405 Thia

Not to be confused with 453 Tea, Theia (planet), or Thiazzi (moon).

405 Thia
Discovery
Discovered byAuguste Charlois
Discovery date23 July 1895
Designations
(405) Thia
Pronunciation/ˈθaɪə/[1]
Named after
Theia
1895 BZ
Main belt
Orbital characteristics[2]
Epoch 2023-Feb-25 (JD 2460000.5)
Uncertainty parameter 0
Observation arc123.54 years
Aphelion3.2145 AU (480.88 Gm)
Perihelion1.9592 AU (293.09 Gm)
2.5861 AU (386.88 Gm)
Eccentricity0.24341
4.16 yr (1518.3 d)
336.81°
0° 14m 13.164s / day
Inclination11.937°
255.19°
2 June 2023[2]
308.65°
Earth MOID0.975 AU (145.9 million km; 379 LD)
Physical characteristics
Dimensions124.90±2.3 km[2]
122.14 ± 7.69 km[3]
Mass(1.38 ± 0.14) × 1018 kg[3]
Mean density
1.44 ± 0.30 g/cm3[3]
10.08 h (0.420 d)
0.0468±0.002
C[2]
8.65

405 Thia is a very large main-belt asteroid. It is classified as a C-type asteroid and is probably composed of carbonaceous material. This object was discovered by Auguste Charlois on July 23, 1895, in Nice, and was named after Theia (sometimes written Thea or Thia), a Titaness in Greek mythology.[4]

In 2002, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.31 AU. The resulting data yielded an effective diameter of 125 ± 16 km.[5] NEOWISE data suggests the asteroid is 110 km in diameter.[2]

On 4 May 1990 Thia passed 0.969 AU (145.0 million km; 377 LD) from Earth[6] and will pass that close again on 29 April 2073.

405 Thia currently has a Minimum orbit intersection distance with Earth of 0.975 AU (145.9 million km; 379 LD)[2] and on 20 March 2023 will be 1.057 AU (158.1 million km; 411 LD) from Earth. Then on 2 June 2023 the asteroid will reach perihelion (closest approach to the Sun).[2]

Thia Earth approach on 2023-Mar-20
Date & time of
closest approach 		Earth distance
(AU) 		Sun distance
(AU) 		Velocity
wrt Earth
(km/s) 		Velocity
wrt Sun
(km/s) 		Uncertainty
region
(3-sigma) 		Reference
2023-03-20 19:40 1.057 AU (158.1 million km; 411 LD) 2.006 AU (300.1 million km; 781 LD) 6.8 23.3 ± 16 km Horizons
  1. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ^ a b c d e f g Cite error: The named reference jpldata was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Carry2012 was invoked but never defined (see the help page).
  4. ^ Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Berlin, Heidelberg, New York: Springer. p. 48. ISBN 3-540-00238-3. Archived from the original on 14 March 2014.
  5. ^ Cite error: The named reference icarus186_1_126 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Horizons1990 was invoked but never defined (see the help page).