Somehow I missed this news a couple of months back.

For quite a long time, Eris was the most distant object known in the solar system. Perversely, it was discovered very near to its aphelion (ie its greatest distance from the sun). Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

In November of 2018, the team at Mauna Kea Observatory discovered a body they’ve nicknamed Farout, at around 125 AU, plus or minus 29 AU . It has been given the provisional designation 2018 VG18.

It is only about 500 km across so it is pretty remarkable that it was discovered out there. Its orbital parameters are not yet known, and it will take some years of study to nail them down, because its apparent motion is slow … like a fraction of a degree per year. I’m guessing that it will eventually be determined to be a Scattered Disc Object.

dv said:

Somehow I missed this news a couple of months back.

For quite a long time, Eris was the most distant object known in the solar system. Perversely, it was discovered very near to its aphelion (ie its greatest distance from the sun). Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

In November of 2018, the team at Mauna Kea Observatory discovered a body they’ve nicknamed Farout, at around 125 AU, plus or minus 29 AU . It has been given the provisional designation 2018 VG18.

It is only about 500 km across so it is pretty remarkable that it was discovered out there. Its orbital parameters are not yet known, and it will take some years of study to nail them down, because its apparent motion is slow … like a fraction of a degree per year. I’m guessing that it will eventually be determined to be a Scattered Disc Object.

That is far out.

Funnily enough, about a month after that, the asteroid that is closest to the Sun (on average) was discovered. That is 2019 AQ3, discovered on 4 January 2019, with an average distance from the sun of 0.589 AU. It’s only about 1 km wide though.

dv said:

Somehow I missed this news a couple of months back.

For quite a long time, Eris was the most distant object known in the solar system. Perversely, it was discovered very near to its aphelion (ie its greatest distance from the sun). Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

In November of 2018, the team at Mauna Kea Observatory discovered a body they’ve nicknamed Farout, at around 125 AU, plus or minus 29 AU . It has been given the provisional designation 2018 VG18.

It is only about 500 km across so it is pretty remarkable that it was discovered out there. Its orbital parameters are not yet known, and it will take some years of study to nail them down, because its apparent motion is slow … like a fraction of a degree per year. I’m guessing that it will eventually be determined to be a Scattered Disc Object.

Yes. It is classed as a Scattered disk object in the minor planet database.

Somebody on the forum didn’t miss it, but back then the discovery was so new that its orbit was unknown.

I was surprised that Eris held the previous record, but that did make sense because Eris is large enough and has high enough albedo to see at large distances. Although Sedna’s orbit takes it a long way outside Eris’s, Sedna is currently nearer than Eris.

Here’s 2018 VG18 compared to Eris and Sedna.

Prov. Des. q Q H Epoch M Peri. Node Incl. e a
2018 VG18 21.739 169 3.6 20181118 73.8 32.9 247.4 31.7 0.772 95.234
(Eris)2003 UB313 38.019 97.471 -1.1 20190427 205.4 151.7 35.9 44.1 0.439 67.745
(Sedna)2003 VB12 76.164 882 1.5 20190427 358.0 311.5 144.3 11.9 0.841

Sedna goes from 76 to 882 AU
Eris goes from 38 to 97 AU
2018 VG18 goes from 21 to 169 AU. The large value of 3.6 for M means that it’s very large, bigger than all but 5 or so known SDOs, bigger than about 99% of them.

But 2018 VG18 was detected at 125 AU, very much further than any other similar object. Presumably because it was detected by accident by a very powerful infrared telescope with a limited field of view.

dv said:

Funnily enough, about a month after that, the asteroid that is closest to the Sun (on average) was discovered. That is 2019 AQ3, discovered on 4 January 2019, with an average distance from the sun of 0.589 AU. It’s only about 1 km wide though.

I missed that one. Semi-major axis 0.589 AU. It’s one of the Aten asteroids.

Only one asteroid is closer. The Semi-major axis of 2016 XK24 is 0.580 AU. And 2016 XK24 is significantly smaller than 2019 AQ3.

References, sortable lists:
For SDOs, https://www.minorplanetcenter.net/iau/lists/t_centaurs.html
For Atens, https://www.minorplanetcenter.net/iau/lists/t_atens.html

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

furious said:

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

An au unit is the distance from the Earth to the sun

1 astronomical unit, or AU, is the average distance from the Earth to the Sun – about 150 million km. Pluto’s perihelion is 29.7 AU, and its aphelion is 49.3 AU. Pluto’s average distance, or semi-major axis, is 39.5 AU

Eris is about twice Pluto’s distance at its aphelion

• An au unit is the distance from the Earth to the sun

I see that you missed my point…

Tau.Neutrino said:

furious said:

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

An au unit is the distance from the Earth to the sun

1 astronomical unit, or AU, is the average distance from the Earth to the Sun – about 150 million km. Pluto’s perihelion is 29.7 AU, and its aphelion is 49.3 AU. Pluto’s average distance, or semi-major axis, is 39.5 AU

Eris is about twice Pluto’s distance at its aphelion

I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

The Rev Dodgson said:

Tau.Neutrino said:

furious said:

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

An au unit is the distance from the Earth to the sun

1 astronomical unit, or AU, is the average distance from the Earth to the Sun – about 150 million km. Pluto’s perihelion is 29.7 AU, and its aphelion is 49.3 AU. Pluto’s average distance, or semi-major axis, is 39.5 AU

Eris is about twice Pluto’s distance at its aphelion

I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

An AU unit is around 150 million kilometers

Eris is about fourteen billion, four hundred million km away

The perihelion is the point in the orbit of a planet, asteroid or comet that is nearest to the sun. It is the opposite of aphelion, which is the point farthest from the sun.
https://simple.wikipedia.org/wiki/Perihelion

The aphelion is the point in the orbit of an object where it is farthest from the Sun. The point in orbit where an object is nearest to the sun is called the perihelion. The word aphelion derives from the Greek words, apo meaning away, off, apart and Helios.
https://simple.wikipedia.org/wiki/Aphelion

Tau.Neutrino said:

The Rev Dodgson said:

Tau.Neutrino said:

An au unit is the distance from the Earth to the sun

1 astronomical unit, or AU, is the average distance from the Earth to the Sun – about 150 million km. Pluto’s perihelion is 29.7 AU, and its aphelion is 49.3 AU. Pluto’s average distance, or semi-major axis, is 39.5 AU

Eris is about twice Pluto’s distance at its aphelion

I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

An AU unit is around 150 million kilometers

Eris is about fourteen billion, four hundred million km away

The perihelion is the point in the orbit of a planet, asteroid or comet that is nearest to the sun. It is the opposite of aphelion, which is the point farthest from the sun.
https://simple.wikipedia.org/wiki/Perihelion

The aphelion is the point in the orbit of an object where it is farthest from the Sun. The point in orbit where an object is nearest to the sun is called the perihelion. The word aphelion derives from the Greek words, apo meaning away, off, apart and Helios.
https://simple.wikipedia.org/wiki/Aphelion

You are still missing the point, but I see the words in question were actually posted by dv, so I’ll let you off.

• An AU unit is around 150 million kilometers

I think you still miss the point…

• I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

This is, basically, what I was getting at…

furious said:

• An AU unit is around 150 million kilometers

I think you still miss the point…

• I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

This is, basically, what I was getting at…

Neither of T.N’s responses answered the question, but in my opinion the first was the closest, but the second was the nearest.

The Rev Dodgson said:

Tau.Neutrino said:

The Rev Dodgson said:

I’m pretty sure furious was more concerned about the large difference between “closest” and “nearest” distances, rather than all the technical stuff.

An AU unit is around 150 million kilometers

Eris is about fourteen billion, four hundred million km away

The perihelion is the point in the orbit of a planet, asteroid or comet that is nearest to the sun. It is the opposite of aphelion, which is the point farthest from the sun.
https://simple.wikipedia.org/wiki/Perihelion

The aphelion is the point in the orbit of an object where it is farthest from the Sun. The point in orbit where an object is nearest to the sun is called the perihelion. The word aphelion derives from the Greek words, apo meaning away, off, apart and Helios.
https://simple.wikipedia.org/wiki/Aphelion

You are still missing the point, but I see the words in question were actually posted by dv, so I’ll let you off.

Reads dv post.

Ah.

Ok.

furious said:

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

Simple braino. I meant at its closest it is 38 AU off, at its furthest, 98 AU.

• Simple braino. I meant at its closest it is 38 AU off, at its furthest, 98 AU.

Thank you for the clarification…

dv said:

furious said:

• Eris is currently ~96 AU from the sun: at its closest it is 38 AU off, at its nearest, 98 AU.

Is it too early for me to make sense of it or does that not make sense?

Simple braino. I meant at its closest it is 38 AU off, at its furthest, 98 AU.

You can see with them being so far out even at their closest how they can be missed add in small in size as well