This question category requires you to simplify or summarize a highlighted sentence from the passage. You will be presented with several answer choices from which you need to select the most appropriate one.<\/p>\n\n\n\n
In an effort to resolve these apparent contradictions, scientists developed a fourth hypothesis for the origin of the Moon, one that involves a giant impact early in Earth\u2019s history. There is increasing evidence that large chunks of material\u2014objects of essentially planetary mass\u2014were orbiting in the inner solar system at the time that the terrestrial planets formed. The giant impact hypothesis envisions Earth being struck obliquely by an object approximately one-tenth Earth\u2019s mass\u2014a \u201cbullet\u201d about the size of Mars. This is very nearly the largest impact Earth could experience without being Shattered.<\/p>\n\n\n\n
Such an impact would disrupt much of Earth and eject a vast amount of material into space, releasing almost enough energy to break the planet apart. Computer simulations indicate that material totaling several percent of Earth\u2019s mass could be ejected in such an impact. Most of this material would be from the stony mantles of Earth and the impacting body, not from their metal cores. This ejected rock vapor then cooled and formed a ring of material orbiting Earth. It was this ring that ultimately condensed into the Moon.<\/p>\n\n\n\n
While we do not have any current way of showing that the giant impact hypothesis is the correct model of the Moon\u2019s origin, it does offer potential solutions to most of the major problems raised by the chemistry of the Moon. First, since the Moon\u2019s raw material is derived from the mantles of Earth and the projectile, the absence of metals is easily understood. Second, most of the volatile elements would have been lost during the high- temperature phase following the impact, explaining the lack of these materials on the Moon. Yet, by making the Moon primarily of terrestrial mantle material, it is also possible to understand similarities such as identical abundances of various oxygen Isotopes.<\/p>\n\n\n\n
a) Objects of planetary mass usually orbit the inner solar system. <\/p>\n\n\n\n
b) More and more evidence exists that indicates that big objects orbited the inner solar system when the terrestrial planets were created. <\/p>\n\n\n\n
c) There is more evidence to suggest that the terrestrial planets were formed in the inner solar system. <\/p>\n\n\n\n
d) The terrestrial planets formed when they were orbiting the inner solar system. <\/p>\n\n\n\n
Correct Answer: B<\/strong><\/p>\n\n\n\nTips To Remember <\/span><\/h2>\n\n\n\n
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