(29075) 1950 DA
is a risk-listed asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group, approximately in diameter. It once had the highest known probability of impacting Earth. In 2002, it had the highest Palermo scale rating with a value of 0.17 and a probability of 1 in 306 for a possible collision in 2880. Since that time, the estimated risk has been updated several times. In December 2015, the odds of an Earth impact were revised to 1 in 8,300 with a Palermo scale rating of −1.42., it is listed on the Sentry Risk Table with the highest cumulative Palermo scale rating of −0.93. is not assigned a Torino scale rating, because the 2880 date is over 100 years in the future. As of 11 September 2025, the odds of an Earth impact are 1 in 2,600.
Discovery and nomenclature
was first discovered on 23 February 1950 by Carl A. Wirtanen at Lick Observatory. It was observed for seventeen days and then lost because this short observation arc resulted in large uncertainties in Wirtanen's orbital solution. On 31 December 2000, it was recovered at Lowell Observatory and was announced as on 4 January 2001. Just two hours later it was recognized as.Observations
On 5 March 2001, made a close approach to Earth at a distance of. It was studied by radar at the Goldstone and Arecibo observatories from March 3 to 7, 2001.The studies showed that the asteroid has a mean diameter of 1.1 km, assuming that is a retrograde rotator. Optical lightcurve analysis by Lenka Šarounová and Petr Pravec shows that its rotation period is hours. Due to its short rotation period and high radar albedo, is thought to be fairly dense and likely composed of nickel–iron. In August 2014, scientists from the University of Tennessee determined that is a rubble pile rotating faster than the breakup limit for its density, implying the asteroid is held together by van der Waals forces rather than gravity.
made distant approaches to Earth on 20 May 2012, 5 February 2021 and 5 February 2023. However, at these times it was a quarter to half an AU away from Earth, preventing more useful astrometrics and timing that occurs when an object is closer to Earth. The next close approach that presents a good opportunity to observe the asteroid will be on 2 March 2032, when it will be from Earth. The following table lists the approaches closer than 0.1 AU until the year 2500. By 2136 the close approach solutions are becoming notably more divergent.
| Date | JPL SBDB nominal geocentric distance | uncertainty region |
| 2 March 2032 | ±10 km | |
| 19 March 2074 | ±30 km | |
| 10 March 2105 | ±43 km | |
| 11 March 2136 | ±387 km | |
| 8 March 2187 | ±1717 km | |
| 20 March 2218 | ±8712 km | |
| 18 March 2373 | ±2508 km | |
| 6 March 2455 | ±1650 km |
Possible Earth impact
has one of the best-determined asteroid orbital solutions. This is due to a combination of:- an orbit moderately inclined to the ecliptic plane ;
- high-precision radar astrometry, which provides its distance and is complementary to the measurements of angular positions;
- a 74-year observation arc;
- an uncertainty region controlled by resonance.
The energy released by a collision with an object the size of would cause major effects on the climate and biosphere, which would be devastating to human civilization. The discovery of the potential impact heightened interest in asteroid deflection strategies.