Can we expect extra-terrestrial visitors any time soon? And if so will they be friendly?
H G Wells’s “War of the Worlds”, published over a hundred years ago, was probably the first story to suggest that visitors might not be.
The popularity of sci-fi films in the 1950s probably reflected feelings of paranoia and insecurity during the cold war period.
More recently films like “Men in Black“, “Mars Invasion” and “Galaxy Quest” presented a more humorous aspect and the latest version of “V” presents aliens as beautiful people (those who saw it the first time round know better of course – beauty is only skin deep!).
So it might reassure you to know that the United Nations already has an Office for Outer Space Affairs (Unoosa) and has a designated “first contact” person (although this has now been disputed by the UN).
So who do you think will have the responsibility to be the Earth’s official representative of humankind? The Pope, The President of the USA, The Secretary General of the UN, the Queen, or (and forgive me for even thinking this) someone who has bombarded the airwaves like Simon Cowell or the self-obsessed twit(terer) Stephen Fry?
The answer is none of these but a little known Malaysian astrophysicist called Mazian Othman, head of Unoosa, who said that the UN must be ready to coordinate humanity’s response to any first contact.
Whilst the possibly of alien contact might be increasing with the discovery of many new planets the chance of them being humanoid rather than microbes is tiny. A more realistic visitor from outer space might be a meteor causing an impact event.
Meteor impacts on earth have had devastating results such as wiping out the dinosaurs 65 million years ago (but allowing mammals and birds to survive) and it’s even been suggested that life on earth arrived through a meteor impact introducing microbes into our ecology.
Nasa scientists said that amino acids carried to earth in meteorites may have been the seed of life on Earth. Apparently we only have “left-handed” amino acids here and a disproportionate amount of that type have been found in meteorite samples. Source: Times 20/1/11
These near earth objects (NEOs) are regularly tracked by NASA and astronomers around the world and the risk of their colliding with earth is assessed.
Every year many small NEOs enter the atmosphere and burn up with some larger ones occasionally reaching the surface with the impact of a small atomic bomb which could create a tsunami or a crater.
To help you assess the risk, scientists at Purdue university have created an on-line tool for you to assess the impact of a meteor strike somewhere near you. So if you want to know how safe you would be from such an impact go to http://www.purdue.edu/impactearth
Updated 16 November 2010: A colourful 2-page spread in The Observer (114/11/10) described the hunt for exoplanets ie those that exits outside our solar system. The first one was discovered in 1992 orbiting the star PSR 1257+12 and since then, with better techniques, another 500 have been discovered.
Last year astronomers discovered 5 planets orbiting Gliese 581, a star in the constellation Libra, including one the size of earth. This year scientists in Santa Cruz said they had found a sixth and, more importantly, it was orbiting in a region known as the “Goldilocks” zone. These are areas where it’s not too hot and not too cold but just right to support life (and where water won’t either be frozen or unable to condense because of the heat). On Earth water exists in vapour, liquid, and solid form.
Swiss scientists dispute the presence of planet Gliese 581g (Gliese was a German astronomer) but another discovery may be more exciting. Planet Gliese 1214b, in the constellation Ophiuchus, appears to be composed largely of water, considered one of the essential building blocks for life.
Updated 24 january 2011: It now looks like NASA were over-optimistic about the news that an earth-like planet had been found – a rocky sphere with a diameter 1.4 times that of earth orbiting a star named Kepler-10.
Kepler-10 is 560 light years from Earth and scientists were over the moon about the discovery with one describing it as the “missing link between gas giant planets and our Earth”. Unfortunately it now appears to have a hellish environment. Far from falling within the Goldilocks zone it is only a few million miles from its sun and has a surface temperature of 1,300C, has no atmosphere, and is blasted by radiation. In other words an extreme world with no hope of life as we know it existing.
It now appears that most of the new planets found around other stars are similarly extreme either roasting hot – one of which has a year that lasts only 1.2 earth days, frozen, or with huge temperature swings. Many are huge gas giants as big as Jupiter but orbiting much closer to their suns which means they travel much faster eg at 200 miles per second which is ten times faster than the Earth goes round the sun.
An American astronomer, Frank Drake, came up with a formula in 1961 which suggested that there might be 10 detectable advanced civilisations in the Milky Way. Now some astronomers believe that we have to face the possibility that we are alone and that there is no realistic possibility of finding intelligent life close enough to Earth to make contact.
The Drake equation did have some impact on us however leading to the setting up of Seti (Search for Extraterrestrial intelligence) and a fascination for alien civilisations as envisaged in Star Trek and films like Space Odyssey.
Updated 8 February 2011: NASA make your mind up! Reports this weekend that the NASA Kepler mission has found six planets round a Sun-like star with one of them in the Goldilocks zone has got everyone excited again about the possibility of life on other worlds.
Kepler-11, is the first sun to have been observed with more than 3 orbiting planets. It definitely has six, most of which have an estimated surface temperature of 400C so too hot for any known form of life, and there may be a seventh, the first ever planet found that may be similar to Earth.
But don’t get too excited – it’s 2,000 light years away and would take 30 million years to get there at the 39,00 mph speed of the Voyager 1 spacecraft. So we aren’t going to travel there any time soon, if ever, and if they visit us first we are probably in big trouble.
In the 156,000 stars Kepler can observe (about 1/4% of the sky) there may even be 5 other Earth-like planets with surface water still to be confirmed. Suddenly science fiction seems more real.