An Alien View of Earth - How Alien Astronomers Would Know the Earth is Habitable - pt. 2 (Nitrogen)

a reply to: JadeStar

I used to hope someone would come to our planet but given what I've seen of the ignorance, hatred and fear of just other human beings who are slightly different from each other I'm not so sure that would be a good thing.

I am sorry Jadestar, please forgive our intolerance. I think as children we accepted one another more readily. So perhaps its the conditioning from media that pushes egoism above all else that is our undoing. I remember watching a 1996 documentary called Blue Eyed which shows that intolerance is deep rooted even if we want believe, that its not. So we all, including myself, need accept our faults and work on it.

Great thread as always, you make my heart smile.

originally posted by: AceWombat04
Wow. So the proposed HDST, if built in the 2030s as planned, will actually be able to visually resolve exoplanets to a degree any average person can view an image captured with it and see a dot!?

Yes!

And the thing is, the light from just that dot will potentially tell us ALOT about that world, it's temperature, what exists in its atmosphere, whether it has oceans, perhaps even if if it has a magnetic field, life or civilization.

That pale blue dot image, once we have it will almost certainly spur on even larger telescopes to see it in even more detail such as the ExoEarth Mapper which NASA envisions in the 2040s.

By 2060 we could very well have fairly detailed images of nearby earths. If of course the resources are put into the tools to do so.

If so, that's the single most exciting thing I've ever heard, and I move that we accelerate funding for it immediately! That's huge both scientifically and in terms of firing the human imagination.

It's great to hear that! Now tell your friends and family. Spread the word because this stuff, cool as it is won't happen without adequite funding.

Once upon a time (the 1990s), following exciting discoveries of Jupiter sized exoplanets, a pair of spacecraft were being planned by NASA called the "Terrestrial Planet Finder". Each would use a different technique to block the light from a parent star in order to actually see its much smaller, dimmer planets. It's pale blue dot, if it had one.

Funding was allocated. Lists of nearby neighboring target stars were drawn up and in the early 00's components were built and tested. People excitedly looked forward to the grand future of discovery that would await following its launch in 2014-15.

The goals of the mission would have been to characterize the surfaces and atmospheres of newfound planets (as our alien astronomer did in my OP) and looking for the chemical signatures of life.

That future would have been happening right now.

We already might have had or been well on our way to having that pale blue dot image had it not been for the Terrestrial Planet Finder being cancelled. One of the darkest days in exoplanet science history:



Had that not happened, the first Terrestrial Planet Finder would have flown into space last year in 2014.

So that future with the HDST in the 2030s is by no means assured. Even though the NASA budget is minuscule in comparison to other federal agencies and programs it is a highly visible target for the ax of a fickle congress as president often unaware of just what profound potential discoveries they are postponing.

Something we could have discovered today now must wait for the 2020s or 2030s. And if there is another major war America decides to waste money on? Or another financial crisis that those "too big to fail" are bailed out from?

Maybe the future gets postponed again.

So do support NASA and tell you friends and family why you support NASA. Every little bit helps. If NASA's budget were even just maintained at current levels as percentage of GDP we can achieve this stuff. Were it increased significantly (say 25-50%) well then some of the sci fi stuff imagined back during the early years of the space age will come to fruition in our lifetime.

It seems the biggest hurdle and dissuading threats from what I'm reading are merely 1) cost, and 2) the current inability to repair it once in orbit. But I have a sneaking suspicion the latter won't be an issue within coming years. (I hope.)

Peace.

You are correct.

Complicating matters is that for some of these telescopes to work best, they need to be very cold and very stable. So unlike the Hubble Space Telescope, you do NOT want them in Earth orbit but somewhere else.

That is why the James Webb Space Telescope, a 6.5 near-infrared telescope which is the often called Hubble's successor is going to be placed at a place between the Earth and Sun called L2.

L2 is what's called a Lagrangian point, a stable position in space where a small object affected only by gravity of the two bodies can maintain a stable position relative to the two large bodies as it is being pulled equally by both.

In other words, it's cold, dark, and stable.

But it's also kinda far so any sort of repair or maintenance missions like we saw with Hubble will be expensive.



The good news is the new Space Launch System/Orion Capsule could be sent to L2 if needed but again, only if the budget allowed. It's an expensive system for human space flight but it does get us out of low earth orbit and out into the solar system as was imagined during the Apollo era.

So blah…blah…blah…"No Bucks, No Buck Rogers"…. support NASA!

Whilst I have absolutely no doubt (belief if you want put a theist slant on it ) that we will, with our ever larger telescopes, finally detect life elsewhere this leads to the next massive question. Can we visit them and/or can they visit us? The answer, with current sublight travel is a resounding no. OK the nearest two or three solar systems may be reachable with a hibernated crew but the turnaround of decades per return trip makes any meaningful intercourse with an alien civilisation exceedingly unlikely.

The only way of having a meaningful interaction is to travel faster than light. Not only that but you must be able to detect the remote civilisation using a faster than light comms signal. Think about it. We detect a signal 1000 light years away. We travel using our FTL drive in a year and discover...nobody because they died out 800 years ago! Or nobody because they have flitted elsewhere 200 years ago.

Unwasted trips to civilisations can only be achieved with FTL detection and travel.

That said we can use sublight travel to visit a planet with life and photograph observe etc. Interaction would be pointless though. Photographing an alien Jurassic world would still be worth the trip!

Summary :

* Observation of any life elsewhere possible with sublight travel but with long turnaround of decades per trip.
* Interaction with alien civilisation only possible with FTL detection and travel.

originally posted by: glend
a reply to: JadeStar

I used to hope someone would come to our planet but given what I've seen of the ignorance, hatred and fear of just other human beings who are slightly different from each other I'm not so sure that would be a good thing.

I am sorry Jadestar, please forgive our intolerance. I think as children we accepted one another more readily. So perhaps its the conditioning from media that pushes egoism above all else that is our undoing.

I think there is something to that. I have very little respect for the media in our country and sometimes feel we'd all get along a lot better without it.

I remember watching a 1996 documentary called Blue Eyed which shows that intolerance is deep rooted even if we want believe, that its not. So we all, including myself, need accept our faults and work on it.

I will have to see if I can find that documentary on Youtube. I was maybe a year old when it came out.

I don't know if you were a fan of the sci-fi series "Falling Skies" but I just watched the conclusion of it and one can only hope that it would not take the events of that series to bring us all together.

Unfortunately, humanity often is only at its best during times of crisis. I couldn't help but think, perhaps cynically after the character Tom Mason gave this speech at the Lincoln Memorial (site of the victory of Earth over the alien invasion):



"….And tomorrow things start to return back to the same petty squabbles, mistrust, bigotry and hatred, only now there is an ET species who were allies with humanity during the war to hate on."

sad huh?

i still have hope but the older I get the more cynical i feel i am becoming.

Great thread as always, you make my heart smile.

Thank you. ♥

Forgive my ignorance from a layman but first my question would be " would the aliens criteria for a habitable planet be the same as ours"?
Now with that in mind the aliens (by your definition) would be technically advanced to have the equipment to search. That technological level MUST have comunicational technology to collate the data between entities.
So my next question is " why do you think SETI is using this method to search for exterrestrial life"?
The answer is if you find technology you've found inteligent life, ergo a habitable planet. But it might not be the habitat that your species want.
As we've been told we have been sending these signals of our technology galaxy wide since we first sent a radio signal.
Yes, I know the light spectrum travels faster than the sound waves, but as is already been postulated the spectrum for habitability from a distant world could be eronious as that world may have already passed into unhability.

originally posted by: yorkshirelad
Whilst I have absolutely no doubt (belief if you want put a theist slant on it ) that we will, with our ever larger telescopes, finally detect life elsewhere this leads to the next massive question. Can we visit them and/or can they visit us?

The answer to both questions is yes.

There is nothing which we know would rule out interstellar travel. Even with our current technology, if we had to we could build ships which would take a few hundred years to reach the nearest star systems. It would require resources and global cooperation far beyond what we currently use for space exploration but if our survival depended on it we absolutely could build something like a "generation ship" or "space ark".

There was a science fiction docudrama recently called "Evacuate Earth" in which just that happened. The series like my OP used a sci-fi scenario to draw attention to and illustrate current scientific research in exoplanets, space propulsion, astrobiology and space colonization:

The answer, with current sublight travel is a resounding no.

It actually isn't.

The answer would be no if you are limiting travel time to that of a human lifetime but:

1) There is no reason why such travel need be limited to that (see the above scenario).

2) There is no way to know how long the average lifetime of members of an alien species is. We know of species on earth which live longer than we humans.

A Galápagos tortoise has an average lifespan of 150 years.
Bowhead whale can live up to 200 years.

There could be alien species with lifespans which exceed that. In fact we ourselves in the not too distant future may learn how to prolong our own human life span to hundreds of years.

So a 100 year trip to a habitable planet around Alpha Centauri, as this 1980s study concluded was feasible, would not be such a big deal.

And that was just with our current technology which if pushed to its maximum would get us to around 5-10% of the speed of light.

Increase that to 25% or 50%, perhaps through something like anti-matter propulsion and you've just shortened that trip to 10-25 years.

OK the nearest two or three solar systems may be reachable with a hibernated crew but the turnaround of decades per return trip makes any meaningful intercourse with an alien civilisation exceedingly unlikely.

Those would have to be some very sexy aliens to want to have intercourse with them

I get what you're saying though but we also have to remember, we're new at this space travel stuff. Our limitations may not necessarily be theirs.

I've not addressed things like EM Drives, Warp Drives or other visionary propulsion schemes like the stuff Harold White is looking into at NASA/JPL's "Eagleworks" lab:



If that stuff is feasible then the world of Star Trek will have arrived.

That said, there is a lot which could be learned even without actual physically traveling or even communications with such a civilization.

The only way of having a meaningful interaction is to travel faster than light.

Not at all. It would just be slow communication, in the example planet of my OP a signal (laser, radio, whatever) would take about 47 years to reach Earth.

Thinking in terms of the average human lifetime is what may be limiting your perspective.

Not only that but you must be able to detect the remote civilisation using a faster than light comms signal. Think about it. We detect a signal 1000 light years away. We travel using our FTL drive in a year and discover...nobody because they died out 800 years ago! Or nobody because they have flitted elsewhere 200 years ago.

Still, wouldn't THAT be a remarkable discovery in its own right? I get that people have this romantic sci-fi inspired idea of meeting, conversing with, shaking hands and perhaps drinking with aliens who look not too unlike humans at roughly our same level of technological development but given what is known about our galaxy the chances of that are remote.

We're either likely to:

a) Discover or be discovered by aliens which are millions or billions of years more advanced than us.

b) Discover intelligent species which are pre-technological like early hominids were, through very careful, detailed observations of exoplanets with far future hyper telescopes or perhaps interstellar probes.

The chances of us meeting anyone at our level are minuscule compared to those two because most star systems are older than ours or younger than ours. Very ew are exactly around our age.

Unwasted trips to civilisations can only be achieved with FTL detection and travel.

That said we can use sublight travel to visit a planet with life and photograph observe etc. Interaction would be pointless though. Photographing an alien Jurassic world would still be worth the trip!

Exactly.

Even in the Star Trek universe they still use telescopes and have "stellar cartography" for that reason.

originally posted by: crayzeed
Forgive my ignorance from a layman but first my question would be " would the aliens criteria for a habitable planet be the same as ours"?

That is *NOT* an ignorant question at all. It's a very good one.

The answers are: "not necessarily", "maybe" and "we don't know."

Until we find out if our type of life is the most common and most likely to produce other intelligent, curious beings then we simply don't know.

We have good reasons to suspect that it might be but those reasons all to some degree are based on our lone example of the Earth.

A good analogy is that when they started looking for other planets they looked for planets like Jupiter (big and easy to detect) at distances from its star similar to Jupiter's distance from our own Sun.

Why?

Because our models were biased towards producing solar systems like our own.

In reality the first exoplanets we found were Jupiter sized worlds orbiting closer to their star than Mercury orbits our Sun. Our best models had not really predicted them.

So nature doesn't care about us or our Earth/Solar-centric biases.

For all we know moons like Titan might be considered habitable worlds to the majority of alien civilizations and our Earth a big hot, steamy, mess to them.

We just don't know at this point.

Now with that in mind the aliens (by your definition) would be technically advanced to have the equipment to search. That technological level MUST have comunicational technology to collate the data between entities.

Correct.

So my next question is " why do you think SETI is using this method to search for exterrestrial life"?

SETI uses a lot of methods to search for extraterrestrial life. Not all of them involve searching for intentional or intercepted communication either:

I gave a broad range of them in this ATS post: Denying Ignorance About SETI: It's Not Just About Radio Anymore

The answer is if you find technology you've found inteligent life, ergo a habitable planet. But it might not be the habitat that your species want.

Very true. Personally I'd find it much more interesting if we found an intelligent species inhabiting a planet a lot different than our Earth.

It would mean that nature again surprised us and showed us greater possibilities and diversity than we imagined.

As we've been told we have been sending these signals of our technology galaxy wide since we first sent a radio signal.

Close. We've produced radio signals which were theoretically detectable at interstellar distances for about 75-80 years such signals would only have travelled a distance of about 75 light years.

The Milky Way galaxy is 100,000 light years across.

On the other hand, we've had artificial city lights since the late 1800s. If anyone is home at a star system 125 light years away they may just be seeing us turning them on for the first time if they have a sizable space telescope array.

Beyond that, the Earth itself has been broadcasting a kind of signal that life of some kind is here since plants and other things which produce oxygen through photosynthesis changed our atmosphere 2 billion years ago.

Oxygen is kinda promiscuous. It doesn't like to just hang out by itself. It likes to hook up with other molecules like carbon (CO - Carbon Monoxide, CO2 - Carbon Dioxide, H2O - Water Vapor, SiO2 - Sand, NO2 - Nitrite, NO3 - Nitrate, N20 - Nitrous Oxide, and so on).

It doesn't last long in a planet's atmosphere unless something is replenishing it. In our case that something is our trees and plants.

So if the aliens looked at our Earth in the last 2 billion years they would find O2 (free molecular oxygen) and/or O3 (ozone). Both of which kinda give away the fact that Earth probably has some type of life going on. And this is what we ourselves hope to detect in the atmospheres of nearby Earth-sized exoplanets.

So while the whole galaxy wouldn't necessarily know intelligent life is here, the whole galaxy could know that life is here even if all they saw of the Earth was a pale blue dot.

Yes, I know the light spectrum travels faster than the sound waves, but as is already been postulated the spectrum for habitability from a distant world could be eronious as that world may have already passed into unhability.

True. The habitability of a planet changes over time as the star it orbits goes through its life cycle.

Our own Sun will make Earth uninhabitable for us in about a billion years and uninhabitable for all life as we know it in 2 billion years.

But this takes place on a LONG time scale.

Unless a species makes its own planet uninhabitable through its technology. Something we are doing right now btw. Even if you don't believe in warming due to CO2 trapping our planets heat, our electronics and other technologies are warming the planet thermally in a way that if an alien species 60 light years away were to look at out planet with an advanced 300 meter near-infrared ground based telescope, or a 40 meter near-IR space telescope they could know something was heating the Earth beyond what would be expected naturally.

And that something? technology. So your own use of that computer, iPad or smart phone (and everyone else's) could be giving away our existence and a technological species to someone else out there.





So…

At some point our world even if we produced no greenhouse gasses, would be warmed to an uninhabitable point just by our own technology's waste heat unless we find ways to make it a lot cooler and more efficient.

This is called the "Heat Death" scenario. And believe it or not there are people like me interested in looking for dead civilizations which may have been overwhelmed by it or even wiped out by nuclear war. (I will post more on looking for dead civilizations in another future post.)

a reply to: JadeStar

I will certainly do so! As I said, very, very exciting. No one I know has even heard of this, so I'll definitely introduce them to the hopes for this new telescope. I know it isn't always the most popular thing in these parts (for reasons I don't personally agree with, but I respect people's opinions) but I do definitely support NASA getting greater funding.

Thanks for the explanations and for tantalizing my imagination with these possibilities.

Peace.

originally posted by: crayzeed
Forgive my ignorance from a layman but first my question would be " would the aliens criteria for a habitable planet be the same as ours"?

The working assumption with most SETI projects is that we're looking for aliens who are going to be pretty much like us. Star Trek and Star Wars type aliens, who view reality in much the same way we do, and who are approximately as smart as we are.

We really have no use for other kinds of exotic aliens. We can barely stand Earthlings who are different than us.

a reply to: JadeStar

Wow, bravo sir on the post. I love this stuff.

originally posted by: staticfl
a reply to: JadeStar

Wow, bravo sir on the post. I love this stuff.

Thank you, but I'm not a sir nor a duke. I'm not a dame nor a duchess either though I'd be closer to the last two than the first two.

a reply to: JadeStar

And tomorrow things start to return back to the same petty squabbles, mistrust, bigotry and hatred, only now there is an ET species who were allies with humanity during the war to hate on.

sad huh?

i still have hope but the older I get the more cynical i feel i am becoming.

Yes sad but you are too young to get cynical, I believe in the great Arundhati Roy's view this world and agree her prediction that a new world is coming (see last 30 seconds video below). The current cycle of consumerism is ending soon. The new world will demand a more intelligent and compassionate race. Hopefully one that celebrates our differences instead of fearing them. Small steps Jade.

originally posted by: glend
a reply to: JadeStar

And tomorrow things start to return back to the same petty squabbles, mistrust, bigotry and hatred, only now there is an ET species who were allies with humanity during the war to hate on.

sad huh?

i still have hope but the older I get the more cynical i feel i am becoming.

Yes sad but you are too young to get cynical, I believe in the great Arundhati Roy's view this world and agree her prediction that a new world is coming (see last 30 seconds video below). The current cycle of consumerism is ending soon. The new world will demand a more intelligent and compassionate race. Hopefully one that celebrates our differences instead of fearing them. Small steps Jade.

Thank you for that. She is an inspiration.

I tend to agree with you and her though that particular day I witnessed a great deal of the worst of humanity in one ATS thread and made the mistake of watching the national TV news prior to the final episode of Falling Skies so I was in a cynical mood.

Some days are better than others.

a reply to: JadeStar

Re: a new/better world... It may take us 100s of years, but I believe we will get there. If we don't destroy ourselves first.

When I start to feel cynical or lose hope for humanity, these days I hop on Periscope. Sound weird? I thought so, too, at first. I resisted using it for the longest time. Even in just my 30s, I'm already old and crotchety enough (I've lived a lot in those short 3 decades + lol) to automatically resist anything that has become a new popular trend, especially anything "social media" related, as I'm not very social. (I'm not anti-social. I'm just NOT social lol.)

But a couple of close friends finally persuaded me to do it. It completely changed my mind about our chances as a species to overcome our petty differences. You can click anywhere on a map of the world and find people in just about any country (obviously no one in North Korea though,) and watch them. And with 100% consistency... these total strangers from around the world (with the rare exception of someone being drunk and incoherent) were courteous, average people just living their lives. Which shouldn't be surprising, yet is somehow very encouraging.

Listening to rock and pop music (recognizable as such through sound and composition, though I couldn't understand the words,) driving to and from work, making breakfast, appreciating a sunrise or sunset, playing an instrument, talking about their latest romantic heartbreak, talking about their latest job prospects, etc. etc. Just living. And they were often just as surprised to see someone from overseas being so friendly, too.

Things like that are breaking down preconceptions and eroding the xenophobia of people. It's a very hopeful sign imho. It will become much more difficult to propagandize people as "other" and adversaries as dehumanized. Because people will already know thanks to uncontrolled and emergent technologies like streaming media, that people everywhere are just people.

Another thing less real-world I do when I start to lose hope for humanity, as silly as it may seem, is watch this old clip from Star Trek The Next Generation. To me, there's a moment in this scene that always gives me goosebumps, because I believe it sums up Gene Roddenberry's hope for our future. As a primitive woman from a species far less advanced than the Federation discovers that interstellar travel is a reality, Picard is trying to explain to her that his people are not gods (as her people believe,) but merely more advanced people just like her. Once she realizes this, she says perhaps one day her people will achieve such technological feats as well. Picard's response is a moving affirmation that, although fictional, always fills me with hope.



We will get there. "Of that I have absolutely no doubt."

Peace.

a reply to: JadeStar

You are an absolute breath of fresh air at ATS. Thank you for taking the time to make interesting post !
S&F

a reply to: JadeStar

I used to hope someone would come to our planet but given what I've seen of the ignorance, hatred and fear of just other human beings who are slightly different from each other I'm not so sure that would be a good thing.

It would most likely destroy all social barriers if we could put everyone on the moon for a day. No more black/white/brown/Christians/muslims/athiests...just humans. A visitor from another planet would force many to reconsider what makes them so different from other people.

originally posted by: 727Sky
a reply to: JadeStar

You are an absolute breath of fresh air at ATS. Thank you for taking the time to make interesting post !
S&F

Thank you. I'm just me. I do what I can.

originally posted by: QuietSpeech

a reply to: JadeStar

I used to hope someone would come to our planet but given what I've seen of the ignorance, hatred and fear of just other human beings who are slightly different from each other I'm not so sure that would be a good thing.

It would most likely destroy all social barriers if we could put everyone on the moon for a day. No more black/white/brown/Christians/muslims/athiests...just humans. A visitor from another planet would force many to reconsider what makes them so different from other people.

I agree.

Most astronauts have remarked at the life changing effect seeing our world from above or in the case of the moon afar has had on them.

Someday I believe, the average person will experience that view. Probably within my lifetime if space tourism takes off in a big way.

originally posted by: AceWombat04
a reply to: JadeStar

Re: a new/better world... It may take us 100s of years, but I believe we will get there. If we don't destroy ourselves first.

I agree. Just keep the unbalanced people, demagogues, megalomaniacs and overly aggressive away from the shiny red buttons.

And I love Periscope. I was an early adopter. It's probably my fav social network (certainly more than twitter or fb).

Another thing less real-world I do when I start to lose hope for humanity, as silly as it may seem, is watch this old clip from Star Trek The Next Generation. To me, there's a moment in this scene that always gives me goosebumps, because I believe it sums up Gene Roddenberry's hope for our future. As a primitive woman from a species far less advanced than the Federation discovers that interstellar travel is a reality, Picard is trying to explain to her that his people are not gods (as her people believe,) but merely more advanced people just like her. Once she realizes this, she says perhaps one day her people will achieve such technological feats as well. Picard's response is a moving affirmation that, although fictional, always fills me with hope.

We will get there. "Of that I have absolutely no doubt."

Peace.

I ♥ Star Trek. It transcends sci-fi. It is a reservoir of hope.

I can't wait for the day, if it should happen, that one of these super space telescopes spots a giant space station orbiting a planet, or maybe artificial lighting on the night side.