Discovery [1] | |
---|---|
Discovered by | Brian P. Roman |
Discovery site | Palomar Obs. |
Discovery date | 23 September 1990 |
Designations | |
(4954) Eric | |
1990 SQ | |
Orbital characteristics [2] | |
Epoch 13 January 2016 (JD 2457400.5) | |
Uncertainty parameter 0 | |
Observation arc | 14681 days (40.19 yr) |
Aphelion | 2.8993 AU (433.73 Gm) |
Perihelion | 1.10393 AU (165.146 Gm) |
2.0016 AU (299.44 Gm) | |
Eccentricity | 0.44848 |
2.83 yr (1034.4 d) | |
314.18° | |
0° 20m 52.944s / day | |
Inclination | 17.4461° |
358.52° | |
52.429° | |
Earth MOID | 0.194843 AU (29.1481 Gm) |
Physical characteristics | |
Dimensions | 10.8 km |
5.4 km | |
12.052 [3] hours | |
S (SMASSII) | |
12.6 | |
4954 Eric (prov. designation: 1990 SQ) is an eccentric, stony asteroid, classified as near-Earth object of the Amor group, approximately 11 kilometers (6.8 miles) in diameter. It was discovered by American astronomer Brian Roman at Palomar Observatory on 23 September 1990. [4] The asteroid was named after its discoverer's son, Eric Roman.
It is the largest near-Earth asteroid discovered since 3552 Don Quixote in 1983. [2] On 2007 October 11 the asteroid passed 0.2865 AU (42,860,000 km; 26,630,000 mi) from Earth. [4] It currently makes closer approaches to Mars than it does Earth. The asteroid has a rotation period of 12.05 hours. [3]
Other large near-Earth asteroids include 1036 Ganymed (32 km), 3552 Don Quixote (19 km), 433 Eros (17 km), and 1866 Sisyphus (8.5 km). [2] [5]
3552 Don Quixote, provisionally designated 1983 SA, is an exceptionally eccentric asteroid, classified as a near-Earth object of the Amor group, Mars-crosser and Jupiter-crosser, as well as a weakly active comet.
1866 Sisyphus is a binary stony asteroid, near-Earth object and the largest member of the Apollo group, approximately 7 kilometers in diameter.
2002 MN is the provisional designation given to a 73-meter Apollo near-Earth asteroid that on 14 June 2002 passed Earth at a distance of 0.0008 AU, about one third the distance to the Moon (0.3 LD). The close approach was second only to the Earth approach by the 10-meter asteroid 1994 XM1. 2002 MN was discovered on 17 June 2002, three days after closest approach. Its mass and relative velocity were in the same general range as the object ascribed to the Tunguska event of 1908, which leveled over 2,100 km2 (800 sq mi) of trees in Siberia.
2006 RH120 is a tiny near-Earth asteroid and fast rotator with a diameter of approximately 2–3 meters that ordinarily orbits the Sun but makes close approaches to the Earth–Moon system around every twenty years, when it can temporarily enter Earth orbit through temporary satellite capture (TSC). Most recently, it was in Earth orbit from July 2006 to July 2007, during which time it was never more than 0.0116 AU (1.74 million km) from Earth. As a consequence of its temporary orbit around the Earth, it is currently the second smallest asteroid in the Solar System with a well-known orbit, after 2021 GM1. Until given a minor planet designation on 18 February 2008, the object was known as 6R10DB9, an internal identification number assigned by the Catalina Sky Survey.
(4953) 1990 MU is a large Earth-crossing asteroid (ECA) belonging to the Apollo group of near-Earth objects which also cross the orbits of Mars and Venus. At approximately 3 km in diameter, it is one of the largest known ECAs. It has been assigned a permanent number from the Minor Planet Center (4953) indicating that its orbit has been very well determined. With an observation arc of 45 years, the asteroid's trajectory and uncertainty regions are well known through to the year 2186.
6144 Kondojiro (1994 EQ3) is an asteroid discovered on 14 March 1994 by Kin Endate and Kazuro Watanabe at the Kitami Observatory in eastern Hokkaidō, Japan. It is named after Jiro Kondo, a Japanese Egyptologist and professor of archaeology at Waseda University.
2011 CQ1 is a meteoroid discovered on 4 February 2011 by Richard A. Kowalski, at the Catalina Sky Survey. On the same day the meteoroid passed within 0.85 Earth radii (5,480 kilometers (3,410 mi)) of Earth's surface, and was perturbed from the Apollo class to the Aten class of near-Earth objects. With a relative velocity of only 9.7 km/s, had the asteroid passed less than 0.5 Earth radii from Earth's surface, it would have fallen as a brilliant fireball. The meteoroid is between 80 centimeters (31 in) and 2.6 meters (100 in) wide. The meteoroid was removed from the Sentry Risk Table on 5 February 2011.
(7888) 1993 UC is a near-Earth minor planet in the Apollo group. It was discovered by Robert H. McNaught at the Siding Spring Observatory in Coonabarabran, New South Wales, Australia, on 20 October 1993. The asteroid has an observation arc of 34 years and has a well determined orbit. Its estimated size is 2.3 to 5.2 km.
(612358) 2002 JE9 (also written 2002 JE9) is an Apollo near-Earth asteroid and potentially hazardous object. It has a well determined orbit with an observation arc of 10 years and an Uncertainty Parameter of 1. It was removed from the Sentry Risk Table on 10 May 2002. 2002 JE9 was discovered on 6 May 2002 by the Lincoln Near-Earth Asteroid Research (LINEAR) project using a 1.0-metre (39 in) Reflecting telescope; at the time of discovery, the asteroid possessed an apparent magnitude of 19.1.
(152680) 1998 KJ9 is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. Based on absolute magnitude, it is the third largest asteroid known to have passed closer than the Moon.
(308242) 2005 GO21 is a large Aten near-Earth asteroid and potentially hazardous object. It has a well determined orbit with an observation arc of 7 years and an uncertainty parameter of 0. It was discovered on 1 April 2005 by the Siding Spring Survey at an apparent magnitude of 18.1 using the 0.5-metre (20 in) Uppsala Southern Schmidt Telescope.
(511002) 2013 MZ5, provisional designation 2013 MZ5, is a sub-kilometer asteroid, classified as a near-Earth object of the Amor group, estimated to measure approximately 300 meters (1,000 feet) in diameter. It was discovered on 18 June 2013, by astronomers with the Pan-STARRS survey at Haleakala Observatory on the island of Maui, Hawaii, in the United States. It was the 10,000th near-Earth object ever discovered.
(523662) 2012 MU2, provisional designation 2012 MU2, is a sub-kilometer asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 18 June 2012 by astronomers of the Catalina Sky Survey at an apparent magnitude of 19.9 using a 0.68-meter (27 in) Schmidt–Cassegrain telescope. It has an estimated diameter of 240 meters (790 ft). The asteroid was listed on Sentry Risk Table with a Torino Scale rating of 1 on 23 June 2012.
(415029) 2011 UL21, provisional designation 2011 UL21, is an Apollo class potentially hazardous asteroid discovered on October 17, 2011, by the Catalina Sky Survey project. The asteroid is estimated to have a diameter of 2.5 kilometres (1.6 mi). It was rated at Torino Scale 1 on October 27, 2011, with an observation arc of 9.6 days.
2017 VW13 is an Apollo near-Earth asteroid roughly 250 meters (820 feet) in diameter. It was discovered on 13 November 2017 when the asteroid was about 0.069 AU (10,300,000 km; 6,400,000 mi) from Earth and had a solar elongation of 110 degrees. Ten days earlier, on 3 November 2017, the asteroid had passed 0.02818 AU (4,216,000 km; 2,619,000 mi) from Earth, but only had a solar elongation of 65 degrees.
2018 XB4 (also written 2018 XB4) is an Apollo near-Earth asteroid roughly 53 meters (170 feet) in diameter. It was discovered on 13 December 2018 when the asteroid was about 0.125 AU (18,700,000 km; 11,600,000 mi) from Earth and had a solar elongation of 146°. It passed closest approach to Earth on 1 January 2019. Of the asteroids discovered in 2018, it had the highest Palermo scale rating at –3.6. In mid-2019 it was recovered which extended the observation arc to 177 days and was removed from the Sentry Risk Table on 12 June 2019. It is now known that on 22 June 2092 the asteroid will pass about 0.033±0.015 AU from Earth.
(501647) 2014 SD224 is an Aten near-Earth asteroid around 150 meters (490 feet) in diameter. It was discovered on 22 September 2014 when the asteroid was 0.29 AU (43 million km; 110 LD) from Earth and had a solar elongation of 123 degrees. The glare of the Sun had masked the approach of the asteroid as it passed closest approach to Earth on 11 August 2014. The asteroid now has a 6-year observation arc and a well-determined orbit. It also makes close approaches to Venus.
2020 LD is an Apollo near-Earth asteroid roughly 140 meters in diameter. It was discovered on 7 June 2020 when the asteroid was about 0.03 AU from Earth and had a solar elongation of 154 degrees. The glare of the Sun had masked the approach of the asteroid since November 2019. The asteroid passed closest approach to Earth on 5 June 2020 at a distance of 0.002 AU. The close approach distance is now known with an accuracy of roughly ± 1000 km. This is the largest asteroid to pass closer than the Moon this year and possibly the largest since (308635) 2005 YU55 in November 2011. The asteroid makes close approaches to Mercury, Venus, Earth, and Mars. It will be brighter than apparent magnitude 24 until 18 July 2020.
2020 XR is an Apollo near-Earth object and potentially hazardous asteroid roughly 390 meters in diameter. With a 5-day observation arc it was briefly listed as having a 1 in 11,000 chance of impacting Earth on 1 December 2028 placing it at the top of the Sentry Risk Table with a Palermo scale rating of -0.70.
2020 AP1 is an Apollo near-Earth object roughly 5 meters (20 feet) in diameter. On 2 January 2020 it passed 0.00218 AU (326 thousand km; 0.85 LD) from Earth. With a short 1-day observation arc it was roughly expected to pass about 0.01 AU (1.5 million km; 3.9 LD) from Earth on 7 January 2022, but with an uncertainty of ±8 days for the close approach date it could have passed significantly closer or further.