No Moon Needed For Extraterrestrial Life 246
sciencehabit writes "Given the generally accepted idea of how Earth got its big moon — through a dramatic collision with a Mars-sized body that knocked a huge chunk of Earth loose — astronomers estimate that only 1% of all Earth-like planets in the universe might actually have such a hefty companion. That would mean planets harboring complex life might be relatively rare. But researchers have now carried out large numbers of detailed numerical simulations of 'moon-less Earths,' which show that the consequences are less dire than is generally assumed. According to the simulations, these planets would have ample time for advanced land life to evolve. As a result, the number of Earth-like extrasolar planets suitable for harboring advanced life could be 10 times higher than has been assumed until now."
Please explain (Score:5, Interesting)
Why was there ever an assumption that a moon is required for complex life? Stabilization of the axis and climate regions? Or did we just assume it because it worked here?
This is a SIGNIFICANT problem (Score:3, Interesting)
Here's what a rational, realistic analysis of tech progression would expect. GIVEN that life on earth can self replicate itself and use a huge range of molecules for fuel, it seems obvious that more sophisticated life is possible than already exists. Our star exhausts enormous amounts of free energy into space every second. Thus, one would expect that some day, perhaps next century or thousands of years from now, we will develop more sophisticated life that can use ALL of the matter in our solar system (rather than just a narrow range in the biosphere) and will use solar energy to rapidly convert all matter into parts of this life. This expectation is known as the singularity, and generally is assumed to require both artificial intelligence and molecular manufacturing (nanotechnology) to take place. There are plausible reasons to think that this event might happen in this century.
Well, if this is GOING to happen, and one would expect other intelligent life to do the same, and to eventually reach the same point. Then why don't we see the evidence of this out in space? Most of the stars should be missing, radiating mostly in the infrared. There should be a cacophony of data transmission between stars, although we might not be able to detect this. There should be other evidence of lively interstellar civilizations.
Theories :
1. The singularity is not physically possible. That means, of course, that our theories of physics are massively wrong as well, and that all our assumptions about intelligent life are as well.
2. Every single intelligent civilization self destructs. This also seems ludicrous...even if it happens some times, there should at least be remnants.
3. We are the first within our region of space. It took life on this planet ~3 billion years to get to this point, and many billions of years for this planet to form with the elements it has. The universe is only ~13 billion years old. Possible...
4. Technology can do even more than we assume. Maybe you don't actually need to surround stars with solar collectors to get energy...And our neighbors obey the prime directive...
And so forth. The number of possible theories is infinite, the number of probable theories large.
Re:Please explain (Score:4, Interesting)
And, I think that the tides provided by a moon would keep things moving around instead of stagnating.
Not to mention the tidal forces make the Earth's surface flex about 1ft (as evidenced by my GPS) per day. All that flexing keeps the insides hot as well as triggers earthquakes that would otherwise be more devastating, and helps lava flow so that smaller, more frequent volcanic outbursts occur instead of less frequent super volcanic activities that would extinct us all.
Conversely, why the hell we think only land life would be sentient and capable of technology is beyond me -- Seems that artificial water filled environments might be easier to maintain in space too (holds heat better, freezes at the edges for insulation, shields against certain UV wavelengths... There's a reason life happened in the watter first, making it to land doesn't seem all that important to me. Dolphins may actually be close to sentience -- they returned to the water because land life was harsh.