You will learn the names and features of the objects that surround us: asteroid, comet, meteor, atmosphere, habitable zone, exoplanet, and you will learn the difference between them, because they are constantly confused.
You will also learn how scientists write and speak: with may, might, it is thought that, is estimated to and believe. Scientific texts avoid certainty, and using the right hedge is a skill this lesson measures directly.
Ön Bilgi
You need three things ready.
First, the present passive, because scientific statements are usually impersonal: The age of the universe is estimated to be about 13.8 billion years, the planet is called Mars. If you write these sentences with a personal subject, they sound odd.
Second, comparatives and superlatives, because almost every space fact is a comparison: Jupiter is the biggest planet, Mercury is closer to the Sun than Venus.
Third, the difference between countable and uncountable nouns in this topic: space, gravity, water, life are uncountable, while planet, galaxy, moon, star, telescope are countable.
Basit Örnek ve Günlük Yaşam
Read this short scientific text and notice the hedged language.
Scientists believe that the universe is about 13.8 billion years old. It contains billions of galaxies, and our own galaxy is called the Milky Way. The Sun is an ordinary star, and it is one of hundreds of billions in this galaxy. Astronomers think that many stars have planets, and some of those planets may have liquid water.
Three signals of careful scientific writing appear: Scientists believe that, is about and may have. None of them states a bare fact, and that is deliberate.
Now write four sentences about Mars using at least two hedging expressions.
Adım Adım Çözülmüş Örnek
Follow these steps to write a correct sentence about space.
- Step 1 — Choose the subject and use the passive if it is a fact about a thing. The telescope was launched in 1990.
- Step 2 — Choose the verb. For size and position use is plus a comparative or superlative: Jupiter is the biggest planet.
- Step 3 — Add a hedge if the information is an estimate. The age of the universe is estimated to be 13.8 billion years. / It is thought that many galaxies exist.
- Step 4 — For possibility use may or might plus the base form. There may be water under the ice. Never may to be.
- Step 5 — Check the uncountable nouns. Space is cold, Gravity is weaker on the Moon — no plural -s.
Karşılaştırma Tablosu
Space objects are often confused. This table separates them.
| Object | What it is | Example |
|---|
| star | a body that produces light by fusion | The Sun is a star. |
| planet | a body orbiting a star | Mars is a planet. |
| moon | a body orbiting a planet | The Moon orbits the Earth. |
| galaxy | a huge group of stars, gas and dust | The Milky Way is our galaxy. |
| solar system | a star and the bodies orbiting it | Our solar system has eight planets. |
| asteroid | a rocky body | Asteroids orbit between Mars and Jupiter. |
| comet | ice and dust that grows a tail | The comet became visible at night. |
| meteor | the light of a stone burning in the atmosphere | We saw a meteor in August. |
| orbit | the path of one body around another | The satellite is in orbit. |
| light-year | the distance light travels in a year | The star is eight light-years away. |
Careful: a galaxy contains many star systems; our solar system is not a galaxy.
Kendini Dene
Answer in full sentences and then check the key.
- Complete: There ____ (may / may to) be water under the ice.
- Which sentence is correct? (a) Gravities are weaker on the Moon. (b) Gravity is weaker on the Moon. (c) Gravity are weaker on the Moon.
- Rewrite correctly: The solar system is a galaxy.
- Fill in: The age of the universe is ____ (estimate) to be about 13.8 billion years.
- Which object is ice and dust and grows a bright tail?
- Write a five-sentence paragraph about the search for life on Mars. Use two hedging expressions, one comparative and one uncountable noun.
Answer key: 1) may — a modal is followed by the base form. 2) (b) — gravity is uncountable and takes a singular verb. 3) The solar system is part of a galaxy. 4) estimated — the pattern is is estimated to be. 5) a comet. 6) Any correct text, e.g. Mars is smaller than the Earth, and its atmosphere is much thinner. It is thought that water ice exists below the surface at the poles. There may have been rivers on the planet millions of years ago. Scientists believe that any life would have been very simple. No evidence of life has been found yet, so research continues.