ASTRO 101 ADVANCED EXAM PAPER NEWEST
2026 WITH 100 PERCENT SOLVED QUESTIONS
AND EXPERT VERIFIED ANSWERS
◉Define astronomical unit and light-year. Answer: Astronomical Unit
(AU): The average distance of Earth from the Sun (150 million km/93
million mi)
Light-year (ly): The distance light travels in 1 year (9.46 trillion km).
◉Explain the statement "The farther away we look in distance, the
further back we look in time." Answer: This statement means that when
we look at objects that are very far away, we see them as they existed in
the past rather than how they are now in the current moment (as the light
left those objects a long time ago).
This is on account of how long it takes light to travel across vast expanse
of space. The further an object is from the observer, the older the light
they are seeing is, and therefore the further back in time they are
looking.
,◉In what sense are we "star stuff"? Answer: The elements that make up
all living things (including ourselves) and the Earth were created inside
stars via nuclear fusion and stellar explosions.
After the death of these stars, their material became part of the cloud that
formed our solar system, meaning we, who are a product of processes
and materials in our solar system, are also literally made of star stuff.
◉Briefly explain Earth's daily rotation and annual orbit, defining the
terms ecliptic plane and axis tilt. Answer: Earth's daily rotation is its
spin around its axis (an imaginary line which links the North and South
Poles) that it completes every 24 hours. This rotation is what causes the
Sun and stars to look like they are rising in the east and setting in the
west.
Its annual orbit is the Earth's revolution around the Sun, which takes 365
days. The orbit's path lies in a flat plane that scientists refer to as the
ecliptic plane.
Earth's axis is tilted 23.5 degrees from a line perpendicular to this
ecliptic plane.
The Earth orbits the Sun the same direction that it rotates on its axis with
both being counterclockwise when viewed from the North Pole.
,◉Observed motion and cause (motion of stars/sun/moon and changes in
stars seen throughout year) Answer: Observed motion: Daily E-W
Motion of Stars.Sun & Moon
-Caused by: Daily W-E Rotation of Earth
Observed motion: Changes inStars/Constellation Seen at night
throughout the year
-caused by: Annual Revolution (orbit) Of Earth around Sun
◉Briefly describe our solar system's location and motion within the
Milky Way Galaxy. Answer: There are 2 main aspects of our solar
system's motion.
Firstly, it is moving relative to nearby stars in our local solar
neighborhood, the Sun's region, and nearby stars.
Speed wise, on average, our sun moves relative to nearby stars at nearly
70,000 km per hour.
The second motion involves the solar system's orbit around the center of
the Milky Way Galaxy which is more organized than the aforementioned
random movement of stars: it travels at a speed of nearly 800,000
kilometers per hour, completing one full orbit of the galaxy in about 230
million years.
, In terms of its location, our solar system is 27,000 light years from the
galactic center. It is on the left side of the galaxy at around 9 o'clock.
◉Why do scientists suspect that most of our galaxy's mass consists of
dark matter? Briefly describe the mystery of dark matter and dark
energy. Answer: because measurements of the speeds of the orbit of
stars suggest that the stars and planets that are visible represent only a
small amount of the galaxy's total mass.
The majority of the mass seems to be outside the visible disk (in galactic
halo) which is unfortunately not visible to our telescopes.
This dark matter is believed to be the dominant source of gravity that has
affected the forming of galaxies.
Scientists have also discovered a force called dark energy which is
helping to accelerate the expansion of the universe and makes up the
majority of the universe's amount of energy
◉What key observations lead us to conclude that the universe is
expanding? Use the raisin cake model to explain how these observations
2026 WITH 100 PERCENT SOLVED QUESTIONS
AND EXPERT VERIFIED ANSWERS
◉Define astronomical unit and light-year. Answer: Astronomical Unit
(AU): The average distance of Earth from the Sun (150 million km/93
million mi)
Light-year (ly): The distance light travels in 1 year (9.46 trillion km).
◉Explain the statement "The farther away we look in distance, the
further back we look in time." Answer: This statement means that when
we look at objects that are very far away, we see them as they existed in
the past rather than how they are now in the current moment (as the light
left those objects a long time ago).
This is on account of how long it takes light to travel across vast expanse
of space. The further an object is from the observer, the older the light
they are seeing is, and therefore the further back in time they are
looking.
,◉In what sense are we "star stuff"? Answer: The elements that make up
all living things (including ourselves) and the Earth were created inside
stars via nuclear fusion and stellar explosions.
After the death of these stars, their material became part of the cloud that
formed our solar system, meaning we, who are a product of processes
and materials in our solar system, are also literally made of star stuff.
◉Briefly explain Earth's daily rotation and annual orbit, defining the
terms ecliptic plane and axis tilt. Answer: Earth's daily rotation is its
spin around its axis (an imaginary line which links the North and South
Poles) that it completes every 24 hours. This rotation is what causes the
Sun and stars to look like they are rising in the east and setting in the
west.
Its annual orbit is the Earth's revolution around the Sun, which takes 365
days. The orbit's path lies in a flat plane that scientists refer to as the
ecliptic plane.
Earth's axis is tilted 23.5 degrees from a line perpendicular to this
ecliptic plane.
The Earth orbits the Sun the same direction that it rotates on its axis with
both being counterclockwise when viewed from the North Pole.
,◉Observed motion and cause (motion of stars/sun/moon and changes in
stars seen throughout year) Answer: Observed motion: Daily E-W
Motion of Stars.Sun & Moon
-Caused by: Daily W-E Rotation of Earth
Observed motion: Changes inStars/Constellation Seen at night
throughout the year
-caused by: Annual Revolution (orbit) Of Earth around Sun
◉Briefly describe our solar system's location and motion within the
Milky Way Galaxy. Answer: There are 2 main aspects of our solar
system's motion.
Firstly, it is moving relative to nearby stars in our local solar
neighborhood, the Sun's region, and nearby stars.
Speed wise, on average, our sun moves relative to nearby stars at nearly
70,000 km per hour.
The second motion involves the solar system's orbit around the center of
the Milky Way Galaxy which is more organized than the aforementioned
random movement of stars: it travels at a speed of nearly 800,000
kilometers per hour, completing one full orbit of the galaxy in about 230
million years.
, In terms of its location, our solar system is 27,000 light years from the
galactic center. It is on the left side of the galaxy at around 9 o'clock.
◉Why do scientists suspect that most of our galaxy's mass consists of
dark matter? Briefly describe the mystery of dark matter and dark
energy. Answer: because measurements of the speeds of the orbit of
stars suggest that the stars and planets that are visible represent only a
small amount of the galaxy's total mass.
The majority of the mass seems to be outside the visible disk (in galactic
halo) which is unfortunately not visible to our telescopes.
This dark matter is believed to be the dominant source of gravity that has
affected the forming of galaxies.
Scientists have also discovered a force called dark energy which is
helping to accelerate the expansion of the universe and makes up the
majority of the universe's amount of energy
◉What key observations lead us to conclude that the universe is
expanding? Use the raisin cake model to explain how these observations
