An angle of 1 arc second is
A net force acting on an object will always cause a change in the...
What atmospheric constituent is responsible for the blue color of...
Olympus Mons is
Which of the following statements about an ellipse is NOT true?
Why does Earth have the strongest magnetic field among the...
How does a 12-month lunar calendar differ from our 12-month solar...
Where is most of the water on Mars?
You are standing on Earth's equator. Which way is Polaris, the...
Which of the following statements best explains why the planets orbit...
What is the acceleration of gravity on Earth?
Suppose you drop a 10-pound weight and a 5-pound weight on the Moon,...
The Chandra X-ray Observatory must operate in space because
We are not yet capable of detecting life on planets around other...
The astronauts feel weightless in the International Space Station,...
Newton showed that Kepler's laws are
Which moons are sometimes called the Galilean moons?
According to modern science, what was the approximate chemical...
The Huygens probe took numerous pictures as it descended to...
According to the universal law of gravitation, if you double the...
Which in its gaseous form is not a greenhouse gas?
Which moon is considered likely to have a deep, subsurface ocean of...
If the Earth's rotation axis was tilted by 45 degrees instead of...
Considering Einstein's famous equation, E=mc^2, which of the...
How do scientists estimate how old the solar system is?
The point along a planet's orbit where it is closest to the Sun is...
In general, how does the size and location of a star's habitable...
What happens during the apparent retrograde motion of a planet?
The angular separation of two stars is 0.1 arc seconds and you...
What is the purpose of adaptive optics?
Kepler's third law, = means that
The Antarctic ice-core plot of carbon dioxide (ppm) shows peaks and...
For most of history, the lack of observable stellar parallax was...
Hot Jupiters were a surprise to astronomers. What is the current...
As an interstellar cloud of hydrogen gas shrinks in size, its rate of...
Compare the energy and speed of infrared and visible light. Which of...
How do we know the mass of Neptune?
If the freezing point of ices of all types was at a much lower...
What kind of thermal radiation does the Earth emit?
Why do the patterns of stars in our sky look the same from year to...
Which of the following discoveries would cause us to re-evaluate the...
Galileo observed all of the following. Which observation offered...
The mass of Jupiter can be calculated by
Which of the following methods uses the principle of orbital...
If we use 1 millimeter to represent 1 light-year, how large in...
According to the universal law of gravitation, the force due to...
A rock held above the ground has potential energy. As the rock falls,...
Which of the following gases, which we can detect (if present) in...
How does the Kepler mission plan to detect Earth-like planets around...