Solar System - Science Olympiad Exam
2026, 240 Questions and Answers
1. How did the terrestrial planets form?
Correct answer: In the proto-Solar-System, after the sun formed, the rest of
the materials orbiting close around it began to clump together too. However,
closer to the sun, lighter materials like gases blew away and only rocky
material was left, causing the four terrestrial planets, and some of their
moons, to form.
2. What are the characteristics of Terrestrial Planets?
Correct answer: Solid bodies with a core surrounded by a mantle and crust.
Comprised mostly of heavier materials, like rocks, stones, and heavy metals
like nickel and iron. They are smaller in size than the gas giants and very
dense in comparison.
3. How old is the Solar System?
Correct answer: 4.6 billion years
4. How did Mercury form?
Correct answer: Like the rest of the terrestrial planets, Mercury was formed
4.55 billion years ago and is primarily rocky. After the sun's formation, the
rocks and metals very close to it began to come together to form Mercury.
However, all of Mercury's gases and atmosphere were blown away, leading to
it being small, but even more rocky than the other planets.
5. How did Venus form?
Correct answer: Venus, like Mercury, was formed by rocks and metals
,coming together to form a large planet. However, solar winds are too weak to
blow away Venus' atmosphere, and the heat has led to a greenhouse gas effect,
causing the planet to be especially hot, even more so than Mercury, though
being further away.
6. How did Earth form?
Correct answer: Earth formed in the same way as the rest of the terrestrial
planets. However, another large body slammed into Earth (which used to be
larger) and the material from that body and the chunk of Earth blown off
formed the moon, which is why it has such a large size in comparison to
Earth.
7. How did Mars form?
Correct answer: Mars was most likely very similar to Earth and it had formed
the same way as well. It possibly even had large oceans. However, for
unknown reasons, they have dried up, leading to Mars' nickname as "The
Red Planet."
8. How did the Moon form?
Correct answer: Long ago, when the Earth was younger and larger, another
body slammed into it. This body blew into pieces that began to orbit the
Earth, along with chunks of Earth blown off from the impact. Together, these
formed the Moon, being responsible for its relatively large size.
9. What are the surface features of Mercury?
Correct answer: Mercury's surface is made of volcanic basalt (a hint towards
prior geologic activity) and is very smooth. However, Mercury has no real
atmosphere, allowing almost any incoming asteroids to impact, though they
are stopped by its thick mantle. As a result, Mercury looks like a smooth, dark
, grey planet peppered with large and small round imprints. Mercury also has
ridges all across its surface. As the magma on Mercury cools, it shrinks, since
solids are more compact than liquids. Mercury's surface is also made up of
intercrater plains, accounting for almost half of the planet's surface area.
Intercrater plains are made up of flatter lands containing older more shallow
craters, while smooth plains are made up of newer land and more recent
deeper craters. Smooth plains make up around 15% of Mercury's surface.
10. What are the internal features of Mercury?
Correct answer: Mercury has an extremely large core relative to its size. The
core is mostly iron and iron compounds and is about 1800 km in diameter.
The mantle and crust are only 600 km in diameter, and are mostly silicates.
This is because the temperature of the early sun evaporated and destroyed a
large portion of the rocky material, causing the core to be larger than it
normally would be, as it is the size of a core in what would be a much larger
planet. The core seems to have a liquid outer core and superdense solid inner
core.
11. What are the surface features of Venus?
Correct answer: Venus has a thick, toxic atmosphere that traps heat, making
it the hottest planet. Its surface is covered with thousands of volcanoes, vast
lava plains, and mountains. It has impact craters but fewer than expected due
to volcanic resurfacing. The surface is hidden beneath clouds of sulfuric acid.
12. What is the atmospheric composition of Venus?
Correct answer: Venus's atmosphere is about 96.5% carbon dioxide and 3.5%
nitrogen, with clouds of sulfuric acid droplets.
2026, 240 Questions and Answers
1. How did the terrestrial planets form?
Correct answer: In the proto-Solar-System, after the sun formed, the rest of
the materials orbiting close around it began to clump together too. However,
closer to the sun, lighter materials like gases blew away and only rocky
material was left, causing the four terrestrial planets, and some of their
moons, to form.
2. What are the characteristics of Terrestrial Planets?
Correct answer: Solid bodies with a core surrounded by a mantle and crust.
Comprised mostly of heavier materials, like rocks, stones, and heavy metals
like nickel and iron. They are smaller in size than the gas giants and very
dense in comparison.
3. How old is the Solar System?
Correct answer: 4.6 billion years
4. How did Mercury form?
Correct answer: Like the rest of the terrestrial planets, Mercury was formed
4.55 billion years ago and is primarily rocky. After the sun's formation, the
rocks and metals very close to it began to come together to form Mercury.
However, all of Mercury's gases and atmosphere were blown away, leading to
it being small, but even more rocky than the other planets.
5. How did Venus form?
Correct answer: Venus, like Mercury, was formed by rocks and metals
,coming together to form a large planet. However, solar winds are too weak to
blow away Venus' atmosphere, and the heat has led to a greenhouse gas effect,
causing the planet to be especially hot, even more so than Mercury, though
being further away.
6. How did Earth form?
Correct answer: Earth formed in the same way as the rest of the terrestrial
planets. However, another large body slammed into Earth (which used to be
larger) and the material from that body and the chunk of Earth blown off
formed the moon, which is why it has such a large size in comparison to
Earth.
7. How did Mars form?
Correct answer: Mars was most likely very similar to Earth and it had formed
the same way as well. It possibly even had large oceans. However, for
unknown reasons, they have dried up, leading to Mars' nickname as "The
Red Planet."
8. How did the Moon form?
Correct answer: Long ago, when the Earth was younger and larger, another
body slammed into it. This body blew into pieces that began to orbit the
Earth, along with chunks of Earth blown off from the impact. Together, these
formed the Moon, being responsible for its relatively large size.
9. What are the surface features of Mercury?
Correct answer: Mercury's surface is made of volcanic basalt (a hint towards
prior geologic activity) and is very smooth. However, Mercury has no real
atmosphere, allowing almost any incoming asteroids to impact, though they
are stopped by its thick mantle. As a result, Mercury looks like a smooth, dark
, grey planet peppered with large and small round imprints. Mercury also has
ridges all across its surface. As the magma on Mercury cools, it shrinks, since
solids are more compact than liquids. Mercury's surface is also made up of
intercrater plains, accounting for almost half of the planet's surface area.
Intercrater plains are made up of flatter lands containing older more shallow
craters, while smooth plains are made up of newer land and more recent
deeper craters. Smooth plains make up around 15% of Mercury's surface.
10. What are the internal features of Mercury?
Correct answer: Mercury has an extremely large core relative to its size. The
core is mostly iron and iron compounds and is about 1800 km in diameter.
The mantle and crust are only 600 km in diameter, and are mostly silicates.
This is because the temperature of the early sun evaporated and destroyed a
large portion of the rocky material, causing the core to be larger than it
normally would be, as it is the size of a core in what would be a much larger
planet. The core seems to have a liquid outer core and superdense solid inner
core.
11. What are the surface features of Venus?
Correct answer: Venus has a thick, toxic atmosphere that traps heat, making
it the hottest planet. Its surface is covered with thousands of volcanoes, vast
lava plains, and mountains. It has impact craters but fewer than expected due
to volcanic resurfacing. The surface is hidden beneath clouds of sulfuric acid.
12. What is the atmospheric composition of Venus?
Correct answer: Venus's atmosphere is about 96.5% carbon dioxide and 3.5%
nitrogen, with clouds of sulfuric acid droplets.
