Lesson 13 - Comparisons
This lesson contains a short video about the exploration of Mars with the Phoenix Lander. This lesson also covers how to make comparisons in English, including how to use the comparative and superlative forms of adjectives.
Mars image credit: NASA/JPL/USGS
The following short video is from NASA and talk about the Phoenix lander and the exploration of Mars. The presenters talk in conversational American English. A transcript of the video is also given to help improve your comprehension.
|dig (dug, have dug)|
EVAN: Hey Globey, today we’re going to talk about the Phoenix Lander. Have you ever heard of it? No? Well the Phoenix Lander is really cool, and its mission was very exciting. It’s a robotic craft that NASA sent to Mars to learn more about our neighboring planet. The Phoenix Lander was sent to Mars for two main reasons. The first was to look for water or a history of water on the planet. The second reason was to test the soil to see if it could support life in the past or present. We call this ability to sustain life "habitability."
CARLA BITTER: Habitability refers to the potential or the ability for anything biological in nature to survive or exist in a place. So when we explore Mars to go looking for life as we know it, would probably be pretty foolish because Mars is really different from Earth. So what we want to know is, is it a possibility? Is it habitable? Does it have the building blocks of life? The carbon, the oxygen, the nitrogen, the phosphorous, and of course water. Liquid water is the huge ingredient which allows Earth to be habitable.
EVAN: The Phoenix Lander touched down on the surface of Mars on May 25th, 2008, completing a journey from Earth that was 680 million kilometers long. That’s a very long way. The Phoenix Lander has all sorts of cool instruments on board. One of those is a robotic arm, which is used to dig trenches in the Martian soil, scoop up soil samples for testing, and also search for evidence of water. Possibly the most exciting discovery was when the robotic arm dug just below the surface of the soil and discovered ice. This was proof that water existed on Mars...even though it was now all frozen or in the form of gas in the atmosphere. If water existed on Mars in a liquid form in the past, then perhaps life did too at some point. The camera on-board the Lander sent photographs of the ice back to scientists on Earth. It was a major discovery! And thanks to the technology of the internet, the whole world shared in this discovery. We saw the pictures just a few hours after the scientists learned about the ice themselves.
CARLA BITTERS: It was very exciting to find it because it said 'yes' all our other instruments, the things we’ve done in the past. The other missions we sent to Mars, that’s all right. That missing ingredient is there. the proof that it is a possibility that Mars was or even currently is habitable by some kind of living thing.
EVAN: And that’s what exploration is all about... discovering new things and determining if what you thought was correct is indeed right.
CARLA BITTERS: Exploration is important to humans because I wouldn’t be standing here today talking about a mission to Mars if my ancestors didn’t cross the ocean. Or didn’t know what was on the other side of the river or over the mountain. And now we have the opportunity and the technology and the possibility to just offload planet Earth altogether. and go see what’s out there, go see the ends of our known universe. So exploration is what we do, it’s how we move forward, not just as a species, but as a thinking group of people that are curious and want to know what’s next.
EVAN: The Phoenix Lander’s mission was designed to last around 90 Sols, which is what we call days on Mars. If you want to count in Earth days, then the Lander was meant to work for 92 days. Remember, days on Mars last longer because the planet is revolving or spinning on its axis at a slower speed than Earth spins on its axis. It takes about 37 minutes longer for Mars to make one complete turn.
EVAN: Because the Phoenix Lander had touched down in the polar region, scientists knew that when the Martian winter arrived, it would become much too cold for the Lander to continue to work. And that’s exactly what happened. One day the scientists here on Earth simply stopped receiving information from the Phoenix Lander. Even though the Phoenix Lander is no longer working, its mission is still an amazing success story. It proved that water ice exists on Mars. During another NASA mission to Mars, scientists will prove that life once existed on the red planet as well. That is so exciting, Globey. I can’t wait to see what those NASA scientists uncover next.
Adjectives are used to describe a quality or attribute of a noun. This lesson covers how to compare a quality of two or more nouns.
To indicate that a noun has the same quality as another noun, the following construction is used:
as <adjective> as
|Today is as cold as yesterday.|
|You are as smart as I am.|
|Your house is as big as my house.|
Indicating Less of a Quality
To indicate that a a noun has less of a quality than another noun, the following construction is used.
not as <adjective> as
The following construction can also be used:
less <adjective> than
|Today is less cold than yesterday.|
|Today is not as cold as yesterday.|
|Your house is not as big as my house.|
There are two ways to indicate that a noun has a greater quality than another noun. The first way is to add "er" to the end of the adjective. This is called the comparative form of the adjective. The second way is to add the word "more" before the adjective. The following rules are used to determine which form to use.
- If the adjective has one syllable and ends in a consonant, er is added to the end of the adjective. Sometimes the final consonant is also doubled.
- If the adjective has one syllable and ends in e, then r is added to the end of the adjective.
- If the adjective is two syllables and ends in y, the y is changed to an i and er is added to the end of the adjective.
- If the adjective is two syllables and ends in ow, then er is added to the end of the adjective.
- If the adjective is two syllables and does not end in y or ow, then the word more is added before the adjective. Some of these two syllable adjectives can use the er suffix instead.
- For adjectives with three or more syllables always use the word more with the adjective. The suffix er is never used with these adjectives.
|quiet||quieter or more quiet|
To indicate that a noun has the most of a quality within a group, either the superlative form of the adjective is used, or the word most is added before the adjective. The following rules are used to determine which form to use.
- If the adjective has one syllable and ends in a consonant, est is added to the end of the adjective. Sometimes the final consonant is also doubled.
- If the adjective has one syllable and ends in e, then st is added to the end of the adjective.
- If the adjective is two syllables and ends in y, the y is changed to an i and est is added to the end of the adjective.
- If the adjective is two syllables and ends in ow, then est is added to the end of the adjective.
- If the adjective is two syllables and does not end in y or ow, then the word most is added before the adjective. Some of these two syllable adjectives can use the est suffix instead.
- For adjectives with three or more syllables always use the word most with the adjective. The suffix est is never used with these adjectives.
|intelligent||more intelligent||most intelligent|
|quiet||quieter or more quiet||quietest or most quiet|
|broken||more broken||most broken|
|That's the biggest dog I've ever seen.|
|That's the oldest house in the neighborhood.|
|Your house is bigger than our house.|
|His car is more expensive than mine.|
|She is the most intelligent person I have ever met.|
Some adjectives have irregular comparative and superlative forms. The following table shows the irregular forms.
The comparative form of adverbs is created by adding the mord more before the adverb the superlative form of adverbs is created by adding the word most before the adverb.
|quietly||more quietly||most quietly|
|frequently||more frequently||most frequently|
|carefully||more carefully||most carefully|
Here is an online quiz to help you learn the English vocabulary introduced in this lesson.