In brief: Meteorites
- Meteoroids are chunks of rocks in space just like asteroids. (only difference is size)
- When these meteoroids strikes the earth’s atmosphere, they appear are flash of light called meteor.
- In its travel to earth it the meteor survives it is called as meteorite.
- Thus meteorites are inter-planetary rocks that have been formed elsewhere in the solar system but have reached the earth.
Significance of Meteorites
- Since the meteorites have note undergone the geological processes on earth or any other planet, they are said to be pristine objects formed at the beginning of solar system.
- Thus Meteorites are significant in revealing the origin and evolution of Solar System.
- This is done by studying the elements they contain.
Origin of elements
- Any star including our own sun basically survives on the fusion reaction in its core.
- Different elements we see in nature are formed by different processes.
- In our Sun, hydrogen atoms are undergoing fusion reaction to form helium at extremely high temperatures.
- In massive stars (1000 times bigger than sun), the heaviest element formed due to fusion reaction is Iron.
- Note: The maximum temperatures that can be achieved in the core of the star is only enough to make iron.
- Elements heavier than Iron are formed are formed in various other events such as
- Super nova explosion
- This is because due to high pressure of explosion leads to higher temperatures making fusion of heavier elements possible
- Solar flares
- These are high energy pulses released by sun’s corona.
- The solar flares are violent eruptions of sun that occur at intense magnetic fields at the corona. (called sunspots)
- A solar flare can have as much energy as 100 trillion nuclear bombs.
- Such high energy can result in fusion of heavier elements.
The study of Efremovka Meteorite
- The meteorite found in Efremovka is known to be the one of the most pristine meteorites formed during early stages of solar system.
- The early elements formed during solar flare eruptions during early ages of sun (about 5 lakh years old) are calcium and aluminium.
- The study shows how meteorites ended up containing beryllium-10.
- Beryllium-10 is known to form due to fission of oxygen or carbon.
- The study of the Efremovka meteorite has revealed how beryllium-9 decayed into beryllium-7 which in turn fused to form beryllium-10 in the meateorite.
- So far this was believed that beryllium-10 formed only during a supernova event.
- Now the study has confirmed that the Solar flares of early sun had so much energy that it fused lighter elements into heavier ones
Section : Science & Tech