Review of science in 2012: A big red planet and a tiny particle

It is not often we witness the greatest discovery of our time. The announcement in July that scientists had found the elusive Higgs boson, a subatomic particle that could explain some of the deeper mysteries of the universe, could easily be a contender for the prize.

For more than half a century, scientists have postulated the existence of a sub-atomic particle that creates an invisible force field that permeates the entire cosmos, imparting mass to matter but having no effect on other kinds of mass-less particles, such as photons of light.

When Peter Higgs, now a retired professor at the University of Edinburgh who will celebrate his 84th birthday in 2013, first dreamt of such an idea in 1964, few would have expected it to take this long to prove him right – or wrong.

The Higgs boson, or 'God particle' as some have called it, is central to the Standard Model of physics. This is the model on which physicists have based their understanding of most of the fundamental forces of nature, from the weak electrostatic interactions between charged particles to the ultra-strong nuclear forces at the heart of the atom.

From what they knew about the Standard Model, theoretical physicists postulated there must be a missing sub-atomic particle which creates a field that interferes with the movement of other particles. Some types of matter find it difficult to move through this field, which means they have a greater mass than other kinds of matter that moves through it more easily.

It is a deceptively simple concept but one that was devilishly difficult to prove. In the end it required the combined effort of thousands of the brightest minds in science, several decades of painstaking experiments and a £2.6bn machine in the form of the Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (Cern) in Geneva.

Early one July morning, the leaders of the two teams working on the key LHC experiments gave details of their findings to their enraptured colleagues. Despite the dizzying display of charts, it soon became clear from the reaction of the assembled cognoscenti that the LHC had done its job and found a particle that fitted the description of the Higgs boson.

"As a layman, I would say that I think we have it. Do you agree?" Rolf-Dieter Heuer, director general of Cern, asked the audience at the end of the two presentations. The applause said it all.

Other scientists throwing high-fives in 2012 were the team at the US National Aeronautics and Space Administration (Nasa) who successfully landed a sophisticated roving robot on Mars using the unconventional technique of lowering it down to the Martian surface from a 'sky crane' about 25ft overhead.

The successful landing on 6 August followed "seven minutes of terror", the period which started when the rover and its mother ship crashed through the Martian atmosphere at 13,200mph. It took seven minutes and the combined effort of a heat shield, S-shaped flight manoeuvres, parachutes and retro-rockets to slow it down enough to carry out the final, delicate delivery by sky crane.

The Curiosity rover, a robot the size of a large car, is loaded with sophisticated instruments designed to analyse the make-up of the Red Planet. It could tell us whether the conditions were ever ripe on Mars for the origin and evolution of primitive extra-terrestrial life-forms.

If life on Mars ever existed, it is likely to have long ago disappeared with the planet's rivers and oceans. An environmental disaster on Mars led many millions of years ago to the loss of the vital ingredient of life – liquid water.

The big question as 2012 ends is whether life on Earth is heading for something similar. The planet is in little danger of losing its water, but there is every sign that its climate is destined for a major upheaval in the coming decades.

In September, scientists reported the biggest loss of Arctic sea ice since satellite records began in 1978. Other scientists confirmed that melting ice sheets in Greenland and Antarctica were contributing to a marked rise in sea levels.

The amount of carbon dioxide released into the atmosphere from the burning of fossil fuels continued unabated in 2012, despite the global economic crisis. A separate team of researchers found evidence that the rising acidification of the oceans around Antarctica was beginning to corrode the shells of the tiny marine creatures forming the base of the food chain.

All the signs suggest it is business as usual in terms of climate change. If the Higgs boson was the greatest discovery of our time, then global warming threatens to be the greatest slow-motion disaster of our age.

@SethMacFarlane Never thought I'd say this, but Newt's got it right on this issue. Ignore the naysayers & think big w/ space exploration

Seth MacFarlane, comedy writer

@ProfBrianCox Making this series, I've finally understood how powerful and elegant Darwin's theory of evolution by natural selection actually is

Professor Brian Cox, physicist and television presenter

@Jonno hopkins Radio 1 are trying to explain the Higgs boson to their listeners. Unless it's duetting on Rihanna's latest single I think it's a lost cause

Jonathan Hopkins, blogger

@Phlaimeaux SCIENCE! You should know I only believe you when you're told to me in the correct mad German scientist accent e.g. "INCRREAASE ZE DOSAGE"

David O'Doherty, comedian

@davidschneider This NASA Mars explorer thing – so is Curiosity Rover it's porn name?

David Schneider, comedian

@inkyhack [On the dog who drove a car] So I have to wonder if they would strap Mitt Romney to the roof if they had to take him anywhere

Patrick Giblin, blogger ‏

@paulocoelho [On Felix Baumgartner's space leap] Never accept your limitations – because there are NO limitations. Viva Felix! #spacejump

Paulo Coelho, author

@helenczerski This iceberg is breaking up as we look at it. Nervous times…

Dr Helen Czerski, physicist and TV presenter