20 ASTRONOMY • JUNE 2020
- Spitzer discovered
Saturn’s outermost ring
in 2009. Named after the
moon Phoebe that orbits
just beyond it, the dusty
ring extends roughly from
3.7 million miles (6 million
km) to 7.4 million miles
(12 million km) from the
planet. This artist’s concept
shows the ring to scale with
Saturn as a dot. (The inset
shows an infrared view
of the planet through the
10-meter Keck Telescope.)
NASA/JPL-CALTECH/R. HURT (SSC)
2
3
1
- Spitzer discovered water
vapor in the atmospheres of
several “hot Jupiters,” gas
giant exoplanets that orbit
close to their host stars.
This illustration depicts an
infrared view of such a
world as it begins to transit
its parent star. ESA/C. CARREAU