Jupiter also has the biggest moon in our solar system, Ganymede. These moons are so big you can see them with just a pair of binoculars. Saturn has 53 moons that have been named. Saturn also has 29 moons awaiting confirmation. If all of these moons get confirmed, Saturn will have 82 moons. One of these moons, named Titan, even has its own atmosphere, which is very unusual for a moon. Lastly, Neptune has 14 named moons.
One of Neptune's moons, Triton, is as big as dwarf planet Pluto. Make no-bake Moon cookies! And here's why:. Given Mercury's small size the smallest planet in the and its proximity to the sun, it's gravity is too weak and it's Hill sphere too small to retain a natural satellite.
Basically, if a large object were to approach Mercury today, to the point that it actually entered its Hill sphere, it would likely be snatched up by the sun's gravity instead. Another way in which Mercury could not have acquired a moon has to do with the scarcity of material in its orbit. This may be due to solar winds and the condensation radii of lighter materials, where trace substances like hydrogen and methane remained in gaseous form nearer to the sun during Mercury's formation, and were thence swept away.
This left only elements like iron and and nickel in solid form, which then coalesced to form Mercury and the other terrestrial planets. For a time in the early s, astronomers thought Mercury might have a moon. Instruments on board NASA's Mariner 10 spacecraft detected large amounts of ultraviolet radiation in the vicinity of Mercury that astronomers believed did not belong there.
Hence, some theorized that this radiation was coming from a nearby moon. Unfortunately, the radiation disappeared the next day, and it was later discovered that the source was actually a distant star.
Alas, it seems that planets that are too close to the sun, such as Mercury and Venus, are destined to be without natural satellites. It's a good thing, then, that we Earthlings were lucky enough to live on a world that is far enough from the sun and has a big enough Hill sphere to keep a satellite.
We are also fortunate enough that the massive collision that created our Moon happened so long ago! Explore further. More from Astronomy and Astrophysics. Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page.
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By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use. January 1, Credit: planetary. Source: Universe Today. Citation : How many moons does Mercury have? This document is subject to copyright. Hence, some theorized that this radiation was coming from a nearby moon. Unfortunately, the radiation disappeared the next day, and it was later discovered that the source was actually a distant star. Alas, it seems that planets that are too close to the Sun, such as Mercury and Venus, are destined to be without natural satellites.
We are also fortunate enough that the massive collision that created our Moon happened so long ago! Listen here, Episode Mercury. There appears to be too much difference between earth and the moon for both to be formed from the same building materials. The theory that the moon is a captured passing orb seems to make more sense. Which includes the analyzing of the rocks brought back by the Apollo missions.
We are far more similar than we are different. Mercury has cleared the debris field away and is dense enuff to maintain its iron core… but the solar wind may have swept any smaller objects away the same way mercurys outer crust is decimated creating a smaller crust… it has a magnetic field because the iron core is interacting with the sun… but soon messinger will help decide if i speak the truth or its all speculation.
It has more substantial gravity — and, therefore, a larger Hill sphere — and is substantially farther from the Sun than Mercury. If Mars really captured Phobos and Deimos, or if Theia struck the proto-Earth and formed the moon, then that was mostly a matter of wild luck.
The physics of capturing a moon is about like the physics of a pocket of a pool table. The dimensions matter, a lot. The way I play, at least.
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