Q. Which planet is 7 years per hour

No planet actually experiences seven years per hour in any scientifically accurate sense. This claim likely stems from science fiction, particularly the 2014 film "Interstellar," which depicted a fictional planet near a black hole where extreme gravitational time dilation caused one hour on the planet's surface to equal seven years of time passing elsewhere. While Einstein's theory of relativity does predict that time moves differently in strong gravitational fields, no known planet in our solar system or observed exoplanets experiences anywhere near this extreme level of time distortion.

Time dilation is a real phenomenon confirmed by precise atomic clocks and space missions, but the effects are typically measured in fractions of seconds, not years. Astronauts on the International Space Station, for example, age microseconds less than people on Earth due to their speed and slightly weaker gravitational field, but this is imperceptible in daily experience. The dramatic time dilation depicted in fiction requires conditions near the event horizon of a supermassive black hole—an environment no human technology could survive. Understanding the difference between theoretical physics, cinematic exaggeration, and observable reality helps prevent confusion about actual planetary conditions and the practical limits of space exploration.