Goldilocks Planet – A Goldilocks planet has been found by astronomers.
None are known to be habitable – let alone inhabited – but astronomers who are making the discoveries with NASA’s Kepler spacecraft are meeting this week in California to review the first two years of their quest, which seems tantalizingly close to hitting pay dirt.
At least four times in the last few years, astronomers have announced they have found a celestial body orbiting a star in the the habitable zone – not too hot, not too cold – where water and thus perhaps life are possible.
“Sooner or later, Kepler will find a lukewarm planet with a size making it probably Earthlike,” said Geoffrey Marcy of the University of California, Berkeley, who spends his time tracking down candidates identified by Kepler. “We’re no more than a year away” from such a discovery, he said.
All this has brought to the fore a question long debated by geologists, chemists, paleontologists and cosmologists turned astrobiologists, namely: What does life really need to get going, flourish and evolve on some alien rock?
The answer depends, of course, on whom we expect to be living there. We might dream of green men with big eyes, ants with hive minds, or even cuddly octopuses as an antidote to cosmic loneliness; but what we are most likely to find, a growing number of scientists say, is alien pond slime.
“We are limited by our imaginations,” said Natalie Batalha, a leader of the Kepler team.
Some scientists decry the emphasis on animals like us, saying it is hopelessly parochial and unimaginative.
“Animals are overgrown microbes,” said Paul Falkowski, a biophysicist and biologist from Rutgers. “Plants and animals are an afterthought of microbes.”
So, we should hardly be disappointed if we find our neighbors are microbes. After all, on Earth, microbes were the whole story for almost 4 billion years, paleontologists say.
Looking for Goldilocks
In September, what some astronomers called the best and smallest Goldilocks candidate yet was announced. About 3.6 times as massive as the Earth, it circles a faint orange star in Vela known as HD 85512 at a distance of some 24 million miles, about a quarter of the Earth’s distance from the Sun.
Lisa Kaltenegger, a climate modeler at the Max Planck Institute for Astronomy in Heidelberg, and her colleagues calculated that this planet would be habitable if it had an Earth-type geology and at least 50 percent cloud cover.