2007 FT₃ (also written 2007 FT3) is a lost asteroid^[2] with a short observation arc of 1.2 days that cannot be recovered with targeted observations and awaits serendipitous survey observations. It has a poorly constrained orbit and has not been seen since 2007. It was first observed on 20 March 2007 when the asteroid was estimated to be 0.19 ± 0.01 AU (28.4 ± 1.5 million km) from Earth and had a solar elongation of 107 degrees. 2007 FT₃ is the fourth largest asteroid with better than a 1-in-2 million cumulative chance of impacting Earth after (29075) 1950 DA, 1979 XB, and 101955 Bennu. With a cumulative Palermo Technical Impact Hazard Scale of -2.93, the poorly known orbit and assumed size place 2007 FT₃ fifth on an unconstrained listing of the Sentry Risk Table.^[6]

The 2 October 2013 virtual impactor did not occur.^[5] The uncertainty region of ± 330 million kilometers wrapped around a large portion of the asteroid's orbit so that the asteroid could have been numerous different distances from the Earth.

The 3 October 2019 virtual impactor did not occur. The poorly constrained nominal orbit suggested that the closest approach the asteroid would make to Earth in 2019 was in late March at a distance of 0.14 AU (21,000,000 km; 13,000,000 mi).^[7] But the line of variation (LOV) for this asteroid was hundreds of millions of kilometers long.

There was an estimated 1 in 11 million chance of the asteroid impacting Earth on 3 October 2019.^[5] The nominal JPL Horizons 3 October 2019 Earth distance was 0.93 AU (139,000,000 km; 86,000,000 mi) with a 3-sigma uncertainty of ± 620 million km.^[8] NEODyS listed the nominal 3 October 2019 Earth distance as 0.95 AU (142,000,000 km; 88,000,000 mi).^[7]

Since the asteroid has a short observation arc and the uncertainty in the orbit of the asteroid intersects Earth's orbit, simulations can not rule out the asteroid and Earth being at the same point in space on 3 October 2024. The nominal orbit suggests that closest approach the asteroid will make to Earth in 2024 will not be until the end of December when it may be ~1 AU from Earth (the same distance the Sun is from Earth).^[9] But the line of variation (LOV) for this asteroid is hundreds of millions of kilometers long.^[10]

With a short 1.2 day observation arc, the Sentry Risk Table shows an estimated 1 in 11 million chance of the asteroid impacting Earth on 2 October 2024,^[5] which is 1,900 times lower than the background threat.^{[lower-alpha 2]} The nominal JPL Horizons 2 October 2024 Earth distance is 1.7 AU (250,000,000 km; 160,000,000 mi) with a 3-sigma uncertainty of ± 500 million km.^[10] NEODyS lists the nominal 2 October 2024 Earth distance as 1.7 AU (250,000,000 km; 160,000,000 mi).^[9]

• 1979 XB
• 2014 MV67