1999QX111

1999QX111 is a near-Earth asteroid and potentially hazardous object (PHO) that was first discovered on August 24, 1999, by astronomers at the Lincoln Near-Earth Asteroid Research (LINEAR) program in New Mexico, USA. It belongs to the Apollo group of asteroids, which are characterized by orbits that cross Earth's path and have semi-major axes greater than Earth's.

The asteroid has an estimated diameter of approximately 1.5 kilometers (0.93 miles), making it one of the larger near-Earth objects. Its orbit around the Sun takes about 1.2 years, and it has a highly elliptical trajectory that brings it relatively close to Earth at its closest approach. The asteroid's surface is believed to be composed of silicate materials, similar to those found in stony meteorites.

1999QX111 is classified as a potentially hazardous object due to its size and proximity to Earth. However, its orbit has been well-studied, and current calculations indicate that there is no significant risk of collision with Earth in the foreseeable future. The asteroid has a close approach to Earth roughly every 10 years, with the most recent notable encounter occurring on December 15, 2020, when it passed at a safe distance of about 0.04 astronomical units (approximately 6 million kilometers or 3.7 million miles).

Researchers continue to monitor 1999QX111 and other near-Earth objects to assess any potential future threats. The study of such asteroids helps scientists better understand the dynamics of the solar system and improves early warning systems for potential impact events. Missions like NASA’s Double Asteroid Redirection Test (DART), while focused on a different asteroid, demonstrate ongoing efforts to develop strategies for mitigating risks posed by near-Earth objects.