Download The Carbon-Hydrogen Connection in Outer Space

7.6A: Organic Compounds
Matter and Energy
The Carbon-Hydrogen Connection in Outer Space
(Lexile 780L)
1  Scientists have known for hundreds of years that
carbon is an element. It has also been known that
carbon can combine with other elements. Carbon
forms organic compounds with hydrogen, oxygen,
phosphorus, nitrogen, and sulfur. What had not been
known is that hydrocarbons can be found away from
our Earth. They have even found one on Saturn’s
moons, Hyperion.
2 In 2007, NASA’s Cassini space probe made a survey of Hyperion. It found that the Saturn
moon has cup-like craters filled with hydrocarbons. These are the simplest forms of organic
compound. They contain only carbon and hydrogen. Scientists now believe the basic
chemicals for life are found many places in our solar system. Hyperion does not just have
hydrocarbons. It has water and carbon dioxide (carbon-oxygen compound) as well.
3 Our own Earth is full of hydrocarbons. For about 200 years, scientists have classified
chemical compounds into two categories. They are either organic or inorganic.
Hydrocarbons had been thought of as “organic,” or “living” matter. That definition is not valid
any more. Compounds can now be made in a lab. They may never have been part of a
living organism. There are a few compounds that can be classified either way!
4 In organic chemistry, the three most important elements are carbon, hydrogen, and oxygen.
Other elements like nitrogen, sulfur, or phosphorus can also be found in organic compounds.
Each of these elements makes different kinds of connections. They can combine to form
millions of compounds. All play a role in the function of life on this planet.
5 It is exciting to think that those compounds might be found on other planets or moons.
Scientists will continue to use space probes and experiments. They will look for clues about
the origins of hydrocarbons. They will also continue to survey our solar system to look for
more.
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7.6A: Organic Compounds
Matter and Energy
1
Complete the following analogy:
hydrocarbons:carbon as carbon dioxide:_____
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A
phosphorous
B
sulfur
C
hydrogen
D
oxygen
What could the reader infer from the reading about hydrocarbons?
A
Life started on other planets before it started on Earth.
B
All planets and satellites in the solar system contain hydrocarbons.
C
The building blocks of carbon-based life are found on planets or
satellites other than Earth.
D
No bodies in our solar system except Earth contain hydrocarbons.
What other elements besides carbon are commonly found in organic
compounds?
A
Hydrogen and oxygen
B
Helium and phosphorus
C
Nitrogen and argon
D
Oxygen and lead
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7.6A: Organic Compounds
Matter and Energy
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5
Which of NASA’s spacecraft identified the hydrocarbons on Saturn’s moon?
A
Cassini
B
Voyager II
C
Hubble
D
Mariner
Which of these compounds is a hydrocarbon?
A
Carbon dioxide (made of carbon and oxygen)
B
Calcium carbonate (made of calcium, carbon, and oxygen)
C
Ethanol (made of carbon, hydrogen, and oxygen)
D
Octane (made of carbon and hydrogen)
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