How the Solar System was born
Tests: 9 of 11 right · Exam: 3 of 4 right · Kind: ★ · Understood: 7 of 15 · Run: 2026-10-18, commit f3c23ea72
Lesson 2 of the space course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.
Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.
Test 1 · ★ · wrong ✗
my sister says the planets were all made at different times from bits of other stars. what's closer to the truth?
- 1. The Earth came first and the others millions of years later — ← Mova's choice · no support
- 2. Each planet came from a different star — no support
- 3. They all formed together from the same spinning disc of gas and dust — ✓ the right answer · no support
- 4. The planets were made after the Sun burnt out — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 2 · ★ · right ✓
Spin a ball of pizza dough and it spreads out flat. What in the Solar System's story is like that?
- 1. The spinning cloud flattening into a disc — ← Mova's choice · ✓ the right answer · score 6
- 2. The Moon being knocked off the Earth by a crash — no support
- 3. The planets crashing together into bigger ones — no support
- 4. The Sun slowly cooling down after it switched on — no support
Why: It took the question to ask which statement is true. It chose option 1 with score 6, the only option with support. Its support: lesson 2, line 7: «As the cloud collapsed it spun faster and flattened into a disc, which is why the planets orbit in nearly the same flat plane.», reached through a sentence linked to the one the question matched. What matched: the same action «flatten» (+2); the same doer «cloud» (+2); the same place «disc» (+2). · the question and its options parsed, with trees and pragmatics
Test 3 · ★ · right ✓
A bicycle pump gets warm when you squeeze air into it. What does this help explain?
- 1. How squeezing gas in the cloud's centre made it hot enough to start the Sun — ← Mova's choice · ✓ the right answer · no support
- 2. Why the planets spin — no support
- 3. Why Jupiter is striped — no support
- 4. Why the Moon has craters — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 4 · ★ · right ✓
If the young Earth had formed out beyond the frost line, what might have happened?
- 1. Nothing, every planet ends up the same — no support
- 2. It would have become a star — score 2
- 3. It could have grabbed ice as well as rock and grown much bigger — ← Mova's choice · ✓ the right answer · score 4
- 4. It would have been made only of metal — score 2
Why: It took the question to ask what happens next. It chose option 3 with score 4, against 2 for the next best. Its support: lesson 2, line 11: «Close to the Sun only rock and metal could stay solid, but beyond the frost line, around where the asteroid belt is now, ice could form too, so the outer plane…», reached through what followed the sentence the question matched. What matched: the same action «grow» (+4); the same property (+2). Against it: a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics
Test 5 · ★ · right ✓
Which evidence from meteorites helps date the Solar System?
- 1. They carry written messages from the past — no support
- 2. They are always still warm when they land — no support
- 3. They have tree rings inside them — no support
- 4. Their oldest solid bits contain radioactive atoms that act like a clock — ← Mova's choice · ✓ the right answer · score 8
Why: It took the question to ask who or what does it. It chose option 4 with score 8, the only option with support. Its support: lesson 2, line 15: «The oldest solid bits in meteorites, space rocks that fell to Earth, are about 4.57 billion years old, and their radioactive atoms, which slowly change at a st…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same doer «radioactive atoms» (+4). Against it: a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics
Test 6 · ★ · right ✓
A game starts as an empty map of fog that slowly fills in with land. What part of the real story is like that?
- 1. Dust and gas slowly clumping into planets — ← Mova's choice · ✓ the right answer · no support
- 2. The Sun suddenly exploding into a bright flash — no support
- 3. Earth being carved out of the Moon by a giant — no support
- 4. The planets being made all at once, in one day — no support
Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 7 · ★ · wrong ✗
Rolling a snowball makes it pick up more snow the bigger it gets. Which stage is like that?
- 1. The Sun switching on — ← Mova's choice · no support
- 2. Pebbles and rocks sticking together into planetesimals — ✓ the right answer · no support
- 3. Light leaving the Sun — no support
- 4. The planets moving their orbits slowly further out over time — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 8 · ★ · right ✓
Jake: "The Moon is just a captured asteroid, everyone knows that." What do most scientists actually think?
- 1. It probably formed from debris after Theia hit the Earth — ← Mova's choice · ✓ the right answer · score 18
- 2. He is right, it is a captured asteroid — no support
- 3. It was made by the Sun splitting in half — score 12
- 4. It was a planet that drifted in from another star a long time ago — no support
Why: It took the question to ask what it is done to. It chose option 1 with score 18, against 12 for the next best. Its support: lesson 2, line 13: «Scientists think the Moon formed when a Mars-sized body, nicknamed Theia, smashed into the young Earth and threw out debris that gathered into the Moon; this i…», reached through what was said in the sentence the question matched. What matched: it fills the role the question asks for (+6); the same action «form» (+4); the same doer «moon» (+4); the same thing acted on (+4). · the question and its options parsed, with trees and pragmatics
Test 9 · ★ · right ✓
Why do the small icy bodies far out in the Solar System matter to this story?
- 1. They are the remains of a planet that exploded — no support
- 2. They were placed there after the Moon formed — no support
- 3. The moving giant planets probably scattered them there — ← Mova's choice · ✓ the right answer · score 6
- 4. They are where the Sun keeps its spare fuel for later on — no support
Why: It took the question to ask why something happens (its cause). It chose option 3 with score 6, the only option with support. Its support: lesson 2, line 14: «The giant planets probably moved their orbits after they formed, scattering many small icy bodies inward and outward.», reached through the option's own match among the sentences about the question's things. What matched: the same action «scatter» (+2); the same doer «giant planets» (+2); the same thing acted on «many small icy bodies» (+2). · the question and its options parsed, with trees and pragmatics
Test 10 · ★ · right ✓
What do discs around young stars tell us about our own Solar System?
- 1. They show the same kind of birth that our Solar System probably had — ← Mova's choice · ✓ the right answer · no support
- 2. They tell us nothing about planets — no support
- 3. They show that planets form from stars dying — no support
- 4. They prove our Solar System is unique — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Test 11 · ★ · right ✓
why are the planets all going the same way round, did someone line em up or what
- 1. They inherited the spin of the cloud they formed from — ← Mova's choice · ✓ the right answer · score 8
- 2. Yes, a passing star lined them up — score 6
- 3. They chase each other round and round, pulled by magnetism — no support
- 4. They are pulled along by the Moon — no support
Why: It took the question to ask which statement is true. It chose option 1 with score 8, against 6 for the next best. Its support: lesson 2, line 14: «The giant planets probably moved their orbits after they formed, scattering many small icy bodies inward and outward.», reached through the remembered sentence the question matched. What matched: the same action «form» (+4); the same doer «planets» (+4). · the question and its options parsed, with trees and pragmatics
Exam question 1 · formal language · right ✓
Identify the material from which the Solar System is understood to have formed.
- 1. A collapsing cloud of gas and dust designated the solar nebula — ← Mova's choice · ✓ the right answer · score 4
- 2. A great quantity of water ejected by a distant star into empty space — no support
- 3. The debris of a planet destroyed by the Sun — no support
- 4. Fragments of the Moon dispersed by an impact — no support
Why: It took the question to ask which statement is true. It chose option 1 with score 4, the only option with support. Its support: lesson 2, line 6: «The Solar System formed about 4.6 billion years ago from a huge cloud of gas and dust called the solar nebula, which collapsed under its own gravity.», reached through the same lesson line as the sentence the question matched. What matched: the same action «cloud» (+2); the same thing acted on «gas» (+2). · the question and its options parsed, with trees and pragmatics
Exam question 2 · formal language · wrong ✗
State the principal reason for which the outer planets attained a considerably greater size than the inner planets.
- 1. The outer planets were subject to a weaker solar wind — ← Mova's choice · no support
- 2. The outer planets consumed the inner planets' atmospheres — no support
- 3. Beyond the frost line ices were able to condense in addition to rock — ✓ the right answer · no support
- 4. The outer planets were formed considerably earlier in time than the inner — no support
Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Exam question 3 · formal language · right ✓
Which of the following statements most accurately characterises the prevailing account of the origin of the Moon?
- 1. Debris from a collision of a Mars-sized body with the Earth coalesced — ← Mova's choice · ✓ the right answer · no support
- 2. The Moon was detached from the Sun in its infancy — no support
- 3. The Moon was captured intact from the asteroid belt — no support
- 4. The Moon was formed subsequent to the appearance of life upon the Earth — no support
Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
Exam question 4 · formal language · right ✓
Ascertain the means by which the age of the Solar System has been determined.
- 1. Radioactive dating of the oldest solid components of meteorites — ← Mova's choice · ✓ the right answer · no support
- 2. Measurement of the present temperature of the Sun — no support
- 3. Enumeration of the craters upon the Earth's surface and the Moon's — no support
- 4. Calculation from the number of known planets — no support
Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics
This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/space/2-how-the-solar-system-was-born/