UEA Research Shows Oceans Vital For Possibility of Alien Life 97
An anonymous reader writes New research at the University of East Anglia finds that oceans are vital in the search for alien life. So far, computer simulations of habitable climates on other planets have focused on their atmospheres. But oceans play an equally vital role in moderating climates on planets and bringing stability to the climate, according to the study. From the press release: "The research team from UEA's schools of Mathematics and Environmental Sciences created a computer simulated pattern of ocean circulation on a hypothetical ocean-covered Earth-like planet. They looked at how different planetary rotation rates would impact heat transport with the presence of oceans taken into account. Prof David Stevens from UEA's school of Mathematics said: 'The number of planets being discovered outside our solar system is rapidly increasing. This research will help answer whether or not these planets could sustain alien life. We know that many planets are completely uninhabitable because they are either too close or too far from their sun. A planet's habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water. But until now, most habitability models have neglected the impact of oceans on climate.'"
Re:Correction (Score:2, Interesting)
No one is explicitly ruling out the possibility that there are gaseous lifeforms living in the clouds of gas giants, or silicon-based rock monsters like the one in Star Trek.
Actually, we know almost all basic chemistry, and the range of (stable) molecules that silicon can form is orders of magnitude less than for carbon.
There is a lot of silicon to be found on/in the surface of our planet (over 900 times more than carbon), and yet lifeforms here didn't integrate it in their core chemistry. At most they used it to reinforce surface/skeletal structures.
It also doesn't readily form gaseous molecules like carbon does (CO2), which would help in energy cycles.
Re:Correction (Score:4, Interesting)
There is no scientifically valid way to rule out life forms which are unlike our own
1) Life will require energy flow. More fully, life will operate much like a heat pump tapping energy flow between a high entropy or temperature sink to a lower entropy or temperature sink.
2) Life will require an environment it can survive in. This story attempts to address part of that with the idea of climate buffering.
3) As K. S. Kyosuke noted in his reply, life will require some matrix capable of the complex morphological structures and behaviors that life will need to survive.
4) Life will need time or a shortcut (like a creator) in order to develop. Evolution-based life will need time (measured in generations) for adaptation to occur.
For example, let's take an isolated "rogue planet". First, it's an object massive enough to round itself under the force of its own gravity, but not massive enough to undergo fusion. Second, it's not orbiting a star and basically is slowly cooling down to the temperature of the cosmic microwave background (no external energy inputs of note). The driver for any life would have to be heat flow from the interior due to heat of formation and possible radioactive decay. The situation is contrived (but in a way that actually probably appears billions of times in nature, just in our galaxy) so that there is no other means to provide significant energy flow to the system.
Restriction 2) is rather simply solved since the environment is very stable over billions of years (unless the rogue planet happens to get too close to a star or runs into something).
Restriction 3) requires either complex chemistry (from elements other than hydrogen or helium) or structure from say possibly, the interaction of different phases of metallic hydrogen and electromagnetism at the core of a gas giant.
Restriction 4) means that if it's evolution-based life derived from abiogenesis, then it needs to be in a high enough energy flow over large enough volume so that enough generations can pass to evolve to a state where they can technically qualify as life (such as traits/information passed from past organisms to future ones). We don't know how big that would need to be, but bigger and older is better. Similarly, we would need the presence of complex structures, which are more likely in a high energy flow environment (eg, amino acids created by weather-induced lightning).
If it's creator-derived or evolved elsewhere and migrated, who knows. The resulting organism might be able to fuse deterium and/or helium 3 isotopes, for example. That allows for creation of higher weight elements too.
Neil DeGrasse Tyson (Score:4, Interesting)