Looking back on 2012, we have seen some amazing science – especially in space & astronomy.
1. The Mars Curiosity rover: When this six-wheeled, nuclear-powered robot completed its journey from Earth to Mars on August 5th of this year, it executed a flawless landing sequence that the NASA engineers named the “Seven Minutes of Terror”. So called because of the combination of the seven-minute-long landing sequence and the 14-minutes it took for signals from Mars to reach Earth, the source of the 'terror' was knowing that by the time the engineers received the signal from Curiosity that it was entering the Martian atmosphere, the rover would already have been on the surface of Mars – either intact and ready for its mission or in pieces strewn about the planet's surface – for a period of seven minutes.
After the nail-biting suspense, the engineers were elated when Curiosity reported in that the landing had gone exactly as planned, and they immediately got down to business. In the three months since its landing, the rover has run test after test of its systems and scientific instruments, has taken some spectacular pictures – including several awe-inspiring panoramic views of the Gale Crater and Mount Sharp and an excellent self-portrait – and has already made some great discoveries.
It's first major discovery: a rocky outcrop made up of small rounded rocks cemented together with dust and sand – what geologists call a conglomerate – that appeared to be similar to deposits found in streams and rivers here on Earth. The scientists didn't jump to conclusions, though. Close examination of these rocks by the rover showed the same wearing expected for rocks moved and knocked together repeatedly while being transported by a fluid such as air or water. However, the size of the rocks made them far too heavy to be moved around by Mars' thin atmosphere, even with the planet's lower gravity. They must have been transported and worn down by water, which was also supported by the 'cement' that held the rocks together. There has been plenty of evidence found by other missions that indicated water or water processes in Mars' past, but this was considered the first conclusive evidence that there was flowing water on the surface of Mars at some point.
There have been other discoveries since, such as finding a deposit of gypsum, a type of mineral formed only in the presence of water here on Earth, and more strange spherical rocks, similar to the hematite 'blueberries' found by the rovers Spirit and Opportunity, but with these new ones being very much like ones here on Earth that are created by microbial processes.
The rover's latest discovery? Radiation levels at the planet's surface are roughly the same as astronauts experience in low-Earth-orbit. This is great news for the future of manned missions to Mars, since we now know we will be able to keep our astronauts safe for the duration of their missions there.
2. Felix Baumgartner's 'space' jump: On October 14th, Austrian skydiver Felix Baumgartner performed a 'space' jump from just over 39 kilometres above the Earth's surface – the highest jump ever made – and he set two other records, one for the highest balloon flight and one for being the first person two break the sound barrier without the assistance of a vehicle.
3. Earth-sized planet discovered: In mid-October, astronomers at the La Silla Observatory in Chile reported that they had found an Earth-sized planet orbiting one of the stars in the Alpha Centauri star system – our stellar next-door neighbour. While the planet is too close to Alpha Centauri B to support life, it not only gives us an excellent target for our first exoplanet to explore, but it may only be one of several planets in that star system!
4. 'Large object' strikes Jupiter: On September 10th, amateur astronomers spotted and actually recorded a large object – possible a comet – striking Jupiter, illustrating just how important the massive planet is to the survival of life on Earth as it 'sweeps up' these objects and keeps them from hitting us, and just how important amateur astronomers are in scanning our skies for potential dangers!
5. SpaceX launch 'Dragon' spacecraft: On October 7th, SpaceX Corporation launched their Dragon spacecraft on the first commercial cargo run to the International Space Station. While this isn't an Earth-shattering event in of itself, it makes the list for opening up space to the public. Up until this point, it was government agencies that flew regular missions to space. Private companies, like SpaceX, Orbital Sciences and Virgin Galactic, are ushering in a period of our history that will provide people with unprecedented access to the world, the Moon, and even the other planets in our solar system.
6. Planet Gliese 163 c discovered: Looking back out into space, on September 24th, astronomers reported discovery of the planet Gliese 163 c – a 'super-Earth' planet, roughly 7 times the size of our planet – that immediately jumped to the top of the list of planets (outside our solar system) that have the best chance of supporting life. Gliese 163 c orbits its parent star at a distance where the temperature is just right – not too hot and not too cold – for liquid water to exist on its surface. Given what we know about life here on Earth, with its dependence on water, but also its ability to take hold in nearly every environment that even has the remotest chance of supporting it, makes it a near-certainty that this newly-discovered world harbours at least some form of life.
7. Neptune-like planet discovered: In another amateur contribution this year, on October 16th, it was announced that a 'citizen-scientist' group called Planet Hunters had confirmed the existence of a large Neptune-like planet that was the first planet ever discovered in star system with four stars – with two of the stars orbiting each other near the centre of the star system, and the other two circling each other while they orbit the first pair at a distance of about 20 times the distance that Pluto orbits our Sun. This planet, designated PH-1 (Planet Hunters-1), orbits the two inner stars at a distance equivalent to somewhere between the orbits of Mercury and Venus in our solar system, taking only 126 days to complete one orbit. Again, without the assistance of these amateur citizen scientists, astronomers would likely have taken years to discover PH-1, given the amount of information there is to sift through, and this highlights that we have a chance to make a meaningful contribution to science!
8. Fifth moon orbiting Pluto discovered: On July 11th, the Hubble Space Telescope detected a fifth moon orbiting the 'dwarf planet' Pluto. This new discovery brings with it another potential shift in Pluto's planetary status. Downgraded from Planet status in 2005 with the discovery of Eris, an object that orbited even further out than Pluto, but was 25% more massive than our 9th planet. The decision was made to reclassify Pluto as a dwarf planet, bringing the count of planets in our solar system down to eight. However, with the discovery of this fifth moon, this may be further evidence that Pluto and Charon (the first moon we discovered orbiting Pluto) are in fact a Binary Planet – two planets that share the same orbit around the sun and orbit each other around a point that lies between the two worlds.
9. Light from the very first stars detected: In early November, it was reported that astronomers using the Fermi Gamma Ray Space Telescope had detected the light from the very first stars that lit up our universe. These immense, short-lived stars were the first to form from the swirling clouds of hydrogen gas that condensed in the cooling, expanding new universe. The astronomers were not able to directly observe these stars, but instead used a novel approach to discover the light that the stars had emitted long ago. Using their knowledge of all the light from known sources – the extragalactic background light (EBL) – and using stellar objects known as 'blazars' – compact quasars that emit their radiation beams in the general direction of our region of space – in a way similar to lighthouse beacons, they examined how these radiation beams were diminished by the EBL 'fog' and isolated out the light from these earliest of stars.
10. Thirty-three exoplanets discovered: The Kepler Space Telescope has had a banner year in 2012 so far, with the confirmed discovery of 33 exoplanets orbiting around 16 different stars. More exoplanets are being found and confirmed all the time, with the total reaching 850 in November of this year. This follows a January announcement by the Kepler team that planets very likely outnumber stars in our galaxy, with an average of 1.6 planets per star. Most of the planets discovered so far have little potential for harbouring life, but with so many out there, the chance of finding life-bearing worlds continues to grow.