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    Re: An Embarrassing Conundrum
    From: Frank Reed
    Date: 2018 Oct 6, 15:16 -0700

    If you want to add to your Solar System model, then throw in this recently discovered little world nicknamed "The Goblin" and you'll really get some exercise walking it out:

    It's about 200 miles across, so no "mere" comet, but approximately 25% of the size of dwarf planet Pluto -- so yes, "small". Its perihelion (closest approach to the Sun) is about 65 AU or more than twice Neptune's distance from the Sun (remember: 1AU is the average Earth-Sun distance, roughly 93 million miles). Its aphelion (farthest from Sun) is about 2300 AU. To put that in perspective, this is about 1% of the distance to Proxima Centauri, the nearest star after the Sun. It's way, waaay out there.

    Another way to think about it: the aphelion distance is about 75 times further away from the Sun than Neptune. Imagine if we could illuminate the orbits of the great planets, Jupiter, Saturn, Uranus, and Neptune, and turn them into glowing rings centered on the Sun. As seen from the aphelion of this Goblin world, the glowing orbit of Neptune would be a ring about 90 minutes of arc across, about three times the size of the Moon in our sky while the orbit of Jupiter would be only 15 minutes across. A light or radio signal from the Earth would take over 13 days to get there... This is a long way from home!

    Frank Reed

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