Most of the planets can exist for a long, long time, but they can not last forever. Hungry stars and rigid planetary neighbors can completely destroy the world, while strikes and excessive volcanism may have inhabited the world of sterile stripping the planet of its water. There are also a number of theoretical methods, which could explain the end of the world, but have not, as far as we know.
"The planets are constantly dying right in our galactic vicinity," wrote Sean Raymond, a planetary fashion at the Laboratoire d & # 39; astrophysics de Bordeaux in Bordeaux, France, he blog series about how the world die, Raymond explored the many ways that the world might meet his end. Although not all the planets die, most eventually find their way to planetary morgue.
Earth's climate cycle plays an important role in ensuring the world is not of & # 39; is neither too hot nor too cold to support life. But it did not take long for the climate on a rocky world like Earth, that is thrown out of whack, causing the events that lead either to an incredibly hot planet or snowy com world.
On Earth temperature is controlled amount of carbon dioxide in the atmosphere. Carbon dioxide and other greenhouse gases in the atmosphere (such as water, methane and nitrous oxide) to act as a surface layer, keeping warm the planet, slowing much solar radiation back out into space. If the carbon dioxide accumulates in the atmosphere, it heats the surface of the planet, causing it to rain more, Then Precipitation removes some of the carbon dioxide from the atmosphere and deposits in carbonate rocks on the seabed and the planet begins to cool.
If the carbon dioxide accumulated in the atmosphere faster than it can be absorbed into the rock, due to something like elevated volcanic activity, e.g., it may cause the greenhouse effect. The temperature may rise above the boiling point of water, which can be a challenge to sustain life, seeing all life as we know it requires water. Rising temperatures may also allow the atmosphere to escape into space, removing the protective shield that deflects the light from the Sun and the planets of other stars.
"Greenhouse heating with & # 39 is a fact of life for the atmosphere, and it is desirable to some degree," wrote Raymond. "But things can get out of control."
Heat is not the only way, the climate can turn deadly. When the planet becomes sufficiently cold that the body is transformed into snow world, Rocky about 39 & #; object covered with ice. Ice and snow, bright and reflects most of the heat stars back into space, causing the world to cool down even more. On Earth surface with volcanic eruption can lose carbon dioxide and other gases into the atmosphere, heating the world back up. But if the snow conditions are taking place on the planet that lacks plate tectonics – and, consequently, volcanic eruptions – World can be permanently closed at a snowball state.
According to Raymond, the Life-bearing planets all potentially at risk climate catastropheThat could have a planet uninhabitable, but do not destroy it completely.
Bench or life
Tugboat neighboring world can pull on the orbit of the planet, which puts pressure on the inner part of the planet and increases the heat medium earth layer, the mantle. This heat has to find a way to escape, and the most typical way through the volcano.
Volcanic activity may significantly affect the environment of the planet. In accordance with University Corporation for Atmospheric Research, Gas and dust particles emitted into the atmosphere of the volcano may affect the atmosphere of the planet, the planet cooling and shading it from the incident radiation. In 1815, the eruption Tambora, The largest eruption in the recorded history of the Earth, has thrown so much ash that it lowered global temperatures, which makes the 1816 so-called "year without a summer."
Volcanoes can also cause the opposite effect – global warming – because they emit greenhouse gases into the atmosphere. Frequent and large volcanic eruption can cause a greenhouse effect that will transform the world inhabited like the Earth in the more like Venus.
We do not have to look far for a real example from the world of the volcano. Jupiter Moon Io to 39 & # is the volcanic activity of the body in the solar system, with hundreds of volcanoes, which is cut continuously. If the Earth was pulled as much as Io caused by the force of gravity of Jupiter, the Earth will have 10 times more than Io's volcanic activity, according to Raymond.
Rocky asteroids and icy comets, planetary "chips" that can cause serious & # 39; serious problems in their surrounding world, especially when they stick ice and gas giants.
As the world to settle in their final orbits, their gravitational tugs can move asteroids and comets around. Some of them may be put forward on the edge of the planetary system, while others were thrown inside, eventually colliding with rocky worlds where life can be trying to develop.
In our outer solar system, Neptune's final movement, he settled in its permanent orbit stuffed inside some comets passing them from planet to planet, until they reached Jupiter. Jupiter threw some of these icy bodies out, but others were thrown into the earth during the period known as the Late Heavy Bombardment.
Today the Earth is constantly accumulated about 100 tons (90 metric tons) of interplanetary material every day in the form of dust. On the & # 39; objects larger than about 330 feet (100 meters) to fall to the surface only once every 10,000 years, while the body is more than two-thirds of a mile (1 kilometer) crash down only once every few 100,000 years, in accordance with NASA Center of the Earth & # 39; sites Research.
If the giant planets throw these destructive crumbs to the sun, collisions spike, and the effects are more common. O & # 39; average objects can throw dust and debris into the air that can interfere with atmospheric processes. Giant impacts may lead to even more disastrous consequences, not only because of the damage on the ground zero, but also because they can throw enough rubbish to cause the impact of winter, Throwing the planet into a mini ice age. If enough exposure blurted out in a row, the climatic effects can build on one another until they eventually turns the world uninhabitable.
Based on observations of planetary residues found around other stars, Raymond estimated that about 1000000000 Earth as a planet in the galaxy will eventually be destroyed by the bombardment of asteroids.
Bad big brother
As the most massive of the & # 39; an object in the solar system after the sun, Jupiter It acts as a protective big brother, Defending the small rocky planets from dust and other giants around the worlds are likely to play the same role. But if a gas giant like Jupiter were unstable, it can have a devastating impact on the smaller worlds around him.
After the stars are formed, then Residual material disk It leads to the planets. Gravitational tugs from the gas and dust in the disk exert a force on the planets and gas giants can keep in line during the first few million years. After he left, however, the planet can change its orbit more easily. Because giant planets are much smaller than their rock brothers and sisters, their gravitational shocks can be significant in removing smaller planets orbit. But the big worlds are not immune; two giant planets can pull on each other, and can even pass very close to each other. According to Raymond, these giants are rarely encountered, instead of providing each of gravitational shock one. In the end, some of the worlds can be expelled orbit completely, and become the property of floating in space bound to any star.
Raymond estimated that about 5000000000 rocky worlds were destroyed by the gas giants. Most of the damage is likely to happen soon after the planet formed. However, few are likely to happen at the end of system life, after life has had time to develop. If only 1% of the gas giants have become volatile later in their planetary life, then it is possible that 50 million planetary systems inhabited worlds destroyed by throwing them into a star.
Like planets, stars can come to an end, and their transformation can have serious & # 39; serious consequences for planets orbiting them.
red dwarfsFor example, you may need more than 100 million years to reach its long-term brightness, ten times more than our sun. Planets orbiting the red dwarf can be within the habitable zone of a few million years, but as the star becomes brighter, any life-sustaining water can evaporate at higher temperatures.
But the planets orbiting hot, red dwarf can still support life. "We do not know whether this process dries the planet completely, or simply tear a few outer layers of the ocean," wrote Raymond. "If the planet is trapped in enough water inside (the Earth is believed to be several times its water surface in the mantle), it can withstand later degassing of new loss of their oceans. This complex interaction between geology and astronomy, and the result is unknown – at the moment ". Raymond ratings that 100 billion planets may have been dried their red dwarf.
Sun-like stars give habitable planets more time, to keep the water, giving life a chance. But the temperature of the sun is also changing, slowly lighting for billions of years. In a billion years, he said Raymond, the planet will no longer be in the habitable zone; no more water will remain liquid at the Earth's surface. Instead, the planet will pass quickly the greenhouse effect and eventually the wind looks like Venus.
When the sun, a star reaches 10 billion years, it will run from hydrogen and expansion somewhere between 100 and 200 times its current size. (Our Sun is 4.5 billion years old, so we have some time before that happens.) In our solar system, Venus and Mercury will be swallowed a starWhile the sun as a change of gravity will push the Mars and the outer planets farther out. The land is located right on the edge, and may suffer or fate. About 4000000000 rocky worlds probably consumed slowly lightish star.
The most massive stars explode fiery supernova after a relatively short lifetime of a few million years. Many planets were found around these massive stars, but this may be because so few massive stars and to search for exoplanets is still hard to find, Raymond wrote. In any case, any of these planets around giant stars are likely to be destroyed by the explosive death of a star.
This article was inspired by a series of astronomer Sean Raymond on How Planets Die.