Discovery [1] [2] [3] | |
---|---|
Discovered by | LINEAR |
Discovery site | Lincoln Lab's ETS |
Discovery date | 19 August 1998 |
Designations | |
(285263) 1998 QE2 | |
1998 QE2 | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 19.24 yr (7,029 days) |
Aphelion | 3.8092 AU |
Perihelion | 1.0377 AU |
2.4234 AU | |
Eccentricity | 0.5718 |
3.77 yr (1,378 days) | |
49.758° | |
0° 15m 40.32s / day | |
Inclination | 12.859° |
250.14° | |
345.65° | |
Known satellites | 1 [4] [lower-alpha 1] |
Earth MOID | 0.0345 AU (13.4 LD) |
TJupiter | 3.239 |
Physical characteristics | |
Mean diameter |
|
| |
S (assumed) [5] | |
(285263) 1998 QE2, provisional designation 1998 QE2, is a dark asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Amor group, approximately 3 kilometers in diameter. [7] It was discovered on 19 August 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. [2] Its sub-kilometer minor-planet moon was discovered by radar on 30 May 2013. [4] [lower-alpha 1]
As an Amor asteroid the orbit of 1998 QE2 is entirely beyond Earth's orbit. The asteroid orbits the Sun at a distance of 1.0–3.8 AU once every 3 years and 9 months (1,378 days; semi-major axis of 2.42 AU). Its orbit has an eccentricity of 0.57 and an inclination of 13° with respect to the ecliptic. The Earth minimum orbit intersection distance with the orbit of the asteroid is 0.035 AU (5,200,000 km ; 3,300,000 mi ), which translates into 13.4 lunar distances. As with many members of the Amor group, this asteroid has an aphelion beyond the orbit of Mars (at 1.66 AU) which also makes it a Mars-crosser. [1]
The sooty surface of 1998 QE2 suggested that it might have previously been a comet that experienced a close encounter with the Sun. [11] However, the Tisserand parameter with respect to Jupiter (TJ=3.2) does not make it obvious whether 1998 QE2 was ever a comet, since cometary TJ values are typically below 3. [6]
On 31 May 2013, 1998 QE2 approached within 0.039 AU (5,800,000 km; 3,600,000 mi) (15 lunar distances) of Earth at 20:59 UT (4:59 pm EDT). [12] This was the closest approach the asteroid will make to Earth for at least the next two centuries. [13] It is a very strong radar target for Goldstone from May 30 to June 9 and will be one for Arecibo from June 6 to June 12. [6] At its closest approach the asteroid had an apparent magnitude of 11 and therefore required a small telescope to be seen. [6]
Integrating the orbital solution shows the asteroid passed 0.08 AU (12,000,000 km; 7,400,000 mi) from Earth on 8 June 1975 [12] with an apparent magnitude of about 13.9. [14] The next notable close approach will be 27 May 2221, when the asteroid will pass Earth at a distance of 0.038 AU (5,700,000 km; 3,500,000 mi). [6]
Goldstone radar observations on 29 May 2013 discovered that 1998 QE2 is orbited by a minor-planet moon approximately 600–800 meters in diameter. [4] [15] [lower-alpha 1] In radar images, the satellite appears brighter than 1998 QE2 because it is rotating significantly more slowly, which compresses the radar return of the satellite along the Doppler axis. This makes the satellite appear narrow and bright compared to 1998 QE2. [16] The satellite orbits the primary every 32 hours with a maximum separation of 6.4 kilometers (4.0 mi). [17] Once the satellite's orbit is well determined, astronomers and astrophysicists will be able to determine the mass and density of 1998 QE2.
The surface of 1998 QE2 is covered with a sooty substance, making it optically dark with a geometric albedo of 0.06, [6] meaning it absorbs 94% of the light that hits it, which is indicative for a carbonaceous surface of a C-type asteroid. The asteroid is covered with craters and is dark, red, and primitive. [18]
With a diameter between 2.7 and 3.2 kilometers, 1998 QE2 is one of largest known potentially hazardous asteroid (see PHA-list). [19] Conversely, the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.08 kilometers based on an absolute magnitude of 17.2. [5]
4486 Mithra, is an eccentric asteroid and suspected contact-binary, classified as near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It belongs to the Apollo group of asteroids and is a relatively slow rotator.
66391 Moshup, provisional designation 1999 KW4, is a binary asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Aten group, approximately 1.3 kilometers in diameter. It was discovered on 20 May 1999, by Lincoln Near-Earth Asteroid Research (LINEAR) at the Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States. It is a Mercury-crosser that comes extremely close to the Sun at a perihelion of 0.2 AU.
(33342) 1998 WT24 is a bright, sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid (PHA) of the Aten group, located in Venus's zone of influence that has frequent close encounters with Mercury, Venus, and Earth. It made a close approach to Earth on 11 December 2015, passing at a distance of about 4.2 million kilometers (2.6 million miles, 11 lunar distances) and reaching about apparent magnitude 11.
(153591) 2001 SN263 is a carbonaceous trinary asteroid, classified as near-Earth object and former potentially hazardous asteroid of the Amor group, approximately 2.6 kilometers (1.6 miles) in diameter. It was discovered by the Lincoln Near-Earth Asteroid Research project at Lincoln Lab's Experimental Test Site in Socorro, New Mexico, on 20 September 2001. The two synchronous minor-planet moons measure approximately 770 and 430 meters and have an orbital period of 16.46 and 150 hours, respectively.
4450 Pan is a highly eccentric asteroid and contact binary, classified as a potentially hazardous asteroid and near-Earth object of the Apollo group, approximately 1.1 kilometers in diameter. It was discovered on 25 September 1987, by American astronomers Eugene and Carolyn Shoemaker at Palomar Observatory in California, United States. It was named after Pan from Greek mythology.
3122 Florence is a stony trinary asteroid of the Amor group. It is classified as a near-Earth object and potentially hazardous asteroid. It measures approximately 5 kilometers in diameter. It orbits the Sun at a distance of 1.0–2.5 AU once every 2 years and 4 months ; the orbit has an eccentricity of 0.42 and an inclination of 22° with respect to the ecliptic. Florence has two moons.
(450894) 2008 BT18 is a sub-kilometer asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 31 January 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The eccentric asteroid measures approximately 600 meters in diameter and has a composition of a basaltic achondrite.
(5646) 1990 TR is a probable rare-type binary asteroid classified as near-Earth object of the Amor group, approximately 2.3 kilometers in diameter. It was discovered on 11 October 1990, by Japanese astronomers Seiji Ueda and Hiroshi Kaneda at Kushiro Observatory near Kushiro, in eastern Hokkaido, Japan.
(6037) 1988 EG, is an eccentric, stony asteroid, classified as near-Earth object and potentially hazardous asteroid. It belongs to the group of Apollo asteroids and measures approximately half a kilometer in diameter. It was discovered by American astronomer Jeff T. Alu at the U.S. Palomar Observatory, California, on 12 March 1988.
(7482) 1994 PC1 is a stony asteroid, classified as near-Earth object and potentially hazardous asteroid of 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. The 2022 approach has been observed every month since August 2021.
(242450) 2004 QY2 (prov. designation:2004 QY2) is an asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 3 kilometers (2 miles) in diameter. It was discovered on 20 August 2004 by the Siding Spring Survey at an apparent magnitude of 16.5 using the 0.5-metre (20 in) Uppsala Southern Schmidt Telescope. It is one of the largest potentially hazardous asteroids known to exist.
(163132) 2002 CU11, provisional designation 2002 CU11, is a bright, sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. Based on absolute magnitude, it is the second largest asteroid known to have passed closer than the Moon.
(192642) 1999 RD32, provisional designation: 1999 RD32, is an asteroid and suspected contact binary on an eccentric orbit, classified as a large near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 5 kilometers (3 miles) in diameter. It was discovered on 8 September 1999, at a magnitude of 18, by astronomers of the LINEAR program using its 1-meter telescope at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The asteroid is likely of carbonaceous composition and has a rotation period of 17.08 hours.
(357439) 2004 BL86 is a bright sub-kilometer asteroid and binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters (980 ft) in diameter. It was discovered on 30 January 2004 by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. Its 70-meter (200 ft) moon was discovered during the asteroid's close approach to the Earth in January 2015.
2014 JO25 is a near-Earth asteroid. It was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona - a project of NASA's NEO (Near Earth Object) Observations Program in collaboration with the University of Arizona.
(52768) 1998 OR2 (provisional designation 1998 OR2) is an asteroid on an eccentric orbit, classified as a near-Earth object and potentially hazardous asteroid of the Amor group, with a diameter of 2 kilometers (1.2 mi). It was discovered on 24 July 1998, by astronomers of the Near-Earth Asteroid Tracking (NEAT) program at the Haleakala Observatory, Hawaii. It is one of the brightest and therefore largest potentially hazardous asteroids known to exist. With an observation arc of 35 years, the asteroid has a well-determined orbit, and its trajectory is well known through the year 2197. The asteroid's orbit is only potentially hazardous on a time scale of thousands of years.
2013 GM3 is a micro-asteroid, classified as near-Earth object of the Aten group, approximately 20 meters in diameter. It was first observed on 3 April 2013, by astronomers of the Mount Lemmon Survey conducted at the Mount Lemmon Observatory near Tucson, Arizona, United States.
(505657) 2014 SR339, provisional designation 2014 SR339, is a dark and elongated asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 970 meters (3,200 feet) in diameter. It was discovered on 30 September 2014, by NASA's Wide-field Infrared Survey Explorer telescope (WISE) in Earth's orbit. Closely observed at Goldstone and Arecibo in February 2018, it has a rotation period of 8.7 hours.
(164121) 2003 YT1, provisional designation 2003 YT1, is a bright asteroid and synchronous binary system on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 2 kilometers (1.2 miles) in diameter. It was discovered on 18 December 2003, by astronomers with the Catalina Sky Survey at the Catalina Station near Tucson, Arizona, in the United States. The V-type asteroid has a short rotation period of 2.3 hours. Its 210-meter sized minor-planet moon was discovered at Arecibo Observatory in May 2004.
(85182) 1991 AQ, provisional designation 1991 AQ, is a stony asteroid on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.1 kilometers in diameter. It was discovered on 14 January 1991, by American astronomer Eleanor Helin at the Palomar Observatory in California. Based on its brightness variation of 0.69 magnitude, this Q-type asteroid is likely elongated. It belongs to the small group of potentially hazardous asteroids larger than one kilometer.