Planetary scientists
seek to fill in gaps in
outer solar system’s
formative years
Rock,
Rattle
Rolland
By Nadia Drake
Most scientists don’t wear protective headgear while giving talks. Then again, most scientists aren’t the
target of pastry-wielding colleagues.
past. Some of the proposals complement
a widely accepted theory that describes a
good chunk of the solar system’s formative years. Other ideas attempt to deal
with some apparent snags in the theory,
called the Nice model.
Named for the city in France where
researchers pulled it together, the
Nice story begins once the four giants
are fully grown and plants them much
closer together. Early chapters include
a few million years of the giant siblings
jostling and poking one another. The
tale’s middle is dominated by a period
of extreme turbulence that eventually
leads to a cataclysmic rearrangement
of the solar system — a dissonance that
resolves itself by the system’s billionth
birthday, with the giant planets moving
into the orbits occupied today.
Though this story explains many
observations about the solar system, it
doesn’t answer all the questions, such
NICOLLE RAGER FULLER
www.sciencenews.org
