Collegeboard REAL CR Q's

indie500
Fri, 30 Sep 2011 20:11:50 +0000

The rock that sprang to Martian “life” late last summer
did not shock me by offering up apparent fossils of an extinct
alien form of life. I had long believed that the universe teems
Line with life elsewhere, and that our failure to find it simply
5 results from a lack of exploration. What did amaze me about
the potato-size rock that fell from Mars was that it had trav-
eled millions of miles across space to land here, blasted
from world to world by a planetary collision of the sort that
purportedly killed off our dinosaurs, and had lain waiting
10 for millennia upon an Antarctic ice field, until an observant
young woman traveling in an expedition party picked it up,
because she figured that it had come from another world.
How could she know such a thing?
The composition of ALH 84001, as the much scruti-
15 nized rock is designated, closely matches the makeup
of Martian matter that was analyzed on site in 1976 by
miniature chemistry laboratories aboard two Viking
Mars landers. As a result of this positive identification,
no astronomer seriously doubts the meteorite’s Martian
20 origin. Researchers think they have pinpointed its former
resting place to just two possible sites—a region called
Sinus Sabaeus, fourteen degrees south of the Martian
equator, or a crater east of the Hesperia Planitia region.
The bold precision of this assessment is for me the most
25 stunning surprise dealt by the rock from Mars—even more
mind-boggling than the suggestive traces of something that
might once have lived and died in its microscopic fissures.
I cannot resist comparing this new intimacy with our solar
system to the shoebox diorama of the planets I designed for
30 my grade-school science fair. I used marbles, jack balls,
and Ping-Pong balls, all hanging on strings and painted
different colors, all inside a box representing our solar
system. This crude assortment of materials allowed a
reasonable representation of what was known 40 years
35 ago about the nine planets: Mars was red and had two
moons; Jupiter dwarfed the other planets (I should have
used a basketball but it wouldn’t fit in the box); Saturn
had rings. If my school-age daughter were to attempt such
a construction today, she’d need handfuls of jelly beans
40 and gum balls to model the newly discovered satellites of
the giant planets. She’d want rings around Jupiter, Uranus,
Neptune, too, not to mention a moon for Pluto.
Similarly, our solar system, once considered unique,
now stands as merely the first known example of a
45 planetary system in our galaxy. Since October of 1995,
astronomers at ground-based observatories in Europe
and the United States have announced that they’ve found
evidence of at least seven alien planets orbiting other stars.
As yet, not one of these large planets—some of which
50 are many times the mass of Jupiter—has actually been
seen through a telescope; we know about them indirectly
through the gravitational effects they exert on their parent
stars. Yet, even though we have no picture of what they
look like, enough information has been deduced about
55 their atmospheric conditions to grant the nickname
Goldilocks to a planet attending the star 70 Virginis,
an appellation suggesting that the cloud-top temperature
is “just right,” as the storybook Goldilocks would say, for
the presence of liquid water. Liquid water, not known to
60 exist anywhere in our solar system now except on Earth,
is thought crucial to biological life; thus, only a short
leap of faith is needed to carry hopeful scientists from
the presence of water to the existence of extraterrestrial
life. To raise the specter of the Mars rock once again,
65 the primitive life-forms that pressed their memory inside
it likewise suggest an era when dry-as-dust Mars was a
wet world, where rivers flowed.

22 The reasoning process presented in lines 49-53 (“As . . . stars”) is best described as
(A) inference based on an untested theory
(B) extrapolation from similar situations
(C) analysis of a single case by multiple observers
(D) hypothesis confirmed by direct observation
(E) comparison of theory with physical evidence

WHERE ARE THE SIMILAR SITUATOINS?