Fatty Knees Sailboat For Sale What happens when a small body approaches the earth

Roche limit

Two different state bodies in the gaseous, spherical in shape, which we will call primary and secondary, have masses M and m respectively. Their radii are R yry their densities are ρ and ρ _{M m} . The distance between the two bodies is d. See Figure 1.

When the distance r, R d are comparable. The concept of comparability is a bit biased, but we can try to understand considering that the Earth Moon system is comparable radii and distances. Indeed, the radius of the earth is 6400 km, 1738 km from the moon and the distances between the two is 384.000 km.

The distance d is 60 times and 220 times r. R Although a wide representation imply large distances has been considered that this range of measures can be considered comparable, as the systems formed by each planet and each of its moons.

Figure 1

M m bodies exert a force on each other, resulting in deformation each of them, being most notable in the small body of mass m.

In Figures 2 to 6 we can observe the effect of the force exerted by the large body on the small, depending on the distance d.

Figure 2

A body fluid, which maintains its structure for its internal gravity and orbiting a larger object, has a spherical shape while away the Roche limit. Roche limit represented by the white circle line.

Figure 3

Closer to the Roche limit the fluid is deformed by the action of tidal forces

Figure 4

Roche Within the limits of gravity of the fluid is not sufficient to maintain its shape and the body is broken by the action of the tidal force.

CHT MLXC

Figure 5

The red arrows represent the orbital velocity of the dispersed remnants of the satellite. The internal particles orbit more quickly than the outer.

The name comes from the Roche limit French astronomer Édouard Roche , who first proposed this effect and calculated the theoretical limit ; rich 1848.

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Roche limit depends on the severity of the central body, but also the characteristics of density and size of the satellite.

Some satellites, both natural and artificial, orbit at distances less than the Roche limit, maintaining its structure by forces other than gravity: the strength of the material. Among the moons of Jupiter both Adrastea Metis as are examples of natural bodies that maintain their cohesiónmeyond their Roche limits. However, any object on the surface can be shelled and broken up by tidal forces. A less cohesive body, like a comet will be destroyed when passing through the Roche limit. The comet Shoemaker-Levy 9 crossed the Jupiter's Roche limit in July 1992 , breaking into numerous fragments. In 1994 the remains of comet impacts on Earth's surface.

deformab Bodies Rigid Bodies them

The other extreme case a satellite is able to deform without any resistance, just as you would a liquid. Although the exact calculation can not be done analytically, a fair approximation can be given by the following formula:

The table below shows the average density and the equatorial radius of different objects in the Solar System .

Body	Density (kg / m³)	Radio (m)
Sun	1,400	695,000. 000
Jupiter	1,330	71,500,000
Earth	5,515 C HTMLXC	6,376,500
Luna	3,340	1,737,400

With

these data, the Roche limit for rigid bodies and deformable bodies can be easily calculated. The average density of comets

can be seen around 500 kg / m³.

True Roche limit depends on the flexibility of satelliteelite, so it will be somewhere between the limits calculated for the rigid body and deformable body perfectly calculated above. If the central body has a density greater than half the orbiting body, the Roche limit is reached below the radius of the planet and the satellite can not reach this limit. This is the case, for example, the Roche limit for the system Sun - Earth. The following table gives the limits of Roche expressed in meters and radios central body. CH

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Roche limit (hard) Roche limit (not hard) Distance (m) Distance (m) Earth Earth So is interesting to consider how close they are different moons of Solar System

Main Satellite
			Radio		Radio
	CHTMLX LunaC 9,495,665	1.49	18,261,459	2.86
	Comet 17,883,432	2.80	34,392,279		5.39
l Earth	554,441,389	0.80	1,066,266,402	1.53
Sun	Comet 1,234,186,562	1.78	2373. 509,071	C3.42 HTMLXC

their Roche limits. The following table gives the orbital radius of each satellite divided by its Roche limit in both cases of rigid and flexible body. In the case of the giant planets have only considered the smaller inner satellites. The main and satellite Io in Jupiter or Titan in Saturn are at distances greater than their Roche limits.

central body (Rigid) Sun Earth Luna Mars Phobos Deimos Jupiter Adrastea Amalthea Tebe Saturn Pan HTMLXC Prometheus Pandora Epimetheus Uranus Ofelia Bianca Cressida Thelassa is interesting that the smaller satellites of giant planets near their Roche limits, its structure maintained by internal forces cohesióny not only by gravity. In the region dominated by rings, like the rings of Saturn

Satellite	Radio Orbital: Roche limit
		(Not Hard)
	Mercury 104:1	54:1
	41:1	21:1
	171%	89%
	456%	237%
	Metis 191%	99%
	192%	100%
	178%	93%
	331%	172%
	177%	92%	CAtlas
	182%	95%
	185%	96 %
	188%	98%
	198 % C HTMLXC	103%
Cordelia	155%	81%
	168%	87%
	184%	96%
	193%	100%
Neptune Naiades	144%	75%
	149% CH78%	TMLXC	Despina
	157%	82%	Galatea
	184%	96%	Larissa
	219%	114%	Pluto
Charon	13:1	6,8:1

, groups it is impossibleation of particles in large bodies because they would be dispersed by the effects of the tidal force

. These satellites probably had its origin in remote regions of the giant planets and their orbits were later modified perhaps by the gravitational interaction of the other satellites. Alternatively, perhaps they were formed in regions close to their current positions when the planets were still in full power background, and had a lower mass. This second scenario is less likely however. Roche limit depends on the rigidity of the satellite orbiting the planet. On the one hand, this could be a perfect sphere in which case the Roche limit is

R

Where is the
radio

the main body, ρ

M is your density and ρ m is the density of the satellite. _{If the moon has a density greater than twice the density of the planet, justas may occur in a satellite orbiting a gas giant rock, then the Roche limit would be within the planet itself and a magnitude would be relevant.}

SOLAR SYSTEM GENERAL

Sidereal Period is the time it takes for a planet return to the same place in its orbit, relative to the stars.

Perihelion and aphelion distances are the closest and farthest planet from the Sun

The inclination is relative to the Earth's orbital plane, the plane of the ecliptic.

Globes Planets:

The Flattening (Oblateness) is a measure of how the figure of the planet moves away from the ball.

The rotation period for each planet, is the period relative to the stars. It is slightly different from the period covered by the Sun, the Earth called the day.

to the planets Venus, Uranus and Pluto, the inclination of the axis of rotation (Tilt) is greater than 90 degrees, and these planets (and satellites of Uranus) rotate in the opposite direction to their orbits. In contrast, all other planets, their satellites and the Sun, rotate and move around the Sun with the same rotation.

concepts and images Source: wikipedia

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