2014 XL7

2014 XL7
Discovery[1]
Discovered by Mt. Lemmon Survey (G96)
Discovery date 11 December 2014
Designations
MPC designation 2014 XL7
Apollo NEO,
PHA[2]
Orbital characteristics[2]
Epoch 2014-Dec-09
(Uncertainty=7)[2]
Aphelion 2.54 AU (Q)
Perihelion 0.771 AU (q)
1.66 AU (a)
Eccentricity 0.534
2.13 yr
49.9° (M)
Inclination 7.52 °
74.59°
250.6°
Physical characteristics
Dimensions ~230 meters[3]
170 – 380 meters[4]
21[2]

    2014 XL7 (also written 2014 XL7) was the most dangerous potentially hazardous asteroid discovered in 2014 that remained on the Sentry Risk Table at the end of 2014.[5] The asteroid is estimated to be roughly 230 meters in diameter and had a cumulative 1 in 83000 chance of impacting Earth on 4–5 June between the years 2048 and 2084.[3] It was removed from the Sentry Risk Table on 15 January 2015 using JPL solution 9 with an observation arc of 35 days.[6]

    On 1 September 2014 the asteroid passed about 0.259 AU (38,700,000 km; 24,100,000 mi) from Earth,[7] but at that time the asteroid had an apparent magnitude of 25 and was roughly 25 degrees from the Sun.[8] It was discovered on 11 December 2014 by the Mount Lemmon Survey at an apparent magnitude of 20 using a 1.5-meter (59 in) reflecting telescope.[1] The asteroid has an observation arc of 35 days with an uncertainty parameter of 6.[2] The asteroid was last observed on 15 January 2015,[2] and is still being actively observed to better constrain the orbit. The asteroid will not drop below magnitude 25 until March 2015.[9]

    With an absolute magnitude of 21,[2] the asteroid is about 170–380 meters in diameter.[4]

    With an observation arc of 19 days, it had a cumulative Palermo Scale rating of –2.85 and was briefly the 9th most dangerous asteroid known.[5] It was calculated that on 4 June 2065 there was a 1 in 270000 chance of impact and on 4 June 2076 there was a 1 in 137000 chance of impact.[3] On 15 January 2015 the asteroid was recovered by Cerro Paranal Observatory which extended the observation arc to 35 days,[10] and 2014 XL7 was removed from the Sentry Risk Table.[6]

    References

    1. ↑ 1.0 1.1 "MPEC 2014-X76 : 2014 XL7". IAU Minor Planet Center. 2014-12-15. Retrieved 2015-01-01. (K14X07L)
    2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "JPL Small-Body Database Browser: (2014 XL7)" (last observation: 2014-12-30; arc: 19 days). Jet Propulsion Laboratory. Retrieved 2015-01-01.
    3. ↑ 3.0 3.1 3.2 "Earth Impact Risk Summary: 2014 XL7". WayBack Machine: NASA/JPL Near-Earth Object Program Office. 2014-12-31. Retrieved 2015-01-01.
    4. ↑ 4.0 4.1 "Absolute Magnitude (H)". NASA/JPL. Retrieved 2015-01-01.
    5. ↑ 5.0 5.1 "Sentry Risk Table". WayBack Machine: NASA/JPL Near-Earth Object Program Office. 2014-12-31. Retrieved 2015-01-01. (PS=–2.85)
    6. ↑ 6.0 6.1 "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Retrieved 2015-01-16.
    7. ↑ "JPL Close-Approach Data: (2014 XL7)" (last observation: 2014-12-30; arc: 19 days). Retrieved 2015-01-01.
    8. ↑ "2014XL7 Ephemerides for 1 September 2014". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2015-01-01.
    9. ↑ "2014XL7 Ephemerides for 1 January 2015 through 1 April 2015". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2014-12-12.
    10. ↑ "2014 XL7 Orbit". IAU Minor Planet Center. Retrieved 2015-01-16.