253 Mathilde
Asteroid 253 Mathilde is a significant celestial object within the asteroid belt located between Mars and Jupiter. Discovered on November 12, 1885, by the Austrian astronomer Johann Palisa, Mathilde is a large, irregularly shaped asteroid with a size of approximately 50 kilometers (31 miles) in diameter. This asteroid orbits the Sun at an average distance of about 330 million kilometers (205 million miles) and completes one orbit roughly every 4.3 Earth years. In 1997, the NASA spacecraft NEAR Shoemaker performed a historic flyby of Mathilde, making it the first spacecraft to encounter and study a C-type asteroid up close. The encounter provided invaluable data and detailed images, revealing that Mathilde has a heavily cratered surface, suggesting it has undergone impacts over billions of years. The asteroid's dark, primitive composition containing carbon-rich material indicated that it might represent one of the oldest and most primitive bodies in the solar system, providing crucial insights into the composition and history of these celestial objects.