SoylentNews is people
SoylentNews
In the past few decades, thousands of extra-solar planets have been discovered within our galaxy. As of July 28th, 2018, a total of 3,374 extra-solar planets have been confirmed in 2,814 planetary systems. While the majority of these planets have been gas giants, an increasing number have been terrestrial (i.e. rocky) in nature and were found to be orbiting within their stars' respective habitable zones (HZ).
However, as the case of the Solar System shows, HZs do not necessary mean a planet can support life. Even though Mars and Venus are at the inner and the outer edge of the Sun's HZ (respectively), neither is capable of supporting life on its surface. And with more potentially-habitable planets being discovered all the time, a new study suggests that it might be time to refine our definition of habitable zones.
Welcome to the Inhospitable Zone.
(Score: 3, Informative) by takyon on Tuesday July 31 2018, @06:22PM (3 children)
We do have multiple environments on our n=1 Earth. The average temperature is just an average. The "habitable zone" is just a range where liquid water MIGHT be present SOMEWHERE on the surface, if other factors are right. Venus and Mars may be considered part of the "habitable zone", but other conditions are wrong. If Mars had a greater mass and denser atmosphere, maybe it could have some surface oceans today.
https://en.wikipedia.org/wiki/Climate_of_Mars#Temperature [wikipedia.org]
NASA Climate Modeling Suggests Venus May Have Been Habitable [nasa.gov]
Evidence of Giant Tsunami on Mars Suggests an Early Ocean [soylentnews.org]
Evidence of Sea Floor Hydrothermal Deposits Found on Mars [soylentnews.org]
Mars's Oceans May Have Been Older and Shallower Than Previously Thought [soylentnews.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by VLM on Tuesday July 31 2018, @07:03PM (2 children)
Not really disagreeing with anything else you wrote, but I was inspired to think about the treeline, which aside from the usual world wide climate variations affecting it a little is about 12 kilofeet ASL everywhere on the planet. So in the insane variation of life and climate all over the planet, none the less trees basically don't live above 12000 ft ASL so their HZ is below 12000 ft worldwide regardless of species or climate. There are variations of up to 2 or 3 kilofeet based on wind conditions, geology, shape of the mountain, climate, but 12K is pretty accurate most times.
When you talk about "life" in generic its hard to specify, but for "forest biomes" its pretty easy to see a hard criteria of sub 12000 feet ASL +/- minor small local variations.
(Score: 2) by takyon on Tuesday July 31 2018, @08:03PM
Multiple environments also includes stuff like hydrothermal vents, geysers, and arctic oceans where life nonetheless exists despite being extremes compared to our average conditions. Some exoplanets/exomoons are going to have life that exists almost entirely "on the edge". And if there's no water on the surface, it's not considered "habitable". Even if Europa and Enceladus had basic microbial life in a subsurface ocean... not habitable zone material.
I'd assume the treeline thing is because of a few killer factors like lower atmospheric pressure/density [engineeringtoolbox.com], colder temperatures, less/no liquid water, cloudiness, etc.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Wednesday August 01 2018, @12:40AM
Horrific mixture of metric and imperial units. Use FFF next time.