Major scientific discoveries of 2011

Exoplanets ahoyIn January, Nasa's Kepler spacecraft spotted the smallest exoplanet to date. The rocky Kepler-10b is about 560 light years away and has diameter roughly 1.4 times that of Earth. But unlike Earth, the proximity of Kepler-10b to its star means it would have a scorching environment incompatible with life as we know it.

This year the Kepler, which keeps track of about 150,000 stars, also found an exoplanet in the “habitable zone”, which is not too hot or cold for liquid water. In December, Nasa announced details of Kepler-22b, which is about 600 light years from Earth.

In Hawaii, researchers analysing data from a telescope saw the proto-exoplanet LkCa 15 b, about 450 light years away from Earth, which they said has “likely been caught at its epoch of assembly”.

Stem-cell alchemy

In November, US researchers published that they had been able to coax embryonic stem cells to develop into a type of dopamine-producing brain cell lost in Parkinson’s disease and introduce them successfully into various animal models.

In May, researchers in the US and China announced they had used stem cells to grow a type of brain cell called astrocytes

in large numbers in the lab. This development could boost the generation of “disease in a dish” models to help research. And we heard reports from a small, early-stage trial in the US to treat patients with a form of heart failure by introducing an infusion of their own cardiac stem cells. The approach has shown encouraging results and could be a step closer to a potential stem-cell-based treatment for one of the world’s biggest killers.

Higgs boson – watch this space

This year saw some exciting hints in the hunt for the Higgs boson, a theorised particle that is predicted to give mass to other particles.

It’s the missing piece in a theory called the Standard Model, which explains the universe in terms of the most fundamental particles.

The search for the Higgs boson is on at the Large Hadron Collider in Cern, Geneva, where protons are raced around a giant ring-shaped underground tunnel before smashing together at high speed. By monitoring the aftermath, scientists look for signals that a Higgs has decayed to form other types of particle.

In December Cern put the world on tenterhooks with talk of homing in further on the elusive quarry. But at the time of writing, the Higgs had not been confirmed found.

Mars missions, real and pretend

During 2011, plenty of interesting information about Mars was beamed back to Earth. One of the most recent finds, revealed in December, was that a small mineral vein seen on the red planet apparently contains gypsum, a hydrated form of calcium suphate.

“This tells a slam-dunk story that water flowed through underground fractures in the rock,” says Steve Squyres of Cornell University, principal investigator for Nasa’s Opportunity rover. The gypsum deposit is “not uncommon on Earth,” he says, “but on Mars, it’s the kind of thing that makes geologists jump out of their chairs.”

Also jumping out of their chairs this year were the participants of Mars500, a 17-month-long experiment supported by the European Space Agency, which saw six men sealed into a mocked-up spacecraft in Russia. The mission simulated a round-trip to Mars and even included a stint exploring the planet’s surface. It ended in November when the crew emerged, and initial indications were that they fared well psychologically on the dry run.

Neutrinos and the cosmic speed limit

In September, a team of scientists announced a startling scenario relating to subatomic particles called neutrinos. They analysed data from experiments that fired neutrinos from Cern in Geneva to a facility more than 700km away in Italy, and claimed the results showed the neutrinos had travelled faster than the speed of light in a vacuum.

If neutrinos (or anything else) can break that cosmic speed limit, it would challenge many assumptions about physics and the universe – including Einstein’s theory of special relativity – and it could even have implications for the possibility of time travel.

A flurry of raised eyebrows, analyses and revisited experiments later, the claim is still open to question, facing arguments that the finding could be down to an error of measurement.

Hot stuff underwater

This summer, an Irish-led expedition discovered a previously uncharted field of hydrothermal vents along the Mid-Atlantic Ridge, the first to be explored north of the Azores. The team aboard the RV Celtic Explorer found the vent field about 3,000m below the sea’s surface by using a remotely operated vehicle to probe the depths. “Using the ROV’s high-definition video camera, we’ve watched unusual orange-bodied shrimp . . . among clusters of tiny green limpets,” said researcher Jon Copley. “Elsewhere there are writhing scale-worms, swirling mats of bacteria and eel-like fish — a riot of life in this unlikely haven on the ocean floor.”