2135 Aristaeus is a potentially hazardous asteroid (PHA) because its minimum orbit intersection distance (MOID) is less than 0.05 AU and its diameter is greater than 150 meters. The Earth-MOID is 0.0100 AU (1,500,000 km; 930,000 mi).[1] Its orbit is well-determined for the next several hundred years.
The asteroid made its closest approach to Earth on April 1, 1977, at a nominal distance of 0.03216 AU (4,811,000 km; 2,989,000 mi).[1] It will make its next closest approach on April 2, 2064, at a nominal distance of 0.0546 AU (8,170,000 km; 5,080,000 mi).[1]