# (7482) 1994 PC1

(7482) 1994 PC$_1$ is a stony asteroid and near-Earth object, currently estimated to be the most potentially hazardous asteroid over the next 1000 years. It is in the Apollo group, approximately 1.1 kilometers in diameter. It was discovered on 9 August 1994, by astronomer Robert McNaught at the Siding Spring Observatory in Coonabarabran, Australia. With an observation arc of 47 years it has a very well known orbit and was observed by Goldstone radar in January 1997.
Of all the known asteroids larger than 1 km, 1994 PC$_1$ has the largest probability of a “deep close encounter” with us over the next 1000 years. It has a close encounter with Earth in 2525, after which the uncertainty of its orbit increases.

## Orbit and classification

1994 PC$_1$ orbits the Sun at a distance of 0.9–1.8 AU once every 1 years and 7 months (572 days). Its orbit has an eccentricity of 0.33 and an inclination of 33° with respect to the ecliptic.
On 17 January 1933, it passed 811,350 km (504,150 mi) from the Moon and then about an hour later made its closest known approach to Earth of 1,125,400 km (699,300 mi). On 18 January 2022, it passed about 1,981,468 km (1,231,227 mi) from Earth.
Close approaches :
| Date | JPL SBDB nominal geocentric distance | uncertainty region (3-sigma) |
| 1933-01-17 | 1125383 km | ± 65 km |
| 2022-01-18 | 1981468 km | ± 47 km |
| 2105-01-18 | 2328125 km | ± 1069 km |

## Physical characteristics

In the SMASS classification, 1994 PC$_1$ is a common stony S-type asteroid.

### Rotation period

In 1998, a rotational lightcurve of 1994 PC$_1$ was obtained from photometric observations by Petr Pravec. Lightcurve analysis gave a well-defined rotation period of 2.5999 hours with a brightness amplitude of 0.29 magnitude (U=3).

### Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 1994 PC$_1$ measures 1.052 kilometers in diameter and its surface has an albedo of 0.277. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and calculates a diameter of 1.30 kilometers based on an absolute magnitude of 16.8.

## 2022 flyby

At 18 January 2022 21:51 UTC, 1994 PC$_1$ passed 5.15 lunar distances from Earth and had a 3-sigma uncertainty region of less than ± 50 km. It peaked at an apparent magnitude of about 10 placing it just outside the reach of common 7×50 binoculars. The nearly Full moon being about 100 degrees from the asteroid during closest approach may have made it more difficult to observe with smaller telescopes.
2022 Moon/Earth approach :
| Date & Time | Approach to | Nominal distance |
| 2022-01-18 18:58 | Moon | 2085780 km |
| 2022-01-18 21:51 | Earth | 1981468 km |
* v
* t
* e
| PHA | Date | Approach distance (lunar dist.) | Approach distance (lunar dist.) | Approach distance (lunar dist.) | Abs. mag (H) | Diameter $^{(C)}$ (m) | Ref $^{(D)}$ |
| PHA | Date | Nomi- nal$^{(B)}$ | Mini- mum | Maxi- mum | Abs. mag (H) | Diameter $^{(C)}$ (m) | Ref $^{(D)}$ |
| (33342) 1998 WT24 | 1908-12-16 | 3.542 | 3.537 | 3.547 | 17.9 | 556–1795 | data |
| (458732) 2011 MD5 | 1918-09-17 | 0.911 | 0.909 | 0.913 | 17.9 | 556–1795 | data |
| (7482) 1994 PC1 | 1933-01-17 | 2.927 | 2.927 | 2.928 | 16.8 | 749–1357 | data |
| 69230 Hermes | 1937-10-30 | 1.926 | 1.926 | 1.927 | 17.5 | 668–2158 | data |
| 69230 Hermes | 1942-04-26 | 1.651 | 1.651 | 1.651 | 17.5 | 668–2158 | data |
| (137108) 1999 AN10 | 1946-08-07 | 2.432 | 2.429 | 2.435 | 17.9 | 556–1795 | data |
| (33342) 1998 WT24 | 1956-12-16 | 3.523 | 3.523 | 3.523 | 17.9 | 556–1795 | data |
| (163243) 2002 FB3 | 1961-04-12 | 4.903 | 4.900 | 4.906 | 16.4 | 1669–1695 | data |
| (192642) 1999 RD32 | 1969-08-27 | 3.627 | 3.625 | 3.630 | 16.3 | 1161–3750 | data |
| (143651) 2003 QO104 | 1981-05-18 | 2.761 | 2.760 | 2.761 | 16.0 | 1333–4306 | data |
| 2017 CH1 | 1992-06-05 | 4.691 | 3.391 | 6.037 | 17.9 | 556–1795 | data |
| (170086) 2002 XR14 | 1995-06-24 | 4.259 | 4.259 | 4.260 | 18.0 | 531–1714 | data |
| (33342) 1998 WT24 | 2001-12-16 | 4.859 | 4.859 | 4.859 | 17.9 | 556–1795 | data |
| 4179 Toutatis | 2004-09-29 | 4.031 | 4.031 | 4.031 | 15.3 | 2440–2450 | data |
| 2014 JO25 | 2017-04-19 | 4.573 | 4.573 | 4.573 | 17.8 | 582–1879 | data |
| (137108) 1999 AN10 | 2027-08-07 | 1.014 | 1.010 | 1.019 | 17.9 | 556–1795 | data |
| (35396) 1997 XF11 | 2028-10-26 | 2.417 | 2.417 | 2.418 | 16.9 | 881–2845 | data |
| (154276) 2002 SY50 | 2071-10-30 | 3.415 | 3.412 | 3.418 | 17.6 | 714–1406 | data |
| (164121) 2003 YT1 | 2073-04-29 | 4.409 | 4.409 | 4.409 | 16.2 | 1167–2267 | data |
| (385343) 2002 LV | 2076-08-04 | 4.184 | 4.183 | 4.185 | 16.6 | 1011–3266 | data |
| (52768) 1998 OR2 | 2079-04-16 | 4.611 | 4.611 | 4.612 | 15.8 | 1462–4721 | data |
| (33342) 1998 WT24 | 2099-12-18 | 4.919 | 4.919 | 4.919 | 17.9 | 556–1795 | data |
| (85182) 1991 AQ | 2130-01-27 | 4.140 | 4.139 | 4.141 | 17.1 | 1100 | data |
| 314082 Dryope | 2186-07-16 | 3.709 | 2.996 | 4.786 | 17.5 | 668–2158 | data |
| (137126) 1999 CF9 | 2192-08-21 | 4.970 | 4.967 | 4.973 | 18.0 | 531–1714 | data |
| (290772) 2005 VC | 2198-05-05 | 1.951 | 1.791 | 2.134 | 17.6 | 638–2061 | data |
| $^{(A)}$ List includes near-Earth approaches of less than 5 lunar distances (LD) of objects with H brighter than 18. $^{(B)}$ Nominal geocentric distance from the Earth's center to the object's center (Earth radius≈0.017 LD). $^{(C)}$ Diameter: estimated, theoretical mean-diameter based on H and albedo range between X and Y. $^{(D)}$ Reference: data source from the JPL SBDB, with AU converted into LD (1 AU≈390 LD) $^{(E)}$ Color codes: unobserved at close approach observed during close approach upcoming approaches ||||||||

## Naming

As of 2022, this minor planet has not been named.