's frog (Lepidobatrachus laevis) differ in diet and last shared a common ancestor about 110 million years ago but what they were found to have in common could help researchers on the path to prevention of intestinal birth defects. 

Like most tadpoles, Xenopus exist primarily on a diet of algae, and their long, simple digestive tracts are not able to process insects or proteins until they become adult frogs. Budgett's is an aggressive species of frog which is carnivorous – and cannibalistic – in the tadpole stage.

During the late Pleistocene, which ended about 12,000 years ago, a remarkably diverse assemblage of large-bodied mammals inhabited the "mammoth steppe," a cold and dry environment that extended from western Europe through northern Asia and across the Bering land bridge to the Yukon.

Of the large predators - wolves, bears, and big cats - only the wolves and bears were able to maintain their ranges well after the end of the last ice age and a new study suggests that dietary flexibility may have been an important factor giving wolves and bears an edge over saber-toothed cats and cave lions. 

When comparing men and women who have dyslexia to non-dyslexic control groups, researchers found significant differences in brain anatomy, suggesting that the disorder may have a different brain-based manifestation when it comes to gender.

The greater wax moth (Galleria mellonella of the family Pyralidae) is capable of sensing sound frequencies of up to 300 kHz, making it possessor of the highest recorded frequency sensitivity of any animal in the natural world.

Humans are only capable of hearing sounds from 20 Hz up to around 20 kHz maximum and that drops as we age, while our pets can hear at higher frequencies (leading to concern about things like the hum from ballasts in CFL bulbs) but even dolphins, famous for their ultrasound, only cap out at around 160 kHz.

If you are not an experienced baseball player, a ball coming at you 40 or 50 miles per hour is fast. You are almost certain to swing too late and then, when you realize that is fast, you will swing too early. You are almost as certain to miss.

So how can players hit a 95 M.P.H. fastball?  Given that it can be inside or outside of the strike zone, high or low, and also is rarely straight, it can be difficult even for them.

Researchers say they have pinpointed how the brain tracks such fast-moving objects and that can help understand how humans predict the trajectory of moving objects when it can take one-tenth of a second for the brain to process what the eye sees.