The editors of the journal Science have chosen the possible discovery of the elusive Higgs boson as the biggest breakthrough of 2012.
The subatomic particle, named 50 years ago by physicist Peter Higgs, is what scientists believe gives mass to matter. The discovery is monumental because it confirms that the universe works the way that theoretical physicists think it does.
Nine other groundbreaking achievements from 2012 were given honorable mention, including the safe landing of the Mars rover Curiosity this summer, and definitive proof that paralyzed patients could use their mind to move a robotic arm.
Here are the earth-shattering events of the year:
1. NASA's Mars Curiosity rover lands on Mars.
A special "sky crane" landing system placed NASA's Curiosity rover on Mars on Aug. 5. The complicated landing maneuver was famously dubbed the "seven minutes of terror" by NASA engineers because that's how long it took Curiosity to get from the top of the Martian atmosphere down to the surface of the Red Planet. The mission control team had no contact with the one-ton robot during those critical minutes.
Curiosity survived the landing with 100 percent working parts, and is going strong five months into her two-year mission on Mars, sending back new photos and crucial data for future space travel each day.
2. Scientists created eggs from mice stem cells for the first time.
Japanese researchers showed that embryonic stem cells from mice could be made into viable egg cells, that could be fertilized and result in healthy babies. The healthy mouse pups shown here were bred from the eggs they created. The experiment only involved mice, but may one day be used to treat infertility in humans.
3. Scientists discovered the structure of a protein involved in the transmission of African sleeping sickness.
Membrane proteins span the outer shell of each and every cell in our bodies, sending signals and shuttling stuff between the inside of the cell and the outside. These proteins play a role in almost everything the cells do, and their involvement is critical in the transmission of diseases and disease-fighting drugs, so understanding their structure is important for developing new drugs to target the disease.
Researchers used an X-ray laser a billion times brighter than traditional X-ray sources to provide a detailed structure of one of these membrane proteins, which plays an important role in the transmission of the parasite that causes African sleeping sickness, a disease that kills around 30,000 people each year.
4. Subatomic particles known as neutrinos are caught changing from one type to another.
Some nuclear reactions, including those that take place inside the sun, create neutrinos. Neutrinos and their corresponding antineutrinos come in three basic “flavors": electron, muon and tau.
Measurements from the Daya Bay Neutrino Experiment in China revealed how electron antineutrinos transform into different flavors — either muon or tau — as they travel at the near-speed of light. The results could help explain why the universe contains so much more matter than antimatter.
5. Researchers sequenced the genome of the Denisovians, a group of ancient humans that lived 41,000 years ago in Siberia.
Along with the sequencing of the Neanderthal genome, researchers also sequenced the genome of the group of ancient humans named the Denisovians, who lived 41,000 years ago in Siberia. They isolated DNA from a bone fragment, a finger bone that belonged to a girl with brown eyes, brown hair and brown skin who died in Siberia between 74,000 and 82,000 years ago.