Midterm #1
The point along the Moon's orbit where it is farthest from the Earth is called the orbit's
apogee
In the early 20th Century, it was thought that planets are usually formed by near collisions between stars. Which of the following best explains why we can rule out this idea?
Stellar near collisions are far too rare to explain all the planets now known to orbit nearby stars
What method has been used to determine the most recent time the Tharsis volcanoes on Mars have erupted?
counting the craters on their slopes
What percentage of a star's total lifetime is spent on the main sequence?
90%
How is intelligence defined in the Drake Equation?
a civilization willing and able to communicate over interstellar distances
Who observed four moons orbiting the planet Jupiter?
Galileo
The age of our solar system is approximately
4.5 billion years
More than 96% of the mass of living cells are made of
carbon, oxygen, hydrogen, and nitrogen
Which method of extrasolar planet detection is able to measure the compositions of extrasolar planet atmospheres?
transit technique
The first multicellular organism appears around
1.2 billion years ago
What law implies that on its orbit around the Sun, a planet moves faster when it is nearer to the Sun than when it is farther away from the Sun?
Kepler's 2nd Law
The fossil fuel deposits we use today are the remains of organisms from which period in Earth's history?
the Carboniferous Period
Why did the era of nucleosynthesis end?
The temperature of the universe became too low.
The [blank] determines how much fuel is needed per kilogram of payload that
a rocket carries to space.
rocket equation
What law states that planets with large average distances from the Sun take more time to complete a full revolution around the Sun than planets with small average distances from the Sun?
Kepler's 3rd Law
The sense of revolution and rotation in the solar system is due to the conservation of
angular momentum
Titan is roughly the same size as Mercury, yet Titan has an atmosphere while Mercury does not. How can this be?
Even though Titan's gravity is weak, it is much colder, allowing molecules to be trapped in its atmosphere
Why does the Sun brighten with time?
as hydrogen is converted into helium in the core, the number of hydrogen nuclei decreases, decreasing the fusion rate. To maintain the balance with gravity pressing inward, the core compensates by shrinking and heating up
The observed slowing down of time predicted by Einstein's Special Theory of Relativity for an object traveling close to the speed of light is referred to as
time dilation
Which is closest to the temperature of the Sun's core?
10 million K
Which three branches of science are most important in our study of life in the universe?
astronomy, planetary science, and biology
Life on Earth can use a variety of different carbon and energy sources. However, the one thing that no organism on Earth can survive without is
liquid water
Which is the only moon in our Solar System that has an atmosphere?
Titan
On a Hertzsprung-Russell diagram, where would you find stars that are cool and luminous?
upper right
[blank] said that "Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke