| 19 August 1998|
6346 days (17.37 yr)
19 August 1998
| 3.8081 AU (569.68 Gm) (Q)|
1.0376 AU (155.22 Gm) (q)
Lincoln Near-Earth Asteroid Research
367943 Duende, 2013 TV135, Nova Centauri 2013, Kepler‑37b, 2013 EC
(285263) 1998 QE2 is an Amor near-Earth asteroid 2.75 kilometers (1.71 mi) in diameter. It was discovered on August 19, 1998, by the Lincoln Near Earth Asteroid Research (LINEAR) program located near Socorro, New Mexico. 1998 QE2 has an observation arc of 14 years and a well-determined orbit.
(285263) 1998 QE2 Wikipedia
The surface of (285263) 1998 QE2 is covered with a sooty substance, suggesting that it might have previously been a comet that experienced a close encounter with the Sun. However, the Tisserand parameter with respect to Jupiter (TJ=3.2) does not make it obvious whether (285263) 1998 QE2 was ever a comet. The asteroid is optically dark with an albedo of 0.06, meaning it absorbs 94% of the light that hits it. The asteroid is covered with craters and is dark, red, and primitive. As an Amor asteroid, the orbit of (285263) 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 (5,200,000 km; 3,300,000 mi). The asteroid has an orbital period of 3.77 years.
Goldstone radar observations on May 29, 2013 discovered that (285263) 1998 QE2 is orbited by a minor-planet moon roughly 600 meters (2,000 ft) in diameter. In radar images, the satellite appears brighter than (285263) 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 (285263) 1998 QE2. The satellite orbits the primary every 32 hours with a maximum separation of 6.4 kilometers (4.0 mi). Once the satellite's orbit is well determined, astronomers and astrophysicists will be able to determine the mass and density of (285263) 1998 QE2.
On May 31, 2013, (285263) 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). This was the closest approach the asteroid will make to Earth for at least the next two centuries. 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. At its closest approach the asteroid had an apparent magnitude of 11 and therefore required a small telescope to be seen.
Integrating the orbital solution shows the asteroid passed 0.08 AU (12,000,000 km; 7,400,000 mi) from Earth on June 8, 1975, with an apparent magnitude of about 13.9. 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).