2009 DD45 is a very small Apollo asteroid that passed near Earth at an altitude of 63,500 km (39,500 mi) on 2 March 2009 at 13:44 UTC. It was discovered by Australian astronomers with the Siding Spring Survey at the Siding Spring Observatory on 27 February 2009, only three days before its closest approach to the Earth.[4][5] Its estimated diameter is between 15 and 23 metres.[2] This is about the same size as a hypothetical object that could have caused the Tunguska event in 1908.[6]

BBC News Online cites the minimum distance as 72,000 km (45,000 mi) (about 1/5 lunar distances).[6][7] 2009 DD45 passed farther away (40 thousand miles versus 4 thousand miles) but was substantially larger than 2004 FU162, a small asteroid about 6 m (20 ft) across which came within about 6,500 km (4,000 mi) in 2004,[6] and is more similar in size to 2004 FH. With an observation arc of 7 days and an uncertainty parameter of 3, the asteroid will make its next close encounter with Earth on 29 February 2056 and then potentially around 3 March 2067.[2]

See also

References

  1. ^ a b c d "2009 DD45". Minor Planet Center. Retrieved 9 September 2020.
  2. ^ a b c d e f g h i j "JPL Small-Body Database Browser: (2009 DD45)" (2009-03-06 last obs.). Jet Propulsion Laboratory. Retrieved 9 September 2020.
  3. ^ "LCDB Data for (2009+DD45)". Asteroid Lightcurve Database (LCDB). Retrieved 9 September 2020.
  4. ^ Kelly Beatty (1 March 2009). "Space Rock 2009 DD45 Buzzes Earth". Sky & Telescope. Archived from the original on 6 March 2009. Retrieved 4 March 2009.
  5. ^ Victoria Jaggard (2 March 2009). "Surprise Asteroid Just Buzzed Earth". National Geographic Society. Archived from the original on 4 March 2009. Retrieved 4 March 2009.
  6. ^ a b c "Space rock makes close approach". BBC News Online. 3 March 2009. Archived from the original on 4 March 2009. Retrieved 3 March 2009.
  7. ^ Scientific American, May 2009 issue, listed the minimum distance as 72,200 km (p. 26)


Allikas: https://en.wikipedia.org/wiki/2009_DD45
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