Hidden planets/moons around Earth

[Crescent Pulsar S]

Some may remember the old topic, but I wanted to re-establish what I remember and add a new criteria. For the things that I may not remember, which might have been mentioned before, someone will have to refresh my memory.

What I remember: Juraihelm (Magical Project S), Siren (Girls Bravo), and Gaea (Vision of Escaflowne).

New criteria: any planet/moon that could conceivably be placed or hidden in orbit around the Earth, even if one or both of those conditions hadn't been a part of the canon from which they belong. For instance, unless it's otherwise stated somewhere in canon, the "universe of the four gods," from Fushigi Yuugi, could be a hidden world orbiting Earth.

[PCHeintz72]

Well... I assume you mean only fictional, not true astrological ones like in the oort cloud.


In any case, for a fanfiction based one there is also Nemesis, which was in the Ranma Multi crossover called 'On A Clear Say You Can See Forever'.

For one from Godzilla,there was the one Toho movie that had the planet exactly opposite the sun from Earth, in the same orbit, thus invisible to us. Cannot however remember its name off the top of my head. It basically was a fictional portrayal of the abandoned counter earth theory....

Hardly the only such example.

The Sailor Moon Musicals Sailor Moon musicals had a planet called Vulcan along with its moon, Astarte is said to be on the other side of the sun.

Both Space Battleship Yamato and Space 1999 had additional Planets in the solar system not readily visible from Earth.

Didn't the the Alien in Duck Dodgers come from a hidden plant called 'Planet X'... I know a Bugs Bunny Short had bugs accidentally sent there.

A quick on-line search had a invisible 10th planet in the series Exo-sqad, which I never watched.

EDIT: A couple more occur to me.

Buck Rogers had a planet called Pandora that was Earths equivelent in its universe, accessible only y a special nav program and going into a singularity similar to a black hole.

A runner up might be in Dragonaut the series has a planetoid called Thanatos that destroyed Pluto and took up its position.

And then there is Howard the Duck...

[TerraEpon]

Don't forget about Gor.


Oh wait, DO. Please.

[Ellen Kuhfeld]

There was a moon made of gold that showed up in Uncle Scrooge. It was a hitherto-undetected moon of Earth that came out and caused an eclipse one day (predicted by a wonderful watch Scrooge had). To do a quick quote from a comics site:

The rush is on to claim the Earth's hitherto undetected second (solid gold) moon. Uncle Scrooge, Donald and the boys arrive first -- only to find a marooned Venusian has beaten them by 800 years. So jaded has the alien become, however, `impoverished with only atoms of gold', that he will trade his 24 karat moon for a handful of dirt. Gobsmacked, Uncle Scrooge hands over the dirt -- fortuitously brought by Donald to assuage his homesickness -- and then watches in awe as the alien uses it to seed a new planet. `I now nave a world of my own,' the green man yells delightedly, waving adieu from a swelling orb covered in seas and forests, `complete with food, and drink, and life!' Rocked, Uncle Scrooge knocks the crown off the golden statue he has made of himself. `Greatest deal in history', he sighs. `solid gold moon for a handful of dirt, and darned if he didn't get the better of the deal.'

If we add in some astronomy, the gold moon was probably hiding at the L2 Lagrange point, behind Earth's better-known moon. (The various counter-Earths would hide at the L3 point behind the sun.) But since these points are unstable, sooner or later the Gold Moon would peek out to be seen -- and who but Scrooge McDuck would be the first to see it?

[Maximara]

The problem with hidden moons and planets is any that were big enough to natually have an atmosphere able to support life as we know it would have been detected even with the tools and models available in the 19th century.

In fact, due to Mercury's behavior Newtonian physics indicated a planet existed between it and the Sun. Dubbed Vulcan based on what Mercury's orbit was doing and possible sightings in 1859 it was thought to be 0.17 AU from the sun with an orbit of 26 days, diameter of 1,100 miles, density of 6.5, gravity of 0.16 and tide locked with a sun side temperature of 1220 F, 950 F twilight side, and near 3 K on night side.

The only way to salvage such hidden moon/planet is to have it be high tech and beyond the orbit of Pluto or in Earth's orbit but not in our plane of existence (Phantom's Girl's Bgztl is one such example)

[Ellen Kuhfeld]

The least improbable habitable planet (of the unseen variety, in our solar system) would be counter-Earth. On the far side of the Sun, we would not see it. That is definitely ruled out these days -- we've looked. It should have been detected, in the early days of decent orbital mathematics, back when we were calculating the orbits of the unseen Uranus and Vulcan. The gravity of counter-Earth would affect the orbital speed of Earth, so the two would be orbiting just a hair faster than they should. And like Vulcan, that would tell us something was wrong with either the mechanics or the math.

But counter-Earth would be sitting in the Lagrange L3 point relative to Earth, and that's unstable. Sooner or later -- certainly during the age of our Solar system -- it would have moved to where we could see it, and it could see us. At that point, either we go all Ringworld Engineers on the situation, or mistrust the calculations.

There's another science-fiction solution as well, presented in David Weber's Mutineers' Moon: It's there, we can see it just fine -- it's simply a spacecraft the size of a moon or planet, disguised as one. Lots of living space on the inside, even if the surface looks barren.

[Spokavriel]

In one of the last 3 shuttle missions to the ISS a satellite was launched to go Z positive of the solar system to get data on the planets in orbit of the sun to finally give proof to the people who don't accept the math that discounts the possibility of an alter earth.

[Spica75]

Well, while reading i just did happen to think of a fictional one so far not mentioned.
The "Hime Star" from My Hime. More of an "object" than a planet though.

In one of the last 3 shuttle missions to the ISS a satellite was launched to go Z positive of the solar system to get data on the planets in orbit of the sun to finally give proof to the people who don't accept the math that discounts the possibility of an alter earth.

Not just because of that, but yeah...

OTOH, math have shown to be wrong before(usually because there´s a variable you don´t know about), so adding empirical evidence for confirmation is never a bad thing.

There's another science-fiction solution as well, presented in David Weber's Mutineers' Moon: It's there, we can see it just fine -- it's simply a spacecraft the size of a moon or planet, disguised as one. Lots of living space on the inside, even if the surface looks barren.

Oh yes, the Dahak/fifth empire series. Excellent books. "Empire from the ashes." has all 3 books in one. Recommended along with his Harrington series.

[Knight of L-sama]

The least improbable habitable planet (of the unseen variety, in our solar system) would be counter-Earth. On the far side of the Sun, we would not see it. That is definitely ruled out these days -- we've looked. It should have been detected, in the early days of decent orbital mathematics, back when we were calculating the orbits of the unseen Uranus and Vulcan. The gravity of counter-Earth would affect the orbital speed of Earth, so the two would be orbiting just a hair faster than they should. And like Vulcan, that would tell us something was wrong with either the mechanics or the math.

But counter-Earth would be sitting in the Lagrange L3 point relative to Earth, and that's unstable. Sooner or later -- certainly during the age of our Solar system -- it would have moved to where we could see it, and it could see us. At that point, either we go all Ringworld Engineers on the situation, or mistrust the calculations.

Also, oft forgotten in these discussions it seems is that there is a rather specific mass ratio needed for a Lagrange point to be stable. Specifically the second mass (Earth in this case) must be 24.5 times larger than the third mass. As such any hypothetical body in a Earth-Sun L3 orbit is going to be tiny by planetary standards.

[Dumbledork]

There's 'Fenarinarsa' (フェナリナーサ) from 'Magical Princess Minky Momo'

http://en.wikipedia.org/wiki/Magical_Pr ... Minky_Momo

But there are also other dimensions that could be planets for all we know. At least they are connected to the Earth and might qualify.

For example the Magical Worlds from Magical Doremi, Sugar Sugar Rune, and all the other old magical girl shows.

These might qualify since we don't know where they are and can be reached from Earth.

Alfea (Winx Club)

Kandrakar (W.I.T.C.H.)

[PCHeintz72]

There's 'Fenarinarsa' (フェナリナーサ) from 'Magical Princess Minky Momo'

http://en.wikipedia.org/wiki/Magical_Pr ... Minky_Momo

But there are also other dimensions that could be planets for all we know. At least they are connected to the Earth and might qualify.

For example the Magical Worlds from Magical Doremi, Sugar Sugar Rune, and all the other old magical girl shows.

These might qualify since we don't know where they are and can be reached from Earth.

Alfea (Winx Club)

Kandrakar (W.I.T.C.H.)

If you are going that route, there is also El Hazard... we never were truly given a good explanation whether it was another dimension on top of our solar system, or another system within our dimension.

[Ellen Kuhfeld]

Also, oft forgotten in these discussions it seems is that there is a rather specific mass ratio needed for a Lagrange point to be stable. Specifically the second mass (Earth in this case) must be 24.5 times larger than the third mass. As such any hypothetical body in a Earth-Sun L3 orbit is going to be tiny by planetary standards.

There are now sixteen solutions to the three-body problem. The set of Lagrange points together are only one of them. Research proceeds upon the stability of the other fifteen, some of which are blatantly ludicrous. (Follow the link to see how ludicrous.)