2017 TD₆ is a micro-asteroid, classified as a near-Earth object of the Apollo group, approximately 10–20 meters in diameter. It was first observed by Pan-STARRS at Haleakala Observatory, Hawaii, on 11 October 2017.^[2]

On 19 October 2017, the asteroid transited Earth at a nominal distance of 191,000 km; 119,000 mi (0.001278 AU), which corresponds to 0.5 lunar distances (LD). On the following day it also passed near the Moon at 113,000 km (0.00075575 AU).^[1] Peaking near a magnitude of 18, the object was too faint to be seen—except for the largest telescopes.^[3]

As of 2018, 2017 TD₆ has a poorly determined orbit with an uncertainty of 6 and a short observation arc of 8 days only. Due to its small size, the asteroid is likely to remain unobserved until its next, still relatively distant approach, predicted to occur in March 2044, at a distance of 2,030,000 km (0.01358 AU) or 5.3 LD from Earth.^[1]

• 2012 TC4 – A similar small asteroid that passed close to the earth on 12 October 2017

• MPEC 2017-U33 : 2017 TD6, Minor Planet Electronic Circular (MPEC)
• Near-Earth asteroid 2017 TD6 very close encounter: an image (18 Oct. 2017)
• Asteroid 2017 TD6 to flyby Earth at 0.5 LD on October 19, 2017, The Watchers, 18 October 2017
• 2017 TD6 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 2017 TD6 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• 2017 TD6 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters