If an asteroid got caught by the earth's gravity and ends up orbiting earth, is that asteroid legally a moon?

Question

what if the asteroid is 1/8th the size of the moon, will astronomers classify that asteroid as earth's moon?

Answer 1

Absolutely. Anything orbiting another planet(excluding artificial satellites), is a natural satellite. We only have one, but Jupiter has 63. If Earth managed to capture an asteroid with it's gravity and not burn it up in the atmosphere or break it up due to tidal forces, and if the asteroid had a stable orbit around the Earth, it would become one of Earth's moons, and we would have two. It does not matter how big it is, it could be 1 mile across or 1000 miles across.

Answer 2

There is currently no official definition of what constitutes a moon. Any natural satellite can be considered a moon. It would not be against or enforced by any law.

However, orbiting is a cycle! If this asteroid came from far away, it would have to go back far away or else get destroyed locally, for example through a collision with our planet. Some special phenomena, such as two large asteroids colliding each other nearby the earth, will have to occur for a new satellite to start orbiting nearby. In such a case, we would have much more than just an extra moon, but yes it would be an extra moon. 1/8 th the size of the moon is still quite large. It would still appear like an extra moon.

Answer 3

Not a matter of de jure legality but de facto practicality: does it have a stable orbit?

Triton, Neptune's largest moon is a captured KBO, Both of Mars' moons, Phobos and Deimos are captured asteroids. There is no conceptual difficulty in referring to them as moons so why not this new hypothetical baby sister to our Moon as well? Have you got some better word in mind?

SIZE

I don't see that size should matter. There is a wide variety of sizes among the 163 known planetary moons. The latest addition announced in April, a 57th moon for Saturn is only 7 kilometres in diameter.

A sphere that is one-eighth the size of another sphere has half its diameter so a new Moon that was one-eighth the volume of our Moon would have a diameter of 0,1365 of Earth's diameter and still be the 8th largest planetary moon out of the 164 (as it would then be). See table below: it would be larger than Titania Rhea and Oberon

DIAMETERS of ten largest satellites (cf Earth = 1)

1. Ganymede 0.413 (Jupiter)
2. Titan 0.404 (Saturn)
3. Callisto 0.378 (Jupiter)
4. Io 0.286 (Jupiter)

5. The Moon 0.273 (Earth)

6. Europa 0.245 (Jupiter)
7. Triton 0.2122 (Neptune)

8. Titania 0.1237 (Uranus)
9. Rhea 0.1198 (Saturn)
10. Oberon 0.1194 (Uranus)

To strike a realistic note, though, there are no asteroids that size to fit the bill! The biggest 4 with their diameters in kilometres are:

1 Ceres 952
2 Pallas 531
4 Vesta 529
10 Hygiea 407

and our Moon has a diameter of 3474.2 kms so its new sibling would need to be the size of Eris or Pluto!

Answer 4

It cant be considered as our second moon atleast for hundereds of years coz these cases happen now and then but considerind one with 1/8 th of moon size means a different case but there are still asteroids circlling around earth but they slowly escape from earth's gravity after hundereds of years but luckily moon is in stable orbit but the chance of an asteroid captured by gravity to form a stable orbit is very less.

Answer 5

There are a few theories about how our moon got here. For me, the most fun one is that an asteroid or something like it actually blew through the Earth very early in its formation, then got caught in our planets gravity well, and became the Moon.

Answer 6

"sounds like as quickly as and asteroid or a meteorite reaches the earth's orbit, it gets pulled in till it smashes directly to the exterior of the planet." whilst did those activities happen?! Lmao, you curiously do no longer understand what share asteroids come interior moon's distance from Earth.

Answer 7

Yes,but scientically speaking,that asteroid will eventually crashed into Earth.1/8 the size of the Moon?You mad?
Moon diameter:3400+km.
Asteroid diameter:3400+/8=440+km
It could wipe out almost 2/3 continents!And then we start to be extinct like what the dinosaurs did roughly 65 million years ago!

Answer 8

If that were to happen, then yes, it would become a moon of the earth. There are many moons of other planets that are believed to be captured asteroids: Phobos and Diemos around Mars, plus many others around Jupiter and Saturn.

Answer 9

Count ourselves darn lucky if such an "asteroid" were to divert from smashing into us and glide into a smooth planetary orbit. Ah, the stuff of fantasy.

Really.....we could only be so lucky.

One's comming....and we better bone up real fast on some sound ways to deal with it.

My advice: elect people who haven't given up on life to political office: make it clear it's time to full throttle back up NASA now. Root out and vote out the empowered who are either too stupid to know what's happening or really don't care at all.

You can save the planet....if you vote WISELY for a change.

Answer 10

Nope I'm afraid it would still be considered a asteroid even if did find it's way to one of earths La Grange points, however it would be much closer to earth and could be mined for minerals and then used a colony for early settlers or maybe the asteroid could be used a as the ultimate maximum security prison.