As of 2014, there is no single piece of concrete evidence to prove the existence of alien life, although most scientists today agree that the potential of discovering life outside Earth is much greater than previously thought. According to Discovery News, alien life is considered highly probable and will likely be discovered by the year 2024.Know More
Fictional accounts of aliens found in mainstream media aren't considered an accurate representation of alien life. Some scientists believe that aliens will be simple life forms such as bacteria or single celled organisms while others believe that more complex forms of life exist. Within the Milky Way galaxy, there are several planets that may be able to support some type of life.
NBC News has stated that over half of the galaxies visible from Earth's telescopes may have planets and solar systems similar to our own. Scientists often determine the probability of alien life by examining the availability of water on other planets. Currently, there are several planets that are thought to have some form of water available, including Mars and Titan, one of Saturn's moons.
The debate of whether alien life exists is hinged on the lack of definite proof of other species outside Earth. According to New Scientist, there are some examples that point to irrefutable evidence. For example, methane has been found on Mars. The presence of methane is linked to the metabolic process that occurs when life forms process organic compounds for energy. This evidence is controversial and has only been accepted as proof of alien life by a portion of scientists.Learn more about Astronomy
A solar eclipse occurs when the moon moves directly between the Earth and the sun. The moon's shadow travels over the surface of the Earth and blocks out the light from the sun seen on Earth.Full Answer >
As of 2014, over 3,700 man-made satellites orbit around the Earth. However, only approximately 1,100 of these are currently active. The rest are defunct or temporarily inactive.Full Answer >
Terrestrial radiation is the energy released by the Earth itself as opposed to solar radiation that it receives from the Sun. Apart from the energy generated by the decay of radioactive minerals in rock, the energy that drives terrestrial radiation ultimately comes from the Sun, and it is a major factor in the study of global warming.Full Answer >
Copernicus discovered that the planets revolved around the sun, rather than around the Earth. Called the heliocentric model of the solar system, the concept was at odds with the conventional wisdom of the time, which held that all heavenly bodies rotated around the Earth.Full Answer >