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What causes this disk to form and flatten?

What causes this disk to form and flatten?

It is the angular momentum, which results from rotation, that leads to the eventual disk shape. The disk remains in orbit, and it flattens because of angular momentum. Eventually this disk will give rise to planets, asteroids, and planetesimals.

What is a protoplanetary disk quizlet?

Protoplanetary Disk. A rotating circumstellar disk of dense gas surrounding a young newly formed star. It is thought that planets are eventually formed from the gas and dust within the protoplanetary disk.

What is an accretion disk and what are its characteristics?

An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. Accretion disks of young stars and protostars radiate in the infrared; those around neutron stars and black holes in the X-ray part of the spectrum.

What is primarily responsible for the continued growth of kilometer sized planetesimals in an accretion disk?

Assume the particle is part of an accretion disk. How much material in an accretion disk goes into forming the planets, moons, and smaller objects? What is primarily responsible for the continued growth of kilometer-sized planetesimals in an accretion disk? ice.

What is the process of accretion?

In planetary science, accretion is the process in which solids agglomerate to form larger and larger objects and eventually planets are produced. The initial conditions are a disc of gas and microscopic solid particles, with a total mass of about 1% of the gas mass. Accretion has to be effective and fast.

What are the steps of accretion?

Step 1: accretion of cm sized particles. Step 2: Physical Collision on km scale. Step 3: Gravitational accretion on 10-100 km scale. Step 4: Molten protoplanet from the heat of accretion.

What is an example of accretion?

Accretion is defined as the part of something that has been added. An example of an accretion is the garage someone may build on his home. The definition of accretion is the state of having gone through extension or addition of length or overall size.

Which is the proper order of accretion?

A first process is the sticking of microscopic dust into larger grains and pebbles. A second process is the formation of an intermediate class of objects called planetesimals. A third accretion process has to lead from planetesimals to planets.

What force is needed for accretion?

Electrostatic forces are the cause of accretion until the particles are massive enough for gravity to cause attraction.

Does a accretion disk spin?

The three artist’s concepts represent the different types of spin: retrograde rotation, where the disk of matter falling onto the hole, called an accretion disk, moves in the opposite direction of the black hole; no spin; and prograde rotation, where the disk spins in the same direction as the black hole.

What is the process of accretion quizlet?

accretion. The process by which planets form as material orbiting some stars gathers together through collisions and gravitational or electrostatic attraction, eventually forming larger and larger bodies.

What is the nebular theory?

The nebular hypothesis is the idea that a spinning cloud of dust made of mostly light elements, called a nebula, flattened into a protoplanetary disk, and became a solar system consisting of a star with orbiting planets [12].

Why was the nebular theory rejected?

The main problem involved angular momentum distribution between the Sun and planets. The planets have 99% of the angular momentum, and this fact could not be explained by the nebular model. As a result, astronomers largely abandoned this theory of planet formation at the beginning of the 20th century.

What evidence supports nebular theory?

Comets, asteroids, and meteorites recovered on Earth also provide a number of clues and evidence of Nebular-type development. And the motions of most solar system objects orbit and rotate in an organized fashion. There are a few exceptions to what we would expect to find.

What is nebular theory of Laplace?

what is now called Laplace’s nebular hypothesis, a theory of the origin of the solar system. Laplace imagined that the planets had condensed from the primitive solar atmosphere, which originally extended far beyond the limits of the present-day system.

What is wrong with nebular hypothesis?

Because the nebular hypothesis is erroneous researchers assumed Earth’s diameter never changes, and, faced with the possibility the Earth might be expanding after the Atlantic basin was discovered to be widening, this assumption led to the unworkable concept of subduction to maintain a constant diameter Earth.

What are the two major flaws of nebular hypothesis?

However, there are two major problems for a theory of this type. One is that hot gas expands, not contracts. So lumps of hot gas would not form planets. The second is that encounters between stars are extremely rare, so rare as to be improbable in the lifetime of the Universe (15 billion years).

What nebula means?

Definition: A nebula is a formation in space which is constituted mostly of helium, dust, and other gases in various concentrations. A nebula is also believed to be one of the primary stages in the formation of stars.

What is the difference between nebular hypothesis and solar nebula theory?

Answer. Answer: The Nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). The widely accepted modern variant of the nebular theory is the solar nebular disk model (SNDM) or solar nebular model.

How are solar nebula formed?

Formation. Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova. When this dust cloud collapsed, it formed a solar nebula—a spinning, swirling disk of material.

Who created the nebular theory?

Emanual Swedenborg

Why are there two main types of planets?

why are there two major types of planets? accretion built ice-rich planetesimals in the outer solar system, and some of these icy planetesimals grew large enough for their gravity to draw in hydrogen and helium gas, building the jovian planets.

What is the condensation theory?

The Condensation Theory: This theory proposes that the Moon and the Earth condensed individually from the nebula that formed the solar system, with the Moon formed in orbit around the Earth. However, if the Moon formed in the vicinity of the Earth it should have nearly the same composition.

Why do you believe in nebular theory?

The nebular theory is an explanation for the formation of solar systems. The word “nebula” is Latin for “cloud,” and according to the explanation, stars are born from clouds of interstellar gas and dust.

What is the key ingredient in the modern condensation theory?

The key ingredient in the modern Condensation Theory is dust, which helps to cool the gas, and forms the nuclei for planetesimals to grow.

Which comes first condensation or accretion?

Step 5: Accretion o After condensation, growth of solid particles occurs due to collisions. o Accretion is growth of grains through collisions – the real planet building process.