Is Our Search For Extraterrestial Life Too Narrow?

While new exoplanets are continuously being discovered, the question of "how exactly the habitable zone is defined" increasingly seems to split the scientific community. I realized that once again when reading an article on the topic (see excerpt below) which essentially challenges the general assumption that life can probably only evolve under conditions found in a certain, very limited distance of a planet from its sun.

Article: Think Outside the Box to Find Extraterrestrial Life


The article is based on an interview with theoretical physicist Sara Seager (Massachusetts Institute of Technology), a specialist for extrasolar planets. Here's an excerpt with her main arguments:

Many researchers hold that potentially "habitable" planets have to be rocky and within a limited zone in relation to their central sun—conditions that allow for the continuing presence of liquid water on their surfaces. (Related: "Most Earthlike Planets Found Yet: A 'Breakthrough.'")

But in a provocative review article published this week in the journal Science, theoretical physicist Sara Seager of the Massachusetts Institute of Technology lays out a case for habitability being potentially more common than generally predicted. As a pioneer in the study of exoplanet atmospheres, she paints a different picture of what kinds of planets might support life.

"Our basic premise is that to be habitable, a planet has to have liquid water," Seager said in an interview. "In addition, planets with thin atmospheres are mostly heated by their stars."

"But what primarily controls surface temperature is the greenhouse effect, what types of gases are in the atmosphere, and how massive a planet's atmosphere is. That's what we really have to understand". With that in mind, Seager describes how large planets ten times farther from their stars than Earth is from the sun could also have liquid water and potentially life if, for instance, they had enough hydrogen gas in their atmospheres (...)

Source: National Geographic

The current definition of the "Habitable Zone" is based on planets within our solar system and ranges from 0.725 to 3.0 astronomical units (1 AU is roughly the distance between Earth & Sun), though arriving at these estimates has been challenging for a variety of reasons (see here for details).

An illustration comparing Kepler 22 with our own solar system helps 'imagining' the habitable zone:

Image courtesy: NASA/Ames/JPL-Caltech

Accordingly, Venus and Mars more or less lie 'close to' or 'on' the outer edges of the habitable zone, depending on the exact definition. I'll leave it at that and just wanted to provide these pieces of information for further discussion in this forum ...

Truth be told, nobody except a few biologists is interested in finding life that doesn't kind of look like something from Star Trek or Star Wars. Finding some weird bug made out of crystals on some distant planet means nothing to most people. They want Avatar. They want to ride in flying saucers and find out if Jesus made it to their planet, too. So that's where we concentrate our search.

Funny thing is, there may be other kinds of "life" all around us right now on this planet, but we just don't recognize it.

It's quite useless to widen the "search" as we cannot find any answers to whether or not there is life anyway.
When we manage to create "life" ourselves and can make it happen in different challenging climates, only then can we broaden the "search". But even then, we can then only find these planets to be "habitable", not that there is life.

Look at Mars. We're physically there, we know that there is great potential, but we still can't say.
Doing that on planets that we can't even see is hopeless.

Originally posted by jeep3r

While new exoplanets are continuously being discovered, the question of "how exactly the habitable zone is defined" increasingly seems to split the scientific community.

That is something which nobody could possibly know 'exactly'.

Since it is all speculation, it's necessary to approach the question with various different possibilities.

reply to post by jeep3r

I think we should be looking out of just our limited inhabitable view. For example, if an alien life form is tremendously advanced from our own, the goldilocks concept for their own species may not be that important. Suppose they have found a way to change a planets atmosphere, through technology, or they have found a way to change a limited space around their own individual body, to sustain their own life. This would be a lot more advanced and reliable than just a space suit. I like to call this a personal environment.

Thinking outside the box, allows us to look in inhospitable places, which might just be where they are. We shouldn't just leave these areas out, because we can't quite understand the advanced technology it took for these people to get there.

Originally posted by Nevertheless
It's quite useless to widen the "search" as we cannot find any answers to whether or not there is life anyway.
When we manage to create "life" ourselves and can make it happen in different challenging climates, only then can we broaden the "search". But even then, we can then only find these planets to be "habitable", not that there is life.

Well, if we can get a decent spectrograph of its atmosphere, we can determine whether or not there is life on it like we have here on Earth. We wouldn't have the atmosphere we have without life. We wouldn't have nearly as much oxygen, nitrogen, methane, and the particular mix of gasses we have. But again, that would be life similar to what we have here. Not people necessarily, but some kind of bacteria and maybe bugs and plants. Otherwise, though, we might not recognize a planet with a combination of atmospheric gasses different than ours as having any life on it.

Originally posted by Blue Shift

 

Finding some weird bug made out of crystals on some distant planet means nothing to most people. They want Avatar. They want to ride in flying saucers and find out if Jesus made it to their planet, too. So that's where we concentrate our search.

You're probably right concerning mainstream opinion and desires with regards to ETs!

Whereas I'm not sure whether or not Seager was referring to such exotic life (I'm pretty sure though she wasn't). I think she's rather trying to entertain the possibility of 'similar conditions' (as in the current paradigm of habitability) on planets that are further away from the star they're orbiting ... but taking into account different parameters, chemical processes, composition of the atmosphere, green-house gases etc.

... ultimately leading to the same kind of habitability.

reply to post by Blue Shift


Great point!

While some may indicate the search is too narrow, it is equally possible that the search is not narrow enough. It seems that only physical world traits shared by us as humans are searched for and given the term 'life'.

Since we are nothing more than a highly orchestrated energy/frequency/spirit held inside a bag of meat and bones, how is it that the meat and bones aspect of life gives full definition to what life actually is? Just because most people can't connect with energys of various forms, it should not be a conclusion that these energys are not 'life'.

After all, if energys that don't hold a physical world presence are able to travel worlds unknown to us on our frequencies of operation, wouldn't it be safe to say that they could be labeled as Extraterrestrial as well?

I'm no expert in the field but the definition of intelligence itself needs to be explored. We have trap disarming gorillas, Dolphins and dogs that save humans. Birds that gather and mourn their dead. Elephants that paint self portraits. That is just mammals. Just because Man has all these questions that will hardly ever be satisfied does not mean that we can define intelligence.

Life on the otherhand is like a virus of some sort. Once it takes root it will explode. When we envision space aliens, we just envision one life form and forgetting the fact that they probably have the same equivalents as us. They probaby had mice equivalents, dog equivalents, horse equivalents and probably even little blood sucking mosquito equivalents.

I feel that life is everywhere. But like the article suggests, we are only looking for things that are equivalents or things that we can understand and like other worlds that are in Goldilock's Zone that doesn't necessarily mean it has formed life that looks to the stars or wonders in the capacity that we do.

To me there is all sorts of intelligent life on this world. We have just failed to realize this because we are creatures of vanity. We need to udnerstand all this before we can possibly relate to anything we find "out there".

Originally posted by BrokenCircles

Originally posted by jeep3r
While new exoplanets are continuously being discovered, the question of "how exactly the habitable zone is defined" increasingly seems to split the scientific community.

That is something which nobody could possibly know 'exactly'.
Since it is all speculation, it's necessary to approach the question with various different possibilities.

In general, we don't know of anything resembling life that can exist in something like boiling hot molten lava or liquid nitrogen. Or in an environment being blasted with high levels of radiation. Maybe it's possible.

But most people are not going to care about those kinds of alien lifeforms, anyway. Most people don't care all that much about the extreme lifeforms we have here on Earth. We're all about finding other creatures like us. And honestly, we don't really care all that much about other humans unless they're like us. There are loads of fascinating human cultures on Earth that most people couldn't care less about.

Originally posted by Blue Shift

In general, we don't know of anything resembling life that can exist in something like boiling hot molten lava or liquid nitrogen. Or in an environment being blasted with high levels of radiation. Maybe it's possible.

Obviously, those don't seem to be very likely possibilities, but [color=CFC297]nothing should be ruled out entirely,






We just don't know exactly what is truly 'out there'. Yeah, we can guess at it, and we can assume that other lifeforms are similar to us, and require the same needs as us, but we cannot know for sure.

Many feel that our understandings of the Laws of Physics are undeniably Universal, but as far as 'm concerned, we don't know that either. Quantum Physics has supposedly shown contradictions when compared to the more common Laws of Physics, and that's just right here in this one lil teeny tiny spot.



What is 'out there' could be something completely unthinkable to us, something which is far above and beyond even our own most wildest imaginations. Maybe they don't like water. Maybe to them, water is comparable to acid for us.

There is also the possibility of other life-forms existing much closer to us than we think is possible. Maybe the light from their planet has just not quite reached our telescopes yet.

Is Our Search For Extraterrestial Life Too Narrow?

No...

The "Search For Extraterrestial Life" is nothing but a huge mind control OP with a stealth agenda.

MSM such as National Geographic are nothing but stealth propaganda.

Doubt everything in the mainstream apparatus and assume if they are airing something publicly, it is agenda driven.

If I have learned ONE thing about propaganda it's this:

Believe the OPPOSITE of what they are saying.

"Science" is no longer Science...

It has become a Religion.

Science and education are nothing but MASSIVE forms of mind control...

It isn't really a search of alien life as much as a search for potentially habitable planets. But the OP's post makes valid points. Take Jupiter's moon Europa for example. There could be an icy moon with an underground ocean, orbiting a gas giant, that could support life purely from the heat induced by the ice giant's gravitation (tidal forces).

Originally posted by Murgatroid

 

The "Search For Extraterrestial Life" is nothing but a huge mind control OP with a stealth agenda. MSM such as National Geographic are nothing but stealth propaganda.

Doubt everything in the mainstream apparatus and assume if they are airing something publicly, it is agenda driven. If I have learned ONE thing about propaganda it's this: Believe the OPPOSITE of what they are saying.

Thanks to you and all others for your replies up to now!

Regarding the quote above: you know this is going through all media, National Geographic is just one outlet to pick it up (and sometimes they do inteviews). But I (and most others here on ATS) are mostly resistant to propaganda and you will have noticed that I didn't include my personal opinion in the OP.

Here's my personal view on the subject:
I think that there is ET life out there (needless to say for those who followed my posts) and, further, that we're going to find it. Either with advanced space observatories (eg. Kepler, Gaia, James Webb etc.) or, the other possibility, some kind of life (if it is intelligent and sufficiently advanced) will find us or already found us without this having been officially communicated. When taking into account the amount of planets that can be scanned and analyzed with those observatories, I think it may even happen in our lifetime. Whether the search is narrow (habitable zone) or not (wider scope), I'm confident we're going to find something very soon.

Potential cover-ups and conspiracies aside: I still think it is necessary to discuss the possibility of ET life on planets that lie beyond the usual habitable zone from a scientific (non-conspiracy) perspective. Thinking about this will lead to answers as to what we're supposed to be looking for ... the bio-signatures and chemical traces in such worlds may vary from those that we know. Ultimately, this will help build devices that can detect exactly that. And of course: with such articles, scientists try to make aware of further investments, get bigger budgets etc., but in the end, it may actually be worth it IMHO.

Apart from that, someone mentioned that the search for extraterrestial life is not necessarily linked to exoplanets, which is correct. But vice versa: for me, exoplanets are always linked with the search for extraterrestial life ...

The question of habitable is more than just type of planet and distance from the sun, but also atmosphere and many other factors. We have to narrow it down, because we only have so many resources to investigate them, and have to put those resources to work on the most likely candidates. Personally, I believe our ideas are completely WRONG and that the Universe is TEEMING with life, in various forms, but for now, we have to go on what we know as a basis for comparison, and that sadly, is only Earth.

reply to post by Gazrok


Live doesn't need an atmosphere. Two basic requirements for life, as we know it, are liquid water and a source of energy (solar, chemical, or even radiation).

en.wikipedia.org...
en.wikipedia.org...

The point of my earlier post (which I forgot to make clear) is that if Europa may potentially support life, there's no need for a sun-like star or an atmosphere.

I personally think it's mostly a waste of time & precious funding. Sure it increases our knowledge & understanding of what's out there but at the end of the day, it truly means jack sh1t if we can never get out there in person! Exact same goes for searching for alien signals. Your talking hundreds, thousands or even 100's of thousands of years before they would get our response & at that point in-time they (or even indeed ourselves) may not be around any longer.

All our efforts & endeavors should (imo) be solely focused on developing the uber advanced technology that would enable us to get to these places in person in as short order as possible. Not only will it allow us to explore these places up close & personal instead looking at feint dots on a display & guessing as to their composition & make-up but it will allow our species to colonize outwards & secure our species survival. Perhaps even one day directly come into personal contact with another race while out on our travels.

reply to post by Blue Shift


Speak for yourself.

reply to post by Murgatroid


I cannot even begin to wrap my brain around what you saying here. What would you replace science with?