Exploring the Trans-Neptunian Solar System (1998) / Chapter Skim
Currently Skimming:
1 The New Worlds Beyond 30 AU
1 The New Worlds Beyond 30 AU
Pages 7-17
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 7... ...
As a class, the trans-neptunian objects are primitive compared with inner solar system objects, but they do show evidence for diversity9 and for evolutionary processes having occurred.~° These newly discovered objects and their relationships represent a fertile, relatively unexplored region for investigation of fundamental questions on the origin and evolution of the solar system.
|
From page 9... ...
Because the inner part of the Kuiper Belt is unstable with respect to gravitational perturbations by Neptune, KBOs are suspected to be the major source for short-period comets that now reside within a few astronomical units of the Sun. The Centaurs appear to be former KBOs.~7 i~ That is, they are recently departed members of the Kuiper Belt, on their way to the inner solar system.
|
From page 10... ...
It is not explored in detail in this report, because it is beyond the scope of the current study. This report includes a general discussion of the five themes that characterize the outstanding scientific issues of the outer solar system, a review of current understanding of objects in the distant outer solar system, a description of observations that could address the outstanding issues, and a discussion of the technological developments that are necessary for these measurements.
|
From page 11... ...
in the outer solar nebula than in the inner solar nebula. Comets and the trans-neptunian objects are the relics of bodies in the outer solar system that failed to be incorporated into the giant planets during the runaway growth of their cores.
|
From page 12... ...
Figure courtesy of Dale Cruikshank, NASA Ames Research Center. Most of the inner solar system is devoid of remnants of these planet-building bodies.
|
From page 13... ...
Geology Voyager images of the icy satellites of the giant planets suggest that the level of geological activity depends on composition, silicate content (which leads to radioactive heating) , and the presence or absence of tidal heating.27 Further complications arise if relatively large impacts have disrupted the satellites in question: a situation argued to occur for moons close to their parent giant planets whose strong gravity focuses impactor trajectories or for satellites that may have undergone major collisions during capture.
|
From page 14... ...
Currently, although the color of some of the KBOs has been measured,28 there is little information about their surface compositions, and it is useful to consider the Centaurs Pholus and Chiron as illustrations of how comparison of surface composition may provide information about the different surface processes experienced by trans-neptunian objects. If it is assumed that both Pholus and Chiron began with similar complements of surface materials, then the observed strong difference in color and near-infrared spectral features suggests that these bodies experienced very different processes that produced their current surface compositions.
|
From page 15... ...
might be capable of detecting our own dust disk.34 Furthermore, it is interesting to note that many of the dust disks around other stars appear to have an inner edge, similar to the inner edge of the Kuiper Belt.35 Since the inner boundary of the Kuiper Belt is thought to be carved out by the dynamical influence of Neptune, it seems reasonable to infer that extrasolar dust disks with inner boundaries indicate the presence of planets. PREBIOTIC CHEMISTRY As remnants of the early solar system, trans-neptunian objects can provide critical clues about processes of prebiotic chemistry and about the materials that would have been delivered to the early Earth.
|
From page 16... ...
As such, it may be that the existence of Kuiper Belt objects about a star could be an indication that prebiotic chemical evolution might also be occurring in that solar system. Observational programs designed to detect extrasolar planets might someday provide information that could be correlated with the distribution of life elsewhere in the galaxy.
|
From page 17... ...
Luu and D.C. Jewitt, "Color Diversity Among the Centaurs and Kuiper Belt Objects," Astronomical Journal 112:2310, 1996.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.