How many M-Class planets do you think there are?

In so many Trek episodes they land on "oxygen/nitrogen planets", usually with lush vegetation (and often with very human-like inhabitants, even though many sport latex and putty facial features). And inhabitants conveniently speak modern English (sometimes explained by the "universal translator").

We are "finding" so many planets, quite a few that seem to be in an "inhabitable zone". I say "find", because we can't actually see other planets, we detect them by their periodic occlusion of their stars. Each eclipse dips a star's light output. Diffraction prevents us from seeing them; we couldn't even see Pluto until a fly-by --- the lens diameter to see features on Pluto from Earth would have to be thousands of miles wide. Imagine how big of a lens it would take to see planets around other stars!

https://phys.libretexts.org/Bookshe...ction/4.06:_Circular_Apertures_and_Resolution

Free oxygen on a planet indicates life; it is not a stable material, left to its own it would degrade to oxides. On Earth the greatest oxygen generator is phytoplankton (converting CO2). So "Class M" by definition indicates a working biosphere. There are billions of stars, in billions of galaxies (but most are diffuse), and billions and billions of planets.

So how many "Class M" planets do you think there are, where actors ...I-I-I mean explorers can walk around blissfully without a space suit?

Wouldn't it be fun to book a weekend at a resort on Risa, with several moons lighting a sparkling tropical beach?

What are the odds?

 

Pretty low

 

Hah hah hah!

Fifty six, in all the planets around all the stars in all the galaxies???

 

Uh...do you mean in real life or in Star Trek?

In real life it's impossible to know, but considering how many factors need to be juuuust right...I'd say they are probably not that common, but that would still lead to a large number considering how many stars there are in this galaxy alone. If even one in a million star systems have one of those planets that would still lead to something like one hundred thousand life bearing planets in the galaxy.

In Star Trek they just seem very common, I'd say a lot more common than in reality. Though it stands to reason that we usually just don't see the episodes where they just scan lifeless systems for the data.

 

Well, let's say there are 5 planets per star on average (some estimates are lower, some higher), and there are 400 billion stars in the galaxy. That gives us about 2 trillion planets.

According to T'pol about 1 in 42,000 is Minshara class. Assuming Minshara class is the same as M-class, that would come down to around 50 million M-class planets in the galaxy.

 

Real life.

Thanx for the reply -- let's focus on your "one in a million" idea. Is that valid? Diffuse galaxies are more common, but don't have planets. "Life" may not be water-based carboniferous as we experience, but by definition it has complex molecular processes. Radiation is known to break molecules, that's why it's effective to prevent food-born illnesses. And there's so many other things; right sun, right planet in the right orbit (inhabitable zone, "Goldilocks" planet), radiation shield, on and on.

Would 1,000,000 be fair?

Yeah, that's it -- we watch these Star Trek shows, and almost every show they have a planet where people can walk around sans helmets and air supplies. That makes for interesting plots. Even if we have ships capable of star-travel, it's impossible to have a perfect closed environmental system. There would always have to be a planetary base, to replenish breathable air. One can have only so much sodium or lithium hydroxide. Maybe; perhaps mining and manufacturing could create more air gasses and scrubbers.

(If you had a company specializing in Moon Mining and Manufacturing, what would you call it?)

So that leaves either "many-worlds" (which is not our decision), or terraforming. I'm just wondering what people think about the "many-worlds" idea? There are often reports on the news about "Scientists find another Earth-like planet" -- Really? What does everyone think?

 

Maybe more than in this universe, due to ancient races terraforming large numbers of planets?

 

Wow -- you think there could be 50,000,000? It's not just that a planet is in the "inhabitable zone"; Jupiter protects us in our system, do you remember a few years back when comets hit it? Better Jupiter than us.

[SIZE=4]
Orphalesion said, "considering how many factors need to be juuuust right".[/SIZE]
Please click on this link, and tell what you think?

How many factors should we consider that may be needed for life?
Just wonderin'...

 

Of course that would only be in the Star Trek universe, the 1: 42,000 bit is purely Star Trek lore after all.

As for the real life answer, I don't think we know enough yet to give a reasonable estimate. As the Asimov story The Last Question says it : 'INSUFFICIENT DATA FOR MEANINGFUL ANSWER'.

 

Well, terraforming is intriguing -- that's desirable for exploration. But "ancient races" gets back to the original question, "how many M-Class planets could there be?"

Suppose Earth got hit by a meteor that stripped us of atmosphere (this is a concern of something called "Globalism", which worries that we should colonize other planets to avoid extinction, Of course, they have other terrifying ideas, but that's beyond this discussion). If we build bases on other planets, how shall we fill them with air? Can we manufacture enough oxygen and nitrogen, and lithium hydroxide?

When we build our first Enterprise NCC1701, where will we go? How often would it have to return to Earth to replenish its air?

 

Well, it was asking about Star Trek's representation of real life. Per the show, there are lots of "M-Class" -- and I was wondering if that was likely?

Clearly Star Trek has influenced a lot of things; fans succeeded in getting one of the shuttles renamed "Enterprise". If we build an interstellar Enterprise (actually, I secretly believe we already have), what will we find? Are there really Vulcans, Romulans, Goa'uld and Tokra? (Wait, I may be mixing shows...)

 

Obviously - 42 must be the correct answer...

 

Another gas besides methane and oxygen to look for in a planetary atmosphere as a possible sign of Earth-type life is isoprene (C5H8 2-methylbuta-1,3-diene). As ever, Anton Petrov has already made a video about it:



One study estimates as many as six billion Earth-like planets in the Milky Way galaxy - one for every five Sun-like stars:

As many as six billion Earth-like planets in our galaxy, according to new estimates -- ScienceDaily

 

With the "one in a million" I was really only speaking about our galaxy or galaxies like ours. I honestly don't know that much about astronomy beyond some basics and whatever I happen to read in articles and such.
I just felt that "one in a million" would be a reasonable figure. Thing is...we don't know. And we won't know until we have actually managed to explore more, and I have seen so many numbers over the years. I've read articles where it talked about 1 million inhabitable planets in the galaxy, or just 100.
This article from 2020 meanwhile says it could be as much as 300 million in our galaxy alone.
https://www.inverse.com/science/how-many-planets-host-life

And this all just talks about Earth like conditions, we still don't know what other ways complex life could evolve in alien environment. Heck, we don't even know whether Earth is the only planet with complex life in the Solar System (there's still things like Europa and Titan)

As for Star Trek, I mean, it works with the idea that billions of years ago a species manipulated evolution on countless worlds to result in something that resembles them and that's why there are so many planets with Earth like creatures and humanoids and why they can all interbreed.
For all we know that same species also terraformed countless planets to be more Earth-like, or some other ancient super civilization did it. Or the Q did it, for all we know.
That's why I don't really expect for Star Trek's version of the Milky Way to resemble ours all that much. I expect the Sol system to be there with its 8 planets and various dwarf planets and other objects, but even if Vulcan is located in 40 Eridani, I do not expect Star Trek's 40 Eridani to resemble "our"40 Eridani.

 

8675309?

 

1 confirmed but that one won't be around much longer since a species of stupid apes is doing their best to destroy it...

 

You can have sterile planets with a lot of oxygen as I recall.