July 11, 2011 marks the first full orbit of the planet Neptune since its discovery on the night of September 23-24, 1846. The discovery of Neptune is a fascinating story, full of near misses and the triumph of math.

For many years we've been taught that the discovery of Neptune was done by mathematical calculations. This came about in 1821 when Alexis Bouvard was publishing his findings for Uranus and noticed a gravitational perturbation in Uranus' orbit. This led him to hypothesize an unknown body was crossing the path. Enter miscommunications, politics and astronomer John Adams...

"It is more likely that Adams realised that his proposed orbits were moving ever closer to a "forbidden" zone of resonance." says Brian Sheen of Roseland Observatory. "Uranus orbits in 84 years, Neptune in 165, nearly a 2:1 resonance, this brings about much greater perturbations than were being measured. In fact the mid 19th century is a quiet period and much bigger swings are evident now."

In 1843 John Couch Adams used the data Bouvard proposed to begin working on a proposed orbit, but it would be several years later before Urbain Le Verrier verified its existence through physical observation - at the same time as Johann Gottfried Galle. Says Sheen; "It is often said that Adams never published his results. In fact a published paper was printed by November 1846 and appeared in the 1851 Nautical Almanack published in 1847."

Genetic instructions for developing limbs and digits were present in primitive fish millions of years before their descendants first crawled on to land, researchers have discovered.

Genetic switches control the timing and location of gene activity. When a particular switch taken from fish DNA is placed into mouse embryos, the segment can activate genes in the developing limb region of embryos, University of Chicago researchers report in Proceedings of the National Academy of Sciences. The successful swap suggests that the recipe for limb development is conserved in species separated by 400 million years of evolution.

"The genetic switches that drive the expression of genes in the digits of mice are not only present in fish, but the fish sequence can actually activate the expression in mice," said Igor Schneider, PhD, postdoctoral researcher in the Department of Organismal Biology and Anatomy at the University of Chicago and lead author on the paper. "This tells us how the antecedents of the limb go back in time at every level, from fossils to genes."

You've heard of scientists testing drugs on mice - but what if those mice were part human? MIT researchers have developed an artificial liver that can be transplanted into mice, allowing them to metabolize drugs as if they were human beings. This could foster more accurate and efficient drug testing.

In order to create this liver, researchers cultured hepatocytes - human liver cells - in a controlled environment with other factors, such as mouse skin cells. The team then implanted the artificial liver under the skin or inside the body cavity of mice, successfully recreating many of the functions of a human liver.

While previous attempts to engineer "humanized mice" have led to varied, often negative results, MIT's team says this discovery will produce consistently healthy mice that can emulate human liver functionality. This could result in a number of positive applications - researchers could use these mice to test out pharmaceuticals, experiment with metabolic functions, and monitor the interactions between multiple types of drugs - all without using a single human test subject.

Humanized mice can be extremely beneficial to scientists across the world, says MIT researcher Alice A. Chen.

On a rainy weekend last year, Patrick Priebe, a German lab technician and Iron Man fanatic who rewatches the film and its sequel every week, decided to build a compact yet powerful laser inspired by Tony Stark's repulsor-beam weapon. In the U.S., the maximum strength for consumer laser pointers is typically five milliwatts; Priebe's handheld laser is 1,000 milliwatts, enough to instantly blind anyone not wearing special safety glasses.

Priebe began his project by sculpting a two-millimeter sheet of brass into a C-shape so that he would be able to slip the weapon onto his hand. Inside the housing, he made a large ring that holds a laser diode from a Casio projector and works as a heat sink. The device runs on 7.4 volts from lithium-ion batteries, which a component called a driver keeps from spiking dangerously and damaging the diode.

Finally, Priebe, who spends his workdays refining paint and polymers, painstakingly applied the primer, filler, base coat and matte to give it a striking look. Although his beam can't blow guerrilla soldiers off their feet like his comic-book hero's could, it can easily scorch balloons, wood, a CD case or a piece of raw chicken.

The "Rare Earth" hypothesis is the idea that life is a staggeringly unlikely event, and that the reason we haven't seen hide nor hair (nor scale nor weird gel-layer) of aliens is that there aren't any. It's had some time in the spotlight, it makes us sound very important, and it's wrong.

The Rare Earth argument ignores a number of essential factors, the first being how staggeringly huge the numbers involved are. Even the Milky Way has 200 to 400 billion stars, and it's only one of a hundred billion galaxies in the observable universe, and there have been billions of years for things to happen. Countering "it's really unlikely" with "but there are lots of things!" might sound weak, but it's the Rare Earthers who are taking the burden of proof - claiming that nothing happens anywhere else ever. The more places there are, the worse their argument gets.

Geologist Peter Ward and astrobiologist Donald Brownlee, both of the University of Washington have outlined a short list of conditions needed: Right distance from a star; habitat for complex life; liquid water near surface; far enough to avoid tidal lock; right mass of star with long enough lifetime and not too much ultraviolet; stable planetary orbits; right planet mass to maintain atmosphere and ocean with a solid molten core and enough heat for plate tectonics; a Jupiter-like neighbor to clear out comets and asteroids; plate tectonics to build up land mass, enhance bio-diversity, and enable a magnetic field; not too much, nor too little ocean; a large moon at the right distance to stabilize tilt; a small Mars-like neighbor as possible source to seed Earth-like planet; maintenance of adequate temperature, composition and pressure for plants and animals; a galaxy with enough heavy elements, not too small, ellipitcal or irregular; right position the galaxy; few giant impacts like had 65 million years ago; enough carbon for life, but not enough for runaway greenhouse effect; evolution of oxygen and photosynthesis; and, of course, biological evolution.

Scientists from British Antarctic Survey (BAS) have discovered previously unknown volcanoes in the ocean waters around the remote South Sandwich Islands.

Using ship-borne sea-floor mapping technology during research cruises onboard the RRS James Clark Ross, the scientists found 12 volcanoes beneath the sea surface -- some up to 3km high. They found 5km diameter craters left by collapsing volcanoes and 7 active volcanoes visible above the sea as a chain of islands.

The research is important also for understanding what happens when volcanoes erupt or collapse underwater and their potential for creating serious hazards such as tsunamis. Also this sub-sea landscape, with its waters warmed by volcanic activity creates a rich habitat for many species of wildlife and adds valuable new insight about life on earth.

Cows have best friends and become stressed if they are separated, according to a scientist.

Krista McLennan, who made the discovery while working on her PhD at Northampton University, believes her findings could help improve milk yields.

The 27-year-old measured the heart rates and cortisol levels of cows to see how they cope when isolated.

NASA's Dawn spacecraft is closing in on Vesta, and from now until the ion-powered spacecraft goes into orbit in mid-July, every picture of the giant asteroid will be the best one ever taken. What will researchers do with this unprecedented clarity?

"For starters," says Dawn chief engineer Marc Rayman, "we're going to look for an asteroid moon."

You might think of asteroids as isolated bodies tumbling alone through space, but it's entirely possible for these old "loners" to have companions. Indeed, 19-mile-wide Ida, 90-mile-wide Pulcova, 103-mile-wide Kalliope, and 135-mile-wide Eugenia each have a moon. And 175-mile-wide Sylvia has two moons. Measuring 330 miles across, Vesta is much larger than these other examples, so a "Vesta moon" is entirely possible.

Where do such moons come from?

Rayman suggests one source: "When another large body collides with an asteroid, the resulting debris is sprayed into orbit around the asteroid and can gradually collapse to form a moon."

Larry Agenbroad, the principal investigator and site director of the Mammoth Site in Hot Springs announced that Earthwatch volunteers uncovered the site's 119th tusk on Wednesday. That discovery is the first tusk of the 60th mammoth at the site. Fifty-seven are Columbian mammoths and three are woolly.

The Earthwatch volunteers and Agenbroad's staff will be excavating new areas, looking for more mammoths and other species of animals that became trapped and died in the sinkhole death trap 26,000 years ago. In addition to mammoths, the site has yielded 85 other species of animals and plants as well as several unidentified insects.

The laboratory is open for viewing by the visiting public. Visitors can see into the laboratory and view the work being conducted there.

Manila, Philippines - Neptune will appear in the sky as a faint light early Tuesday as the planet completes its orbit around the sun for the first time since its discovery in 1846, according to a bulletin of the government-run weather bureau.

But the rainy weather is expected to cast gloom over the sky show, which is supposed to be the first time the planet could be viewed in Earth's sky.

The observatory of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said people would unlikely to see Neptune's rendezvous with the Aquarius and Pisces constellations at 1 a.m. on Tuesday.

Even in clear skies, however, Neptune's apparition could only be viewed via telescope and could not be seen with the naked eye because of its slight sparkle.