Related Experiment Video
Updated: Apr 26, 2026
06:48
Surface Mapping of Earth-like Exoplanets using Single Point Light Curves
Published on: May 10, 2020
3.0K
On the evolution of the protolunar disc
1Planetary Science Directorate, Southwest Research Institute, Boulder, CO 80027, USA ward@boulder.swri.edu.
Summary
This study models a post-impact protolunar disc, revealing a stratified structure with a stable vapor layer and an unstable magma layer. The magma layer spreads viscously over years, influencing accretion and moonlet formation before vapor depletion.
Area of Science:
- Planetary Science
- Astrophysics
- Geophysics
Background:
- Post-impact protolunar disc evolution is crucial for understanding Moon formation.
- Previous models suggested discs hover near gravitational instability.
Purpose of the Study:
- To analyze the structure and viscous evolution of a post-impact protolunar disc.
- To investigate both vertically mixed and stratified disc models.
- To determine the impact of disc structure on accretion and moonlet formation.
Main Methods:
- Employed equations for a silicate disc in two-phase (vapor-liquid) equilibrium.
- Derived analytical solutions for vertical disc structure.
- Explored the viscous evolution of a stratified disc model.
Main Results:
- A stratified disc model features a gravitationally stable vapor layer (x~1) and an unstable magma layer.
- The magma layer viscously spreads over 3-4 years, with continuous vapor condensation.
- Material flows inward for accretion by Earth and outward for moonlet formation.
Conclusions:
- The stratified model provides a new framework for protolunar disc evolution.
- Viscous spreading and vapor condensation drive disc evolution and material redistribution.
- The process influences Earth accretion and the formation of early moonlets over 50-100 years.
Related Concept Videos
01:10Kepler's First Law of Planetary Motion
4.8K
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
4.8K
01:29Kepler's Second Law of Planetary Motion
4.6K
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. His first law states that all planets orbit the Sun in an elliptical orbit, with the Sun at one of the ellipse's foci. Therefore, the distance of a planet from the Sun varies throughout its revolution around the Sun.
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
4.6K
01:18Kepler's Third Law of Planetary Motion
3.6K
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. In 1909, he formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe. However, in 1918, he published his third law of planetary motion, which gives a precise mathematical relationship between a planet's average distance from the Sun and the amount of time it takes to revolve around the Sun. It...
3.6K
01:16Circular Orbits and Critical Velocity for Satellites
2.8K
The Moon orbits around the Earth. In turn, the Earth (and other planets) orbit the Sun. The space directly above our atmosphere is filled with artificial satellites in orbit. One can examine the circular orbit, the simplest kind of orbit, to understand the relationship between the speed and the period of planets and satellites with respect to their positions and the bodies that they orbit.
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
2.8K
01:17Design Example: Calculating Safe Diameter for Wind-Exposed Disc
403
Assessing safety in wind-exposed installations is crucial to preventing potential failures. This example explores the calculation and design adjustments needed to mount a circular disc on a building facade, where wind forces are a primary concern. A 4-meter diameter disc was initially designed as an aesthetic feature facing winds at a velocity of 25 meters per second, with an air density of 1.25 kilograms per cubic meter. Given these conditions, the drag force on the disc was determined using...
403
01:24Eukaryotic Evolution
19.4K
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
19.4K