New Results on the Composition of the Outer Planets and Titandoi:10.1017/S1539299600017421Thierry FouchetCambridge University Press
Stars and planets are formed from the same cosmic gas and dust. In the course of the formation process, some of the material condenses and forms rocky planets, the rest is either accumulated by the star or becomes part of gaseous planets. The assumption of a connection between the compositi...
smoothly varying function of pressure at pressures beyond 0.4 脳 10 6 million atmospheres in all three planets; ( c ) the outer core of the Earth is a high-pressure modification of ultrabasic rock; ( d ) each planet has an inner core chemically distinct from the matter in the outer core...
What planets are inner and outer? Mercury, Venus, Earth and Mars are the inner planets, whereas the outer planets of the solar system are Jupiter, Saturn, Uranus and Neptune. Why is Mars an inner planet? Mars is an inner planet because it is made up of rocks, orbits closer to the sun...
A basic premise when estimating elemental budgets of planets is that they were constructed from material represented by our collection of undifferentiated, chondritic meteorites. This assumption has recently come under close scrutiny due to the super-chondritic 142Nd/144Nd composition of the accessible...
This peculiarity also holds in comparisons with solar analogs known to have close-in giant planets while the majority of solar analogs found not to have such giant planets in radial velocity monitoring show the solar abundance pattern. We discuss various explanations for this peculiarity, including ...
The population of planets smaller than approximately 1.7 Earth radii (R⊕) is widely interpreted as consisting of rocky worlds, generally referred to as super-Earths. This picture is largely corroborated by radial velocity mass measurements for close-in super-Earths but lacks constraints at lower...
. All known planets in this mass regime have lower densities requiring significant fractions of volatiles or H/He gas. We also constrain the mass and period of the outer companion in the Kepler-93 system from the long-term radial velocity trend and archival adaptive optics images. As the ...
Mercury’s unique characteristics are its high orbital eccentricity (0.2056 compared to 0.0067- 0.094 for the other seven planets), the large size of its Fe core compared to its mantle, and its similarity to the Moon, with craters upon craters, ejecta, impact basins, and smooth plains that ...
For over fifty years, a number of nations have been involved in the exploration of outer space. This research has been very costly, of course. Has this money been well spent or wasted? Some people believe that all or most space research should be eliminated because of its incredible expense...