User:Ashill/Sandbox/chronology

'''Chronology has been merged to Formation and evolution of the Solar System. Anyone's welcome to keep playing here for testing, but real edits should go there.''' ASHill (talk | contribs) 21:13, 9 May 2008 (UTC)

Chronology
The time frame of the Solar System's formation has been determined using radiometric dating. Scientists estimate that the Solar System is 4.6 billion years old. The oldest rocks on Earth are approximately 4.4 billion years old. Rocks this old are rare, as Earth's surface is constantly being reshaped by erosion, volcanism and plate tectonics. To estimate the age of the Solar System, scientists use meteorites, which were formed during the early condensation of the solar nebula. Almost all meteorites (see the Canyon Diablo meteorite) are found to have an age of 4.6 billion years, suggesting that the Solar System must be at least this old.

Studies of discs around other stars have also done much to establish a time frame for Solar System formation. Stars between one and three million years old possess discs rich in gas, whereas discs around stars more than 10 million years old have little to no gas, suggesting that planets within them have ceased forming.

Studies of stars in the later stages of their evolution have also allowed astronomers to plot the Sun's possible future course.

Note: All dates and times in this chronology are approximate and should be taken as an order of magnitude indicator only.