NASA announces discovery of Earth-like planet with earth similarity index 0.98 • Hacker News Board

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

#81

Post by jfoster » Thu, Jul 23, 2015, 2:13 PM UTC

tartuffe78 wrote: post #67

humanfromearth wrote: post #58

Earlier quoted context omitted.

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.

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

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

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

#82

Post by ParadigmBlender » Thu, Jul 23, 2015, 2:14 PM UTC

joshontheweb wrote: post #16

wrboyce wrote: post #6

Earlier quoted context omitted.

For those who also dislike timezone-juggling: http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/...

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 also recommend http://www.worldtimebuddy.com/. Sounds like it would fit your use case well.

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

#83

Post by danielweber » Thu, Jul 23, 2015, 2:14 PM UTC

wrboyce wrote: post #6

allcentury wrote: post #3

Earlier quoted context omitted.

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

For those who also dislike timezone-juggling: http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/...

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."

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

#84

Post by wuliwong » Thu, Jul 23, 2015, 2:15 PM UTC

Benjamin_Dobell wrote: post #70

Apparently there's already a Kepler discovered planet with an ESI of 0.98: http://phl.upr.edu/projects/habitable-exoplanets-catalog/dat... EDIT: Unless that list was literally just updated with ESI 0.98 planet this thread is referring to...

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?

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

#85

Post by logfromblammo » Thu, Jul 23, 2015, 2:16 PM UTC

Osmium wrote: post #64

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.

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.

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.

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

#86

Post by jneal » Thu, Jul 23, 2015, 2:21 PM UTC

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.

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

#87

Post by Asbostos » Thu, Jul 23, 2015, 2:23 PM UTC

danielweber wrote: post #83

wrboyce wrote: post #6

Earlier quoted context omitted.

For those who also dislike timezone-juggling: http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/...

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."

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

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

#88

Post by chucksmash » Thu, Jul 23, 2015, 2:25 PM UTC

underyx wrote: post #44

colinramsay wrote: post #8

Earlier quoted context omitted.

"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?

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.

[1]: https://en.wikipedia.org/wiki/Earth_Similarity_Index#Formula...

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

#89

Post by williamhpark » Thu, Jul 23, 2015, 2:26 PM UTC

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

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

#90

Post by ycombobreaker » Thu, Jul 23, 2015, 2:27 PM UTC

danielweber wrote: post #83

wrboyce wrote: post #6

Earlier quoted context omitted.

For those who also dislike timezone-juggling: http://time.is/1200_23_July_2015_in_EDT?http://www.nasa.gov/...

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."

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.