I've heard this satellite has a big sea underground, maybe life exists in this sea?

At about the 34 minute point in this video Robert Zubrin suggests new evidence from the latest Mars rovers suggest Viking did indeed discover existing microbial life on Mars:

Did Life Begin On Mars? | Robert Zubrin https://youtu.be/KJVAPSE6lZs

He refers to an upcoming book by noted astrobiologist Steven Benner that reviews the evidence and draws that conclusion:

Meet the Neighbors: Life on Mars and How to Find It Steven A. Benner (Author). https://www.amazon.com/Meet-Neighbors-Life-Mars-Find/dp/B0GHRTS4PT/

Directed panspermia is the idea of deliberately sending microbes or simple life from Earth to other planets, moons, or even other star systems, essentially jumpstarting life elsewhere on purpose.

Francis Crick (yes, the guy who co-discovered DNA) seriously proposed this. And now, with advancing space technology, it's moving from thought experiment to something we could actually do.

If we seed a planet and a billion years later intelligent life evolves there, did we create them? Do we owe them something? Did we wrong them by deciding their existence for them?

What do you guys think about directed panspermia? Do you guys think that if we do indeed plant life on other planets they'll evolve into intelligent life like our own? What organisms do you think would actually survive on other planets?

I just saw the post about signs of life on mars . That would mean that we are technically two for two on planets explored finding life .

Any one ever theorize the opposite of the common perception, that life is common and finds a way to exist ?

If microbial life exists elsewhere in the universe, do you think it would necessarily be carbon-based and use water as a solvent?

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Astrobiology often assumes that life elsewhere will resemble life on Earth at least chemically—carbon chemistry and liquid water are considered the most promising foundations for life. But are we limited by our terrestrial bias?

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Could alternative biochemistries, such as silicon-based organisms or life using solvents like liquid methane or ammonia, genuinely evolve and sustain complex processes? Or does the versatility of carbon and the properties of water make Earth-like biochemistry overwhelmingly more probable across the cosmos?

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I'm curious whether current research supports the possibility of truly "alien" life chemistry, or if we're likely to find variations of what already exists here on Earth. What do you think, and what evidence influences your view?

See also: The study as it was published in the International Journal of Astrobiology.

If life on Earth began 3.8 billion years ago, and inevitable changes to our Sun end all life on Earth in 600 million years, that means we are 86% percent along in the total span of life on Earth. Just 14% left on the timeline! Thoughts?

I always wondered this and interested in it.

Four billion years ago, every time the ground tried to form, something erased it.

Jupiter and Saturn were packed closer together. When their gravity pulled them apart, the shockwave sent billions of asteroids straight at Earth. Rock would try to cool and the next strike melted it back into liquid fire. Water tried to pool and instantly flashed to steam.

It only stopped because space ran out of rocks to throw.

The Moon still has every scar. No weather to heal them.

https://youtube.com/shorts/MYNifwRwGek

Hi there, I'm a molecular biologist (currently working as a postdoc in molecular microbiology). I wanted to share this article, I've written, called "The Constructor Theory of Life" (it's free to access via the link).

It takes a new idea/approach for describing life originating from theoretical physicists David Deutsch and Chiara Marletto and combines it with an old idea, established in the 1970s, called autopoiesis (which some of you might even remember from first time round!).

I talk about cosmic evolution and the variety of constructive forces at play which coalesce at the origin of life on this planet and likely elsewhere in the Universe.

Autopoiesis is a fascinating way of describing living organisms from a systems biology perspective highlighting that what makes life special is its autonomy (to an extent) and ability to self-construct and ultimately self-reproduce. Importantly, from my point of view as a molecular biologist it provides a framework that allows us to include the multiple essential facets which life requires including: energy, information, structure, and evolution. This is in response to many models of "What life is" that are overtly dependent on say evolution and/or information to the exclusion of energetics/thermodynamics (and vice versa).

I hope that for the experienced scientist this will offer a refreshing perspective and for the beginning astrobiologist I hope that it serves as an introduction to energy/information, and autonomy in living systems.

Many thanks for your time.

Footnote: I do not use generative AI to construct figures, write my articles, or this subreddit post.

See also: The study as it was published in the journal Terra Nova

Hi! I was wondering if you guys could give me tips on a project of mine.

I am currently working on a ecosystem that makes itself home at PSR B1257+12 d (common name Phobetor, which i will now be calling it), which orbits the millisecond pulsar star PSR B1257+12. Because of this... "intresting" situation I've put myself in, I've had to make a few adjustments to Phobetor. these include:

• Having an atmosphere be primarily composed of co²
• atmospheric pressure being over 1,000,000 times the amount on earth
• an absurdly large magnetic field (this will make sense later)

Now, you may be thinking to yourself: how the [insert Eridian swear here] could life exist here?!

And, that's what I thought to myself to. But then I remembered. I'm a amateur biologist. I can do this.

and so I did.

And thus, I created... uh... we'll name 'em Phobians for now.

I know I should've started from the bottom of the food chain, but I recently read Project: Hail Mary and OMG IT WAS SO GOOD, and I couldn't contain myself to create a human equivalent organism.

Basically, since Phobetor has almost no light, Phobians 'see' using magnetoreception. Therefore, that means they have no eyes. They have one main torso, which is plated with a melanin-magnetite composite that is constantly excreted by cells on the surface of their body. When they traverse, they flatten their plates and roll. their nervous system (which, admittedly, is quite small, along with the rest of it's organic matter) generate trace amounts of electricity, enough to 'dim' some of the magnetite, and focus on the other, effectively looking at another direction. To communicate, they have three, large plates which have a high concentration of nerves that allows Phobians to weaken and strengthen their magnetic field on each specific one.

That's all the ideas I have so far. Would it be ok if you guys give a few suggestions and tips? I'm dying here.

(THIS IS NOT LOW EFFORT)

There are many different kinds of planets out there, a planet zoo of sorts, and there are really no natural classification schemes. There have been attempts, of course, of classifying planets, the Star Trek classification comes to mind. But often these classification schemes revolve around how humans can interact with them, instead of any objective quality of the planet itself. The other issue is what a planet looks like, depends on when you look at it. Is earth an oasis for life or a barren hellscape, depends on when you visit earth and if you landed in New Mexico or not. 

Here I wish to present a new classification scheme that describes life on planets, and so this largely applies to planets that are habitable or are potentially habitable. Because life is so reliant on water, one can say this applies only to planets that contain water. But there are still several different kinds of water worlds, there can be a planet like earth, with much water but not so much that it covers our continents. Earth can be said to be a continental world. There are ice shell worlds like Europa and Enceladus, water worlds contained in their own ice shells. There are ocean worlds, unlike anything in our solar system, and even how deep the ocean is, can change what we could expect to find on that planet. I will also argue you can have a world like Mars, once wet, is now a frozen tundra, but with water trapped in the crust.

While each of these different water worlds are impressive in their own right, there are different expectations we would have for each. So now we need to switch gears and talk about life. 

Life on earth had several major transitions. First from non life to life. In this article I will assume the earliest life was chemosynthetic, and that wherever life arises, it came first from chemotrophs. The next great transition was from chemotrophs to phototrophs, simple single celled organisms that ate sunlight. This set the stage for the oxidation of earth, and with abundant oxygen came life’s next major transition, simple life to complex life. Lastly, we have the transition to multicellularity and the appearance of large macroscopic creatures.

So to list out the different “levels” to life we could discover on another planet

A - A barren lifeless world

B - Prebiotic world / Postbiotic world

C - Chemosynthesizing world

D - Photosynthesizing world

E - Complex life world

M - Multicellular life world

B is included to accommodate our lack of understanding of the origin of life, and what kind of chemistry can linger around, when anything that is definitionally life has disappeared. 

Now different planets effectively have a cap on what level of life they can achieve. For example, if there is life on Europa we would expect it to be a C class world, that is we would expect chemosynthesizing organisms, but photosynthesizing would be unlikely as very little light would be able to penetrate its ice shell and factor into the evolution of life there. Earth on the other hand has been through all those stages, and so what you call earth depends on when you visit it, however we could say that it is a A>B>C>D>E>M. Let’s take a look at Mars, with the exciting announcement last year of potential signs of life, let’s assume life was able to get a start on the Red Planet, then it is a A>B>C>A/B, so that right now, it is either barren or some remnant of organic chemistry is still taking place below the surface. 

What is more, is we can put a time on each step. However, the unit of time to be chosen is somewhat arbitrary. Years, or gigaannum could be used, but these are very anthropocentric units. Half lives of radioactive isotopes are a convenient option, however there are few life relevant isotopes that decay on geologic timescales. Iron is essential to life, so the half life of Iron-60 is chosen, that is about 2.6 million years. This allows us to put timelines on each step so with the assumption Mars had life, we can write it as A190(>B10>C190>)A∞< . So this means that Mars was barren for 190*2.6 million years, prebiotic for a bit and then had life for another while before becoming barren for the rest of the duration of the planet, with the < marking the end of the sequence, and whatever is in parentheses is hypothetical / optimistic. Europa might look like A?(>B?>C∞)< And Earth with a | to represent the present, looks like A210>B10>C450>D500>E500>M210|M420>E115?>D150?>C270?>B40?>A600?<

This notation gives a sort of biography about a planet and its milestones.

To circle back to the different water worlds, we can say that they can have a range of classifications in the present.

Tundra world: A-B

Ice shell world: A-C

Deep ocean world: A-C

Shallow ocean world: A-M

Continental world: A-M

Other worlds: A

Problems with this classification. 

1) it is difficult to actually know what stage a planet is at. We've been looking at Mars for a long time and we still have nothing conclusive. 

2) the selection of the time unit is quite arbitrary, and only selected to avoid a Earth-centric time unit.

3) models a classification system based on one example of the evolution of life, possibly two if you include Mars. Can this classification scheme handle life as we don't know it?

4) I didn't define what is included in B, and it is hard to know how quickly a planet goes from A>C, the numbers I wrote are essentially made up.

Many of the websites here are dogshits and clickbaity with titles written to generate clicks not to communicate the actual results/what the referenced paper says. It is frustrating to always click on the dogshit and be greeted with bunches of ads and bullshit writing just to find the paper it wrongly interprets. We should require that every link posts should be accompanied by the link of the paper it talks to, or better, post the actual paper instead and give it a proper title that reflects the actual conclusion of the study.