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.
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)
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?
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).
I agree, wrong timezone (DST or not?) is as bad as no timezone. I have gotten in the habit of using Olson timezone names, US/Eastern for example, because I have seen CT used to refer to both US and European Central time.
Welcome the world of pain that is timezones and DST... As someone who has had to write an extensive amount of deal with these two concepts they are the worst things ever. We should just abolish timezones, DST, and move to the International Fixed Calendar. Time sucks. I'm even in favor of moving to a seconds-based time unit like kiloseconds, miliseconds, etc instead of minutes/hours/days/weeks/months/years/etc. "Metric Time" if you will...
I haven't had my morning coffee and I misread 'reply' as the username and thought you were having a big, multi-threaded conversation with yourself. :) I even vaguely thought 'is that guy's name reply?'
Thanks for sharing that. I've been looking for something like this. Traveling and juggling meetings in multiple timezones is a big source of anxiety for me. I'm always wondering if I did the math wrong or if there is a daylight savings I haven't accounted for.
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."
That's not true at all! So not true that I went and checked the top comment on every page; not one of 30 came close to what you claim. Instead I saw top comments that:
People often make false generalizations about HN. I doubt that's particular to HN—probably just humans in general being human, with sample bias and all. But getting the wrong generalizations in your head can prevent you from seeing things. Here that might mean seeing less of what's good about HN, and thus getting less out of it.
This is on my mind because we've been thinking lately about new ways to highlight the positive and amazing things this community comes up with, many of which go unseen by the majority of readers.
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... :/
"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
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."
By all accounts NASA's getting ready to announce they've found an earth-like planet and you guys are like "yeah but I'm sure it won't compare the experience of taking my favorite drug." That's a sad and closed-minded way of looking at things.
It reminds me of Jon Stewart's character in Half Baked who thought everything was better "on weeeeed!" If your drug of choice prevents you from enjoying other experiences, like staring in wonder at the mysteries of the universe, that's like being in an abusive relationship.
There's no good reason the existence of a drug should prevent you from enjoying an announcement like this. There's definitely no good reason to assume that in this 16 billion year old universe which you've been part of for a negligible amount of time, which you've physically experienced only a negligible amount of, that you've already found the weirdest or most interesting thing ever.
This is a ludicrous reduction of the point McKenna was making. You're acting like he didn't directly address this fallacy. Go read The Invisible Landscape, listen to one of the lectures that covers this material (such as Eros and the Eschaton and / or his address to the Jung Society), and then address the whole of what he was saying.
If you don't think that human neurochemistry is astonishing, I think that's weird. But don't sit here and straw man his research; that doesn't help anyone.
Neurochemistry and the experience of consciousness are very astonishing, I just think it's a bit egocentric to assume they're the most astonishing things in the universe.
Nobody said they were the "most astonishing things in the universe" - I'm not sure where you get this stuff. It's another straw man.
McKenna says that neurochemistry, and its material application called "the psychedelic experience," is the most astonishing thing you can personally suppose, or in some cases, even that you can't suppose. But that doesn't say anything about the (real or imagined) notion of a totality of "things in the universe."
The psychedelic experience is the most intense experience anyone can have on this planet, and it cannot be compared or described by anything else one has experienced in his/her life.
Surely there's no good reason to assume anything but you do assume and in the most cliche way. Maybe first you should chuck 5 gramms of dried mushrooms with some lemonade and come back and tells us what you think after that.
I'm not sure if the parent was advocating or saying this. It was in reference to Terrence Mckenna's view of the present assumptions that mankind has about what aliens should look like and how one should go about contacting them (and that DMT and mushrooms are probably an alien artifact).
And certainly one can lose the plot and spend his entire life tripping. Noone is saying thats a good thing.
> ...and it cannot be compared or described by anything else one has experienced in his/her life
Many long-term meditators who have previous experience with psychedelics would disagree with you.
I'm only making the assumption of agnosticism, that it's fundamentally impossible for you to know that something already within your realm of experience will trump all that exists in the unknown.
Because I'm tired of arguing with nerds talking theory over matters that ultimately are experiential, I'll say the following two points and I don't mind being downvoted.
1) Whomever says the experiences of meditation are akin to those of psychedelics is plainly full of shit. I've done psychedelics for about 4 years, and western ceremonial magic which involved plenty of meditation daily and consistently for about a decade. Apples and oranges. And thats including all the freaky spectacular shit I've experienced.
2) Practically, how much of "all that exists in the unknown" you think you will or can experience living a basic run of the mill western life in a human body? As I said, ingest 5 dried gramms, then come to talk to me about what will get trumped in your realm of experience. Until then, its only thinking you understand sex because you read dirty magazines, only for something that is several orders of magnitudes out there.
From a glance I wouldn't expect this "western ceremonial magic" to bring anything but confusion and maybe the illusion of not-confusion. But if it works for you do your thing.
I've been around enough to reject the notion that an amalgamation of 1001 chemicals is fundamentally different from an amalgamation of 1000. With that goes the illusion of being "deep" while tripping balls. I'm not rejecting the intensity of the psychedelic experience, I'm rejecting the ideas that it's wholly unique in intensity, that it brings unique insight and that it reliably brings insight.
As far as meditation vs psychedelics I defer to people who have done enough of both to have informed opinions on the matter.
> Many long-term meditators who have previous experience with psychedelics would disagree with you.
See, the problem here is that you are debating an argument you haven't bothered to fully read.
Terence McKenna has literally volumes to say about this argument. So now that we've moved beyond this simpleton back-and-forth, what say you about his position vis a vis meditation?
Specifically, what do you say about his argument that, without being willing to ingest a drug, you haven't humbled yourself to the basic notion that your brain is physical and its operations electrical and chemical?
> Terence McKenna has literally volumes to say about this argument. So now that we've moved beyond this simpleton back-and-forth, what say you about his position vis a vis meditation?
If somebody makes a living telling people things like aliens brought us mushrooms and that's why evolution happened they aren't worth my time. They're too far gone. I responded to a comment on a message board encouraging people to not get excited about space exploration and instead focus on the wonders of DMT.
I simply don't care what he says about meditation.
> Specifically, what do you say about his argument that, without being willing to ingest a drug, you haven't humbled yourself to the basic notion that your brain is physical and its operations electrical and chemical?
Narcissistic, egocentric, closed-minded, a little horrifying. I don't understand why he thinks doing drugs is not only the best path but the only path to understanding the realities of being a human. That's how cult-leaders operate, they teach their followers there is no other way and everybody on the outside of their bubble just doesn't get it. Then when people try to help them get out they say "You just don't understand how great our leader is! He even said this would happen!"
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.
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.
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.
DMT no. These are all coming from reports (and from Terrence himself) which I have no problem believing since I've witnessed my fair share of weird shit in general.
I've only done my share of LSD in the past, which by comparison, seems quite tame and merely "psychological" than DMT.
I wonder if you would consider it heretical to question whether and how well Terrence can differentiate between what he does know and what he does not actually know?
For example, you used a rather non-rigorous descriptor, "weird". What constitutes a weird phenomenon?
Can we subject said constituents of a weird phenomenon to the same kinds of validations we can make about known true facts, i.e. observable existent things?
He says it in a few different ways in his lectures, but he believed that the psychedelic experience is so strange and full of content that, even if aliens landed on the White House lawn and it made the biggest story in the history of news, it's still not as astonishing as human neurochemistry.
I'm not sure I agree, but I think it's good to keep this perspective in mind any time we find ourselves tempted to think of something as 'the biggest thing ever.'
I really keep trying to think whether aliens existing would actually radically change my life, individually. On one hand, maybe, but on the other, probably not (and this is more likely).
I feel like I already experience my existence like I am alien to everything that is not me, whether it is talking to a cat or a person or a tree, the whole thing is like 'reality blob' that I am not really sure how all of this happened, nor do I ever have any hope whatsoever of finding the answer to that question. When I wonder thoughts to myself I wonder who it is that thinks the question and who it is that responds with an answer. So many thinkings are just permutations of what has already been heard, and they form patterns and it's really weird.
It's easy to get 'used to things' and 'acclimated to things', I just feel like I have it hardwired in me to perpetually be weirded out by my own existence. Complexity doesn't even describe it, strange doesn't either, as these are all human concepts. You really just have to learn to observe with a completely blank mind. Then it's just like being in this interface that's always super weird and confusing, and it's ridiculous how some people really think they know what they are doing (like in their deepest philosophical and spiritual core, not like 'have to go to work today to feed the kids').
I wouldn't be so quick to say the two are identical. It's different for everyone obviously but they are very different psychedelic experiences for most. DMT is VERY powerful when administered correctly.
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?
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...
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.
In order to take something akin to a photograph of a planet in another solar system, you'd need to build a network of telescopes with a diameter on the order of the size of Earth's distance from the sun. And in addition to being spread apart, they'd need to be pretty huge in order to capture enough photons from the target. (though of course there could be clever ways around this)
This page contains the measurements of the planet which might be the subject of the announcement; it gives you an idea of what kinds of metrics drive such an analysis:
The similarity index measures things that can be worked out without needing a precise image of the planet. These are things like radius, density and surface temperature, which can be measured by examining its orbit and how much light from the star is blocked as it passes.
IANAAP, but I saw a similar question about how the Hubble space telescope could only get blurry pictures of Pluto. The answer was that it was akin to using a microscope as a telescope (or vice-versa), if that makes sense?
Not really. The problem isn't that Pluto is too close (Hubble has taken excellent pictures of Mars), it's that Pluto is tiny, specifically in angular size.
Distance, time, and amount of light. All these things come into effect. The reason why Pluto took so long? Imagine trying to read a magazine with a pair of binoculars vs. somebody taking a picture right next to it. Which do you think will be easier to read?
We've had a pair of binoculars up in space for a while, but it was designed to see way further than Pluto. That is why we have always had blurry images.
We've had blurry images of Pluto because of its tiny angular size. The fact that its closer than some of the things Hubble has taken better pictures of is not relevant.
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
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.
Pretty sure these all apply for Mars and Venus and they're dead planets. Not sure why everyone is assuming some exo-planet must have life when the two other examples we have don't.
I understand, but that's a synthetic benchmark. We actually have no idea why Earth has life and other planets don't and similarity to Earth may not be a big factor (see theories on life in Europa's seas for example or non-carbon based life).
I just feel everyone gets excited over nothing solely because its extra-solar. Our own solar system is fairly diverse. If life was common, we'd probably be seeing more of it here.
maybe life is common enough, but doesn't typically overlap in time. Maybe life on mars or venus died out a billion years ago.
We'll have a better picture when we study our solar system in more detail. Maybe 100 years? I agree that speculation this early in the game isn't enough to get excited over.
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.
They are relevant, you're just misinterpreting. None of these are meant to imply "X must be like Earth for the planet to be habitable," they mean "X is an important factor for habitability and must be considered in our models if we want them to be meaningful, unlike the ESI which captures a mere handful of variables".
For example, "tidal habitable zone" doesn't mean "we need [ocean] tides to survive," it means "tidal heating effects have an enormous impact on planetary conditions". For example, an Earth analogue in orbit around a tiny red dwarf in a seemingly "habitable zone" would be subject to tidal heating effects which would bake the surface, whereas a similar planet in a similar orbit around a sun-like yellow dwarf would not.
Similarly, "rotation rate habitable zone" doesn't mean "the planet must have a ~24 hour day", it means "all else being equal, a planet's rotation rate can greatly affect habitability," mostly due to weather patterns and air/heat circulation. By including rotation rate in our models, some planets previously thought to be inhabitable may turn out not to be, and vice versa.
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?
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.'"
That Wikipedia page doesn't appear to be updated very often. Here (http://phl.upr.edu/projects/habitable-exoplanets-catalog/dat...) is a better list. KOI-4878.01 has been listed as a 0.98 since January 2015. The new may be that it is only now confirmed; but there are other confirmed KOIs with fairly close values of 0.93 and 0.91 already.
edit: the post links to a couple of papers making a few pretty reasonable points about the assumptions underlying the ESIs, and the errors involved in the calculation.
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.
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.
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.)
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.
I'd take it as a proxy for surface gravity. They can't exactly say what the mean surface gravity is, because they don't know how much variation there is in altitude, and whether the exoplanet has a sea level.
Even so, giving a rough estimate of mean surface gravity would make the tables more accessible to non-experts.
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.
Seems unlikely that anything would be physically going there and back any time soon. We haven't even been able to get some soil from Mars back to Earth yet.
2) Some types of molecules involved with life have chirality so the chances are small that our biological components as a whole would be compatible. (Think of it as several different kinds of "endianess." There would be a coin-flip for each molecule type with chirality.) So at worst, if we ate each other, we'd give each other molecular "indigestion."
More complicated operations, like that of viruses hijacking our cells to replicate themselves are probably right out. Invading foreign cells couldn't get very far in our bodies if all of their enzymes malfunction and they find our material "indigestible."
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.
Also they describe the table "These are mostly unconfirmed exoplanets discovered by the NASA Kepler mission (Kepler Candidates from the NASA Exoplanet Archive). Those already confirmed are listed by their Kepler name in the table above." So looks like it is going to get moved up to the confirmed table?
Accessing this with HTTPS Everywhere and Firefox leads to 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.
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.
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.
"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."
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.
The ESI defines a hyperspherical gradient across several different axes of earth similarity. And since each of those axes are defined by a ratio to an Earth value, zeroes would only be found for objects with the following properties:
- Infinite mean radius.
- Zero mean radius.
- Infinite density.
- Zero density.
- Infinite escape velocity.
- Zero escape velocity.
- Infinite surface temperature.
- Zero surface temperature.
As such, the only object I can think of that might qualify would be a theoretical zero-entropy singularity that might have existed existed prior to the Big Bang. Zero radius, infinite density, infinite escape velocity, zero surface temperature.
Given the nature of the calculation, it probably would have been better to define perfectly Earth-like as zero, and assign positive indices to bodies, with higher numbers indicating greater dissimilarity to Earth. It would be a distance calculation along multiple axes of similarity, but adjusted by scale factors to coerce the differences between comparison axes with different units to have an order of magnitude proportional to perceived importance to humans.
If you have a difference function for each axis that yields a number from 0-1 for comfortable, 1-10 for tolerable, 10-100 for survivable, and 100+ for lethal, then you can take the square root of the sums of the difference functions for the overall index.
Anything less than 1 would be a near clone of Earth. Anything less than 10 would definitely be habitable. Anything less than 100 might be explorable. Anything greater than that, and you might just seed it with Earth extremophiles and ignore it for a few million years.
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.
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.
If you look at the formulation for the ESI [1], you'll see that the components are mean radius, bulk density, escape velocity and surface temperature (measured in Kelvins).
Mathematically you could zero out one or all of the multiplicands (e.g. with a surface temperature of 0 degrees K) but constraining oneself to the realm of the possible, you'll always have a non-zero ESI.
Indeed, "earth similarity" should not be taken as "potential habitability", if Earth's unique geological history (the Theia collision) means that it is at the lower bound of mass for a habitable planet. Already there are super-Earths discovered.
https://www.cfa.harvard.edu/news/2008-02
Why would the Theia collision mean that we're at the lower bound of mass for a habitable planet? What does the moon do that would be compensated for by having a larger planet?
It's thought that the collision resulted in a larger metal core, increasing the strength of our magnetosphere and thus our protection from ionized solar particles. As well, the moon slows our rotation and evens out the procession of our axis, which results in milder seasonal climate changes.
The moon also caused tides which increased the environmental pressures on water-based life forms living in tidal pools to evolve to live amphibiously.
It's not the moon itself, it's the molten core of Earth that generates the magentosphere that protects our atmosphere. A larger planet is likelier to have a molten core.
"The aphelion of Venus, for example, touches the inner edge of the zone and while atmospheric pressure at the surface is sufficient for liquid water, a strong greenhouse effect raises surface temperatures to 462 °C (864 °F) at which water can only exist as vapour."
It isn't terribly clear what the criteria are meant to correlate with -- the Wikipedia page explicitly says that it's not about habitability, but doesn't really say what it is about. Maybe the criteria and exponents have been arbitrarily chosen to "get the right answers" according to someone's intuitive notion of similarity.
It certainly seems strange that Venus is scores lower than Mars, too -- by any reasonable definition it's the more "Earth-like" of the two -- it has an atmosphere, it's closer in size and mass and so on. The weights on the surface temperature measure just kill it, though.
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.
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.
