We Are Not Alone- Study: Billions of Earth-Size Planets in Milky Way

[John Done]

NASA estimates that there are at least 100 billion stars in the Milky Way, of which about four billion are similar to the Sun. If only 7% of these stars have habitable planets (a very conservative estimate), then in the Milky Way alone there can be up to 300 million potentially habitable planets.

[kevin baggott]

...

[Paul F]

Gotta' throw out another bit of logic... I've always had to laugh at the people who think we're going to encounter intelligent life and have anything to teach them... or, for some reason, WE(?) will be the superior beings? Let me put it this way... on a timeline representing several billion years... scaled to the length of a football field... ALL of human experience would fit in a hair's width (not length)... at the very very end (there's nothing more recent than today).

Look at electricity... flight... the transistor... the odds are that we're the new kids in the universe... most likely by, at the very least, hundreds of thousands of years... if not millions.

And the funny thing is we'll fight over what computer platform somebody chooses... and kill each other over things not much more significant than that. So... yeah... let's mix it up by introducing ourselves to something with a few million years more advancements... and hope that they'll somehow see us as equals... instead of using the exact same socioeconomic and/or food-chain logic that we use to determine how other living things that live here are treated.

Go SETI! I'm sure that IF there were any success in it... that it would work out great for us.

You make a good point that technological development is exponential. Once the first few billion years of planet development passes and there are enough stable planets then it only takes a few dozen million years of evolution to develop intelligent life. Once that life reaches a certain point, technology takes off at an ever accelerating rate. The assumption we all make is that we or they are able to remain as a stable society for some period of time such that we are this brilliant life form and that somehow, one of these life forms finds a way to defy physics and travel at the speed of light to get to the next planet that has life.

Meanwhile, I'd have to assume that most planetary systems are similar to ours and subjected to random acts of violence every few million years, which extinguishes life and it starts over. It seems every 100 million years or so, we have a bit of a collision on earth and things reset. So is it the same everywhere else? Maybe were due for another asteroid.

It's all nonsense anyway. The reality is that we can't even get along on this planet. We can't even control ourselves to keep the population down to a sustainable level, yet some fools actually think a dead planet like Mars is worthy of populating.

When I go outside at night and I see the stars, I think of those pictures of the earth the astronauts took from the moon and see that razor thin atmosphere protecting us from the void of space... then I really begin to wonder what it's all about. Of course, the answer is ... 42.

[Greg_E]

Brought back alive from 2013.

[Paul F]

Yep, newcomer John Done has been poking around refreshing many an old thread. Troll?

[David Saraceno]

Yep, newcomer John Done has been poking around refreshing many an old thread. Troll?

I noticed that as well.

[cyclone]

I'd have to assume that most planetary systems are similar to ours and subjected to random acts of violence every few million years, which extinguishes life and it starts over. It seems every 100 million years or so, we have a bit of a collision on earth and things reset. So is it the same everywhere else?

Hmmm. Very interesting thought. First time I ever considered that maybe there AREN'T smarter organisms out there.

[JPNola]

NASA estimates that there are at least 100 billion stars in the Milky Way, of which about four billion are similar to the Sun. If only 7% of these stars have habitable planets (a very conservative estimate), then in the Milky Way alone there can be up to 300 million potentially habitable planets.

That's the "old" thought.

The "new" thinking is that, yes, we ARE likely alone:

If the universe is so big, it likely produced intelligent life on other planets. Some of those lives must have built spaceships. Even at relatively slow speeds, given enough time, they’d disperse across the galaxy, just as humans had across the globe. And if that’s the case, as physicist Enrico Fermi famously wondered, where is everybody? Why haven’t we met any extraterrestrials?

“It just hit me with the force of a sledgehammer that all these things that science fiction, and science as well, had told me to expect — that one day soon we would make contact with aliens, and that maybe we’d go out and have all these Star Trek adventures with them — maybe that was all wrong,” says Webb.

https://www.discovermagazine.com/the...-a-lucky-fluke

http://https://www.unilad.co.uk/tech...-the-universe/