From landing the Curiosity rover on Mars after a 350-million-mile journey, to the discovery of the world's most wanted subatomic particle, the top 10 scientific achievements of 2012 have been nominated by the journal of the American Association for the Advancement of Science, showing the march of human knowledge in genetics, physics, cosmology, medicine and nanoscience.
The discovery of the Higgs boson by physicists using the Large Hadron Collider in Switzerland was named breakthrough of the year by Science magazine, with runners-up including the pin-sharp DNA sequencing of a Siberian cave girl who lived 50,000 years ago and a delicate brain implant in a US woman paralysed from the neck down that allowed her to use thought to manipulate a robotic arm to grasp a bottle and take a sip of coffee.
Adrian Cho, a writer on the journal, said: "For all the hype, the discovery of the Higgs boson easily merits recognition as the breakthrough of the year. Its observation completes the standard model, perhaps the most elaborate and precise theory in all of science."
The discovery proves there is an energy field all around us that gives mass to the fundamental particles that make up our world. The announcement of its discovery in Geneva was met by cheers usually heard at football matches or rock concerts.
"The feat marks an intellectual, technological and organisational triumph," said Cho.
The result of the 43-year-long hunt for the Higgs boson was not the only exercise in exploring the world's very smallest particles to make the shortlist.
A team of Chinese physicists won plaudits for describing how elusive particles called neutrinos morph into one another as they zip along at near-light speed. The discovery is likely to open up the field of neutrino physics and may help solve a puzzle that has long vexed scientists: how the universe evolved after its creation to contain so much matter and so little anti-matter.
Researchers believe there could be some as-yet-unknown differences between the two types of particles or else the laws of physics might need to be modified. The breakthrough saw the Chinese beat teams in France, South Korea, Japan and the United States.
In genetics, the results of a £180 million (HK$2.25 billion), decade-long study to create an encyclopedia of DNA elements, known as Encode, were published to wild acclaim, with Britain's Guardian newspaper describing it as "the most significant shift in scientists' understanding of the way our DNA operates since the sequencing of the human genome".
The portrait of DNA helps explain how genes are controlled, and researchers have used the insights to clarify genetic risk factors for diseases such as multiple sclerosis and Crohn's disease.
The other major advances, according to Science, are:
- Scientists in Germany used a new technique to sequence the complete genome of an enigmatic group of humans called the Denisovans, based on a tiny sample teased from a finger bone some 80,000 years old found in a cave in Siberia. Nothing was known about the Denisovans other than that they were contemporaries of the Neanderthals, another "cousin" species of modern humans.
- Japanese scientists created viable egg cells using embryonic stem cells from adult mice. The breakthrough raises the possibility that women who are unable to produce eggs naturally could have them created in a test tube from their own cells and then implanted in their body.
- Nasa engineers landed the3.3 tonne Mars Curiosity rover on the Red Planet by using an innovative landing system that dangled the vehicle, with its wheels out, at the end of three cables. "The flawless landing reassured planners that Nasa could some day land a second mission near an earlier rover to pick up samples the rover collected and return them to earth,"
- Use of an X-ray laser, which shines one billion times brighter than traditional synchroton sources, allowed scientists to determine the structure of a protein involved in the transmission of African sleeping sickness. "The advance demonstrated the potential of X-ray lasers to decipher proteins conventional X-ray sources cannot,"
- A new tool let researchers modify or deactivate genes in test animals. This technology could be as effective as, and even cheaper than, current gene-targeting techniques and could let researchers focus on specific roles for genes and mutations in healthy and sick people.
- Scientists confirmed the existence of Majorana fermions, particles that can act as their own antimatter and destroy themselves. Scientists believe "qubits" made of Majorana fermions could be used to more efficiently store and process data than bits now used in digital computers.
The journal also highlighted a global controversy over the safety of research into bird flu, amid fears over which studies were safe and which could lead to even more devastating strains of the virus that could fall into the hands of terrorists. Fears grew when a Rotterdam-based virologist, Ron Fouchier, said his team had engineered a version of the bird flu virus that could be transmissible between humans.
The journal also predicted next year's breakthroughs, including the most precise map yet of the afterglow of the big bang, when the universe is thought to have been born, and the exploration of a subglacial lake four kilometres beneath the Antarctic ice, which is likely to have been cut off from life on the rest of the planet for millions of years.
Additional reporting by Agence France-Presse