Target asteroid for Hayabusa Mk II 2005

1
Target asteroid for Hayabusa Mk II (2005)

• C-type asteroids
• Low albedo 0.03-0.06
• neutral colors (VISNIR)
• Phyllosilicates, carbon
• Analogue material CM chondrites?
• 20 vol chondrules
• 5 vol CAIs
• 70 vol Fine-grained opaque matrix containing
  abundant phyllosilisates
• Several hundreds ppm Organic material

2
Important science by using samples from C type
asteroids (2005)

• Aim of science To search the origin of life in
  the solar system
• (1) Origin of chirality of terrestrial life
• (2) Origin of water on planets
• To clarify No. 1, a considerable amount of sample
  is required.
• gt total amount of sample 10 g
• 1.5 g for initial analysis
• gt500 mg is enough to determine the chilarity and
  isotopic composition of alanine, which is the
  most abundant organic material in meteorites.
• gt2 sets of the above analysis will be
  performed to evaluate the degree of terrestrial
  contamination
• gt200 mg for the analysis of silicates
  (almost the same amount of the case of the
  Hayabusa mission)
• gt300 mg for the analysis of water in the
  sample

3
Criteria of Success of the Mission

• 1. The spacecraft reaches the target asteroid.
  Imaging of its surface, VIS and NIR spectra, and
  XRS are obtained. (These results are almost the
  same as data obtained by Hayabusa.)
• ? Constitutents of C-type asteroids were
  determined.
• Minimum success without sample return
• 2. Data measured by SSP are obtained.
• ? Identification of surface material of C-type
  asteroids.
• (Mineralogy and absence or presence of
  organic materials)
• Maximum success without sample return
• 3. Sample return to the Earth
• (The same as the maximum result of
  Hayabusa)
• ? Detail analysis of the surface material of
  C-type asteroid. By using these sample, isotopic
  composition of carbon in the sample can be
  determined to discuss the relationships between
  carbon in C-type asteroids and the Earth.
• Minimum success with sample return
• 4. 1-g sample return from the interior of the
  target asteroid (subsurface sample)
• ?In addition to the results in No.3, absence or
  presence of organic matter in the sample can be
  determined.
• Moderate success with sample return
• 5. 10-g sample return form the interior of the
  target asteroid
• ?In addition to the results in No. 4, we can
  determine the chirality of organic matter and
  isotopic compositions of water in the sample to
  discuss the origin of water.
• Maximum success with sample return