Английская Википедия:1991 BA

Материал из Онлайн справочника
Перейти к навигацииПерейти к поиску

Шаблон:Short description Шаблон:Use dmy dates Шаблон:Infobox planet

1991 BA is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group that was first observed by Spacewatch on 18 January 1991, and passed within 160,000 km (100,000 mi) of Earth.[1][2] This is a little less than half the distance to the Moon. With a 5-hour observation arc the asteroid has a poorly constrained orbit and is considered lost. It could be a member of the Beta Taurids.[3]

Description

1991 BA is approximately 5 to 10 meters (15 to 30 ft) in diameter and is listed on the Sentry Risk Table.[4] It follows a highly eccentric (0.68), low-inclination (2.0°) orbit of 3.3 years duration, ranging between 0.71 and 3.7 AU from the Sun. 1991 BA was, at the time of its discovery, the smallest and closest confirmed asteroid outside of Earth's atmosphere.[5] 1991 BA is too faint to be observed except during close approaches to Earth and is considered lost.

Possible impact

The asteroid has a very short 5-hour observation arc that makes future predictions of its position unreliable. Virtual clones of the asteroid that fit the uncertainty region in the known trajectory use to show a 1 in 290,000 chance that the asteroid could impact Earth on 2023 January 18.[4] It is estimated that an impact would produce an upper atmosphere air burst equivalent to 16 kt TNT,[4] roughly equal to Nagasaki's Fat Man. The asteroid would appear as a bright fireball and fragment in the air burst into smaller pieces that would hit the ground at terminal velocity producing a meteorite strewn field. Impacts of objects this size are estimated to occur approximately once a year.[6] Asteroid Шаблон:Mpl was an object of similar size that was discovered less than a day before its impact on Earth on October 7, 2008 and produced a fireball and meteorite strewn field in the Sudan. The 18 January 2023 virtual impactor did not occur.

Virtual impactor[4]
Date Impact
probability
(1 in)
JPL Horizons
nominal geocentric
distance (AU)
NEODyS
nominal geocentric
distance (AU)
MPC[7]
nominal geocentric
distance (AU)
Find_Orb
nominal geocentric
distance (AU)
uncertainty
region
(3-sigma)
2023-01-18 Шаблон:Val Шаблон:Convert[8] Шаблон:Convert[9] Шаблон:Convert Шаблон:Convert[10] Шаблон:Nowrap[8]

There is a 1 in a million chance of impacting Earth on 19 January 2114.[4]

References

Шаблон:Reflist

External links

Шаблон:Small Solar System bodies Шаблон:Authority control

  1. Ошибка цитирования Неверный тег <ref>; для сносок jpl-close не указан текст
  2. Ошибка цитирования Неверный тег <ref>; для сносок MPC-1991BA не указан текст
  3. Peter Jenniskens Meteor Showers and their Parent Comets pg 463 fig 25.7
  4. 4,0 4,1 4,2 4,3 4,4 Ошибка цитирования Неверный тег <ref>; для сносок summary не указан текст
  5. Ошибка цитирования Неверный тег <ref>; для сносок Scotti1991 не указан текст
  6. Шаблон:Cite web
  7. Ошибка цитирования Неверный тег <ref>; для сносок MPC-eph не указан текст
  8. 8,0 8,1 Ошибка цитирования Неверный тег <ref>; для сносок Horizons2023 не указан текст
  9. Ошибка цитирования Неверный тег <ref>; для сносок NEODyS2023 не указан текст
  10. Ошибка цитирования Неверный тег <ref>; для сносок Find_Orb2023 не указан текст