Some materials decay quickly, while others can take millions or even billions of years to fully decay.Ernest Rutherford and Frederick Soddy, working at Mc Gill University, determined that half of any isotope of a radioactive element decays into another isotope at a set rate.

radiometric dating solar system-41

Small particles of dust collected together into larger and larger objects – pebbles, rocks, boulders, etc – until there were many planetoids in the Solar System.

These planetoids collided together and eventually enough came together to become Earth-sized.

At some point in the early history of Earth, a planetoid the size of Mars crashed into our planet.

The resulting collision sent debris into orbit that eventually became the Moon.

The oldest surface rock is found in Canada, Australia and Africa, with ages ranging from 2.5 to 3.8 billion years.

The very oldest rock was discovered in Canada in 1999, and estimated to be just over 4 billion years old.

Of course, it’s not a coincidence; the Sun and the planets all formed together from a diffuse cloud of hydrogen billions of years ago.

In the early Solar System, all of the planets formed in the solar nebula; the remnants left over from the formation of the Sun.

By measuring the amount of three different isotopes of lead (Pb-206, Pb-207, and Pb-208 or Pb-204), geologists can calculate how much Uranium was originally in a sample of material.

If the Solar System formed from a common pool of matter, with uniformly distributed Pb isotopes, then all objects from that pool of matter should show similar amounts of the isotopes.

Scientists assume that all the material in the Solar System formed at the same time.