Synodic orbit visualisation of asteroid (415029) 2011 UL21

Asteroid (415029) 2011 UL21 will pass Earth on 27 June. At 2310 m across, this asteroid is larger than 99% of all known near-Earth objects (NEOs). At its closest point, it will still be more than 17 times as far away as the Moon.

(415029) 2011 UL21 is in an ‘11:34 resonance’ with Earth. It completes 11 revolutions about the Sun in almost the exact same amount of time in which Earth completes 34 revolutions (i.e. 34 years).

The result is a pleasant repeating pattern when you visualise the asteroid’s location relative to Earth over a period of 34 years while keeping Earth fixed in place using a 'Synodic Orbit Visualisation Tool'.