Saturn-Sized Worlds Discovered
Explanation:
The last
decade saw the profound discovery of
many worlds beyond our
solar system, but none analogs of our home
planet Earth.
Exploiting precise observational techniques,
astronomers inferred the presence of well over two dozen
extrasolar planets, most
nearly as massive as gas giant Jupiter or more, in close orbits
around sun-like stars.
Less massive planets must certainly exist, and yesterday
preeminent planet-finders announced the further
detection of two more new worlds -- each a potentially smaller,
saturn-sized planet.
The
parent suns are 79 Ceti
(constellation
Cetus), at a distance of 117 light-years, and
HD46375 (constellation
Monoceros),
109 light-years away.
With at least 70 percent the mass of Saturn, 79 Ceti's planet
orbits
on average 32.5 million miles from the star compared
to 93 million miles for the Earth-Sun
distance.
This arresting artist's vision depicts
the newly discovered world with rings and moons,
known characteristics of giant planets
in our solar system.
HD46375's planet is at least 80 percent Saturn's mass,
orbiting only 3.8 million miles from its parent star.
While
Saturn's mass
is only one third of
Jupiter's, it is still about
100 times that of Earth, and dramatic discoveries
in the
search for smaller
planets are
still to come.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
