THIS DAY IN SPACE

Chelyabinsk Meteor Explodes Over Russia
On February 15, 2013, a meteor entered Earth’s atmosphere and exploded over the city of Chelyabinsk, Russia, creating a powerful shockwave that injured over 1,500 people and damaged thousands of buildings. Weighing an estimated 12,000–13,000 metric tons and measuring about 20 meters in diameter, the meteor was the largest known natural object to enter Earth’s atmosphere since the 1908 Tunguska event. It exploded at an altitude of about 30 kilometers, releasing energy equivalent to nearly 470 kilotons of TNT—roughly 30 times the energy of the Hiroshima atomic bomb. The shockwave shattered windows across six cities, and countless videos of the event went viral, showing a bright fireball streaking across the sky followed by a delayed thunderous boom. The Chelyabinsk event served as a wake-up call to the global scientific community about the potential dangers of near-Earth objects. It spurred renewed interest in planetary defense initiatives and asteroid detection systems, including NASA’s DART mission and international collaborations aimed at tracking and mitigating asteroid threats.

Birth of Galileo Galilei
On February 15, 1564, Galileo Galilei was born in Pisa, Italy. Often hailed as the 'father of modern science,' Galileo revolutionized the fields of physics, astronomy, and mathematics. He was among the first to use a telescope for celestial observation, discovering Jupiter’s four largest moons, the phases of Venus, sunspots, and the rugged surface of the Moon—findings that strongly supported the Copernican heliocentric model. Galileo’s work laid the foundation for Newtonian physics, particularly through his studies of motion and inertia. Despite facing intense opposition from the Catholic Church, culminating in his infamous trial in 1633, Galileo never abandoned his belief in the scientific method. His insistence on empirical evidence and mathematical reasoning redefined how knowledge was pursued. Galileo’s legacy persists in the principles of experimental science and in the design of modern telescopes, spacecraft, and observatories. His life and work continue to inspire scientists and freethinkers across the globe, and his birthday remains a symbol of curiosity, courage, and reason.