# Tag Info

## Hot answers tagged asteroid-belt

72

It's not. The image doesn't show the main asteroid belt. It shows the Jovian Trojans (in green) , and the Hilda Asteroids (in red). The Hildas are a dynamical group of a few thousand known asteroids in elliptical orbits that are locked in a 3:2 orbital resonance with Jupiter, and reach aphelion coinciding with the regions near Sun-Jupiter Lagrange points ...

60

The asteroid belt is affected by Jupiter's gravity. There are stable orbits inside of Jupiter's orbit. Jupiter's Hill Sphere has a radius of 53 million km. If you are more than 53 million km from Jupiter, then the Sun's gravity dominates and you can orbit the sun. But Jupiter orbits 780 million km from the Sun, so there is plenty of space between Mars and ...

18

The mass of the asteroid main belt is estimated at 4% the mass of our moon according to Wikipedia so any object formed from the aggregation of that mass would not be a planet. It would be the size of a very small moon. Even if all the asteroids in the solar system were combined, the total mass would be below a third of the moon's mass.

14

The largest main belt asteroid is 1 Ceres, which alone contains almost a third of the total mass of the whole main asteroid belt. Ceres is large enough to be in hydrostatic equilibrium, i.e. its own gravity is strong enough to pull it into a roughly spherical shape. Since the mass of a spherical planet scales as the cube of the diameter (assuming constant ...

11

There is no chance of a collision in the short term. 2020 CD3 is in a rather chaotic orbit of the Earth that extends well beyond the moon and doesn't come very close to Earth Each orbit is different, but no orbit brings it closer than the moon. The orbit is irregular because it is perturbed both by the moon and by the gravity of the sun. At its furthest ...

11

No. The asteroid Belt is on average about 2.6 AU from the Sun. Earth is 1 AU from Sun, 1.6 AU from the asteroid belt. Jupiter is 5.2 from Sun, 2.6 AU from the asteroid belt. I.e. much further away. Also, it should be easier to see asteroids from inside their orbit since they reflect more sunlight towards us. From Jupiter you would see their shadowed sides....

7

This is actually a very subtle question, much more so than the answers to the similar questions provided in the comments give it credit for. When I was in graduate school at Ohio State I routinely asked this question to visiting dynamicists and invariably got different answers. The very basic answer is that if you have two sufficiently strong resonances ...

5

From Wikipedia: http://en.wikipedia.org/wiki/Asteroid_belt#Formation Planetesimals within the region which would become the asteroid belt were too strongly perturbed by Jupiter's gravity to form a planet. Instead they continued to orbit the Sun as before, and occasionally colliding.[27] In regions where the average velocity of the collisions was too high, ...

5

Inner. The entire asteroid belt is in the Inner Solar System (now). The definition of "Inner" vs. "Outer" is non-arbitrary, based on the current "frost line", approx. 5 a.u. radius. https://en.wikipedia.org/wiki/Frost_line_%28astrophysics%29 https://en.wikipedia.org/wiki/Solar_System#Inner_Solar_System

5

tl;dr: The key part the question is the phrase ...from the asteroid belt... There are lots of asteroids and only some of them are considered to be in "the asteroid belt" or to be main-belt asteroids. As @zephyr's answer to the question Do astronomers generally agree that the distinction between comets and astroids is not so clear? points out, even the ...

5

The only reason I've seen from my research is "because it's there", but I'd like to know a more scientific reason. "Because it's there" is a scientific reason. Couple that with the fact that we know there's a whole lot of stuff we don't know about the asteroids makes studying the asteroids interesting from a pure scientific perspective. That studying ...

4

The full orbital period of an object orbiting the sun is $$T=2\pi \sqrt{\frac{a^3}{GM_\odot}},$$ where $a$ is the semi-major axis of the orbit and $M_\odot$ the mass of the sun. If the asteroid has apoapsis in the asteroid belt ($r_{max}= 3$ AU) and periapsis near Earth ($r_{min}=1$ AU) then the semimajor axis will be $a=(r_{max}+r_{min})/2=2$ AU and going ...

4

Let's start answering your question in reverse. Ceres could not be "the missing Theia", because of its shape. If an object hit the Earth at an angle (as is currently thought), it would be pretty deformed, if it managed to stay together. If it hit the Earth head on . . . Well, it would almost certainly not survive. So if it did survive the impact, it would be ...

3

Asteroids with an orbit of between 1.8 and 2 Au (So their closest approach is is about the same distance to the Earth as the Earth is to the sun) are called Hungaria group asteroids, named after 434 Hungaria. Hungaria itself has an orbit of 1.94 AU, so would be a good example of body. Such asteroids are rather rare. There is a gap in the asteroid belt ...

2

The total mass of the asteroid belt is just about 4% of the mass of our Moon. Even if the asteroids don't collide with other planets in the meanwhile, the mass is too low to form a planet in the sense of the 2006 IAU definition. Even if Ceres would accrete all asteroids in the asteroid belt, its radius wouldn't grow to the double of its present radius, ...

2

Sometime after 4.5 billion years, the sun will change into a red giant star and expand to about 1 AU. Some people think it will be beyond Earth's orbit. (In any case, Earth's orbit would have changed and likely to have struck the surface of the expanded sun.) The asteroids would experience a stronger solar wind and their orbits would become more elliptical, ...

2

Ceres constitutes about 1/3 of the mass of the asteroid belt. Assuming the same density, the whole asteroid belt combined into one planet would have 3 times greater volume than Ceres and $\sqrt[3]{3}=1.44...$ times greater radius.

2

The speed of the collision changes everything. The formation of comets and asteroids is likely to take place the circumstellar disk of matter, perhaps even before the fist plant's formed. As the disk flattens and elliptical orbits tend to lose eccentricity by collision. Low velocity impacts between objects are more common. Protoplanetary disks are ...

2

Since planets are forming from asteroid collisions, I would say those collisions won't necessarily create small objects. Imagine throwing a snowball against a window. If you throw it lightly, some snow will stick to the window and increase the mass of it (at least until it melts away) and the rest of the snowball will be scattered everywhere around but won'...

2

I'm inclined to say no (and footnote, I realize Wikipedia isn't a good source for scientific proof as it's not always right, but I'm using it more to demonstrate a point than than use it as an authoritative definition). Wikipedia: A terrestrial planet, telluric planet or rocky planet is a planet that is composed primarily of silicate rocks or ...

2

Jupiter is a gas giant, with a mass approximately 317.8 times that of Earth, and its atmosphere has a composition that's typical of gas in space: almost 75% hydrogen and almost 24% helium, (barely different to the primordial gas created by the Big Bang). However, its interior also contains rock and metal components. Until quite recently it was thought that ...

1

Carbonaceous asteroids contain carbon in the form of chondrites (small marble-sized nodules),tiny crystals and other sorts of carbon dust. This is mixed in a sort of conglomerate with dust and nodules if silicate material, sometimes even nickel-iron nodules. What resources do they contain? They don't contain diamonds, because diamonds require enormous heat ...

1

Wikipedia states that 99.9% of the mass originally in the asteroid belt was lost in the first 100 million years of the solar system - I am assuming after the protosun initiated fusion. If so, that would put the potential mass at 4000X the moon, or almost twice Neptune's mass. That would be one big planet!

1

I hope it's OK to answer an old question. First, let me say that your proposal is creative. You've explained the possible creation of the asteroid belt (by collision - not impossible), and you've combined it with the formation of the moon by impact. That 2nd part is a little more problematic. There's a principal in scientific theory and it applies to ...

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