The solar systems...
-
The sun....
The Sun (or Sol) is the star at the center of our Solar system. Earth orbits the Sun, as do many other bodies, including other planets, asteroids, meteoroids, comets and dust. Its heat and light support almost all life on Earth.
The Sun is a ball of plasma with a mass of about 2×1030 kg, which is somewhat higher than that of an average star. About 74% of its mass is hydrogen, with 25% helium and the rest made up of trace quantities of heavier elements. It is thought that the Sun is about 5 billion years old, and is about halfway through its main sequence evolution, during which nuclear fusion reactions in its core fuse hydrogen into helium. In about 5 billion years time the Sun will become a white dwarf.[2]
Although it is the nearest star to Earth and has been intensively studied by scientists, many questions about the Sun remain unanswered, such as why its outer atmosphere has a temperature of over 106 K when its visible surface (the photosphere) has a temperature of just 6,000 K.
inside the sun...
The Sun is thought to be a second-generation star, whose formation may have been triggered by shockwaves from a nearby supernova. This is suggested by a high abundance of heavy elements such as iron, gold and uranium in the solar system: the most plausible ways that these elements could be produced are by endothermic nuclear reactions during a supernova or by transmutation via neutron absorption inside a massive first generation star.
Our Sun does not have enough mass to explode as a supernova, and its mass is below the Chandrasekhar limit. Instead, in 4-5 billion years it will enter its red giant phase, its outer layers expanding as the hydrogen fuel in the core is consumed and the core contracts and heats up. Helium fusion will begin when the core temperature reaches about 3×108 K. While it is likely that the expansion of the outer layers of the Sun will reach the current position of Earth's orbit, recent research suggests that mass lost from the Sun earlier in its red giant phase will cause the Earth's orbit to move further out, preventing it from being engulfed. Following the red giant phase, giant thermal pulsations will cause the Sun to throw off its outer layers forming a planetary nebula. The Sun will then evolve into a white dwarf, slowly cooling over eons. This stellar evolution scenario is typical of low to medium mass stars
from wikipedia... -
woo... means 5billion years later, no more sun??
the what happen to earth!!
but then in that 5 billion years... will humans be destroyed by astriod? -
5 billions years ... we may all not existOriginally posted by CSpencer:woo... means 5billion years later, no more sun??
the what happen to earth!!
but then in that 5 billion years... will humans be destroyed by astriod? -
Supposing that humans doesn't destroy mother Earth, the Sun would destroy Earth as it reaches another stage of its life, a red giant star.
The red giant star is said to be hot enough to engulf Mercury and possibly Venus. As Earth is further than these two planets, Earth won't be engulfed. Earth will only be scoorched. Anything on Earth will literally burn and melt, unless we invent a material that can withstand that heat until Sun cools down.
However, when the Sun cools down, there will be no warmth, no sunlight, which will translate to no photosynthesis and no food chains, and eventually, all things on Earth will die out. -
But.. if there isn't any major disaster(eg. Hit by Asteroid) for another 1 or 2 centuries, I guess mankind would already have the technology for space travelling, discovered new planets, build space colonies, etc.Originally posted by ndmmxiaomayi:Supposing that humans doesn't destroy mother Earth, the Sun would destroy Earth as it reaches another stage of its life, a red giant star.
The red giant star is said to be hot enough to engulf Mercury and possibly Venus. As Earth is further than these two planets, Earth won't be engulfed. Earth will only be scoorched. Anything on Earth will literally burn and melt, unless we invent a material that can withstand that heat until Sun cools down.
However, when the Sun cools down, there will be no warmth, no sunlight, which will translate to no photosynthesis and no food chains, and eventually, all things on Earth will die out. -
If you mean staying in Solar System, don't think it is feasible. However, if we can find another Sun out there and planets that are suitable for us to live in, it is possible for us to do that.Originally posted by Mao x 2:But.. if there isn't any major disaster(eg. Hit by Asteroid) for another 1 or 2 centuries, I guess mankind would already have the technology for space travelling, discovered new planets, build space colonies, etc. -
i think we ned to invent faster-than-light travelling spacecraft to reach other similar solar system.Originally posted by ndmmxiaomayi:If you mean staying in Solar System, don't think it is feasible. However, if we can find another Sun out there and planets that are suitable for us to live in, it is possible for us to do that. -
wat is Chandrasekhar limit?
-
The Chandrasekhar limit is the maximum mass of a white dwarfOriginally posted by alwaysdisturbed:wat is Chandrasekhar limit? -
wat is really a white dwarf?Originally posted by RaTtY81:The Chandrasekhar limit is the maximum mass of a white dwarf -
A white dwarf is a very hot dying star.Originally posted by alwaysdisturbed:wat is really a white dwarf?
For more information on white dwarfs, visit:
http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html -
sounds like a meltdwn...Originally posted by ndmmxiaomayi:A white dwarf is a very hot dying star.
For more information on white dwarfs, visit:
http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html -
Yup.Originally posted by alwaysdisturbed:sounds like a meltdwn... -
when we do go to other planet to live, i think humans would have evloved by then..