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Taking your argument to the extreme, if there was a planet that somehow brushed by extremely closely to Earth every thousand years, that planet would be the clo

Taking your argument to the extreme, if there was a planet that somehow brushed by extremely closely to Earth every thousand years, that planet would be the closest neighbor? I would argue not. I think the average is more meaningful.

Ensorceled 3y ago
To return to the analogy, if once a year my brother-in-law parks their RV in my drive, nobody would be confused about who my closest neighbour is. I would argue that MOST people would disagree with you and would say Venus is our closest neighbour but once every 1000 years wobbly Erebus returns from the dark to scare the hell out of us.
xwdv 3y ago
If I have a house and you have a house next to me yet neither of us are ever home, we are still neighbors no matter where in the world we are. Similarly, the entire area earth and Venus clear with their orbits is the planet’s “home”, therefore, we only have two neighbors, Mars and Venus, and Venus is probably the closest.
- hgsgm 3y ago
  It doesn't take me a year to walk a lap around my home. Maybe you could say that the orbit is territory that a planet roams, like a nomadic person or migratory bird.
thx-2718 3y ago
Both have independently useful meaning. The average closest planet would be useful for regularly traveling between two places. The closest at any one time is useful for planning intermittent trips. Let's say we had to pick 2 equal planets we would travel to. Adding the stipulation that planet A is closer on average to HOME than planet B; Planet B has the shortest distance to HOME. If travel is cheap then planet A is more useful to travel to since you can afford to do it regularly. If travel is expensive then planet B is more useful since you can't afford travel all the time and rather need to make sure each trip is worth. If you live in a city it's more reasonable to go to the grocery every week. If you live in a rural area it's more reasonable to wait for the Shwan truck (type of grocery delivery) once a month.
tectec 3y ago
What kind of orbit would that be? In order for it to be that close so rarely it must spend most of its time even further from earth.
- adgjlsfhk1 3y ago
  Haley's comet is a good example. it gets really close every 87 years
  - playingalong 3y ago
    75
    - Someone 3y ago
      74-79, with an average of 76 https://solarsystem.nasa.gov/asteroids-comets-and-meteors/comets/1p-halley/in-depth/ https://solarsystem.nasa.gov/asteroids-comets-and-meteors/co...: “Halley's orbit period is, on average, 76 Earth years. This corresponds to an orbital circumference around the Sun of about 7.6 billion miles (12.2 billion kilometers). The period varies from appearance to appearance because of the gravitational effects of the planets. Measured from one perihelion passage to the next, Halley's period has been as short as 74.42 years (1835-1910) and as long as 79.25 years (451-530).”
BurningFrog 3y ago
Halley's Comet might fit that description.
- Someone 3y ago
  Halley’s Comet doesn’t necessarily get close to earth. https://solarsystem.nasa.gov/asteroids-comets-and-meteors/comets/1p-halley/in-depth/ https://solarsystem.nasa.gov/asteroids-comets-and-meteors/co...: “During its 1986 appearance, Halley's nearest approach to Earth occurred on the outbound leg of the trip at a distance of 0.42 AU (39 million miles or 63 million kilometers)“ (The orbit of Venus is at about 0.7 AU, so 0.3 AU from that of earth, so that was further away than Venus can be to earth (https://theskylive.com/how-far-is-venus https://theskylive.com/how-far-is-venus)) It can get a lot closer, though. From that nasa.gov page: “The comet's closest approach to Earth occurred in 837, at a distance of 0.033 AU (3.07 million miles or 4.94 million kilometers)” That’s about 13 times the earth-moon distance.
  - hgsgm 3y ago
    I don't understand your language. 1986 Halley's comet was closer to Earth then Venus is close to Earth whenever Venus is on the other side of the Sun from Earth
    - aidenn0 3y ago
      I had to read their sentence like 5 times to get it as well. .42AU is a larger distance than the closest that Earth and Venus ever get to each other (i.e. closest than as close as it is possible for Venus to be, with the word "can" being used in this meaning)
- digging 3y ago
  By what metric is Halley's Comet a planet though?
  - BurningFrog 3y ago
    It's not. Still fun to think about odd cases.
dahfizz 3y ago
The term "neighbor" here is confusing. Venus has the planetary orbits right next to Earth's. That makes them "neighbors" - they live right next door from each other. Mercury is the closest planet on average, but calling it the closest neighbor is just confusing.
- forbiddenvoid 3y ago
  This is exactly my thinking. In this context, I think the paper depends on an implied ambiguity of the word 'neighbor' and how it's used in the context of orbiting bodies. When I think of 'neighbors' in the context of the solar system, I am generally thinking of neighboring orbits. It would be hard to argue that Venus's orbit is not the closest orbit to Earth's. Or at least it would seem silly to do so. Maybe I'm being overly pedantic here, but my view is that orbits have neighbors, and planets have orbits, but planets don't necessarily have neighbors. Something in the word 'neighbor' implies persistence to me, so I don't really consider average-closest planet to be a neighbor when exactly which planet is closest to any other changes constantly.
- pleb_nz 3y ago
  Agreed, that was my initial thought and I was going to comment the exact same thing as you and then I decided to check up the meaning if neighbour. Turned out I've misunderstood the meaning my whole life and it doesn't just mean next to, it means nearby. https://www.merriam-webster.com/dictionary/neighbor https://www.merriam-webster.com/dictionary/neighbor So I guess that means venus's orbit is our closest neighbour, but not the planet itself most of the time....
  - kwhitefoot 3y ago
    > doesn't just mean next to, it means nearby. That's why we say "next door neighbour"
    - pleb_nz 3y ago
      That's right

Ensorceled 3y ago

To return to the analogy, if once a year my brother-in-law parks their RV in my drive, nobody would be confused about who my closest neighbour is. I would argue that MOST people would disagree with you and would say Venus is our closest neighbour but once every 1000 years wobbly Erebus returns from the dark to scare the hell out of us.

xwdv 3y ago

If I have a house and you have a house next to me yet neither of us are ever home, we are still neighbors no matter where in the world we are. Similarly, the entire area earth and Venus clear with their orbits is the planet’s “home”, therefore, we only have two neighbors, Mars and Venus, and Venus is probably the closest.

hgsgm 3y ago
It doesn't take me a year to walk a lap around my home. Maybe you could say that the orbit is territory that a planet roams, like a nomadic person or migratory bird.

thx-2718 3y ago

Both have independently useful meaning. The average closest planet would be useful for regularly traveling between two places. The closest at any one time is useful for planning intermittent trips. Let's say we had to pick 2 equal planets we would travel to. Adding the stipulation that planet A is closer on average to HOME than planet B; Planet B has the shortest distance to HOME. If travel is cheap then planet A is more useful to travel to since you can afford to do it regularly. If travel is expensive then planet B is more useful since you can't afford travel all the time and rather need to make sure each trip is worth. If you live in a city it's more reasonable to go to the grocery every week. If you live in a rural area it's more reasonable to wait for the Shwan truck (type of grocery delivery) once a month.

tectec 3y ago

What kind of orbit would that be? In order for it to be that close so rarely it must spend most of its time even further from earth.

adgjlsfhk1 3y ago
Haley's comet is a good example. it gets really close every 87 years
- playingalong 3y ago
  75
  - Someone 3y ago
    74-79, with an average of 76 https://solarsystem.nasa.gov/asteroids-comets-and-meteors/comets/1p-halley/in-depth/ https://solarsystem.nasa.gov/asteroids-comets-and-meteors/co...: “Halley's orbit period is, on average, 76 Earth years. This corresponds to an orbital circumference around the Sun of about 7.6 billion miles (12.2 billion kilometers). The period varies from appearance to appearance because of the gravitational effects of the planets. Measured from one perihelion passage to the next, Halley's period has been as short as 74.42 years (1835-1910) and as long as 79.25 years (451-530).”

BurningFrog 3y ago

Halley's Comet might fit that description.

Someone 3y ago
Halley’s Comet doesn’t necessarily get close to earth. https://solarsystem.nasa.gov/asteroids-comets-and-meteors/comets/1p-halley/in-depth/ https://solarsystem.nasa.gov/asteroids-comets-and-meteors/co...: “During its 1986 appearance, Halley's nearest approach to Earth occurred on the outbound leg of the trip at a distance of 0.42 AU (39 million miles or 63 million kilometers)“ (The orbit of Venus is at about 0.7 AU, so 0.3 AU from that of earth, so that was further away than Venus can be to earth (https://theskylive.com/how-far-is-venus https://theskylive.com/how-far-is-venus)) It can get a lot closer, though. From that nasa.gov page: “The comet's closest approach to Earth occurred in 837, at a distance of 0.033 AU (3.07 million miles or 4.94 million kilometers)” That’s about 13 times the earth-moon distance.
- hgsgm 3y ago
  I don't understand your language. 1986 Halley's comet was closer to Earth then Venus is close to Earth whenever Venus is on the other side of the Sun from Earth
  - aidenn0 3y ago
    I had to read their sentence like 5 times to get it as well. .42AU is a larger distance than the closest that Earth and Venus ever get to each other (i.e. closest than as close as it is possible for Venus to be, with the word "can" being used in this meaning)
digging 3y ago
By what metric is Halley's Comet a planet though?
- BurningFrog 3y ago
  It's not. Still fun to think about odd cases.

dahfizz 3y ago

The term "neighbor" here is confusing. Venus has the planetary orbits right next to Earth's. That makes them "neighbors" - they live right next door from each other. Mercury is the closest planet on average, but calling it the closest neighbor is just confusing.

forbiddenvoid 3y ago
This is exactly my thinking. In this context, I think the paper depends on an implied ambiguity of the word 'neighbor' and how it's used in the context of orbiting bodies. When I think of 'neighbors' in the context of the solar system, I am generally thinking of neighboring orbits. It would be hard to argue that Venus's orbit is not the closest orbit to Earth's. Or at least it would seem silly to do so. Maybe I'm being overly pedantic here, but my view is that orbits have neighbors, and planets have orbits, but planets don't necessarily have neighbors. Something in the word 'neighbor' implies persistence to me, so I don't really consider average-closest planet to be a neighbor when exactly which planet is closest to any other changes constantly.
pleb_nz 3y ago
Agreed, that was my initial thought and I was going to comment the exact same thing as you and then I decided to check up the meaning if neighbour. Turned out I've misunderstood the meaning my whole life and it doesn't just mean next to, it means nearby. https://www.merriam-webster.com/dictionary/neighbor https://www.merriam-webster.com/dictionary/neighbor So I guess that means venus's orbit is our closest neighbour, but not the planet itself most of the time....
- kwhitefoot 3y ago
  > doesn't just mean next to, it means nearby. That's why we say "next door neighbour"
  - pleb_nz 3y ago
    That's right