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For reference 1 AU (Astronomical Unit) is about 150 million km. Saturn ranges from being about 7 to 11 AU away from Earth. Voyager 1 is 152 AU away. This object

For reference 1 AU (Astronomical Unit) is about 150 million km. Saturn ranges from being about 7 to 11 AU away from Earth. Voyager 1 is 152 AU away. This object is excitingly close and will be fun to study.

lopuhin 5y ago
I don't think Saturn comes that close, should be 8 AU at best, given that perihelion is at 9 AU.
- mcorning 5y ago
  https://www.universetoday.com/15311/how-far-is-saturn-from-earth/ https://www.universetoday.com/15311/how-far-is-saturn-from-e... > For the sake of simplicity, Saturn is 1.2 billion km, roughly 7 AU, from the Earth when the two are at their closest approach to one another. They are 1.67 billion km, around 11 AU, from each other when they are at their most distant. Saturn and Earth are the closest to each other when they are on the same side of the Sun and at similar points in their orbits. The are the most distant when on opposite sides of the Sun.
  - Denvercoder9 5y ago
    > Saturn is 1.2 billion km, roughly 7 AU That's a unit conversion error. 1.2 billion / 150 million is 8, not 7.
    - jakeinspace 5y ago
      I believe the 1.2B km was referencing mean orbital distance from the sun, which would be 8 AU, and therefore 7 AU from earth on closest approach.
      - Denvercoder9 5y ago
        No. Saturn's perihelion (closest distance to the Sun) is 1.35B km (9.0 AU), its aphelion (furthest distance) is 1.51B km (10.1 AU), and its mean distance is 1.43B km (9.6 AU). Thus, at closest approach Saturn is 8 AU from Earth (since Earth orbits at an almost-constant 1 AU from the Sun).
        jakeinspace 5y ago
        After checking Wikipedia, you are correct.
- deleted 5y ago
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chronogram 5y ago
How come our culture didn’t base astronomical units around base 10 of our current units?
- detaro 5y ago
  It's an old unit, so there wasn't a global standard yet, and it's exact value wasn't known for a long time, but it was still useful for ratios. E.g. if you observe the orbit time of another planet, you can tell its distance from the sun relative to the distance of Earth to Sun (1 astronomical unit) relatively accurately, even if you can't measure what it is in meters very well.
  - Taek 5y ago
    For my purposes 10 AU has a lot more meaning than 1 billion km. 1 AU has a lot more context
    - dylan604 5y ago
      It's one of those things that I still tilt my head slightly at when thinking about how the human brain struggles with really large numbers. Its just an odd thing.
      - II2II 5y ago
        In a case like this, I suspect it has more to do with visualizing the solar system rather than how large something is. When we speak in AU, we can create a mental model with the Sun, Earth, and other object since everything is normalized to the size of Earth's orbit. When we speak in kilometers, a bit of arithmetic has to be done before creating the model. Regardless of the units though, we aren't directly visualizing the distances since they will be outside the scope of human experience until we actively start traveling the solar system. Edit: for clarity.
  - Pelam 5y ago
    I have more trouble with parsec. I have a rough idea of how big our galaxy is in light years and some idea about nearby stars. Age of the universe helps anchor things in billions of light years. Then suddenly something is measured in parsecs. Probably a similar thing for the experts.
grawprog 5y ago
So pretty much between Saturn and Uranus.... Even as an adult that still always makes me chuckle. I can't help it.
- edgyquant 5y ago
  It’s pronounced your-uh-ness by pretty much everyone (or your-ah-noose if your going by the greek god and not the Latin copy/paste.)
  - SonnyTark 5y ago
    in Arabic (and a bunch of other languages I'm sure) it's pronounced: Oranos, I don't understand why the U in Uranus is not pronounced like the U in Ultra.
    - grishka 5y ago
      In Russian it's simply "Ooran".
    - project2501a 5y ago
      Cuz in Greek (my mother language), we pronounce "Ουρανός" as "Ouranos".
      - Koshkin 5y ago
        > ”Our Good to know, I guess...
    - jazzyjackson 5y ago
      A shot in the dark but I think there’s a lot of “ult”s in English but not many “ura”s Uranium and Urine
  - op00to 5y ago
    Nope. I say your-anus.
Fordec 5y ago
Is it possible to get a probe out that far in time to make a good intercept? I imagine with this (relatively) short notice this is cutting it a bit close to orchestrate a proper orbital insertion by a designed, manufactured and tested program?
- megablast 5y ago
  > Voyager 1 is 152 AU away Hmmm, can we make 11au?? I think so.
  - gravypod 5y ago
    This is not a ridiculous question and does not deserve a mean answer. Voyager 1 has been flying for over 43 years [0]. In that time it went over 150 AU. This averages about 3.5 AU/year. It took, from start of project to launch, about 5 years (1972 - 1977 [1]). If this body is going to be 11 AU away in 10 years away we'd need to move at an average 2.2 AU/year and hit the right launch windows. I think that it falls into the "yes, it's possible" but not into the "of course it's possible, how could you even ask" category. [0] - https://en.wikipedia.org/wiki/Voyager_1 https://en.wikipedia.org/wiki/Voyager_1 [1] - https://voyager.jpl.nasa.gov/mission/timeline/#event-voyager-1-launches https://voyager.jpl.nasa.gov/mission/timeline/#event-voyager...
  - op00to 5y ago
    The question isn’t can we make 11au. That’s facile. Can we make 11au at the exact velocity, location, etc etc etc?
- sojuz151 5y ago
  Some context: It took Cassini-Huygens 7 years to reach saturn with two venus and one jupiter flyby. It took New Horizons 9 years to reach pluton with jupiter flyby. With Inclination of 95.467° and Argument of perihelion of 326.285° flyby could happen near to Ecliptic but for getting to orbit one would need a nice gravity assist from jupiter.
- jerf 5y ago
  Maybe this will motivate us to finally design and launch a probe that launches in two or more launches, all but one of which are fuel. All our normal expectations for probe arrival times and such are based on one-shot launches, straight out of Earth's gravity well into escape velocity in one shot. It's not like launching with fuel suddenly makes it a two-day trip or anything, but it can do quite a bit of shortening and allow for quite a lot more maneuvering. This is one of the next touchstones in space progress I've been looking for. A lot of previously impractical things become practical if we can routinely do multilaunches.
c7DJTLrn 5y ago
That's terrifying, no? A whole planet (yes a dwarf one, but still a PLANET) is just rogue and will wander through the orbit of Sol as it pleases.
- TameAntelope 5y ago
  > I would estimate at an albedo of 0.01-0.08 a diameter of 130-370 kilometers (nominally 160) which puts it on a similar scale, if not larger than, Sarabat's huge comet C/1729 P1, and almost undoubtedly the largest Oort Cloud object ever discovered- almost in dwarf planet territory! So a bit less dramatic but still really cool.
  - mdorazio 5y ago
    For reference, a nominal 160km diameter would put it around the same size as the 40th largest asteroid known. Huge for an object coming from the oort cloud, but not really huge in comparison to other rocky bodies in the solar system.
- Pxtl 5y ago
  It's not a rogue planet, that implies Interstellar. This is an object with a very long orbit that takes it out to he Oort cloud but still - a permanent resident of the solar system. It's basically just an exceptionally large comet. It's not Melancholia.
  - drcode 5y ago
    Love that movie
    - Pxtl 5y ago
      It needs a sequel.
    - infradig 5y ago
      It made me so nauseous I had to stagger out of the cinema.
eb0la 5y ago
Stupid question: The Hubble photos we have from Saturn are a 7-8 AU range, right? Even more stupid question: Pointing the Hubble there is worth the effort? how many pixels wide would be a 200km diameter object at 11 AU?
- autosharp 5y ago
  > how many pixels wide would be a 200km diameter object at 11 AU? Depends on zoom and resolution of the camera.
- de6u99er 5y ago
  Unfortunately Hubble has issues at the moment. There's a couple of HN submissions about that. --> https://hn.algolia.com/?dateRange=all&page=0&prefix=false&query=hubble&sort=byDate&type=story https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...

lopuhin 5y ago

I don't think Saturn comes that close, should be 8 AU at best, given that perihelion is at 9 AU.

mcorning 5y ago
https://www.universetoday.com/15311/how-far-is-saturn-from-earth/ https://www.universetoday.com/15311/how-far-is-saturn-from-e... > For the sake of simplicity, Saturn is 1.2 billion km, roughly 7 AU, from the Earth when the two are at their closest approach to one another. They are 1.67 billion km, around 11 AU, from each other when they are at their most distant. Saturn and Earth are the closest to each other when they are on the same side of the Sun and at similar points in their orbits. The are the most distant when on opposite sides of the Sun.
- Denvercoder9 5y ago
  > Saturn is 1.2 billion km, roughly 7 AU That's a unit conversion error. 1.2 billion / 150 million is 8, not 7.
  - jakeinspace 5y ago
    I believe the 1.2B km was referencing mean orbital distance from the sun, which would be 8 AU, and therefore 7 AU from earth on closest approach.
    - Denvercoder9 5y ago
      No. Saturn's perihelion (closest distance to the Sun) is 1.35B km (9.0 AU), its aphelion (furthest distance) is 1.51B km (10.1 AU), and its mean distance is 1.43B km (9.6 AU). Thus, at closest approach Saturn is 8 AU from Earth (since Earth orbits at an almost-constant 1 AU from the Sun).
      - jakeinspace 5y ago
        After checking Wikipedia, you are correct.
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chronogram 5y ago

How come our culture didn’t base astronomical units around base 10 of our current units?

detaro 5y ago
It's an old unit, so there wasn't a global standard yet, and it's exact value wasn't known for a long time, but it was still useful for ratios. E.g. if you observe the orbit time of another planet, you can tell its distance from the sun relative to the distance of Earth to Sun (1 astronomical unit) relatively accurately, even if you can't measure what it is in meters very well.
- Taek 5y ago
  For my purposes 10 AU has a lot more meaning than 1 billion km. 1 AU has a lot more context
  - dylan604 5y ago
    It's one of those things that I still tilt my head slightly at when thinking about how the human brain struggles with really large numbers. Its just an odd thing.
    - II2II 5y ago
      In a case like this, I suspect it has more to do with visualizing the solar system rather than how large something is. When we speak in AU, we can create a mental model with the Sun, Earth, and other object since everything is normalized to the size of Earth's orbit. When we speak in kilometers, a bit of arithmetic has to be done before creating the model. Regardless of the units though, we aren't directly visualizing the distances since they will be outside the scope of human experience until we actively start traveling the solar system. Edit: for clarity.
- Pelam 5y ago
  I have more trouble with parsec. I have a rough idea of how big our galaxy is in light years and some idea about nearby stars. Age of the universe helps anchor things in billions of light years. Then suddenly something is measured in parsecs. Probably a similar thing for the experts.

grawprog 5y ago

So pretty much between Saturn and Uranus.... Even as an adult that still always makes me chuckle. I can't help it.

edgyquant 5y ago
It’s pronounced your-uh-ness by pretty much everyone (or your-ah-noose if your going by the greek god and not the Latin copy/paste.)
- SonnyTark 5y ago
  in Arabic (and a bunch of other languages I'm sure) it's pronounced: Oranos, I don't understand why the U in Uranus is not pronounced like the U in Ultra.
  - grishka 5y ago
    In Russian it's simply "Ooran".
  - project2501a 5y ago
    Cuz in Greek (my mother language), we pronounce "Ουρανός" as "Ouranos".
    - Koshkin 5y ago
      > ”Our Good to know, I guess...
  - jazzyjackson 5y ago
    A shot in the dark but I think there’s a lot of “ult”s in English but not many “ura”s Uranium and Urine
- op00to 5y ago
  Nope. I say your-anus.

Fordec 5y ago

Is it possible to get a probe out that far in time to make a good intercept? I imagine with this (relatively) short notice this is cutting it a bit close to orchestrate a proper orbital insertion by a designed, manufactured and tested program?

megablast 5y ago
> Voyager 1 is 152 AU away Hmmm, can we make 11au?? I think so.
- gravypod 5y ago
  This is not a ridiculous question and does not deserve a mean answer. Voyager 1 has been flying for over 43 years [0]. In that time it went over 150 AU. This averages about 3.5 AU/year. It took, from start of project to launch, about 5 years (1972 - 1977 [1]). If this body is going to be 11 AU away in 10 years away we'd need to move at an average 2.2 AU/year and hit the right launch windows. I think that it falls into the "yes, it's possible" but not into the "of course it's possible, how could you even ask" category. [0] - https://en.wikipedia.org/wiki/Voyager_1 https://en.wikipedia.org/wiki/Voyager_1 [1] - https://voyager.jpl.nasa.gov/mission/timeline/#event-voyager-1-launches https://voyager.jpl.nasa.gov/mission/timeline/#event-voyager...
- op00to 5y ago
  The question isn’t can we make 11au. That’s facile. Can we make 11au at the exact velocity, location, etc etc etc?
sojuz151 5y ago
Some context: It took Cassini-Huygens 7 years to reach saturn with two venus and one jupiter flyby. It took New Horizons 9 years to reach pluton with jupiter flyby. With Inclination of 95.467° and Argument of perihelion of 326.285° flyby could happen near to Ecliptic but for getting to orbit one would need a nice gravity assist from jupiter.
jerf 5y ago
Maybe this will motivate us to finally design and launch a probe that launches in two or more launches, all but one of which are fuel. All our normal expectations for probe arrival times and such are based on one-shot launches, straight out of Earth's gravity well into escape velocity in one shot. It's not like launching with fuel suddenly makes it a two-day trip or anything, but it can do quite a bit of shortening and allow for quite a lot more maneuvering. This is one of the next touchstones in space progress I've been looking for. A lot of previously impractical things become practical if we can routinely do multilaunches.

c7DJTLrn 5y ago

That's terrifying, no? A whole planet (yes a dwarf one, but still a PLANET) is just rogue and will wander through the orbit of Sol as it pleases.

TameAntelope 5y ago
> I would estimate at an albedo of 0.01-0.08 a diameter of 130-370 kilometers (nominally 160) which puts it on a similar scale, if not larger than, Sarabat's huge comet C/1729 P1, and almost undoubtedly the largest Oort Cloud object ever discovered- almost in dwarf planet territory! So a bit less dramatic but still really cool.
- mdorazio 5y ago
  For reference, a nominal 160km diameter would put it around the same size as the 40th largest asteroid known. Huge for an object coming from the oort cloud, but not really huge in comparison to other rocky bodies in the solar system.
Pxtl 5y ago
It's not a rogue planet, that implies Interstellar. This is an object with a very long orbit that takes it out to he Oort cloud but still - a permanent resident of the solar system. It's basically just an exceptionally large comet. It's not Melancholia.
- drcode 5y ago
  Love that movie
  - Pxtl 5y ago
    It needs a sequel.
  - infradig 5y ago
    It made me so nauseous I had to stagger out of the cinema.

eb0la 5y ago

Stupid question: The Hubble photos we have from Saturn are a 7-8 AU range, right? Even more stupid question: Pointing the Hubble there is worth the effort? how many pixels wide would be a 200km diameter object at 11 AU?

autosharp 5y ago
> how many pixels wide would be a 200km diameter object at 11 AU? Depends on zoom and resolution of the camera.
de6u99er 5y ago
Unfortunately Hubble has issues at the moment. There's a couple of HN submissions about that. --> https://hn.algolia.com/?dateRange=all&page=0&prefix=false&query=hubble&sort=byDate&type=story https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...