SA helps in exoplanet hunting
Cape Town - South African astronomers are involved in the discovery and analysis of possible exoplanets several light years away.
Nasa recently announced that the Kepler telescope found several planets orbiting distant stars, suggesting that exoplanets are more common than previously thought. But analysis of these bodies is difficult and researchers from around the world are assisting in the analysis.
"After only four months of operation, the Kepler team announced the discovery of over 1 200 new candidate exoplanets - a lot of work will be required to follow up and be sure they really are planets since there are several ways that observational data from non-planetary systems could mimic those from planetary systems," SAAO astronomer Dr John Menzies told News24.
He said that the Southern African Large Telescope (Salt) in the Northern Cape province would be critical to the identification of exoplanets when it receives a spectrograph this year as well as the UK-operated superWASP and KELT from the US which are both based in Sutherland.
Gravitational microlensing is also used to find distant planets but requires long observations conducted by a collection of telescopes around the world.
"Sutherland is situated about half way between Australia and Chile, so is a vital node in the PLANET collaboration's observing programme; this collaboration has been operational since 1995.
"This technique finds planets that are significantly further away from their parent stars, and is the only ground-based method of finding earth-mass planets orbiting several astronomical units (distance of earth from Sun) from the parent star," said Menzies.
He would not rule out life being able to exist on planets that may be regarded as unsuitable for life as we understand it on Earth.
Recently, Nasa scientist Richard Hoover made a claim that alien microbe fossils were found in meteorites on Earth. The agency though, has distanced itself from the findings.
In December, Nasa has announced the discovery of a new bacteria that can grow and incorporate arsenic into its DNA.
"We have had this idea that life requires these six elements with no exceptions and here it turns out, well maybe there is an exception," said Ariel Anbar about the discovery.
"In simple terms, life as we understand it is carbon-based, and could exist wherever the ambient temperature allows water to exist in liquid form and the gravity to be sufficiently high to retain an atmosphere; so yes, it would be possible for it to exist on moons of planets," said Menzies.
He said that the hunt for exoplanets has been accelerated with the Kepler telescope and scientists focus on cooler stars as they were more likely candidates for life to exist.
"With the Kepler experiment, there will be a revolution in our knowledge of exoplanet statistics - in about 20 years just over 500 exoplanets have been found from the ground compared with over 1 200 in four months from Kepler."
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