Read the passage carefully and then answer the questions that follow:
Death of the Dinosaurs
65 million years ago, dinosaurs suddenly became extinct, together with a large number of other species. But why did it happen?
Many scientists believe that the cause was a large asteroid crashing into the Earth. According to this theory, the asteroid threw huge amounts of dust and water vapour into the atmosphere, blocking out the light of the sun, the vegetation died off, and the dinosaurs starved to death.
Evidence for the theory came in 1992 when scientists in Mexico uncovered an underground crater 175 kilometers wide, which turned out to be exactly 65 million years old. The crater was probably caused by an asteroid 10 km in diameter hitting the Earth at thousands of miles an hour, with the force of 70 million one-megaton bombs.
According to David Raup of the University of Chicago, this was just one of many such cases. He says that asteroids have caused more than half of species extinctions since life on Earth began 600 million years ago. If he’s right, it seems likely that Homo sapiens will end its days in the same way.
NASA to the Rescue
As we can’t predict when a really big asteroid will arrive, is there really any point in worrying about it? NASA thinks there is. It estimates that there are between 1,000 and 4,000 asteroids at least 1 kilometre in diameter which regularly cross Earth’s orbit. If such an asteroid hits the Earth once every 300,000 years, this gives the average person roughly a one in 4,000 chance of being around when it happens. A small risk, maybe, but much bigger than the risk of dying in an air crash, which is one in 20,000. NASA aims to set up new telescopes and spend the next 25 years working out which large asteroids are likely to arrive within the next century or two. The idea is that once they’ve identified an asteroid heading straight for us, they can move it out of the way by hitting it with powerful nuclear bombs.
1a Why did the dinosaurs starve to death?
1b What is the evidence given by scientists to support that an asteroid caused mass extinction of plant and animal life?
1c What does the author say will be the fate of human beings? Why?
1d NASA thinks that we should be concerned about being hit by an asteroid. Why?
1e What technology do you think would be used to prevent an asteroid from hitting the earth?
1f Make sentences of your own with the following words/phrases from the passage:
i. extent ii. species iii. crashing iv. blocking out
v. homo sapiens vi. estimates
1g Find opposites of the following words from the passage.
i. suddenly ii. huge iii. crashing iv. arrive
1h Nasa has found a large asteroid that will hit the earth in a month’s time. Would you be confident that it would be intercepted? Are you concerned about the debris that might fall on earth and its repercussions?Express your feelings and say how you will protect yourself and your family.
1a. The dinosaurs starved to death because the asteroid impact threw huge amounts of dust and water vapor into the atmosphere, blocking out the light of the sun, causing vegetation to die off.
1b. The evidence given by scientists to support that an asteroid caused the mass extinction includes the discovery of an underground crater in Mexico that is 175 kilometers wide and exactly 65 million years old. This crater was likely caused by an asteroid 10 km in diameter hitting the Earth at a high speed, with the force of 70 million one-megaton bombs.
1c. The author suggests that the fate of Homo sapiens (human beings) may be similar to that of the dinosaurs if a large asteroid were to hit Earth. This is based on the theory that asteroids have caused more than half of species extinctions since life on Earth began, and there are many large asteroids that regularly cross Earth's orbit.
1d. NASA thinks that we should be concerned about being hit by an asteroid because there are between 1,000 and 4,000 asteroids at least 1 kilometer in diameter that regularly cross Earth's orbit. While the average person has a relatively small chance of being around when such an asteroid hits, the consequences could be catastrophic.
1e. NASA aims to prevent an asteroid from hitting Earth by identifying potentially dangerous asteroids and then using powerful nuclear bombs to deflect them from their path.
1f.
i. The extent of the damage caused by the asteroid impact was immense.
ii. The extinction of many species occurred after the asteroid impact.
iii. The asteroid caused mass extinction by crashing into Earth.
iv. The asteroid impact resulted in blocking out the sun's light.
v. Homo sapiens, or human beings, may face a similar fate.
vi. NASA estimates that there are between 1,000 and 4,000 asteroids at least 1 kilometer in diameter.
1g.
i. gradually
ii. small
iii. landing
iv. depart
1h:
If NASA found a large asteroid that would hit Earth in a month's time, there would likely be significant efforts to intercept it. NASA and other space agencies have been studying ways to deflect asteroids, and they would likely use a variety of methods, including launching a spacecraft to collide with the asteroid and alter its trajectory, or using a nuclear explosion to disrupt the asteroid's path.
As for concerns about debris falling on Earth, it would depend on the size of the asteroid and the effectiveness of the interception. If the asteroid were successfully deflected or destroyed, the debris would likely burn up in the Earth's atmosphere or fall harmlessly to the ground. However, if the interception were unsuccessful, there could be significant repercussions, including widespread damage and loss of life.
In such a scenario, it would be important to follow the guidance and instructions of emergency authorities. Taking precautions such as staying indoors, away from windows, and having an emergency kit prepared could help protect oneself and one's family.