Sky and Telescope - June 2018 - 23
OSIRIS-RE X: N ASA GODDA RD SPACE FLIG H T CEN TER CONCEPT UA L
IM AG E L A B; ORBITS: G REGG DINDER M A N / S&T
would give us a rare look at the very material from which
own planet accreted, without ambiguity about its provenance
and context. Planetary scientists thus hope that the
he s m l l
caches Hayabusa 2 and Osiris-REX bring back to Earth
ar t h will
reveal precious new information that even our vast
of fallen meteorites cannot provide.
Petite and Primitive
and OsirisThe diminutive destinations of the Hayabusa 2 and
REX missions are, respectively, the near-Earth asteroids
162173 Ryugu (formerly designated 1999 JU3) and
Bennu (provisionally tagged as 1999 RQ36 when iitt was
discovered). Scientists chose these targets not only
compositions, but also because both are comparatively
ly e y
u ASTEROIDS AMONG US Ryugu and Bennu's orbits nestle among
those of the inner planets, shown here at their locations for July 1st.
They are only two of the nearly 4,000 known asteroids whose orbits lie
within that of Mars (see page 16 for an accurate plot of those bodies).
This summer, two spacecraft will bear down
on their target asteroids, preparing to snatch
rubble and bring it home to scientists.
sk yandtelescope.com * J U N E 2 018