
Water found on a potentially life-friendly alien planet - Leace
https://www.nationalgeographic.com/science/2019/09/first-water-found-in-habitable-exoplanets-atmosphere-hubble-kepler-k2-18b/
======
tunesmith
I got into the Wait Calculation[1] a few weeks back and made a Jupyter
notebook out of it.

At our current max speed (692,000 km/hr, stated max speed of Parker Space
Probe), it would take about 173,000 years to get to that planet.

We could instead choose to Wait and grow our tech. By picking a constant
annual growth rate and then doing some calculus to find the minimum, we can
calculate the shortest possible time it will take for us to arrive there.

One common recommendation for annual energy growth rate is 1.4%, and then
taking the square root to get velocity growth rate since velocity has a square
root relationship with energy.

By plugging that in, we can minimize our time by growing for 1020 years, and
then traveling for 144 years, for a total time-from-now at 1164 years.

Another paper[2] estimated an annual velocity growth rate of 4.72%, quite a
bit faster. Plugging that in, it says we should wait 195 years for a travel
time of about 21 years, or 216 years overall. This is of course incorrect
since it assumes being able to travel FTL. So if you instead look at how long
it would take to get to light speed travel at that rate, you're looking about
about 159 years, or arriving at the planet at a time-from-now of about 270
years.

Of course, if you're seeking to minimize time-from-now from the perspective of
a _traveler_ , maybe you'd take off sooner. Kind of a tradeoff - less time to
wait for the traveler, more time to wait for the home planet. I haven't
figured out that part of the math yet.

[1]
[https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1m...](https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Wait_Calculation.html)
[2] [https://arxiv.org/abs/1705.01481](https://arxiv.org/abs/1705.01481)

~~~
narrator
Progress in physics was much faster in the early 20th century when it wasn't
so fascinated with deep space. Yes, you needed to observe eclipses to verify
relativity, but that was a tool, not the end in itself.

Cosmology involves distances that are so great that it seems like it's pouring
a whole bunch of smart people's efforts down the drain in an ultimately futile
waste of brain power that will never amount to anything much at all. Besides,
when we get faster than light travel we can just pick up exoplanet research
where we left off and it will actually be practical and probably far more
efficient with the computers and such we will have developed by then.

~~~
vermilingua
> when we get faster than light travel

FTL requires numerous things to be true about our universe, that all signs say
are not.

~~~
gisely
The speed of light is just a compute constraint imposed on the physics
simulation that is our universe. If we can just get the gods who are running
that simulation to give us a little extra compute time in our neck of to woods
then we can all be galactic explorers.

~~~
vermilingua
Just for the sake of argument, let's run with that.

If we're in a physics simulation, we don't experience at the rate that the
simulation is processed. One "tick" of the simulation could be processed in
one second of the host universe, or one hour: and we wouldn't feel the
difference. We are processed at the same tickrate as the rest of the universe,
so we experience the passage of time at the same rate that the simulation
flows.

The speed of light isn't just the speed of light, it's the speed of causality.
It just so happens that light moves pretty well at that "speed limit" (in a
vacuum). We could ask our computational hosts to increase or decrease _c_ ,
and we still wouldn't be able to travel any faster than it.

~~~
username90
We could ask the host to update their algorithm to let c be a property of
objects and then just do spaceship.c = 1000 * c.

Would probably be a heck of a refactor to get it working without bugs though.

~~~
dkersten
Just leave the bugs in for the speedrunners to use.

~~~
tripzilch
speedrunners can restart the game if they crash it.

------
manicdee
Some caveats per Marina Koren
[https://twitter.com/marinakoren/status/1171873631808438273](https://twitter.com/marinakoren/status/1171873631808438273)

1\. This planet probably doesn’t have a solid surface

2\. Being in the “habitable zone” doesn’t mean a planet is habitable

3\. The detection is of water molecules, chances are the water only exists as
vapour in the atmosphere of this small gas giant.

4\. If you ask 10 astronomers about this you will get 11 opinions

~~~
brownbat
> Being in the “habitable zone” doesn’t mean a planet is habitable

True. Being a spooky near twin of Earth isn't necessarily enough.

The air inside popcorn factories is basically identical to the Earth's
atmosphere, but breathing in diacetyl, a butter flavor you'll find in that
air, will kill you a few months or years later.

Popcorn lung really undermined my naive view that we would one day be able to
run a scan or a sniff test on a planet and then just breathe without
assistance.

[https://en.wikipedia.org/wiki/Bronchiolitis_obliterans](https://en.wikipedia.org/wiki/Bronchiolitis_obliterans)

You have an identical twin to Earth with slightly different dust composition
and it could shred our lungs. We are highly, highly tuned to our home.

Which doesn't mean we can't go anywhere. But it won't just be advances in
travel speed that will get us off world. It may also require drastic
modifications to the human organism.

~~~
tripzilch
That'd be something, people travel for 30 years to a distant planet, die four
days later because something in the atmosphere we didn't account for and did
not filter properly, or a crystalline fungus that eats away our suits.

~~~
perl4ever
Happens a lot in (bad) science fiction, and parody thereof.

People land on a planet, go "I wonder if the atmosphere is breathable?", then
open their helmet and take a deep breath.

But I think by the time anyone is arriving on a planet around another star, it
will be with biotechnology that allows adaptation to a rather wide variety of
environments.

------
transreal
With a planet this large, visiting it would be a one way trip due to the "The
Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start
finding exo-planets that are closer to Earth in size and which could
potentially have space-faring races (and which we could leave if we were ever
to visit them).

[0] -
[https://www.nasa.gov/mission_pages/station/expeditions/exped...](https://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.html)

~~~
archgoon
It's 111 light years away. For all intents and purposes, that's a one way trip
right there; irregardless of the rocket equation. Even at relativistic speeds,
you can't come home anymore.

~~~
ajconway
Theoretically, you can. At 0.99c 111 light years take about 15 years of ship
time to travel.

~~~
Swizec
So you can survive the trip but even if you come back home, it’s not home
anymore? Imagine leaving 222 years ago and coming back now ...

~~~
atoav
Many european cities would still exist and the mountains I grew up in front of
too.

But granted, all people I know would be dead and some I could find in the
history books maybe..

~~~
yawz
_> and some I could find in the history books maybe.. _

Where you would also be, at that stage.

------
chenning
A very quick search suggests that earth will become uninhabitable somewhere
between 500 million and 2 billion years from now. If we shot a probe to this
life-friendly alien planet with some sort of primordial soup, even traveling
at the speed of light it would take 4 billion earth years to get there. Do I
have that right? Basically we'll never even come close to being around when it
finally arrives, if it ever arrives. Has anyone ever thought about doing this?
We've shot gold records out into space for aliens with turn-tables. Why
haven't we tried this?

~~~
not_a_cop75
It seems like it would be much easier to terraform the real estate around us
than try to opt for something 100 light years away.

Mars has a leaky atmosphere - sure it's a real fixer upper. But we have a
better chance of fixing it, or even correcting the orbit of our planet so that
in 500 million years it's still livable.

~~~
grumpy8
Or sending a HUGE human civilization spaceship somewhere.. maybe it will
outlast the earth?

~~~
cthalupa
In a lot of ways, living on spaceships/space stations/other artificial
constructions is likely a better path forward than looking to colonize new
planets in general. O'Neill cylinders are quite practical, and with advances
in technology that seem likely to occur, even larger projects like Bishop
rings should be doable. They can be linked together to form constellations,
and have enough free floating resources within the solar system to be able to
build enough of them to support populations in the trillions.

It probably sounds less than ideal to you and me, vs. living on a planet, but
it probably wouldn't be so bad to someone born in that sort of environment and
is used to it.

With that in mind, I don't know if it makes sense to try and find human
habitable planets, vs. just places with lots of raw material we can use.
Unless there's alien life we want to go meet up with, at any rate.

~~~
not_a_cop75
O'Neill cylinders are so practical that most of this stuff we have no idea how
to practically accomplish.

Edit: The sizes involved for launch would present no less than a hundred
trillion budget at the moment.

~~~
cthalupa
I mean practical in that there's no exotic science required. Everything
required we have ideas on how to accomplish now, and the big issues are making
it cost effective.

And as for the 100 trillion budget, if you're launching from the earth, sure.
Geologists are pretty sure the moon has plenty of materials useful for
building stuff. We've already built mass drivers, and the physics for building
one that could launch raw materials from the moon are perfectly sound.

Yes, we need to figure out mining materials and building stuff in space. But
we're going to have to figure that out anyway if we want to survive as a
species in the long term, and there's plenty of advantages in starting to
figure that out now, especially since we're staring down the barrel of a gun
vis-a-vis climate change.

------
cryptoz
Lots of discussion on the possibility of going or communicating, but for me
the excitement is the narrowing of uncertainties in the Drake equation and the
focusing of discovery of alien life, intelligent or otherwise.

Discoveries like this improve our understanding of likelihood of
extraterrestrial life, which has direct Earthly implications. It also enables
better estimates and searches for planets that are closer, say ~4 to 20
lightyears away, for those super interested in the traveling & communicating
possibilities.

~~~
tontonius
After reading Liu Cixin's Three body Problem, let's just say I'm less super
interested in communicating :)

------
calgaryeng
Isn't it odd to think that one day, there will be a top post on Hacker News:
"Alien Life Discovered on Nearby Planet (430 points)".

~~~
DC-3
One would like to think that it would get more points than that :-)

~~~
yiyus
But if it gets more than 430, it will have 430 at some point.

~~~
calgaryeng
Peak pedantry - I love it

------
leonroy
Reading about that led me to this article about a water world that was
discovered:

‘A giant waterworld that is wet to its core has been spotted in orbit around a
dim but not too distant star’

With oceans 9000 miles deep (15000 km). For context the Earth’s diameter is
7900 miles (12700 km).

The imagination really does boggle at the thought. I think science fiction is
going to have a hard time keeping up with the incredible science fact we are
observing in our lifetimes.

[https://www.theguardian.com/science/2009/dec/16/waterworld-p...](https://www.theguardian.com/science/2009/dec/16/waterworld-
planet-earth-life)

------
lachlan-sneff
There are lots of people in the comments here talking about how long it would
take to send a probe, or how many generations a generation ship would have,
but it seems clear to me that that's not how humans are going to go to other
solar systems.

Once we solve mind uploading (assuming that it's possible), we can send a blob
of grey goo on a solar sail at a very high acceleration to another solar
system. It can shed half of the sail and bounce the laser back to decelerate.

The grey goo would go and convert part of asteroid or something to
computronium, and then we'd upload a bunch of humans over to the other solar
system.

~~~
ryacko
If we can simulate wetware perfectly, we would also be able to solve any
health condition.

This is all presumptive of the preferences of individual humans. It may be
that the giant extrasolar Earth-type planets could be dismantled and rebuilt
into smaller Earths located at various Lagrange points.

~~~
lachlan-sneff
For sure, maybe future humans won't want to do that. The important takeaway is
that they'll have the opportunity to do so if they wish.

They could even clone them back on the other end and install the preexisting
mind, basically teleportation.

~~~
gremlinsinc
You're assuming that we'll have a means to send data across Galaxy faster than
the speed of light. If not then it'll take 111 years to upload your mind.

~~~
lachlan-sneff
Nah, I was assuming it'd take 111 years to send the minds there. It's really
not a very long time when we have digital immortality.

------
jug
So they finally got there. Detecting atmospheric water vapor on a planet 110
light years away. amazing.

------
ghostbrainalpha
Serious question - Do we have the capability to send human life there now?

Obviously its going to be a one way trip. And it would require a generational
ship.

So could we build a ship that held 12 people initially, 6 couples, all who
were allowed to have 2 children, so 24 people max, and could we load it with
enough supplies to last over 100 years?

Even if the group that eventually arrived had no way to sustain life, and they
just went there for a quick swim before dying... is it possible?

~~~
0xffff2
We don't have the capability to send _anything_ there now. Sending even a tiny
probe that is capable of communicating back to Earth from our closest stellar
neighbor is beyond our current technology. People are actively working on it,
but it's unlikely that we will have the technology to even send an unmanned
probe to this star within our lifetimes. We might send a probe to Alpha
Centauri, but it's even questionable whether it will be fast enough to arrive
within our lifetimes.

~~~
trhway
Project Orion - riding nuke explosions - using existing tech/materials and
those 100K nukes that both sides had at the peak of the Cold War would bring a
30K ton ship to the 5-10% of c. Curiously, getting all that 100K+ ton of
hardware to LEO where one can finally start exploding the nukes seems to be
more complicated task right now.

------
dopamean
What makes a planet an "alien" planet?

~~~
makerofspoons
It is part of a different solar system:
[https://en.wikipedia.org/wiki/Exoplanet](https://en.wikipedia.org/wiki/Exoplanet)

------
sbarre
This reminds me of a sci-fi book I read when I was a kid called Rocheworld by
Robert Forward.

They were going to the Barnard Star, but it had binary planets where one was
all water.

Good book (if I recall)..

------
flywithdolp
That's the kind of news that makes me smile and worry at the same time

All my life I wait for the moment we will find life

I just afraid if it will really happen from everyone reactins

------
carapace
I think we would have to manage to extend human lives to ~10,000 years or more
to be spacefaring.

------
ryeguy_24
Correction, water “was” found. This water was there 111 years ago.

------
known
If water is found can we assume fish like life in that planet?

------
timpannn
Thought this was found multiple years ago?

------
najarvg
Sorry if it's been mentioned in the threads before - Here is Phil Plait's
(@badastronomer on twitter) practical explanation of this finding -
[https://www.syfy.com/syfywire/water-vapor-detected-in-the-
at...](https://www.syfy.com/syfywire/water-vapor-detected-in-the-atmosphere-
of-a-temperate-mini-neptune-exoplanet) TLDR - "NO, THIS DOES NOT MEAN THE
PLANET IS EITHER EARTH-LIKE OR HABITABLE."

------
DoctorOetker
that title should read "Water found on a potentially life-friendly _exo_
planet"

------
russellbeattie
Only 1,050,000,000,000,000 kilometers away...

------
Miner49er
It's depressing to think that if there is intelligent life on that planet, we
won't be able to communicate with them in any way in our lifetime, yet it's so
close. Unless they started sending communications our way over a century ago.

~~~
tyri_kai_psomi
If it is depressing to think about it, then why think about it? Does it have
any real implications for significant outcomes about your life or is it in a
way some type of FOMO?

~~~
Miner49er
Well, I suppose I'm using a bit of hyperbole. Maybe I should say sad. And
don't worry, I won't think about it very long.

~~~
gist
Why is it sad at all? What would it do for you? It would be about as relevant
as being able to communicate in some way with people in the past. Would be
interesting and entertaining but a leap to imagine it would yield some kind of
better quality of life in the current day.

~~~
trianglem
I feel like the ideal of life existing on another planet _would_ improve my
quality of life. The additional potential would do wonders for my everyday
narrative.

~~~
tyri_kai_psomi
I feel like the idea of time travel, teleportation, and eternal youth would
improve my quality of life as well, but they are just as likely at this point
as living on another planet. I certainly don't let the fact that I won't ever
have any of those things get me down.

------
eggpy
> potentially life-friendly

Spoiler: it's not

~~~
0xffff2
Life friendly != human friendly.

~~~
eggpy
I understand that. This planet is far more likely to not be habitable, period.
We might as well consider Neptune to be "potentially life-friendly".

------
ballsyballsman
Calling it "alien planet" has a negative warmongering tone.

------
carrozo
So tired of hearing about “habitable” planets that would take millennia to get
to. Call me when the space elevator has been commissioned.

~~~
0xffff2
If it makes you feel any better, virtually all of them are uninhabitable to
humans. The excitement comes from the idea that they could be locations of
alien life that we would easily recognize. In other words, we need better
communications tools, not better space travel.

~~~
anyfoo
Or even just better observation tools, that would be amazing already. Sadly,
at the scales we are talking here, even "just" getting those tools seems very
improbable, at least...

------
munherty
Someone please correct me, because with a planet that is at 111 light years
away aren't we technically looking back in time?

Any type of observation was only a period Of time and any type of life used to
be there, but may not be there presently?

~~~
Simon_says
Everything you look at is looking back in time.

------
novaRom
I am thinking to get a not very expensive refraktor (120 mm) with Azimutal
mounting, for deep space and terrestrial observations. Just interested in
Astronomy, but have no idea what level of details can be seen with that kind.
I am fascinated by Orion Nebula and Andromeda which I can see with simple 8x42
ED binoculars. Now thinking about telescope. Dobsonians look pretty heavy, I
want something portable and inexpensive. Do you have any suggestion? Are
refractors good for that?

