Choose one answer for each question
How old is the universe?
6,000 years old
380,000 years old
13.8 billion years old
13.8 million years old
A parsec is:
Longer than a light year
The distance between the Earth and the Sun
Approximately 3x10^24 cm
None of the above
The distance to the center of the Galaxy from the Solar Systen is about 8 kpc. If someone there right now looked at Earth with an amazingly powerful telescope, what would they see humans doing?
Looking back with telescopes of their own!
Building pyramids
living as hunter-gatherers and making great cave paintings
Humans werem't around yet
How much would you weigh if both the Earth's mass and radius increased by a factor of 2?
Twice as much
Half as much
4 times as much
1/4 as much
The same
Consider a comet with an extremely eccentric orbit around the Sun, such that at perihelion it is very close to the Sun and at aphelion it is beyond the orbit of Mars, with a semimajor axis of ~1 AU. To complete one orbit around the Sun, the comet will take:
Less than 1 year
More than 1 year
About 1 year
Not enough information
The shape of an orbit is determined by:
The kinetic energy
The angular momentum
The total energy
The kinetic energy AND the angular momentum
The angular momentum AND the total energy
None of these
In order for a lunar eclipse to occur, the Moon must be in what phase?
Full
New
First or third quarter
Any phase
Caltech's latitude is 34 degrees North. Which declination of stars (of those below) is NOT visible to us at any time of the year?
34 degrees
-34 degrees
90 degrees
-75 degrees
Which is longer, a synodic day or a sidereal day?
Synodic day
Sidereal day
Both are equal
Not enough information
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I'm sorry, I do not understand what you are trying to communicate. Can you please provide more context or a clear question?
How old is the universe?
To determine the age of the universe, scientists use a variety of methods including analyzing the cosmic microwave background radiation, the expansion rate of the universe, and the ages of the oldest known objects. The current estimate for the age of the universe is 13.8 billion years old. Therefore, the answer is "13.8 billion years old."
A parsec is:
A parsec is a unit of distance used in astronomy. It is defined as the distance at which one astronomical unit (AU) subtends an angle of one arcsecond. In simpler terms, a parsec is the distance at which an object will have a parallax angle of one arcsecond when observed from opposite points of Earth's orbit around the Sun. Therefore, the answer is "None of the above."
The distance to the center of the Galaxy from the Solar System is about 8 kpc. If someone there right now looked at Earth with an amazingly powerful telescope, what would they see humans doing?
Since light takes time to travel from Earth to the center of the galaxy, any observation made from there is essentially looking back in time. Therefore, if someone at the center of the galaxy looked at Earth with an amazingly powerful telescope, they would see humans in the past. The given options (Looking back with telescopes of their own, Building pyramids, Living as hunter-gatherers and making great cave paintings, Humans weren't around yet) suggest different time periods in human history. The correct answer would be "None of the above" as the exact activity observed would depend on the specific time period being observed.
How much would you weigh if both the Earth's mass and radius increased by a factor of 2?
When both the mass and radius of the Earth increase by the same factor, the gravitational force between an object and the Earth remains unchanged. Therefore, if the Earth's mass and radius both increase by a factor of 2, the answer is "The same."
Consider a comet with an extremely eccentric orbit around the Sun, such that at perihelion it is very close to the Sun and at aphelion it is beyond the orbit of Mars, with a semimajor axis of ~1 AU. To complete one orbit around the Sun, the comet will take:
The time taken for a comet to complete one orbit around the Sun depends on its orbital period which is determined by its distance from the Sun. In this case, the comet has a semimajor axis of ~1 AU, which is the average distance from the Earth to the Sun. A comet with an orbit like this would have a period of approximately 1 year. Therefore, the answer is "About 1 year."
The shape of an orbit is determined by:
The shape of an orbit is determined by the combination of two factors: the kinetic energy and the angular momentum of the object orbiting another. The kinetic energy determines whether the orbit is an ellipse, parabola, or hyperbola, while the angular momentum determines the orientation and size of the ellipse. Therefore, the answer is "The kinetic energy AND the angular momentum."
In order for a lunar eclipse to occur, the Moon must be in what phase?
A lunar eclipse occurs when the Earth passes between the Sun and the Moon, casting a shadow on the Moon. This can only happen during a full moon when the Earth, Moon, and Sun are aligned in that order. Therefore, the answer is "Full."
Caltech's latitude is 34 degrees North. Which declination of stars (of those below) is NOT visible to us at any time of the year?
The declination of stars is a measure of their angular distance above or below the celestial equator. Since Caltech's latitude is 34 degrees North, stars with a declination of -34 degrees (34 degrees below the celestial equator) would not be visible to observers at Caltech at any time of the year. Therefore, the answer is "-34 degrees."
Which is longer, a synodic day or a sidereal day?
A synodic day is the time it takes for a planet to go from one noon to the next noon, as observed from the Earth. A sidereal day is the time it takes for a planet to complete one rotation on its axis relative to the distant stars. Since the Earth is also moving in its orbit around the Sun during a synodic day, it takes slightly longer than a sidereal day. Therefore, the answer is "Synodic day."