Small flat bugs
‘Found, a planet like Earth but 5 billion years away’, ran The Times page 3 headline on 25 April – ‘Best chance yet of extraterrestrial life’. Later the same day, a BBC TV news correspondent solemnly declared that the new planet might be inhabited by ‘small flat bugs’.
The 5 billion years was a miscalculation by The Times – it should have been half a million. But what difference do a few zeros make to a gullible public?
Furthermore, you must understand that the bugs in question have not actually been seen. Nor, come to think of it, has the planet. But then, as Mark Twain once pointed out, ‘It’s amazing how, for a small investment of fact, one can get such a large return in speculation’.
Investment of fact
First, what are the facts? The search for planets (so-called ‘exoplanets’) orbiting stars in distant galaxies is a large and growing area of astronomical research. Over two hundred planets are now known to be orbiting stars other than the Sun.
Most of these planets were detected using the radial velocity method, which involves using spectroscopy to measure the ‘wobble’ of a rotating star caused by an unseen planet’s gravitational pull. An alternative is the transit method which involves measuring the small decrease in apparent brightness of the star as the planet passes in front of it. This method is only sensitive to planets with ‘edge-on’ orbits but if such a planet is detected, its size, mass and orbital characteristics can be determined.
The exoplanet that caused so much excitement in April is one of three believed to be orbiting the star – a red dwarf called Gliese 581 in the constellation Libra.
The planet (Gliese 581c) was detected using the radial velocity method; that is, it has not actually been seen but its presence is inferred from small variations in the star’s rotational speed (deduced from effects in its light spectrum).
Return of speculation
Its discoverers claim that Gliese 581c is a rocky planet with a radius 50% greater than Earth and about five times Earth’s mass. They estimate a surface temperature between -3degC and 40degC.This further suggests the possibility that liquid water might exist there – placing it within the ‘habitable zone’ of its parent star. And if there is liquid water (they argue) then life could have evolved there ‘as it did on Earth’.
Bingo! Small flat bugs! Why flat? Because with a mass five times that of earth, the planet’s gravity would also be five times greater – enough to flatten even a bug.
Why small bugs? Simply because uncritical viewers are more likely to swallow bugs (small ones, of course) than little green men.
Many assumptions
I should make it clear that the planet’s discoverers said nothing about bugs – that was an invention by the BBC. But their claim that Gliese 581c is a rocky planet like earth, and has liquid water on its surface, is itself based on a string of assumptions.
An informed website respondent comments: ‘You must remember that neither the mass nor the radius of this planet are actually known. The mass is the “minimum mass” and since radial velocity cannot determine the angle of the system, the mass could actually be much larger.
‘I would be not surprised if it turned out that these planets are all Jupiter-size. The quoted radius of 1.5 Earth radii is the size the planet would be if it were terrestrial [rocky] which is not known. We actually have no idea what the density of Gliese 581c is’.
Another astronomer points out: ‘The habitable zone isn’t a terribly robust definition. The inconsistencies in temperature [calculated by different correspondents] are due to [assuming] different albedos, that is, how much of the incoming sunlight energy is absorbed … I think a more important difference … is the greenhouse effect, given that many of the most abundant molecules in the galaxy are greenhouse gases’.
Healthy scepticism
All this adds up to the need for the general public to view with healthy scepticism all claims that appear in the media relating to the possibility of extra-terrestrial life. Scientific discoveries are commonly reported in a manner calculated to advance the cause of evolutionary atheism, regardless of the true facts.
And it’s not just the media. The scientific establishment, with government support, often leads the crusade to replace the Creator by the god of evolution. The European Union is currently considering spending over $1 billion to build the world’s largest optical telescope – with the search for extra-terrestrial life as a primary objective.
Of course, as ET has pointed out many times over the years, the discovery of life elsewhere in the universe would prove nothing concerning evolution and creation. But as long as unbelieving men think that such discovery would be a nail in the coffin of creationism, they will pursue it with vigour.
