28861

28861 is a near-Earth asteroid (NEA) classified as a potentially hazardous object (PHO) due to its close orbital proximity to Earth and relatively large size. Discovered on January 29, 2000, by the Lincoln Near-Earth Asteroid Research (LINEAR) program, it belongs to the Apollo group of asteroids, which are known for their Earth-crossing orbits.

The asteroid has an estimated diameter of approximately 0.6 kilometers (0.37 miles), though precise measurements vary depending on observational data. Its orbit around the Sun takes about 1.3 years, and it periodically approaches Earth, with the closest known encounters occurring in the past and projected for the future. The most notable close approach occurred on January 27, 2020, when 28861 passed within about 0.03 astronomical units (AU) of Earth—roughly 4.5 million kilometers (2.8 million miles)—without posing any risk of impact.

Due to its size and trajectory, 28861 is monitored by space agencies and astronomical organizations to assess long-term orbital dynamics. While current calculations suggest no imminent collision risk, its classification as a PHO reflects the need for continued observation to ensure future safety. Asteroids like 28861 are studied to better understand near-Earth objects (NEOs) and refine planetary defense strategies in case of potential future threats.

Researchers also examine such asteroids for scientific purposes, as they may provide insights into the early solar system’s composition and the processes that shaped planetary formation. Observations of 28861 contribute to broader efforts in asteroid characterization, including spectral analysis and radar imaging, which help classify its surface properties and internal structure.