Astronomically speaking the year 2012 has been, ahem, out of this world. The number and consequence of discoveries made in the past 12 months will be properly understood many years down the line.
Astronomically speaking the year 2012 has been, ahem, out of this world. The number and consequence of discoveries made in the past 12 months will be properly understood many years down the line. It is difficult to know where to start, but let’s begin with the astonishing announcement in October that the European Southern Observatory (ESO) had identified an earth-sized planet orbiting Alpha Centauri B.
This is remarkable because the three-star Alpha Centauri system at only 4.37 light-years away contains the closest star to our solar system. This means that the newly discovered planet, designated Alpha Centauri Bb, is the closest exoplanet to our planet.
The first confirmed exoplanet, or extra-solar planet, was discovered only in 1995 and since then the number of confirmations has been rising rapidly. The increase has been so quick that there is not even consensus about how many exoplanets have actually been confirmed. According to the Nasa Exoplanet Archive, at the time of writing there are 817 planets orbiting around 642 stars and 2 320 Kepler planetary candidates.
This is extraordinary because going through the most recent news feeds we see that 17 new planets were added to the Archive in the month of November 2012, yet in the entire history of humanity up to 1995, only nine planets were known.
Exoplanets were first identified by the slight gravitational wobble they induced in their respective host stars. This meant that only really big planets, similar in size to Jupiter were identified. More recently, as different detection methods have been used and instrumentation has improved, it has become possible to identify smaller, Earth-sized bodies.
This is important because what the astronomers are really looking for are habitable worlds.
This year for the first time, several candidate worlds of the right size and right distance from their host stars have been identified, thus bringing us ever closer to finding a place that could support life.
The search for life anywhere other than on Earth is the driving force behind several large projects. For example the Curiosity Rover currently inching its way across Gale Crater on Mars is conducting experiments designed to determine whether life had ever been possible on that planet.
Curiosity landed on Mars on 5 August and has sent back to Earth the most amazing photographs ever taken of another planet. The Rover travels painfully slowly – sometimes only six metres per day – so that it has only covered 677 metres in its first four months, but in this time there have been many opportunities for it to take photos with its 17 cameras.
It has already determined that water once flowed on the surface of Mars and mission controllers have tantalised us with promises of an important announcement within the next few weeks. Speculation is rife that Nasa will reveal information pointing to life that once existed on Mars – or perhaps they may even have detected signs suggesting that primitive life forms could still exist.
Astronomy has also had a massive boost here in South Africa. When the Square Kilometre Array Organisation announced that South Africa would host the lion’s share of the world’s biggest radio telescope, it prompted government to channel more resources to the development of astronomy in this country. The announcement was also indirectly responsible for Rhodes University’s decision to appoint of Prof Oleg Smirnov as the prestigious SKA Chair in Radio Astronomy Techniques and Technologies.
Another significant development this year was the retirement of the Space Shuttle programme. Although the final mission ended last year when the Atlantis completed the 135th mission of the programme, the world’s first reusable space craft made several trips on the back of a Boeing 747 in 2012 so that Americans could see it one last time before the remaining craft were sent off to various museums.
The retirement of the Space Shuttles opened the way for a completely new era of space exploration, as for the first time ever a privately owned spacecraft, the SpaceX Dragon was used to resupply the International Space Station. The commercial flight in October was the first of at least 12 Space X cargo resupply missions to the space station planned for the next four years.
If 2012 was marked by a succession of great achievements, there was one profoundly sad moment with the passing of Neil Armstrong, the first man to set foot on the moon.
He passed away on 25 August 2012 at the age of 82.
