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Ocean world discovered between Mars and Jupiter

Will Dunham, August 11, 2020 6:45PM Reuters

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This representation of the Occator Crater on dwarf planet Ceres from images taken by NASA's Dawn spacecraft from a distance of about 4400km. media_cameraThis representation of the Occator Crater on dwarf planet Ceres from images taken by NASA's Dawn spacecraft from a distance of about 4400km.

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A NASA mission has discovered a saltwater ocean world in the asteroid* belt between Mars and Jupiter.

Until now, freezing dwarf planet Ceres was thought to be a barren space rock.

The new discovery has scientists interested in Ceres as a possible outpost* for life.

Research published on Monday is based on data from NASA’s Dawn spacecraft, which flew as close as 35km from the surface of Ceres in 2018. The data provides a new understanding of Ceres, including evidence it remains geologically active with cryovolcanism — volcanoes oozing icy material.

The findings confirm the presence of a reservoir* of salty water, the remains of a vast subsurface ocean that has been gradually freezing.

“This elevates Ceres to ‘ocean world’ status, noting that this category does not require the ocean to be global,” said planetary scientist and Dawn lead investigator Carol Raymond. “In the case of Ceres, we know the liquid reservoir is regional scale but we cannot tell for sure that it is global. However, what matters most is that there is liquid on a large scale.”

NASA's Dawn spacecraft captured pictures in visible and infrared wavelengths, which were combined to create this false-color view of a region in 57-mile-wide (92-kilometer-wide) Occator Crater on the dwarf planet Ceres. Picture: JPL/NASA media_cameraNASA’s Dawn spacecraft captured pictures in the visible and infra-red wavelengths, which were combined to create this false-colour view of an area in the Occator Crater on Ceres. Picture: JPL/NASA

Ceres has a diameter of about 950km. The scientists focused on the 92km-wide Occator Crater, formed by an impact about 22 million years ago in Ceres’ northern hemisphere.

Occator Crater has two bright areas — salt crusts left by liquid that came up to the surface and evaporated.

The liquid, they concluded, came from a brine* reservoir hundreds of kilometres wide about 40km below the surface, with the impact creating cracks allowing the salty water to escape.

The research was published in the journals Nature Astronomy, Nature Geoscience and Nature Communications.

Water is considered a key ingredient for life. Scientists want to assess whether Ceres was ever habitable by microbial* life.

“There is major interest at this stage,” said planetary scientist Julie Castillo of NASA’s Jet Propulsion Laboratory, “in quantifying* the habitability* potential of the deep brine reservoir, especially considering it is cold and getting quite rich in salts.”

FAST FACT
Other objects in the Solar System where subsurface oceans are known or appear to exist include Jupiter’s moon Europa, Saturn’s moon Enceladus, Neptune’s moon Triton and the dwarf planet Pluto.

GLOSSARY

  • asteroid: small, rocky object orbiting the Sun
  • outpost: an isolated branch or part of something
  • reservoir: dam or store of a liquid
  • brine: salty water
  • microbial: relating to microorganisms
  • quantifying: measuring and expressing as numbers
  • habitability: whether somewhere is habitable, or able to be lived on

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QUICK QUIZ

  1. Where is Ceres?
  2. What is Ceres?
  3. What is the name of the crater the water is underneath?
  4. How far below the surface is the water?
  5. What other places are thought to have subsurface oceans?

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CLASSROOM ACTIVITIES
1. Saltwater Ocean World Creature
Create your own character that lives on the dwarf planet Ceres in a saltwater ocean world. Use the information and facts from the Kids News article to create a character that could inhabit this planet.

Include the following information about your creature/character:

  • Name:
  • Type of creature:
  • Where it lives:
  • What it eats:
  • How it survives on this planet:

Share your character with the class.

Time: allow 25 minutes to complete this activity
Curriculum Links: English, Science, Critical and creative thinking

2. Extension
“Water is considered a key ingredient for life.” How does this quote apply to humans and life on other planets?

Time: allow 10 minutes to complete this activity
Curriculum Links: English, Critical and Creative thinking

VCOP ACTIVITY
Read with Kung Fu Punctuation
Pair up with the article between you and stand up to make it easy to demonstrate your Kung Fu Punctuation.

Practice reading one sentence at a time. Now read it again, while acting out the punctuation as you read.

Read and act 3 sentences before swapping with your partner.

Have 2 turns each.

Now as a challenge ask your partner to read a sentence out loud while you try and act out the punctuation. Can you keep up?

Swap over?

Try acting out 2 sentences.

Are you laughing yet?

Have fun acting out your punctuation.

HAVE YOUR SAY: Which planet should we concentrate on exploring?
No one-word answers. Use full sentences to explain your thinking. No comments will be published until approved by editors.

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