Introduction
Our solar system- indeed, the whole universe- will not live for ever. Scientists now know that in billions of years time the inner planets, including the Earth, will be destroyed by the dying sun. The fate of the universe itself is also gloomy. It will either continue to expand forever, dying slowly until its nothing but a thin mist, or collapse back into a single particle, possibly to be reawakened again in another big bang.
A new home
Humans have so far only visited one alien world in person- the moon. However, as the sun begin to die and expand, conditions on Earth will become too hot for humans to live, and our descendents will be forced to leave this planet in search of a new home. Mars might very well be the first port of call, and could provide a home for humankind for a few million years. However, Mars will too eventually be engulfed by the dying sun. Humans will be forced to travel through space to find an Earth like planet orbiting a younger star.
The sun's future
Like all stars, our own sun was born and will eventually die. Scientists estimate that it is currently halfway through its immense life cycle, quite stable in its main sequence. However, in five billion years the sun's supply of hydrogen will run dry, and it will transform into a redgiant as it burns helium instead. It will eventually expand to over 30 times its present size, engulfing the inner planets, including Earth and Mars. When the helium runs out, the sun will cast off its outer layers to form a planetary nebula, after which its core will remain as nothing more than a tiny dwarf.
Dark matter
Scientists can's see all of the matter that makes up space, even with the most sophesticated telescopes. There is a great deal of matter in the universe that can't easily be spotted from Earth. This is called dark matter. It includes objects such as brown dwarfs and black holes
Our solar system- indeed, the whole universe- will not live for ever. Scientists now know that in billions of years time the inner planets, including the Earth, will be destroyed by the dying sun. The fate of the universe itself is also gloomy. It will either continue to expand forever, dying slowly until its nothing but a thin mist, or collapse back into a single particle, possibly to be reawakened again in another big bang.
A new home
Humans have so far only visited one alien world in person- the moon. However, as the sun begin to die and expand, conditions on Earth will become too hot for humans to live, and our descendents will be forced to leave this planet in search of a new home. Mars might very well be the first port of call, and could provide a home for humankind for a few million years. However, Mars will too eventually be engulfed by the dying sun. Humans will be forced to travel through space to find an Earth like planet orbiting a younger star.
The sun's future
Like all stars, our own sun was born and will eventually die. Scientists estimate that it is currently halfway through its immense life cycle, quite stable in its main sequence. However, in five billion years the sun's supply of hydrogen will run dry, and it will transform into a redgiant as it burns helium instead. It will eventually expand to over 30 times its present size, engulfing the inner planets, including Earth and Mars. When the helium runs out, the sun will cast off its outer layers to form a planetary nebula, after which its core will remain as nothing more than a tiny dwarf.
Dark matter
Scientists can's see all of the matter that makes up space, even with the most sophesticated telescopes. There is a great deal of matter in the universe that can't easily be spotted from Earth. This is called dark matter. It includes objects such as brown dwarfs and black holes
0 comments:
Speak up your mind
Tell us what you're thinking... !