How do we know how old the Earth is?
Earth is not like a human being, who has got documents and parents to be aware of its birth date and how old is it. The age of Earth is a great matter of interest human beings. Many such verifiable pieces of evidence claim the earth is nearly 4.54 billion years of old. Well, this is just an assumption. The scientists have spent numerous amount of time to find and determine the age of the planet earth. The scientists have used the process of dating the rocks and gave the assumed result with an error range close to 50 million years.
One may wonder why it requires to know the age of the earth as practically there is no use of such information. However, this is very much true for a layman but not for the researchers. They carry a number of experiments where the age of the earth can be helpful, and that is why with the help of different methods they have tried to calculate the age of the earth. Though with different methods the researchers have found a huge range of the age, still it is closer to the declared age and hence one can believe that our planet is only 4.54 billion years compared to many others in the universe.
Earth core is made of Iron and Nickel. Now the question arises, where does one find iron in the universe? The answer is in the core of dying star. A star as of the sun may take more than 10 billion years to die. Moreover, certain stars can take up to 1 trillion years to die. There are some who come up with the argument that the formation of the earth in the universe was because of the supernova.
But this assumption is ruled out, as it is not possible to have the presence of water on it which is older than the sun. Scientists have been making attempts from over the past 400 years to calculate the age. Scientists endeavored to foresee the age grounded on altering sea levels, the period it took for Earth or the sun to cool to existing temperatures, and the salinity of the ocean. But as the development in science and technology grew ahead, these techniques were proved to be unreliable.
How old are the rocks?
In an exertion to compute the age of the earth, experts turned to the rocks that shelter its surface. However, since plate tectonics continuously fluctuates and facelifts the crust, the first rocks have long since been castoff, liquefied down and rehabilitated into new boulders. In the early 20th century, researchers sophisticated the process of radiometric dating.
Previous research had revealed that isotopes of some radioactive rudiments decay into other rudiments at rates that can be easily prophesied. By inspecting the present elements, researchers can estimate the preliminary quantity, and thus how long it took for the rudiments to deteriorate, permitting them to decide the age of the rock.
The oldest rock on the planet is the Acasta Gneisses. They are found in northwestern Canada near the Great Slave Lake. They are estimated to be around 4.03 billion years old. The other such old rocks are found in Greenland. These rocks are known as Isua Supracrustal. These rocks are estimated to be around 3.7 to 3.8 years old.
The scientists further began to outward to refine the age of the Earth. The substance that shaped the solar system was a bank of a cloud of dust and gas that enclosed the young sun. Gravitational connections amalgamated this substance into the planets and moons at coarsely the equivalent time. By reviewing other bodies in the solar system, researchers were able to find out more around the early times gone by of the planet.
The adjacent body to Earth, the moon, does not agonize from the resurfacing problems that cover Earth’s scenery. As such, rocks from early lunar past should be existent on the moon. Illustrations reimbursed from missions such as Luna and Apollo revealed ages which are somewhere between 4.4 billion to 4.5 billion years, helping to coerce the age of Earth.
In addition to the huge builds of the solar system, researchers also have premeditated minor rocky visitors to that fell to Earth. Meteorites coil from a wide variety of bases. Some are cast off from other worlds after fierce mashes, while others are surplus chunks from the primary solar system that on no occasion grew large enough to form a consistent body.
Although no rocks have been purposely returned from Mars, examples exist in the form of meteorites that fell to Earth long ago, letting researchers make estimates about the age of rocks on the red planet. Some of these examples have been dated to 4.5 billion years old, backing up other calculations of the date of early terrestrial formation. More than 70 meteorites have tumbled upon the Earth to have their ages considered by radiometric dating. The eldest of these have ages between 4.4 and 4.5 billion years.
Fifty thousand years ago, a rock tossed down from interstellar space to form Meteor Crater in Arizona. Ruins of that asteroid have been poised from the crater rim and baptized for the nearby Canyon Diablo. In 1953, Clair Cameron Patterson determined ratios of lead isotopes in examples that put tight restraints on Earth’s age.
The Canyon Diablo meteorite is significant because it characterizes a class of meteorites with constituents that allow for more accurate dating. The samples obtained from the meteorite show a spread from around 4.53 to 4.58 billion years. Researchers deduce this array as the time it took for the solar system to grow, a measured event that took place over almost 50 million years.
Using not only the rocks on Earth but also evidences gathered about the system that environs it, researchers have been capable of placing the age of the Earth at roughly 4.54 billion years. For contrast, the Milky Way galaxy that comprises the solar system is almost 13.2 billion years old, while the cosmos itself has been dated to 13.8 billion years.