Jules Verne's Prophetic Vision: How 'From the Earth to the Moon' Predates the Apollo Missions and Escape Velocity Science

In 1865, renowned French author Jules Verne envisioned a lunar journey in his novel, "From the Earth to the Moon." Remarkably, many aspects of his fictional account closely resemble the actual Apollo missions that transported astronauts to the Moon. Verne's accurate predictions, such as overcoming Earth's gravitational pull, involved launching a capsule containing travelers from a massive cannon at an initial velocity of roughly 11 km/s (approximately 40,000 km/h). This value, known as escape velocity, is indeed correct.

Escape velocity refers to the necessary speed for an object to break free from a planet's gravitational force. To comprehend its calculation, we must first recognize that an object on a planet's surface possesses gravitational potential energy. This energy must be expended for the object to move away from the celestial body. By giving an object a velocity that equates its kinetic energy to its gravitational potential energy, we enable it to permanently escape the planet's gravitational pull.

This concept is analogous to throwing a tennis ball into the air; its initial velocity determines the height it reaches before falling back down. So, how is escape velocity calculated? It relies on the mass and radius of the planet. For Earth, the value is 11.2 km/s—identical to Verne's calculation. In reality, spacecraft destined for the Moon, or beyond, do not attain escape velocity instantaneously. Instead, they gradually accelerate, exiting Earth's atmosphere before receiving an additional boost to propel them away from our planet.