9969 Braille

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9969 Braille
Discovery [1]
Discovered by E. F. Helin
K. J. Lawrence
Discovery site Palomar Obs.
Discovery date 27 May 1992
Designations
MPC designation 9969 Braille
Named after
Louis Braille
(inventor of braille)[2]
1992 KD
Mars-crosser
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc 23.53 yr (8,596 days)    
Aphelion 3.3551 AU
Perihelion 1.3265 AU
2.3408 AU
Eccentricity 0.4333
3.58 yr (1,308 days)
211.73°
Inclination 28.995°
241.95°
356.13°
Earth MOID 0.3138 AU
Physical characteristics
Dimensions 2.1 km × 1 km × 1 km
1.600±0.511 km[3]
1.64 km (derived)[4]
Mass 7.8×1015g
Mean density
3.9 g cm−3[5]
226.4 h[6]
226 h[7]
0.1289±0.2441[3]
0.18 (assumed)[4]
SMASS = Q
15.8[1]

9969 Braille is a small Mars-crossing asteroid that orbits the Sun once every 3.58 years.[8] It was discovered in 1992 by astronomers at Palomar observatory and later named after Louis Braille, the inventor of the writing system for the blind. It was photographed in closeup by the spacecraft Deep Space 1 in 1999, but a malfunction resulted in indistinct images.

Discovery and naming[edit]

Discovered on May 27, 1992, by E. F. Helin and K. J. Lawrence working at the Palomar observatory as part of NASA's Planet-Crossing Asteroid Survey, it was given the provisional designation 1992 KD.[9] Later, it was renamed Braille in honour of Louis Braille as suggested by Kennedy Space Center software engineer Kerry Babcock in The Planetary Society's contest titled "Name That Asteroid".[10][11]

Orbit[edit]

Orbit of 9969 Braille (blue), planets (red) and the Sun (black). The outermost planet shown is Jupiter.

Braille has an unusually inclined orbit, and belongs to the somewhat rare class of asteroids known as Mars-crossing asteroids. Simulations of its orbit by scientists of the Deep Space 1 project predict that it will evolve into an Earth-crossing orbit in about 4000 years.[12] Although its closest approach to the Sun is closer than Mars orbit, its highly elliptical orbit takes it almost half-way to Jupiter at its apoapsis, and as such its semi-major axis is too large for it to be classified as an Amor asteroid.

Physical characteristics[edit]

Braille is a Q-type asteroid, composed mostly of olivine and pyroxene. Early ground-based observations had suggested that it could have been a V-type asteroid with similarities of composition between it and the much larger 4 Vesta. The asteroid is irregularly shaped, measuring approximately 2.1 km × 1 km × 1 km.

Exploration[edit]

Detailed information about Braille comes primarily from the Deep Space 1 probe, which passed within 26 km of the asteroid on July 29, 1999,[13] and from extensive ground based observations done in conjunction with the mission.[8] By the time Deep Space 1 reached Braille, its ultraviolet spectrometer had failed, but it did return two CCD images of medium resolution and three infrared spectra during the encounter. However, although the probe came within 26 km of Braille, the images and spectra were taken from an approximate distance of 14 000 km, due to problems with the tracking system.[14]

The main purpose of the Deep Space 1 mission was technology testing, but the encounter with Braille was of strong scientific value. No lone asteroid as small as Braille had previously been observed from such a short distance.[15]

References[edit]

  1. ^ a b c "JPL Small-Body Database Browser: 9969 Braille (1992 KD)" (2015-12-09 last obs.). Jet Propulsion Laboratory. Retrieved 30 August 2016. 
  2. ^ Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (9969) Braille. Springer Berlin Heidelberg. p. 715. ISBN 978-3-540-00238-3. Retrieved 30 August 2016. 
  3. ^ a b Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407free to read. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 30 August 2016. 
  4. ^ a b "LCDB Data for (9969) Braille". Asteroid Lightcurve Database (LCDB). Retrieved 30 August 2016. 
  5. ^ Richter, I.; Brinza, D. E.; Cassel, M.; Glassmeier, K.-H.; Kuhnke, F.; Musmann, G.; et al. (December 2000). "First direct magnetic field measurements of an asteroidal magnetic field: DS1 at Braille". Geophysical Research Letters. 28 (10): 1913–1916. Bibcode:2001GeoRL..28.1913R. doi:10.1029/2000GL012679. Retrieved 30 August 2016. 
  6. ^ Oberst, J.; Mottola, S.; Di Martino, M.; Hicks, M.; Buratti, B.; Soderblom, L.; et al. (September 2001). "A Model for Rotation and Shape of Asteroid 9969 Braille from Ground-Based Observations and Images Obtained during the Deep Space 1 (DS1) Flyby". Icarus. 153 (1): 16–23. Bibcode:2001Icar..153...16O. doi:10.1006/icar.2001.6648. Retrieved 30 August 2016. 
  7. ^ di Martino, M.; Oberst, J.; Mottola, S. (September 1999). "Lightcurve studies of asteroid 9969 (1992 KD), fly-by target of the Deep Space 1 spacecraft.". Bulletin of the Astronomical Society. 31 (4): 1131. Bibcode:1999BAAS...31.1131D. Retrieved 30 August 2016. 
  8. ^ a b Buratti, B. J.; Britt, D. T.; Soderblom, L. A.; Hicks, M. D.; Boice, D. C.; Brown, R. H.; et al. (January 2004). "9969 Braille: Deep Space 1 infrared spectroscopy, geometric albedo, and classification". Icarus. 167 (1): 129–135. Bibcode:2004Icar..167..129B. doi:10.1016/j.icarus.2003.06.002. 
  9. ^ Susan Lendroth (July 28, 1999). "Spacecraft Target Asteroid Named in Planetary Society Contest". The Planetary Society. Retrieved January 8, 2008. 
  10. ^ MPC 35492 Minor Planet Center
  11. ^ "Asteroid target gets new name". Cable News Network. July 26, 1999. Archived from the original on February 8, 2008. Retrieved January 8, 2008. 
  12. ^ Calvin J. Hamilton. "Asteroid Braille". 
  13. ^ "A CLOSE-UP OF AN ASTEROID". National Aeronautics and Space Administration. 
  14. ^ M. Lazzarin; S. Fornasier; M. A. Barucci & M. Birlan (May 24, 2001). "Groundbased investigation of asteroid 9969 Braille, target of the spacecraft mission Deep Space 1". Astronomy & Astrophysics. 375 (1): 281–284. Bibcode:2001A&A...375..281L. doi:10.1051/0004-6361:20010789. Retrieved January 7, 2008. 
  15. ^ Oberst, J.; Mottola, S.; di Martino, M.; Hicks, M.; Buratti, B.; Soderblom, L.; Thomas, N. (September 2001). "A Model for Rotation and Shape of Asteroid 9969 Braille from Ground-Based Observations and Images Obtained during the Deep Space 1 (DS1) Flyby". Icarus. 153 (1): 16–23. Bibcode:2001Icar..153...16O. doi:10.1006/icar.2001.6648. 

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