
NASA announces discovery of Earth-like planet with earth similarity index 0.98 - HerrMonnezza
http://www.nasa.gov/news/media/newsaudio/index.html?2015-07-23
======
frostirosti
It's 1075 light years away. If there's life there and they looked at us,
they'd see vikings colonizing northern France and they'd see the Maya
civilization collapse.

~~~
unprepare
Great! they'll start hearing our radio broadcasts (1974) as soon as earth year
3049!

------
BurningFrog
Earth itself is probably at 0.96 by now.

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dr_zoidberg
As of now, the content linked says nothing more than the PR announcement from
yesterday -- so either the title is misleading, or the OP comes from the
future.

(I'm aware he might have other sources for the title, but it's still
misleading)

~~~
allcentury
I think the announcement is live at noon today (EST).

~~~
wrboyce
For those who also dislike timezone-juggling:
[http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/...](http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/news/media/newsaudio/index.html)

~~~
danielweber
People think they are being more precise by saying "EST," but, quick, are we
in daylight savings time now, or out of it?

It turns out we are, and I don't meant to suggest that GP didn't know this.
But what if we weren't in daylight savings time, and GP said "EST"? Would we
have to change an hour?

I highly recommend just saying "Eastern Time."

~~~
Asbostos
Or better yet, UTC or GMT since probably more people in the world know their
offset relative to that, than EST.

~~~
lostbit
True. We know our current offset from UTC (or legacy 'GMT'). I always use the
real offset at that time. Thus, I just inform my clock saying UTC-3 (or UTC-2
when we are in daylight savings time).

------
bsbechtel
I'm disappointed by the negativity expressed in some of the top comments in
this thread. This is an exciting discovery, and the most popular comments here
are basically "humanity is destroying its own planet, if this place was
anything like earth, the inhabitants there would have already destroyed their
planet."

~~~
GBond
It is the new norm of HN. Almost ever top voted comment nowadays is a negative
swipe or a nit-pick that is tangentially related to the OP.

~~~
manifestsilence
Yes, beware! The tendency to value clever quips and memes over actual content
WAS the difference between Reddit and HN. And used to be the difference
between the nicer parts of Reddit and 4Chan before that... :/

~~~
ArekDymalski
"If your account is less than a year old, please don't submit comments saying
that HN is turning into Reddit. It's a common semi-noob illusion, as old as
the hills." taken from
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

;)

~~~
manifestsilence
Whoops, my bad. :s

------
jMyles
Whenever my imagination starts to run wild with the possibility of a huge
announcement of this variety, I always like to remember what Terence McKenna
said about this: "if aliens were to land on the front lawn of the white house
tomorrow, it would not change the fact that the weirdest thing in the universe
is DMT."

~~~
motoboi
Could you elaborate on what is so weird on that molecule?

~~~
d-equivalence
It is weird because it is present in many "mundane" plants and in the human
organism, allegedly released at the time of death. It lasts 10 minutes which
is strange for a psychedelic substance, which after the experience you can go
back as Terrence said "answering phonecalls". Apparently the human body knows
perfectly well how to metabolize it completely without any taxing effects.

From my personal experience in psychedelics, all of them, LSD, mushrooms and
so forth, the user still maintains a reference point to reality around him
however weird it might look. With DMT, the _whole content_ of present reality
disappears and you are seemingly transported in a completely different reality
booming with alien intelligence (described by DMT users as _self transforming
machine elves_ ) that purportedly is also very happy to see you "broken
through". Users also report an incredible amount of information being
transmitted to them, albeit completely indescribable by present human language
and concepts and find themselves being under a dome-like structure (called the
"DMT Dome").

From what I know, these effects are only present if you follow a specific
dosage and no less than that.

Another strange fact is that while all other psychedelics are boundary
dissolving substances with your ego first to get booted, with DMT you
apparently "maintain" your present self throughout the trip.

This is what the "Death by astonishment" quote of the same author, refers to.

~~~
myth_buster
Ah, the white light at the end, the flow of knowledge, being close to the all-
knowing and other statements as described by those who had near-death-
experiences. This seems logical and is quite fascinating. Thanks for
describing it in detail.

~~~
d-equivalence
There are several parallels depending on how far down the rabbit hole you want
to go. Reports of feeling accepted and loved, and the "tone" sound in the
beginning which seems to me really similar with the one you hear when you
astrally project out of your body.

But we are fast getting out of HN accepted topics of discussion so.. :-)

Ultimately one should (not must) explore these things on his/her own instead
of reading it on the web. All this quickly degenerates to entertainment if one
only reads about them online.

------
xamdam
ELI5: until we flew next to Pluto this month all we had is blurry 16-pixel
images. How can we get such precise data on something millions of times
further?

~~~
objclxt
Nearly all of the ways we detect exoplanets involve indirect observation. Most
of them are based on observing the star(s) in the system of the planet. The
two main ways we detect exoplanets are:

* Radial Velocity - just as the gravity of a star effects a planet's orbit, the gravity of a planet also has an impact on the star's. It's just this impact is extremely small. By measuring variations in a star's movement due to the planet's gravity we can both detect the planet and estimate its mass.

* Photometry - when a planet moves in front of a star it reduces both the brightness and spectrum of the light we perceive. By carefully measuring this we can determine not only the size of the planet, but also it's chemical make-up - light from the star travels through the atmosphere of the planet, changing its spectrum in response to the elements present.

There are several other ways we can detect and examine planets, but nearly all
of them are based not on observing the planet itself but its impact on much
larger, detectable things that surround it. There's a comprehensive list here
-
[https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet...](https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets)

~~~
mister_m
As an aside, there is an episode of the Cosmos reboot that talked about
Photometry at a mile-high level. I had never heard of it before, but it is
supremely interesting.

------
V-2
This similarity index only measures radius, density, escape velocity and
surface temperature, so it doesn't mean nearly as much as one would think upon
reading the headline

~~~
sixothree
Does surface temperature imply an awful lot in this situation? How accurate
are we able to measure?

~~~
Osmium
> How accurate are we able to measure?

Quite poorly, I believe. I think surface temperature is estimated based on the
distance from the star, and I think it assumes an albedo (reflection
coefficient) and maybe a typical(?) atmosphere (though I'm not sure about
this). In any case, I imagine the error's quite large.

Unfortunately, we only have our own solar system to go on, and until we find
better ways of studying these exoplanets, we have no good way of knowing if
the planets in our solar system are really representative of what's out there
or not. But that's why this research is so important.

------
qntty
Here are some other planets we've found with comparable similarity. Note that
earth-like similarity does not imply that it is habitable.

[http://phl.upr.edu/projects/habitable-exoplanets-
catalog/dat...](http://phl.upr.edu/projects/habitable-exoplanets-catalog/data)

~~~
EA
A few zones some think need to overlap and be dialed-in to come close to
offering a habitable place:

water habitable zone

ultraviolet habitable zone

photosynthetic habitable zone

ozone habitable zone

planetary rotation rate habitable zone

planetary obliquity habitable zone

tidal habitable zone

astrosphere habitable zone

~~~
saiya-jin
quite a few of those are not relevant for habitability. for example tides,
really? or you wouldn't survive if day would have 40 hours???

~~~
SapphireSun
I think it's more like if the day was 100 msec that you have to worry about.
Also, if the day is too slow, then one side of the planet bakes while the
other side freezes. Think of the rotation axis as a spit roaster.

~~~
Ecco
Nice metaphor :)

------
TomGullen
Is there any way at all for us to be able to see oceans/clouds/continents on
such planets if we have a hundred billion dollars and built equipment
specifically just to look at that one planet?

Or would the star near it just haze everything too much?

Is it _impossible_ to observe a planet in more detail like that without
travelling next to it?

~~~
sktrdie
Yeah I think so. You'd need a telescope bigger than our earth.

------
jMyles
Searching google news for "earth similarity index" gives me no indication that
NASA will make this specific announcement.

Is there a source? If not, it makes sense to change this title to "NASA to
make announcement that 'astronomers are on the cusp' of finding 'another
earth.'"

------
haarts
It's interesting to note that the highest ESI so far has been Kepler-62e with
a score of 0.83
([https://en.wikipedia.org/wiki/Earth_Similarity_Index](https://en.wikipedia.org/wiki/Earth_Similarity_Index)).
So a score of 0.98 would seem significant.

~~~
Osmium
Question: why is 'escape velocity' part of the Earth Similarity Index when,
presumably, it's just a function of radius and density (which are also in the
index)? I feel like I'm missing something.

~~~
weland
It's a reasonable measure of surface gravity, which, along with an idea about
the distance from the star it's orbiting, gives us a good idea about what kind
of atmosphere we can expect (i.e. the lighter and the hotter a gas is, the
easier it can escape a planet with a particular escape velocity), at least a
basic idea about what kind of surface features we might expect and so on.

It's also a parameter that is quick to compute starting from radius and mass,
which are often the first things you know about an exoplanet due to the way
they're found.

~~~
Osmium
Right, but the escape velocity is ~ radius * sqrt(density) anyway, and if you
look at the equation for the Earth Similarity Index[0], each term has an
associated weighting. So why include escape velocity explicitly, rather than
just changing the weighting of radius and density? The weightings seem to be
quite specific numbers too, so I imagine there's a methodology behind it, I
was just curious as to the logic. (Also, e.g., why is the temperature weight
5.58? Wikipedia says the weighting is to 'equalise their meanings', but it's
not clear to me what that means.)

[0]
[https://en.wikipedia.org/wiki/Earth_Similarity_Index#Formula...](https://en.wikipedia.org/wiki/Earth_Similarity_Index#Formulation)

~~~
weland
I think the formula that Wikipedia gives isn't used _that often_ for most
exoplanets. Oftentimes all you know about a planet is the mass, radius and
some information about temperature or at least energy flux to its surface, so
they use those at first.

I guess the parameters were chosen by some curve fitting procedure to make
sure it gives 1.0 for Earth, 0.7-ish for Mars, 0.2 for Uranus and Neptune
which are basically the most "not like the others" in our solar system and so
on. It's not really a measure of habitability or anything like that.
"Equalizing the parameters' meanings" presumably has to do with mapping their
relative variation (and the effects of that variation over various observable
parameters) over a smaller range.

------
jflatow
Briefing materials:

[http://www.nasa.gov/keplerbriefing0723](http://www.nasa.gov/keplerbriefing0723)

([https://news.ycombinator.com/item?id=9936612](https://news.ycombinator.com/item?id=9936612))

------
afarrell
If there is life on that planet, I wonder if it would be similar enough to
host infectious diseases. I know the Apollo team was quarantined when they got
back from the moon. As someone living on a continent that has undergone one
apocalypse, I hope we have a similar procedure to prevent the spread of
spacepox.

~~~
humanfromearth
If there is life there is probably bacteria and viruses. But it's unlikely
they would be harmful for us.

They need to match our platform.

~~~
tartuffe78
They would need to match our platform to perform the mechanisms they have
evolved for, but not necessarily to have adverse effects.

~~~
jfoster
New bacteria probably wouldn't be resistant to antibiotics. The bacteria on
Earth is likely far more dangerous.

------
rndn
In case you have questions about exoplanets, there is an ongoing AMA by
exoplanet researchers on /r/science:
[https://www.reddit.com/r/science/comments/3ebavu/science_ama...](https://www.reddit.com/r/science/comments/3ebavu/science_ama_series_were_the_planet_hunters_team/)

(They mention the upcoming announcement, but they don’t know know what it is
about either.)

------
Benjamin_Dobell
Apparently there's already a Kepler discovered planet with an ESI of 0.98:

[http://phl.upr.edu/projects/habitable-exoplanets-
catalog/dat...](http://phl.upr.edu/projects/habitable-exoplanets-catalog/data)

EDIT: Unless that list was literally just updated with ESI 0.98 planet this
thread is referring to...

~~~
pavlov
1,075 light years away... Assuming we could somehow accelerate a "New New
Horizons" probe to near light speed, that's a disappointingly long time to
wait for a flyby.

~~~
andy_ppp
And once it arrived, slowed down (haha!) and performed the survey it would
only take another _millenia_ for us to _start_ receiving back information.

We need to work out how to bend spacetime.

------
sunseb
It's crazy to think that there may be life everywhere in space and incredible
things we haven't seen yet, that our mind can't even conceive.

------
_jomo
Accessing this with HTTPS Everywhere and Firefox leads to
[http://www.ustream.tv/embed/9407922](http://www.ustream.tv/embed/9407922)
being blocked, so you don't see anything other than the text.

However, The stream has reached "maximum capacity" at this time.

------
colordrops
For reference, here are the ESIs of some planets in our solar system: Mercury
(0.596), Venus (0.444), Mars (0.697).

------
chucksmash
For reference, a 195lb human being (who is assumed here to be spherical in
shape) has an Earth Similarity Index of approximately 0.001:

[https://gist.github.com/anonymous/5351f6185e8473a3c002](https://gist.github.com/anonymous/5351f6185e8473a3c002)

------
coob
Is it this one?

[http://exoplanetarchive.ipac.caltech.edu/cgi-
bin/DisplayOver...](http://exoplanetarchive.ipac.caltech.edu/cgi-
bin/DisplayOverview/nph-
DisplayOverview?objname=K04878.01&type=KEPLER%5fCANDIDATE)

------
almost_started
It HAD an ESI of 0.98 1075 years ago. By now, the inhabitants have burned
through all their fossil fuels and then annihilated each other with nuclear
weapons leaving the planet in both a long-term nuclear winter and with a
runaway greenhouse effect. Its ESI must be at least 1.0 by now.

~~~
psaintla
I'm not sure what fossil fuels and nuclear weapons have to do with this but
1075 years isn't a very long time. There may not be intelligent life on the
planet yet.

~~~
redcalx
"There may not be intelligent life on the planet yet"

Sounds pretty similar.

~~~
psaintla
Yes, let's not celebrate human achievement and think about the positive
possibilities, let's focus on the negative at every turn.

~~~
redcalx
> let's focus on the negative at every turn

You mean like the dearth of humour?

------
3327
I can leak some more info:

its 1400 light years away in habitable zone and the sun is 8% different than
ours (don't quote me on the 8% but its very close in size)

------
ck2
I sense a great disturbance in Hollywood like a screenwriter was just inspired
to write something original...

------
mkagenius
That's exciting news. How far is this planet? Does 0.98 mean high probability
of water being there?

------
waterlesscloud
What's an "earth similarity index"? Is there a definition somewhere?

~~~
colinramsay
"The Earth Similarity Index, ESI or "easy scale" is a measure of how
physically similar a planetary-mass object is to Earth. It is a scale from
zero to one, with Earth having a value of one."

Mars is at 0.697, for reference.

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

~~~
underyx
Well, what has a value of zero?

~~~
jameshart
To have an ESI, an object needs to have a mean radius, a density, an escape
velocity, and a surface temperature. Gas giants and stars, therefore, don't
really have a definable ESI, since they lack a 'surface' where you can take a
temperature.

If something _has_ all of those properties, then because of the way it's
defined, it has an ESI which is strictly > 0 and <= 1 (it can only be zero if,
for one of its properties, x - x0 / x + x0 == 1, i.e. x - x0 == x + x0 - and
since x0 is strictly nonzero, that can't happen). So nothing has an ESI of 0.
But you yourself, to pick an object at random, probably have an ESI very very
close to zero.

Incidentally, the formulation of the ESI is a good generic formula for
creating 'similarity' measurements for, for example, matchmaking algorithms or
similarity searches.

~~~
stcredzero
Then why didn't they just define it so that objects with an "undefinable
surface" have an ESI of 0?

~~~
jameshart
Sure, you could do that. I guess there's just not really much need for ESI to
be defined across the domain of "all things". A similarity index of zero just
means "not at all similar to Earth", which, yes, applies to the Sun and
Jupiter, but also to a blob of tomato ketchup, or moonlight, or schadenfreude.
Most things have an ESI of zero, then.

~~~
stcredzero
Jupiter is a "planet" in our parlance, though. But I guess that's just an
accident of a bunch of very different things having the same range of
brightness in our sky.

------
tilsammans
"This content is not available in your area due to rights restrictions."

------
skapadia
But is it a Class M planet?

------
tiffanyh
... and humans have a similarity index of 0.98 with chimps as well.

------
bberrry
Would be awesome if it had a confirmed oxygen rich atmosphere.

~~~
logfromblammo
Such would be a strong indicator that something is continually generating
gaseous oxygen. Otherwise, the O2 usually ends up oxidizing anything it can
touch, and gets bound up in minerals, or as oxygen-containing gases.

Awesome for potential terraforming would be an atmosphere containing gaseous
NO2, H2O, CO2, NH3, and SO2. That would be oxygen-rich, but not as molecular
O2, which is almost as good as putting up an "OCCUPIED" sign on the planet.

Unless, of course, you're actually looking for alien life. In that case, any
atmosphere with F2, Cl2, O3, O2, NO, CO, H2, or N2 is nearly a dead giveaway.
Those don't persist for long in that form on a geological time scale, so if
you detect them, something must be continually generating them.

------
tremon
requires javascript; didn't read

------
williamhpark
This is so misleading. Even if it turns out to be true, this shouldn't be up
here yet.

------
jneal
Likely off-topic, but Nasa's site feels very weird to me. Like it think I'm on
a tablet. Everything is huge. And I'm on a 1920x1080 laptop using Chrome.

Okay, to make this slightly on-topic now, I am excited to hear about the
discovery in about an hour and a half. Even if it was a 1.00 on the similarity
scale, I'm more interested in finding out how habitable it would be for earth-
like life.

