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> GJ 486 b takes less than 1.5 Earth days to orbit its star and is probably tidally locked Are there any discovered planets where a year is confirmed to be a d

> GJ 486 b takes less than 1.5 Earth days to orbit its star and is probably tidally locked Are there any discovered planets where a year is confirmed to be a day?

sdflhasjd 3y ago
That surely can't be correct? An orbit of literally 36 hours would mean it would be going much too fast
- shric 3y ago
  Not when it's 0.01734 AU from its star, and therefore 1.7% of the distance compared to the earth to its star.
  - sdflhasjd 3y ago
    I just found that on the NASA site, it really is just a tiny orbit. I got the impression the planet was in a habitable zone from the article.
    - chmod775 3y ago
      The article mentions that its surface temperature is around 430 degrees Celsius. It's that "low" because its star also radiates way less energy than our sun. But still, "habitable zone" means liquid water, which you might not find there given the pressures/temperatures involved. Maybe sufficiently cold spots could exist in the areas facing away from its star. So could you say it's in the habitable zone? Depends on your understanding of the term.
      - svachalek 3y ago
        I think it's fair to say that we as a species have no idea what is a habitable zone. We're extrapolating from a set of 1, and even in looking for liquid water you're better off looking at moons far from our Sun than on Mars which is in our habitable zone.
        dotnet00 3y ago
        A habitable zone is simply defined as the region which is most likely to be able to sustain the conditions for life in the form that we know of it. Of course we don't know if other chemistries of life are possible, but that doesn't mean we can't define a habitable zone based on what we do know and expand it later if necessary. As for looking at moons far from the star, it's barely a reliable means of confirming liquid water even within our own system, good luck detecting liquid water on an exomoon orbiting a far out exoplanet. Mars is in our habitable zone and has plenty of evidence of having had liquid water flowing on its surface. The evidence of it having had conditions which could sustain some Earth-like life on it has only been increasing, making our current idea of habitable zones pretty promising. The fact that it currently doesn't have any liquid water on the surface has little bearing on that.
        jamiek88 3y ago
        We can only look for what we know. We have to narrow it down somehow.
shric 3y ago
"The confirmed exoplanet with the shortest orbit is K2-137b, which orbits its host star, K2-137b once every 4 hours, 18 minutes. The planet is 0.89±0.09 times the mass of Earth, and orbits its host star at just 0.0058 times the distance of Earth from the sun."
VikingCoder 3y ago
Well, "Mercury rotates in a way that is unique in the Solar System. It is tidally locked with the Sun in a 3:2 spin–orbit resonance, meaning that relative to the fixed stars, it rotates on its axis exactly three times for every two revolutions it makes around the Sun."
dghughes 3y ago
Maybe some aliens see us and say "Wow that blue planet takes 548 gleeglubs to orbit their star."
- sharkweek 3y ago
  Yeah there’s a lot of things we’ve normalized that are kinda silly from a zoomed out view. “Okay so we have 12 months. About half are 30 days and the other half are 31 days but then ONE of them is 28 days except every fourth year that month with 28 days has a 29th day”
  - m_mueller 3y ago
    https://twitter.com/foone/status/1572260363764400129 https://twitter.com/foone/status/1572260363764400129
    - legutierr 3y ago
      https://twitter.com/Foone/status/1572263752346796033 https://twitter.com/Foone/status/1572263752346796033 In reference to the above tweet, it might surprise you to know that at times in the past (and per Wikipedia, even in some cultures today[0]) March has been considered the first Month, meaning that the new year would start on March 1, the leap day would be the last day of the year, and September, October, November and December would in fact be the seventh, eighth, ninth and tenth months of the year. https://en.wikipedia.org/wiki/March#Origin https://en.wikipedia.org/wiki/March#Origin
    - RugnirViking 3y ago
      to be fair to us the aliens calendar is likely impenetrable as well, especially if they did agriculture. The more I learn about ancient societies the more I learn that calendars were really important and really complicated. It was the hobby of many rich people to stare at the sky and figure out how the stars move based on how the temprature feels and the daylight length. This let them calculate better when to plant/harvest crops, which grow based on the seasons. Calculating the exact number of days including fraction in a year is a nightmare before you figure out the mechanics of how orbits work, which is mindblowingly complicated to do just looking at the sky, and if you get it wrong your food production WILL slowly get worse. Many larger societies had whole quasi state/religous orders whose whole function was to keep the calendar working. Compare for example the mayan calendar. Or the orthodox, or syrian, or basically any culture's calendar. None make sense.

> GJ 486 b takes less than 1.5 Earth days to orbit its star and is probably tidally locked Are there any discovered planets where a year is confirmed to be a day?

sdflhasjd 3y ago

That surely can't be correct? An orbit of literally 36 hours would mean it would be going much too fast

shric 3y ago
Not when it's 0.01734 AU from its star, and therefore 1.7% of the distance compared to the earth to its star.
- sdflhasjd 3y ago
  I just found that on the NASA site, it really is just a tiny orbit. I got the impression the planet was in a habitable zone from the article.
  - chmod775 3y ago
    The article mentions that its surface temperature is around 430 degrees Celsius. It's that "low" because its star also radiates way less energy than our sun. But still, "habitable zone" means liquid water, which you might not find there given the pressures/temperatures involved. Maybe sufficiently cold spots could exist in the areas facing away from its star. So could you say it's in the habitable zone? Depends on your understanding of the term.
    - svachalek 3y ago
      I think it's fair to say that we as a species have no idea what is a habitable zone. We're extrapolating from a set of 1, and even in looking for liquid water you're better off looking at moons far from our Sun than on Mars which is in our habitable zone.
      - dotnet00 3y ago
        A habitable zone is simply defined as the region which is most likely to be able to sustain the conditions for life in the form that we know of it. Of course we don't know if other chemistries of life are possible, but that doesn't mean we can't define a habitable zone based on what we do know and expand it later if necessary. As for looking at moons far from the star, it's barely a reliable means of confirming liquid water even within our own system, good luck detecting liquid water on an exomoon orbiting a far out exoplanet. Mars is in our habitable zone and has plenty of evidence of having had liquid water flowing on its surface. The evidence of it having had conditions which could sustain some Earth-like life on it has only been increasing, making our current idea of habitable zones pretty promising. The fact that it currently doesn't have any liquid water on the surface has little bearing on that.
      - jamiek88 3y ago
        We can only look for what we know. We have to narrow it down somehow.

shric 3y ago

"The confirmed exoplanet with the shortest orbit is K2-137b, which orbits its host star, K2-137b once every 4 hours, 18 minutes. The planet is 0.89±0.09 times the mass of Earth, and orbits its host star at just 0.0058 times the distance of Earth from the sun."

VikingCoder 3y ago

Well, "Mercury rotates in a way that is unique in the Solar System. It is tidally locked with the Sun in a 3:2 spin–orbit resonance, meaning that relative to the fixed stars, it rotates on its axis exactly three times for every two revolutions it makes around the Sun."

dghughes 3y ago

Maybe some aliens see us and say "Wow that blue planet takes 548 gleeglubs to orbit their star."

sharkweek 3y ago
Yeah there’s a lot of things we’ve normalized that are kinda silly from a zoomed out view. “Okay so we have 12 months. About half are 30 days and the other half are 31 days but then ONE of them is 28 days except every fourth year that month with 28 days has a 29th day”
- m_mueller 3y ago
  https://twitter.com/foone/status/1572260363764400129 https://twitter.com/foone/status/1572260363764400129
  - legutierr 3y ago
    https://twitter.com/Foone/status/1572263752346796033 https://twitter.com/Foone/status/1572263752346796033 In reference to the above tweet, it might surprise you to know that at times in the past (and per Wikipedia, even in some cultures today[0]) March has been considered the first Month, meaning that the new year would start on March 1, the leap day would be the last day of the year, and September, October, November and December would in fact be the seventh, eighth, ninth and tenth months of the year. https://en.wikipedia.org/wiki/March#Origin https://en.wikipedia.org/wiki/March#Origin
  - RugnirViking 3y ago
    to be fair to us the aliens calendar is likely impenetrable as well, especially if they did agriculture. The more I learn about ancient societies the more I learn that calendars were really important and really complicated. It was the hobby of many rich people to stare at the sky and figure out how the stars move based on how the temprature feels and the daylight length. This let them calculate better when to plant/harvest crops, which grow based on the seasons. Calculating the exact number of days including fraction in a year is a nightmare before you figure out the mechanics of how orbits work, which is mindblowingly complicated to do just looking at the sky, and if you get it wrong your food production WILL slowly get worse. Many larger societies had whole quasi state/religous orders whose whole function was to keep the calendar working. Compare for example the mayan calendar. Or the orthodox, or syrian, or basically any culture's calendar. None make sense.