2006-10-28 03:09:53 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
No the Moon has no satellites of its own. The problem is that the Earth's gravity would capture such a moon-of-a-moon and make it a a second moon of the earth.
There are some 80 asteroids and Kuiper Belt Objects that have moons. Dactyl, a satellite, only 1.4 km in diameter, of 243 Ida (53.6×24.0×15.2 km) was the first to be discovered by the Galileo probe in 1993.
The second, Petit-Prince (abour 13 kms in diameter), was discovered around 45 Eugenia (diameter 214.6 km) by a ground-based telescope in 1998.
The first Trans Neptunian Object with a moon, 1998 WW31 (diameter 133±15 km) was resolved optically in 2002.
87 Sylvia has two moons, Romulus and Remus and its dimensions are 384×264×232 km,
Romulus (discovered February 18, 2001) is 18±4 km in diameter and orbits at a distance of 1356±5 km, taking 3.6496±0.0007 days (87.59 hours) to complete an orbit of Sylvia.
Remus (discovered August 9, 2004) is 7±2 km in diameter and orbits at a distance of 706±5 km, taking 1.3788±0.0007 days (33.09 hours) to complete an orbit of Sylvia.
Astronomers believe that these moons were broken off Sylvia by an impact in the past, and that other, smaller moons may also be found.
Later in 2005, the KBO (136108) 2003 EL61 (1960×1518×996 km) nicknamed Santa, was also discovered to have two moons, (one nicknamed Rudolph) making it the second known KBO to have at least two moons after Pluto.
2006-10-28 03:23:44 · answer #1 · answered by Mint_Julip 2 · 2⤊ 0⤋
any body with gravitational attraction, ie any body with mass, can have another mass in orbit around it. Pluto is smaller than the moon and it has a moon.
However, which body is the moon and which is the parent object gets fuzzy - technically both objects orbit their common centre of gravity. With the Earth-Sun or Moon-Earth, the centre of mass is almost at the centre of the larger body, so it seems that one is moving around the other. With Pluto and Charon (its moon), their masses are more alike so they would seem to spin around each other (noones seen it close up yet).
As for the smallest body KNOWN to have a natural satellite, there are asteroids in the asteroid belt a few kilometres across that have smaller asteroids the size of boulders swinging around them. However, the smaller the masses involved, the more likely it is that the "moon" will be disturbed by another mass and pass out of orbit. The further the bodies are from spherical also increases the instability of the orbits.
In reference to the answer above, our moon could quite easily have a satellite of its own. Below a certain distance, the orbit would be circular. Even if it passed far enough for the earth to affect it, it could still be stable, and have a fairly simple (kind of eggshaped) orbit.
2006-10-28 03:56:19 · answer #2 · answered by dm_cork 3 · 0⤊ 0⤋
The moon has no natural satellites. The orbital parameters of a stable orbit around the moon would be much too specific for random chance to provide one.
There can't be a "smallest body." Any mass bends space, and any two masses will orbit the center of mass between them. Unless there are other forces in play, like the electromagnetic force.
But generally speaking, there is no smallest astronomical body that could have a satellite. It just gets exponentially more unlikely as you go down the hierarchy.
2006-10-28 03:42:01 · answer #3 · answered by galaxy625 2 · 0⤊ 0⤋
Our moon is roughly the size of Texas and has almost no atmosphere; it DOESN'T SPIN either. These factors, particularly the LACK OF ROTATION, make is so our moon can't have natural satellites. Things just crash into it. In general, a moon is not something that can have moons. If a moon has a moon than usually one of them is desegnated a planet. Such was the case with the Pluto and Charon flip-flop. In rare cases, however there are duel moons and even weirder things that involve more than 2 moons.
Mass/density along with rotation can make even the very small bodies capable of supporting a sustaned natural orbit. Atmosphere plays a role too. I don't know the scientific formula but I'm sure someone will give it to you.
2006-10-28 03:56:58 · answer #4 · answered by Lightbringer 6 · 0⤊ 0⤋
Generally, moons cannot have satellites most likely due to the fact that they ARE moons, and therefore caught in the gravitational pull of a larger body. Because of this, anything orbiting around the moon would tend to have to deal with the gravity of the main planet, as well. It could probably happen, but the orbital characteristics of the sub-moon(?) would probably be VERY complex.
Not sure about the second part of the question, as I am not a whiz at physics, but the mass of the objects involved would have to be high enough for them to actually attract each other.
2006-10-28 03:33:00 · answer #5 · answered by Wally M 4 · 0⤊ 0⤋
No, the moon doesn't have any natural satellites.
There is no limit to how small an object can be and have satellites. Technically, if you could use an experiment involving a marble and a dust speck and were far enough away from any other object's gravitational effects, you could have the dustspeck being a satelite to the marble! (yes--for real!)
2006-10-28 04:10:42 · answer #6 · answered by Anonymous · 0⤊ 0⤋
It is not possible in general. But what is important is the mass of the planet than it's size. If the planet in question is having high density it may be possible it could be smaller than it's moon.
2016-05-22 02:58:37 · answer #7 · answered by Anonymous · 0⤊ 0⤋
If your talking smallest then i gotta ask if electrons are sateliites cause they're pretty small revolve and rotate around the neucleus of elemental atoms and they are quite natural too.
but idunno perhaps electons are more like planets and have moons of their own.
Ob1
2006-10-28 06:08:24 · answer #8 · answered by old_brain 5 · 0⤊ 0⤋