Contents
1
AROUND AND AROUND
The Importance of Being Lucrezio / Eccentric Kepler / Tyge the
Astrologer / Newton Shoulders / Perturbations / Drawing
Orbits / Neptune’s Karma / Planets on a Diet / Gone with the Tides /
The opening of
the book pays tribute to the celebrated Latin poet Lucrezio describing
in his “De Rerum Natura” the principle of relative motion. Some basic
celestial mechanics follows: Kepler’s laws runling orbital motion,
gravitation and its many consequences.
2 THREE BODIES AND NO SOLUTION
Celestial Mechanics get the Blues / Lagrange in Equilibrium / Periodic
Solutions / Mapping Chaos / KAM and All That / Inside the Rings of
Saturn / A Flash in the Night
What happens when
more than two celestial bodies attract each other? Trajectories become
more and more complex until chaos enters the scene. The dynamics of the
spectacular ring system encircling Saturn provides fascinating
astronomical examples. A portrait of Henry Poincaré and of the
intriguing events which led to the discovery of chaos is used to
explain why his work still represents an enlightening source of
inspiration.
3 CELESTIAL WALTZ
Heavenly Resonances / Commensurable Motions / Greeks and Trojans /
Famous Affairs / The Chance of Chaos / Colombo's egg /
Resonances are
the key for understanding the stability and the evolution of dynamical
systems. The occurrence of commensurable motions in our Solar System is
more frequent than due to chance - from the well known case of Trojan
asteroids to the many ring-satellite interactions. Interplanetary
probes are also using resonances as an efficient means for reducing
fuel consumption.
4 COSMIC SPINNING
TOPS
Spin and Orbit / The Dark Side of the Moon / Tidal Frictions /
Geostationary Satellites / A Portrait of Mercury / Tidy Chaos / The
Obliquity of the Planets / Raiders of the Lost Equinoxes / Is the Land
of Atlantis really lost? / Astronology
The coupling
between the rotation of a celestial body and its orbital motion has
widespread consequences for celestial mechanics. Stable synchronous
(Moon-like) rotation is very common among natural satellites, while the
chaotic behaviour of the obliquity of a planet drives the long-term
evolution of the climate, thus being responsible of the development of
life. As concerning the Earth, the precession of the equinoxes and its
consequences is used for riding the lost celestial mechanics in search
of the ancient civilization which invented the constellations, until a
possible explanation of the myth of Atlantis is found.
5 OUR CHAOTIC
SOLAR SYSTEM
The Ubiquity of Chaos / Propagating Orbits / Planets in Numbers / The
Stability of the Solar System / Close Encounters
/ Raining
Comets / The long Journey of Meteorites / Jurassic Asteroids /
Chaos is a
leading field of study for modern planetary science. In the last two
decades it has provided the long-sought answer to many astronomical
problems, as for example the origin of meteorites and of the near-Earth
asteroids, the source region for periodic comets and the strange orbit
of Pluto.
6 SINGULARITIES,
COLLISIONS AND THREATENING BODIES
From Zero to Infinity / Collisions in the Solar System / Astroblames /
Near Earth Asteroids / Impact Probability / Don’t Panic / Mitigation /
When the distance
between two celestial bodies appearing at the denominator of Newton’s
law goes to zero, mathematically speaking we are dealing with a
singularity. Whenever the relative distance between two celestial
bodies becomes less than the sum of their radii, then a collision
occurs. The consequences of these two definitions are explained in
detail: the treatment of singularities as well as the mitigation
strategies developed for avoiding a catastrophic impact on our planet.
7 OF MOON AND MAN
The Cycles of Selene / Acts of the Gods / Eclipsed by the Saros /
Lunar Theories / Holidays in Elatina / Moonshadows / Ways to the Moon /
The Moon has
followed in many respects the evolution of mankind: science, religion,
myths and legends often end up in focusing on our satellite. Celestial
mechanics explains why and how the apparently simple motion of the Moon
(Newton is reported to have said it made his head ache) had influence
on the birth and the development of life on our planet: from the modern
interpretation of ancient eclipse prediction cycles to the recent
discovery of the Moon stabilizing effect on the Earth’s rotation.
8 ROCK AROUND THE
PLANETS
Space in Flight / Orbiting the Earth / Space Debris / The Accessibility
of Celestial Bodies / Going Deep Space / Highways to the Planets / Last
but not Least /
Spaceflight
dynamics does not only represents an “engineering” application of
celestial mechanics: in the years following the beginning of the space
era it has grown as a self-standing discipline. Its success is
witnessed by the great variety of orbital patterns now confidently
followed by the artificial satellites orbiting our planet as well as by
the deep space probes exploring the Solar System. With unavoidable
side-effects such as the overcrowding of the near-Earth space with
orbiting debris.
9 LORDS OF THE
RINGS
Ringed Worlds / Forbidden Regions / Jovian Halos / Sightseeing Saturn /
Elliptic rings / Arcs in the Skies / One upon a ring
Four hundred
years of observations, from Galileo Galilei to the Voyager and Cassini
missions, allow a comparative analysis of the ring systems surrounding
the outer planets. Although their extension and composition
significantly differs from planet to planet, celestial mechanics
represents the common driving force for explaining their present
appearance.
10 AT THE EDGE OF
THE SOLAR SYSTEM
Beyond Pluto / Smiley and the Others / Big Brothers are Watching Us /
Chiron and the Centaurs / Planet X /
Understanding the
nature of the transneptunian objects (TNO) represents the last frontier
of planetary science, In the ten years spent since the discovery of the
first TNO the population has grown sufficiently enough to allow a
preliminary characterization from a dynamical point of view. The
feeling is that we are only at the beginning of a long path eventually
leading to bridging the gap between the last of the planets and the
distant Oort cloud.
11 ON THE ROAD TO
EXOLIFE
Beyond the Solar System / Hunting for Exoplanets / A Galactic Zoo /
Astrobiology / Back to the Future /
The XIX.th
century great expectations on the existence of evolved life forms in
the Solar System have not been confirmed by the images sent back by
interplanetary probes. Yet at the end of the XX.th century the
detection of planets around other stars has extended the traditional
domain of celestial mechanics opening new perspectives for the quest of
life in the Universe.
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