Searching for the Start of Life

A

The beginnings of life provide scientists with some of the most difficult questions of modern science. Our knowledge of the development of cells， from which all forms of life are made， is not complete because we do not understand very well the conditions on our planet four billion years ago. Why and how did cells first appear？ Was this very likely to happen under the conditions then， or was it due to chance？ Might this happen in other places in the universe？

B

A group of scientists at University College London are trying to answer these questions. They started by studying the ways in which the first cells on Earth might have been formed. Next they will use a powerful new telescope to look at places far away in the universe. The scientists hope that the results will improve our understanding of the development of life on Earth and help us to find life on other planets.

C

Dr Nick Lane， who is in charge of the University College London team， has suggested that 4 billion years ago warm water springs on the floor of the Earth’s ocean might have helped to create life. Each spring consists of tiny connected holes that water passes through. The team have created models of these springs in their lab. They have found that they encourage chemical reactions between hydrogen in the liquids that come out of them and the carbon dioxide in the sea water. These chemical reactions can create the ‘building blocks’ of life. These building blocks are not living themselves， but when there are enough of them joined together in the right way， they can make living things. The water in the system of springs moves the building blocks around until there are a lot of them in a small area. Things that look very much like real living cells can be made in this way.

D

These reactions and changes show us how life on Earth and on other planets could begin. When sea water goes through tiny holes in the Earth’s surface， it gets very hot and causes a chemical reaction with rocks. When this very hot water goes back up and meets the cold sea water again， other chemical reactions happen. Lane explains， ‘The conditions needed for life are rock， water and carbon dioxide. These could be found on millions of exoplanets， so basic life should be everywhere.’

E

Because the ingredients for life are basic and should be all over the universe， there is a very good chance that we could soon find signs of life on other planets. Furthermore， a new space satellite is going to start helping with this search. The name of the satellite is ‘Twinkle’ and it will be the first space satellite searching other planets for life. Until now， almost 2，000 exoplanets have been discovered but not much is known about them. Katy Chubb of University College London explains， ‘We’ve been discovering all of these planets but now we need to find out what they’re made of and what the conditions are like on them’.

F

A team from University College London and Surrey Satellite Technology will send the satellite into space in the next few years. The small， low-cost satellite will study light coming from other planets. This will help the scientists to understand their conditions. When an exoplanet passes in front of its star， some of the light has to pass through the gases around that planet. Studying the light can help scientists to find out about the chemistry， temperature and weather conditions of the planet. This will allow them to find planets which may have life on them.

Activity 1

Before you read， match the word or phrase to a definition.

1. carbon dioxide 2. cell 3. chemical reaction 4. form

5. hydrogen 6. satellite 7. spring 8. telescope

a. a gas that is made when living things breathe

b. a place where liquid comes out of the earth

c. an object which is put in space to send and receive messages

d. begin to exist

e. changes that happen when different chemicals are mixed together

f. something we use to look at stars and planets

g. the lightest gas there is—it joins with oxygen to make water as H2O

h. the smallest part of a plant or animal

Activity 1

Before you read， match the word or phrase to a definition.

1. carbon dioxide 2. cell 3. chemical reaction 4. form

5. hydrogen 6. satellite 7. spring 8. telescope

a. a gas that is made when living things breathe

b. a place where liquid comes out of the earth

c. an object which is put in space to send and receive messages

d. begin to exist

e. changes that happen when different chemicals are mixed together

f. something we use to look at stars and planets

g. the lightest gas there is—it joins with oxygen to make water as H2O

h. the smallest part of a plant or animal

Activity 3

Reference words are used to avoid repetition：

A group of researchers at University College London have been trying to answer these questions. They started by studying the beginnings of the first cells on Earth.

When sea water goes through tiny holes in the Earth’s surface， it gets very hot.

The small， low-cost satellite will study light coming from other planets. This will help the scientists to understand their conditions

Rewrite the sentences to avoid the repetition. Use ‘it’， ‘they’， ‘them’ or ‘this’.

Example： I do exercise everyday. Exercise keeps me healthy.

I do exercise everyday. It keeps me healthy.

1. My computer has been really slow for a while now. My computer is pretty old so that is probably why.____________

2. It is difficult for me to keep up with the latest technology. The latest technology just changes so quickly.____________

3. Children need to do physical exercise but children like to watch TV， too！____________

4. Science is becoming more popular with young people. Science becoming popular with young people is a good thing.____________

5. Scientists are confident they will find life on other planets soon. Finding life on other planets soon will help scientists understand life on Earth better._____________

Activity 4

Why do you think it is difficult for scientists to find out how life on Earth began？

Do you think that the scientists will find life on other planets soon？ Why？/Why not？

Is it important to find out if there is life on other planets？ Why？/Why not？

Answers

Activity 1" "1. a; 2. h; 3. e; 4. d; 5. g; 6. c; 7. b; 8. f

Activity 2" "B. 3; C. 6; D. 2; E. 4; F. 1

Activity 3

1. My computer has been really slow for a while now. It is pretty old so that is probably why.

2. It is difficult for me to keep up with the latest technology. It just changes so quickly.

3. Children need to do physical exercise but they like to watch TV， too！

4. Science is becoming more popular with young people. This is a good thing.

5. Scientists are confident they will find life on other planets soon. This will help them understand life on Earth better.