ASTR Test 1

If the Sun were to suddenly vanish, we would learn about it

8 minutes later

The scientist who formulated the three laws of planetary motion by analyzing the data on the precise location of planets in the sky was:

Johannes Kepler

The planet in our solar system with the shortest period of revolution is:

Mercury

The star that is currently closest to the North Celestial Pole is

Polaris

The first artificial satellite the human race sent into orbit was called:

Sputnik

A good example of Newton's third law is the following: A bullet leaves the front of a rifle at high speed, and the rifle's rear end really hurts the shoulder of an inexperienced shooter.

TRUE

According to Newton's first law, a spacecraft like Voyager, which is escaping from the solar system, but not headed toward a nearby star, will just keep going in space.

TRUE

Astronauts in the International Space Station don't feel their weight because they are falling around the Earth.

TRUE

Kepler's third law relates a planet's orbital period to the semi-major axis of the orbit.

TRUE

The person who first measured the size of the Earth using the angles at which sunlight hit the surface of the Earth was Eratosthenes.

TRUE

The ratio of the distance between the foci of an ellipse to the length of its semimajor axis is called its eccentricity.

TRUE

The reason we have a regular cycle of day and night on Earth is that our planet rotates on its axis.

TRUE

When the moon is at perigee, it looks a little bit bigger in our skies.

TRUE

While ancient thinkers expected the motions of the planets to be circles, Kepler used Tycho Brahe's data to show that planets moved around the Sun in ellipses.

TRUE

The natural object (not one that humans built) in space that's closest to Earth is

The moon

Kepler's 3rd Law

The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

Astronomy is considered a historical science - what we observe in the universe has already happened and we can't change it.

True

Scientific models and hypotheses can change as new experiments or observations are done, often with better equipment.

True

Scientific models are always an approximation of nature.

True

Newton showed that to change the direction in which an object is moving, one needs to apply:

a force

We now know that the orbit of a stable planet around a star like the Sun is always in the shape of:

an ellipse

From a city in the U.S., where in the sky would you look to see a star that is not turning with the motion of the sky in the course of a night?

at the north celestial pole

The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called

constellations

The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called

precession

The south celestial pole and the north celestial pole lie in the sky directly above

the Earth's axis

In an ellipse, the ratio of the distance between the foci and the length of the major axis is called

the eccentricity

Of these, which is the largest?

universe

The point in the sky directly above your head at any given time is called the

zenith

Our home galaxy, the Milky Way, is small enough that we can see every star in it with our unaided eye (no telescope required.)

False

The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was

Galileo

The Renaissance astronomer who wrote the pioneering book that suggested the Earth probably orbits the Sun (instead of the other way around) was:

Copernicus

In the United States, at night, the direction north is always directly above your head.

FALSE

Kepler discovered his three laws of planetary motion by looking at the planets through a large telescope in his private observatory.

FALSE

Neptune travels faster in that part of its orbit when it's a little further from the Sun, so it can cover the extra distance.

FALSE

The Earth's period of rotation is equal to 1 year

FALSE

The density of an object is its mass multiplied by its volume.

FALSE

The most eccentric orbit among the planets in our solar system is that of Mars.

FALSE

The path that the Sun appears to make in the sky over the course of a year is called the celestial equator

FALSE

To leave the gravitational pull of the Earth, and explore other planets, satellites must have at least:

escape velocity