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Read a scientific article about asteroids to practise and improve your reading skills.

Do the preparation task first. Then read the text and do the exercises.

Reading text


In 2010, the planetary defence team at NASA had identified and logged 90 per cent of the asteroids near Earth measuring 1km wide. These 'near-Earth objects', or NEOs, are the size of mountains and include anything within 50 million kilometres of Earth's orbit. With an estimated 50 left to log, NASA says none of the 887 it knows about are a significant danger to the planet.


Now NASA is working towards logging some of the smaller asteroids, those measuring 140 metres wide or more. Of the 25,000 estimated asteroids of this size, so far about 8,000 have been logged, leaving 17,000 unaccounted for. Considering that a 19-metre asteroid that exploded above the city of Chelyabinsk in Russia in 2013 injured 1,200 people, these middle-sized asteroids would be a serious danger if they enter Earth's orbit.


Whether NASA can find the remaining middle-sized NEOs depends on getting the money to build NEOCam, a 0.5-metre space telescope which would use infrared light to locate asteroids. If it did get the money, it could probably achieve its goal in ten years. Once logged, the planetary defence team would still need to work out how to defend the planet against being hit by the truly worrying asteroids – the PHAs.


'Potentially Hazardous Asteroids' are rocks close enough to pass within 7.5 million kilometres of Earth's orbit. NASA has created a map of 1,400 PHAs, none of which are expected to be a threat in the next one hundred years. With technology already available, NASA can track these objects and make predictions about possible impact, at which point two defence solutions could be launched.


The first is DART – the Double Asteroid Redirection Test. Plans are scheduled to test DART on the moon of an asteroid called Didymos. 'Didymoon' is 150 metres wide, orbiting its 800-metre mother, and hopefully the impact of DART will knock it out of its orbit enough for Earth-based telescopes to pick up.


Another suggested defence against a PHA on course to hit Earth is to blow it up using a nuclear weapon. It may sound like a plot from a film, and it was the subject of the 1998 film Armageddon, but the Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER) is a genuine NASA proposal. The eight-ton rockets would be fired at an approaching asteroid with the hope of bumping it off course. If the asteroid was too close to Earth for this plan to work, the rockets would carry nuclear bombs to blow it up instead.



Nivel de idioma

Upper intermediate: B2


At first i would be both surprised and amazed. So significant and exciting thing is happening. Then common sense will reassert itself and panic will come out because can scientists do anything? And will they do it? I will be worried about how large the damage will be, who will be the sacrifices of this accident, will I and my family survive? I will turn on radio, tv and other broadcasting media to get the answers. I hope, they will work. And there are two different situations of my next actions: there is enough time before asteroid, for example 2 weeks, and a little time such as 5 minutes. In the first case I will look for my parents, and will try to make a bunker or maybe government will provide ways to survive, then we will use them. My only aim will be to stay alive myself and keep my family alive, they mean a lot for me. In the second case my actions depend on where i will be then. If it's the hit zone and i don't have time to escape, i will cry, and remember all best moments in my life, and maybe will try to hug somebody, if there will be people of course. If the hit zone is far away, I will find my family, and wait until the situation will become better. Or maybe my help will be useful, then I will do everything that I can to help people who would suffered.
In conclusion i want to say that humanity is partly ready for such emergency situation. Science in not developed enough to predict and prevent all risks. But i hope, everything will be done to get minimum damage and I will try to contribute to it.

If an asteroid is near Earth and the collision is inminent, the first thing I would do is to get as much information as I could. A news of such dimension definitely wouldn't go unnoticed and it probably would be broadcasted all over the world.The .priority would be to know where it's going to crash and how big the damage it would be. After that I would look for shelter for me and my family, buy provisions of all kind ( mostly the ones that last very long ) wait until the asteroid reach and crash to the Earth and hope for the best.

Hi Teacher,
I think the writer should use will instead of using would since this is a first conditional statement. Please correct me if I am wrong.

"these middle-sized asteroids would be a serious danger if they enter Earth's orbit"

Hello mxoubi0,

You could certainly say 'will' here, and if you saw a sentence like this on a grammar test, that would be the best choice since, as you point out, it follows the rules that are taught about the first conditional.

These rules about conditionals explain how grammar is used most of the time, but they are rules designed by teachers to help students. In reality, you can find sentences like this one, which is perfectly correct. Here, I imagine that the writer chose to say 'enter' since the previous sentence mentions a specific middle-sized asteroid that did indeed enter Earth's orbit. But the danger such an asteroid would pose is still regarded as hypothetical, which is more in line with what the writer's tone in the rest of the text.

I can see how that may be a little confusing, but I hope this helps you make sense of it.

Best wishes,


The LearnEnglish Team


Firstly, I'm gonna check if the information is true or not . If it's true I will stay with my family hoping that NASA could find a solution LOL

Wow, it's a difficult question.. I think that with everybody crying in state of panic, I couldn't do many things.
Try to stay with my family believing in the salvation jjjjj

Firstly, I will confirm whether the information is true or not through ISRO/NASA latest updates and if it is correct, then I'll check regarding the extent of damage it may cause.
If it is going to be too serious , then I will first apologize to everyone if I had done anything wrong to them and secondly remain with my family till the problem is not over.
It's better if we all remain together during such times.

I think I will rewatch the movie about space, and try to applying it in my situation. This is a huge problem, so it need a huge solution too

Firstly, I would make sure if this news true or fake. Secondly, i would inform my family about it. Then, i would follow the authorities. Finally, i would pray.