Astro Exam 1 practice
dominant gravitational attraction of the Sun within the solar system
Calculating the orbits of celestial bodies within the solar system is easier than those outside it because of the _____.
It shows that not everything has to revolve around Earth.
Examining the planets, Galileo found four moons revolving about Jupiter in times ranging from just under 2 days to about 17 days. Which of the following is the significance of this discovery?
eccentricity
For an ellipse, the ratio of the distance between the foci to the length of the major axis is called its _____.
the simultaneous emission of a photon
Generally, an atom remains excited for only a very brief time, after which an electron drops back spontaneously to its ground state with _____.
Asteroids have orbits with smaller semimajor axes than do comets.
How do the orbits of asteroids differ from those of comets?
By increasing its orbital speed
How does Earth conserve its angular momentum as it gets closer to the Sun in the course of its orbit around the star?
Words are often unable to sufficiently describe complex scientific phenomena.
Information about the universe comes to Earth almost exclusively through various forms of light.
zenith
Matthew, an adventurer, looks up at the sky and believes that it is a great hollow dome with him at the center, and all the stars are at an equal distance from him on the surface of the dome. The top of that dome or the point directly above his head is called the _____.
She is in free fall in space.
Mimi, an astronaut, floats around within her spacecraft that orbits Earth at a close distance. She also sees objects such as a pen and a guitar float past her. Which of the following is likely to be the cause of her ability to float?
denote the positions of objects in the sky.
Right ascension and declination are used by astronomers to:
Frictional drag generated by the swelling of Earth's atmosphere
The Republic of Maziland launched its first satellite into space. The satellite was launched into low Earth orbit with surgical precision. However, to the dismay of the scientists who worked on this project, the satellite became unstable and was pulled back into Earth's atmosphere. Which of the following mostly likely caused this mishap?
Andromeda galaxy
The _____ is the nearest large spiral galaxy that is similar to the Milky Way Galaxy.
1.496 ×108 km.
The distance between the Sun and Earth is 149.6 million km. This number is expressed in scientific notation as:
the Sun appears to take around the celestial sphere
The ecliptic is the path _____.
perihelion
The place where a planet is closest to the Sun and moves the fastest is called the _____.
Earth's orbital motion
The stellar parallax is caused by _____.
ecliptic crosses the celestial equator.
The vernal equinox is a point in the sky where the:
one of the sectors into which the sky is divided
Today, the term constellation refers to _____.
many zeros that can seem overwhelming to a reader.
Using scientific notation to describe numbers is very appealing because it eliminates the:
annular eclipses
When seen from Earth, _____ occur when the Sun and the Moon are perfectly aligned in the sky but the Moon appears slightly smaller than the Sun due to being at apogee.
The distance between the two planets
Which of the following factors makes the existence of the asteroid belt between Mars and Jupiter possible?
It is in a relatively stable position compared to other stars.
Which of the following is a feature of Polaris that distinguishes it from other stars in the sky?
It must orbit a star.
Which of the following is a necessary condition for a celestial body to be deemed a planet?
The typical atom is far emptier than our solar system out to Neptune.
Which of the following is a reason atoms are not like a miniature solar system?
Information about the universe comes to Earth almost exclusively through various forms of light.
Which of the following is a reason for the speed of light being a natural unit of distance for astronomers?
To avoid cutting through groups of islands
Which of the following is a reason why the International Date Line bends along the line?
He had assumed that all celestial motion had to be in circles.
Which of the following is one of the factors that complicated Ptolemy's model of the solar system?
Sidereal day is defined in terms of the rotation period of Earth with respect to the stars, whereas solar day is defined in terms of the rotation period of Earth with respect to the Sun.
Which of the following is the difference between a solar day and a sidereal day?
They all travel at the same speed in a vacuum.
Which of the following is the similarity between all types of electromagnetic waves?
They would appear to be parallel.
Which of the following is true of rays coming from an infinitely distant light source?
Half the Moon is illuminated at this time
Which of the following is true of the third quarter of the Moon's phases when observed from Earth?
They are absorbed by water molecules.
Which of the following properties make microwaves effective in heating food?
Venus goes through phases like the Moon.
Which of the following provides the strongest evidence that the Sun is the center of the solar system?
It tilts sideways in relation to the Sun.
Which of the following statements accurately describes the tilt of Earth's Northern Hemisphere during the equinoxes?
They do not require a medium in which to travel.
Which of the following statements is true about electromagnetic waves?
It is an especially noticeable star pattern within a constellation.
Which of the following statements is true of an asterism?
A hypothesis is a proposed explanation that must be able to be tested.
Which of the following statements is true of hypotheses?
It is part of the raw material for stars.
Which of the following statements is true of interstellar dust?
They are the smallest particles into which any matter can be divided while still retaining its chemical properties.
Which of the following statements is true of molecules?
They are the most distant objects observable in space.
Which of the following statements is true of quasars?
The ellipse would become more elongated.
Which of the following would occur if the eccentricity of an ellipse were increased?
Because they maintain fixed patterns among themselves through many generations
Why are certain celestial objects known as fixed stars?
They are very energetic.
Why are gamma rays dangerous for living tissues?
The Moon can block the Sun's light during solar eclipses.
Why did Aristotle think that the Sun is farther away from Earth than the Moon?
Because a star always rises at the same sidereal time every day
Why do astronomers prefer sidereal time for planning their observations?
Because of their elliptical orbits
Why do the speeds of the planets of the solar system in their orbits around the Sun vary?
Because of the inclination of the ecliptic
Why does the Sun move north and south in the sky as the seasons change on Earth?
Because many stars emit in the visible band
Why is the color of a star a rough indicator of its temperature?
they are stopped by the large number of atoms in Earth's atmosphere with which they interact.
X-rays coming from space can only be studied above Earth's atmosphere because:
Astrology
_____ is an ancient belief system in which the positions of the Moon, Sun, and planets among the stars of the zodiac are thought to hold the key to understanding what one can expect from life.