What does it take for a planet to be habitable by complex life?
Complex life in particular probably needs many of the things that we Earthlings enjoy: a rocky terrestrial planet similar in size and composition to the Earth, with plate tectonics to recycle nutrients, and the right kind of atmosphere; a large, well placed moon to contribute to tides and stabilize the tilt of the planet’s axis. That planet needs to be just the right distance from the right kind of single star, in a nearly circular orbit–to maintain liquid water on its surface.
It also needs a home within a stable planetary system that includes some outlying giant planets to protect the inner system from too many deadly comet impacts. That planetary system must be nestled in a safe neighborhood in the right kind of galaxy, with enough heavy elements to build terrestrial planets. And that planet will need to form during the narrow habitable window of cosmic history. (This is to say nothing of having a universe with a fine-tuned set of physical laws to make stars, planets, and people possible in the first place. But that’s another long and complicated story.)
That’s a tall order and it’s not even an exhaustive list of all the requirements.
Now keeping that list in mind, Christian apologist Peter Williams explains how the latest discovery of an exoplanet that might support life was presented to the media by the excited scientists.
Nasa scientist and Nobel laureate in physics John Mather’s recent comment about ‘Earth-like’ planets was rather timely. Mather said: ‘We know there are earth-like planets out there, but what we don’t know is whether any of them are capable of supporting life.’ Well, Nasa have announced that: “If confirmed, [Gliese 581g] would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one.”
Thus far we have an unconfirmed report that Gliese 581g might be rocky (since it may be too small to be a gas giant – although the mass given is a minimum figure) and that it seems to be in the right ‘goldilocks’ temperature zone for liquid water – that’s if there is any water there and if the atmosphere is of the right composition!
Of course, the phrase ‘Earth-like’ is being used with some lattitude here: the gravity on Gliese 581g is higher than on earth (because its about three to four times the size of Earth). Moreover, the planet is ‘tidally locked’, meaning it doesn’t rotate (i.e. no seasons). This probably means that there’s only a narrow ‘twilight zone’ of the planet that’s even potentially habitable; assuming, of course, that the atmosphere (if it even has one) hasn’t frozen out over time to the night side of the planet!
At most (it’s hard to extrapolate here), this discovery may indicate that rocky planets in the habitable zone of stars aren’t all that rare; but consider this interesting passage from The Hiffington Post article on the discovery:
‘Vogt and Butler ran some calculations, with giant fudge factors built in, and figured that as much as one out of five to 10 stars in the universe have planets that are Earth-sized and in the habitable zone. With an estimated 200 billion stars in the Milky Way galaxy, that means maybe 40 billion planets that have the potential for life, Vogt said. However, Ohio State University’s Scott Gaudi cautioned that is too speculative about how common these planets are.’
There’s more to habitability – let alone the origin of life – than a chunk of rock at the right temperature!
This is Peter Pan science. They believe what they want to believe.
Many people want to believe that we are nothing special simplifying the world so that they don’t have to worry that maybe, somehow, they were created for a relationship with a cosmic Creator and Designer. Because if that were true,then they might not be free to just do whatever they want without any moral rules in order to make themselves happy. What they really want is to have all the benefits of being created by a loving God, without any of the responsibilities. They like sex, but they don’t like being told how to use it. So they jump at any news story that breaks down the evidence for a Creator/Designer. And they praise moral evil to the skies in order while bashing moral good down, in order to obliterate any vestiges of the idea that there might be any way that they ought to act. They don’t want to be accountable to God. They don’t want moral obligations.
Now look at the latest news from the New Scientist.
Last month, a team of astronomers announced the discovery of the first alien world that could host life on its surface. Now a second team can find no evidence of the planet, casting doubt on its existence.
The planet, dubbed Gliese 581 g, was found to orbit a dim, red dwarf star every 37 days, according to an analysis by Steven Vogt of the University of California, Santa Cruz, Paul Butler of the Carnegie Institution of Washington in DC, and their colleagues.
Unlike the four previously known planets in the same system and hundreds of others found throughout the Milky Way galaxy, Gliese 581 g sits in the middle of its host star’s habitable zone, where temperatures are in the right range for liquid water to exist. It is also puny enough – weighing about three Earths – to have what is likely a rocky, solid surface.
But it might be too early to claim a definitive detection. A second team of astronomers have looked for signals of Gliese 581 g in their own data and failed to find it.
“We easily recover the four previously announced planets, “b”, “c”, “d”, and “e”. However, we do not see any evidence for a fifth planet in an orbit of 37 days,” says Francesco Pepe of the Geneva Observatory in Switzerland. He presented the results on Monday at an International Astronomical Union symposium in Turin, Italy.
They wanted to believe we were cosmic accidents. Did they distort their data to prove what they wanted to believe? Like hiding the decline to “prove” that capitalism is evil?
We have to be careful about what some educated academic people want. Some educated academic people are sufficiently wealthy and powerful that they can avoid being hurt by most other people. So what they want is to pursue pleasure without being limited by moral rules. So they want to break them down because they view them as “speed bumps” on the road to pleasure in this life. Whatever they say has to be interpreted in light of this desire to get free from moral obligations and moral judgments by you and by your children. They want to normalize the idea that selfishness that causes damage to others is morally neutral. The breakdown of moral realism is what is behind many fads like Dan Brown, sex education, moral relativism, etc.
My previous article on what it takes to make a planet that is habitable by complex life.