Smacked asteroid’s debris trail more than 6,000 miles long

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Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. spew / spyu / (v.) – to flow out of something in a fast and forceful way

    Black smoke spewed from his old car.

  2. tenuous / ˈtɛn yu əs / (adj.) – very thin in form

    The smoke trail from the jet became tenuous until it disappeared.

  3. hurl / hɜrl / (v.) – to throw something with a lot of force

    He hurled the baseball at the batter with all his strength.

  4. head-on / ˈhɛdˈɒn / (adj.) – crashing towards each other with the head or front, especially of two things such as vehicles

    The impact of the head-on collision of the trucks was very strong.

  5. dress rehearsal / drɛs rɪˈhɜr səl / (n.) – a practice for how a more important event at a later time will be performed

    Tonight’s performance is a dress rehearsal for the play’s grand opening next week.


Read the text below.

The asteroid that got smacked by a NASA spacecraft is now being trailed by thousands of miles of debris from the impact.

Astronomers captured the scene millions of miles away with a telescope in Chile. Their remarkable observation two days after last month’s planetary defense test was recently released at the National Science Foundation lab in Arizona.

The image shows an expanding, comet-like tail more than 6,000 miles (10,000 kilometers) long, consisting of dust and other material spewed from the impact crater.

This plume is accelerating away from the harmless asteroid, in large part, because of pressure on it from solar radiation, said Matthew Knight of the U.S. Naval Research Laboratory, who made the observation along with Lowell Observatory’s Teddy Kareta using the Southern Astrophysical Research Telescope.

Scientists expect the tail to get even longer and disperse even more, becoming so tenuous at one point that it’s undetectable.

“At that point, the material will be like any other dust floating around the solar system,” Knight said in an email.

More observations are planned to determine how much and what kind of material was hurled from the 525-foot (160-meter) Dimorphos, a moonlet of a larger asteroid.

Launched nearly a year ago, NASA’s Dart spacecraft was destroyed in the head-on collision. The $325 million mission to deflect an asteroid’s orbit was intended as a dress rehearsal for the day a killer rock heads our way. Dimorphos and its companion rock never posed a threat to Earth and still do not, according to NASA.

This article was provided by The Associated Press.

Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

  • The $325 million mission to deflect an asteroid’s orbit was intended as a dress rehearsal for the day a killer rock heads our way. What do you think about this (ex. it’s worth it, it’s wasteful)? Discuss.
  • Given that NASA was able to change the asteroid’s orbit, are you confident that we would survive in case an asteroid heads for Earth? If given the chance, would you ever want to be a part of a study or mission to protect Earth from outside threats? Why or why not? Discuss.

Discussion B

  • Do you think NASA should inform people right away if they eventually detect a killer rock that could wipe out the entire humanity? Why or why not? Discuss.
  • If you heard that a killer rock is approaching the Earth and authorities said there’s a very low chance they could prevent it, what are you going to do? Why? Discuss.