It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Astronomers have always thought that because life emerged quickly on Earth, it must be likely to occur elsewhere. That thinking now turns out to be wrong.
The Drake equation is one of those rare mathematical beasts that has leaked into the public consciousness. It estimates the number of extraterrestrial civilisations that we might be able to detect today or in the near future. The equation was devised by Frank Drake at the University of California, Santa Cruz in 1960. He attempted to quantify the number by asking what fraction of stars have planets, what fraction of these might be habitable, then the fraction of these on which life actually evolves and the fraction of these on which life becomes intelligent and so on. Many of these numbers are little more than wild guesses. For example, the number of ET civilisations we can detect now is hugely sensitive to the fraction that destroy themselves with their own technology, through nuclear war for example. Obviously we have no way of knowing this figure.
The new study suggests that a wider variety of alien habitats may be open to life than scientists had imagined. The results even extend the possibility of life beyond planets, to the strange "failed stars" known as brown dwarfs, researchers said. After all, if Earth bacteria can breed in 400,000 G's, the 10-to-100 G's possibly found on a brown dwarf shouldn't be much of an impediment. And some brown dwarfs may be cool enough to support life as we know it, researchers said.
Based on such extrapolation, it is estimated that perhaps 20% of sunlike stars have at least one giant planet while at least 40% may have planets of lower mass.
Regardless of the exact fraction of stars with planets, the total number of exoplanets must be very large. Since our own Milky Way Galaxy has at least 200 billion stars, it must also contain billions of planets if not hundreds of billions of them.
Yes, the chances of life appearing on any one planet would be arbitrarily small. In fact it would be so small that it might take billions of years before you even see signs of the simplest forms of life.
Yes, but has every planet existed for that long? And did they all reach hospitable levels at the same time? What point are you trying to make anyway?
We have 15 Billion years of light history to look at, meaning that there has been plenty of time for something to happen.
Originally posted by TheUniverse
reply to post by Bigwhammy
Life is ubiquitous(everywhere) throughout the universe
The Universe is filled with
The Drake equation states that:
N = the number of civilizations in our galaxy with which communication might be possible; and
R* = the average rate of star formation per year in our galaxy
fp = the fraction of those stars that have planets
ne = the average number of planets that can potentially support life per star that has planets
fℓ = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent life
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space.