Excellent study material for all civil services aspirants - begin learning - Kar ke dikhayenge!
SHARE:
Was "Oumuamua" an alien spacecraft - the big debate
Read more on - Polity | Economy | Schemes | S&T | Environment
- The startling 2017 discovery: An object came hurtling in from deep space, from the direction of Vega, a star 25 light-years away. It crossed the orbital plane of the solar system, within which the Earth and the other planets revolve around the sun, on September 6th 2017. Now under the influence of the sun’s gravitation, the object accelerated to around 2,00,000 mph as it made its closest approach to the star on September 9th. Its trajectory then took it out of the solar system. A month after the object had arrived, it was well on its way back to interstellar space, moving towards the constellation of Pegasus.
- Finally found: As it catapulted past the sun and began to head off, no one on Earth had any idea of the object’s existence. Astronomers discovered it only on October 19th; it was hidden in the data collected by their network of telescopes, as a point of light that travelled too fast to be trapped by the sun’s gravity. They gave it a name: 'Oumuamua', Hawaiian for 'scout'. Astronomers quickly confirmed that 'Oumuamua' was the first interstellar object recorded as having passed through the solar system. Initially it was thought most likely to have been an asteroid or a comet; but available data indicated that ‘Oumuamua was small (around 400 metres long) and shiny (perhaps ten times shinier than any asteroid or comet seen before). It seemed to have an elongated, cigar-like shape, at least five to ten times longer than it was wide. There never was anything like it!
- Strange path: In addition to these physical peculiarities, Oumuamua had travelled along a path through the solar system that could not be explained by the gravity of the sun alone. This was the most eyebrow-raising bit of data accumulated over the roughly two weeks it was seen. Scientist Avi Loeb, an astronomer, wrote his account in the book “Extraterrestrial”. Loeb concluded that the simplest explanation for the exotic strangeness of Oumuamua was that it had been created by an intelligent civilisation beyond Earth. Most scientists laughed it off!
- SETI story: Carl Sagan, an American astronomer, once said: “Extraordinary claims require extraordinary evidence.” There is a project on search for extraterrestrial intelligence, commonly known as SETI. Since the 1960s astronomers have been listening to the skies for any signs of radio signals sent out by technologically capable life beyond Earth. But SETI has been marginalised, dismissed as a lesser use of time and resources than the more prestigious study of black holes, subatomic particles, stars, galaxies and other “real” physics.
- Loeb’s view: He says SETI must be taken more seriously, simply because far more nebulous ideas are being taken seriously! Modern mainstream theoretical physicists accept the study of spatial dimensions beyond the three (length, breadth and depth) with which people are familiar. Experimental evidence for these dimensions does not exist. Cosmologists also think that this universe is one among an infinite number of others that exist together in a “multiverse”. But experimental evidence does not exist. String theory, the putative “theory of everything” that is meant to bind together the physics of the cosmos with that of subatomic particles, is considered scientific even though there is no direct evidence to prove it is real.
- So why not ET: Compared with these abstract theories, the notion that there could be life elsewhere in the universe, when it is known to exist on Earth, should not seem so radical a subject of study. Loeb thinks resistance to it comes from two sources. First, the “laughable” popular narratives in which aliens lay waste to Earth’s cities and possess superhuman wisdom. He is no fan of science fiction that ignores the laws of physics. But the more important reason, he says, is a conservatism within science, which is sustained by the desire of individual scientists to keep risk low and funding high: By limiting interpretations or placing blinders on our telescopes, we risk missing discoveries.
- Another big project: In 2016 Loeb was the astrophysical brain behind Breakthrough Starshot, a $100m project funded by Yuri Milner, a Russian tech billionaire, the goal of which is to dispatch a fleet of tiny probes called Starchips to Alpha Centauri, the nearest star to the sun. They are to be equipped with cameras able to relay any signs of life they might find back to Earth.Mr Loeb worked out that it might be possible to accelerate a Starchip to around 20% of the speed of light if it were fitted with an ultra-thin sail and a 100-gigawatt laser were directed towards it for a few minutes. So launched, the Starchips would in theory make the 4.4-light-year journey to Alpha Centauri in between 20 and 30 years. The Breakthrough Starshot project was announced a year before the discovery of Oumuamua.
- Summary: No one knows what Oumuamua was, a spacecraft, or simply a large piece of rock. But science must keep investigating. As someone said, there may or may not be life elsewhere in this Universe, and both prospects are terrifying.
COMMENTS