News by Levels · Level 2 · Student worksheet

Comet Deliveries May Have Been Rare on Early Earth

Name: __________________________ Date: __________________

Read the story

One theory suggests that comets brought chemicals needed for the early steps toward life to Earth. A new study led by Cambridge researchers challenges how often that could have happened.

The team modelled the journey of comets and focused on hydrogen cyanide, a chemical involved in reactions that can produce ingredients for life. The models suggest that delivering enough of it intact to Earth's surface would have been very rare.

The researchers do not say a delivery was impossible or that they have solved the origin of life. Their study appeared in Scientific Reports on October 28.

Source: University of Cambridge, via Brightsurf, 2026-10-28. https://www.brightsurf.com/news/LVDO943L/comets-probably-didnt-seed-life-on-earth-after-all-new-study-suggests.html

Read and practise

1. Which chemical did the team focus on in its models?

   1. Hydrogen cyanide
   2. Carbon dioxide
   3. Methane

2. What do the researchers say about comet delivery?

   1. A delivery was impossible
   2. A delivery cannot be ruled out
   3. The origin of life has been solved

Your turn

How did the model change the researchers’ view of comet delivery, and what does it leave uncertain?

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Read online: https://newsbylevels.com/news/comet-ingredients-life-earth-cambridge-study-october-2026/level-2/