Exo- und Riesenplaneten: Physik der Riesen- und Subriesenplaneten

T. Spohn, DLR-PF, Berlin

Überblick

Literatur:

Guillot und Gautier: Giant Planets. Treatise on Geophysics, Vol. 10Elsevier, p.439-464.

Spohn und Grenfell, Planets of the outer solar system, Landolt Börnstein, Group VI, Volume 4, Subvolume B, Springer Verlag, p. 392-403

Grenfell, Exoplanets, Landolt Börnstein, Group VI, Volume 4, Subvolume B, Springer Verlag, p. 404-407

Jupiter Saturn Uranus Neptun

Magnetic Fields

Jupiter Saturn Uranus Neptune

Moment [G R³] 4,3535 0,2108 0,2284 0,1424

Displacement [planetary radii]

0.11 0.004 0.33 0.55

Tilt [°] 9.5 1 60 47

Offset Tilted Dipole (OTD) models of the magnetic fields of the giant and sub-giant planets.

Magnetfelder

Radiation beltRadar on CassiniMicrowave radio emmission 13.8 GHz

19,2 AE

30,0 AE39,2 AE

9,6 AE

5,2 AE

CoRoT-7b: hot super-Earth

55 Cancri A

J

Chemical Components:Gas (H, He), Ice (NH3, CH4, H2O), Rock/Iron

Mars

Ganymede

Jupiter

Water Cloud Thunderstorm Northwest of Great Red Spot

Jupiter Lightning

Jupiter Inner Satellites and Rings

47

Large Satellites, Small Planets

Radius vs Density

Dichte ist unmittelbar mit der chemischen Zusammensetzung korreliert

Interior Structure

Interior Structure models aim at

the bulk chemistry of the planetthe masses of major chemical reservoirsthe depths to chemical discontinuities and phase transition boundariesthe variation with depth of thermodynamic state variables (ρ, P, T)

Interior Structure

ConstraintsMassMoment of inertia factorGravity fieldCloud chemistryCosmochemical constraintsLaboratory dataLuminosityMagnetic fieldSeismology

Gravity

Gravitational Potential

J2 and Moments of Inertia

More Complete Representation

e.g., Spohn et al., 1998oder auch Spohn in Bergmann Schäfer

June 24, 200353

Doppler Principle

Radau-Darwin-Relation for Planets in hydrostatic equilibrium

Rotation parameter m: Graviational acceleration at equator/Rotation acceleration at equator

Masse-Radius Beziehung (Zustandsgleichung)

The outer layer is primarily composed of molecular hydrogen. At greater depths the hydrogen starts resembling a liquid. At 10,000 kilometers below Jupiter's cloud top liquid hydrogen reaches a pressure of 1,000,000 bar with a temperature of 6,000° K. At this state hydrogen changes into a phase of liquid metallic hydrogen. In this state, the hydrogen atoms break down yeilding ionized protons and electrons similar to the Sun's interior. Below this is a layer dominated by ice where "ice" denotes a soupy liquid mixture of water, methane, and ammonia under high temperatures and pressures. Finally at the center is a rocky or rocky-ice core of up to 10 Earth masses.

The outer layer is primarily composed of molecular hydrogen. As we go deeper where the presure reaches 100,000 bars, the gas starts to resemble a hot liquid. When the hydrogen reaches a pressure of 1,000,000 bar, hydrogen changes into a new state of metallic hydrogen. In this state it resembles a molten metal. This metalic hydrogen state occurs at about half of Saturn's radius. Below this is a layer dominated by ice where "ice" denotes a soupy liquid mixture of water, methane, and ammonia under high temperatures and pressures. Finally at the center is a rocky or rocky-ice core.

This cut-away view shows Uranus composed of an outer envelope of molecular hydrogen, helium and methane roughly the mass of one to two Earths. Below this region Uranus appears to be composed of a mantle rich in water, methane, ammonia, and other elements. These elements are under high temperatures and pressures deep within the planet. The mantle is equivalent to 10 to 15 earth masses. Uranus's core is composed of rock and ice, and is likely no more than one Earth mass.

This cut-away view shows Neptune composed of an outer envelope of molecular hydrogen, helium and methane roughly the mass of one to two Earths. Below this region Neptune appears to be composed of a mantle rich in water, methane, ammonia, and other elements. These elements are under high temperatures and pressures deep within the planet. The mantle is equivalent to 10 to 15 earth masses. Neptune's core is composed of rock and ice, andis likely no more than one Earth mass.

Die beiden Voyager Sonden fliegen zu äußersten Grenze unseres Sonnensystems und suchen nach der Heliopause.

Die Heliopause ist etwa 8 – 23 Milliarden Kilometer von uns entfernt und sollte irgendwann in den nächsten zwei Jahrzehnten erreicht werden.

Die Voyagersonden haben Energie bis 2020. Dann werden die beiden Sonden etwa 15 Milliarden Kilometer von uns entfernt sein.

In etwa 296,000 Jahren wird Voyager 2 bei Sirius, dem hellsten Sern am nördlichen Nachthimmel, vorbeifliegen.