Q. Which day was Earth born

Earth formed approximately 4.54 billion years ago through a process called accretion, where dust and rocks in the solar nebula gradually clumped together through gravitational attraction. This formation wasn't an instantaneous event but rather occurred over tens of millions of years as material orbiting the young Sun collided and merged. Scientists determine this age through radiometric dating of the oldest rocks on Earth, meteorites, and lunar samples, which all point to a formation period shortly after the Sun itself formed about 4.6 billion years ago.

The newly formed Earth was initially a molten ball of rock, constantly bombarded by asteroids and comets in a violent period called the Late Heavy Bombardment. Over hundreds of millions of years, the planet cooled enough to form a solid crust, and water vapor in the atmosphere condensed to create the oceans. The exact "birthday" cannot be pinpointed to a specific day because planetary formation is gradual, but the 4.54-billion-year figure represents when Earth had accumulated most of its mass and achieved a relatively stable orbit. Understanding Earth's formation helps scientists study planetary evolution, the development of conditions suitable for life, and how our planet continues to change through geological processes that have been active for billions of years.