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NASA announces discovery of Earth-like planet with earth similarity index 0.98

nasa.gov

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Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#41

Post by bitshiffed »

haarts wrote: post #26

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 ). So a score of 0.98 would seem significant.

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.

Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#42

Post by resolutionx »

dogma1138 wrote: post #32
motoboi wrote: post #30

Earlier quoted context omitted.

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

It's a psychedelic type substance similar to LSD. What he meant is that the weirdest things you can ever experience is you on acid.

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.

Regardless this is a bit off topic.

Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#43

Post by spdustin »

hdevalence wrote: post #28
panglott wrote: post #20

Earlier quoted context omitted.

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.

Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#44

Post by underyx »

colinramsay wrote: post #8
waterlesscloud wrote: post #7

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

"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

Well, what has a value of zero?

Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#49

Post by shoo »

bitshiffed wrote: post #41
haarts wrote: post #26

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 ). So a score of 0.98 would seem significant.

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.

https://en.wikipedia.org/wiki/KOI-4878.01

Interesting comment by `admiralrewd` regarding KOI-4878.01 & general critique of ESIs on reddit from 6 months ago:

http://www.reddit.com/r/space/comments/2rbjo9/if_confirmed_k...

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.

Re: NASA announces discovery of Earth-like planet with earth similarity index 0.98

#50

Post by repsilat »

waterlesscloud wrote: post #14
cschmidt wrote: post #9

Earlier quoted context omitted.

LMGTFY https://en.wikipedia.org/wiki/Earth_Similarity_Index

That seems like a really shallow set of criteria.

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.

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