(285263) 1998 QE2
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(285263) 1998 QE2 is a near-Earth asteroid 2.75 kilometers (1.71 mi) in diameter.[1] It was discovered on August 19, 1998, by the Lincoln Near Earth Asteroid Research (LINEAR) program located near Socorro, New Mexico.[2] 1998 QE2 has an observation arc of 14 years and has a well-determined orbit.[3]
Characteristics
The surface of 1998 QE2 is covered with a sooty substance, suggesting that this asteroid may have previously been a comet that experienced a close encounter with the Sun.[4] However, the Tisserand parameter with respect to Jupiter (TJ=3.2) does not make it obvious whether 1998 QE2 was ever a comet.[1] The asteroid is optically dark with an albedo of 0.06.[1] As an Amor asteroid,[3] the orbit of 1998 QE2 is entirely beyond Earth's orbit. The Earth minimum orbit intersection distance (E-MOID) with the orbit of the asteroid is 0.035 AU.[3] The asteroid has an orbital period of 3.77 years.
Satellite
Goldstone radar observations on May 29, 2013, discovered that a minor-planet moon roughly 600 meters (2,000 ft) in diameter orbits 1998 QE2.[6] In radar images, the satellite appears brighter than 1998 QE2 because it is rotating significantly more slowly and the much slower rotation rate compresses the radar return of the satellite along the Doppler axis. This makes the satellite appear narrow and bright compared to 1998 QE2.[7] Once the satellite's orbit is well determined, astronomers and astrophysicists will be able to determine the mass and density of 1998 QE2.
Earth approaches
On May 31, 2013, 1998 QE2 approached within 0.039 AU (15 lunar distances) of Earth at 20:59 UT (4:59 pm EDT).[3] This was the closest approach the asteroid will make to Earth for at least the next two centuries.[8] It will be a very strong radar target at Goldstone from May 30 to June 9 and Arecibo from June 6 to June 12.[1] At its closest approach the asteroid had an apparent magnitude of 11 and required a telescope to be seen.[1]
Integrating the orbital solution shows the asteroid passed 0.08 AU from Earth on June 8, 1975,[3] with an apparent magnitude of about 13.9.[9] The next notable close approach will be May 27, 2221, when the asteroid will pass Earth at a distance of 0.038 AU (5,700,000 km; 3,500,000 mi).[1]
References
- ^ a b c d e f Dr. Lance A. M. Benner (2013 May 28). "(285263) 1998 QE2 Goldstone Radar Observations Planning". NASA/JPL Asteroid Radar Research. Retrieved 2013-05-30.
{{cite web}}: Check date values in:|date=(help) - ^ "MPEC 1998-Q19 : 1998 QE2". IAU Minor Planet Center. 1998-08-22. Retrieved 2013-05-30. (J98Q02E)
- ^ a b c d e "JPL Close-Approach Data: 285263 (1998 QE2)". 2013-05-28 last obs (arc=14.7 years; Uncertainty=0). Retrieved 2013-05-30.
{{cite web}}: Check date values in:|date=(help) - ^ Deborah Netburn (May 24, 2013). "Dark, massive asteroid to fly by Earth on May 31". Retrieved May 24, 2013.
- ^ "JPL Small-Body Database Browser - 285263 (1998 QE2)". NASA. June 2, 2013. Retrieved June 2, 2013.
{{cite web}}: Cite uses deprecated parameter|authors=(help) - ^ "NASA Radar Reveals Asteroid Has Its Own Moon". NASA/JPL. May 30, 2013. Retrieved 2013-05-30.
- ^ Emily Lakdawalla (2013 May 30). "Say "hi!" to asteroid -- actually, asteroids -- (285263) 1998 QE2". The Planetary Society. Retrieved 2013-05-30.
{{cite web}}: Check date values in:|date=(help) - ^ "Asteroid 1998 QE2 to Sail Past Earth Nine Times Larger Than Cruise Ship". NASA/JPL Asteroid Radar Research. 2013 May 15. Retrieved 2013-06-01.
{{cite web}}: Check date values in:|date=(help) - ^ "(285263) 1998QE2 Ephemerides for 8 June 1975". NEODyS (Near Earth Objects - Dynamic Site). Retrieved 2013-05-30.