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Scientists create 3D map revealing the true shape of the Milky Way

Harry Pettit, February 5, 2019 6:00PM The Sun

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Artist's impression of the twisted Milky Way galaxy. Picture: Chen Xiaodian media_cameraArtist's impression of the twisted Milky Way galaxy. Picture: Chen Xiaodian

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Reading level: orange

Scientists believed the Milky Way is a flat disc like a pancake.

But a 3D map created by an international team including Australian scientists has revealed our galaxy is actually warped*, twisted and more like an S shape.

This crooked shape is caused by the extreme forces generated by the spinning of the Milky Way’s massive inner disc of stars.

The incredible find “offers new insights into the formation of our home galaxy,” said study author Professor Richard de Grijs from Macquarie University in Sydney, NSW.

A team of Chinese and Australian scientists created the map by measuring the distances between 1300 large, pulsating* stars.

Part of the Milky Way seen from the Larapinta Trail, Northern Territory. All the stars we see in the night sky are part of the Milky Way. Picture: iStock media_cameraPart of the Milky Way seen from the Larapinta Trail, Northern Territory. All the stars we see in the night sky are part of the Milky Way. Picture: iStock

The stars, known as “classical Cepheids”, are 20 times bigger than our sun and shine 100,000 times brighter, meaning they can be mapped accurately even when they’re incredibly far away.

This makes them perfect for scientists trying to chart the Milky Way, and allowed the team to create the most accurate 3D map of the galaxy so far.

Part of the 3D map of the Milky Way that researchers created by charting about 1300 stars, which are the dots on the map. Picture: Chen Xiaodian media_cameraPart of the 3D map of the Milky Way that researchers created by charting about 1300 stars, which are the dots on the map. Picture: Chen Xiaodian

Professor de Grijs said the find revealed how the outer edges of the Milky Way have become more and more twisted over time.

He blamed extreme torque*, or rotational* force, in the Milky Way’s spinning inner disc for our misshapen* home.

Information on the classical Cepheid stars was provided by a NASA telescope in space called the Wide-field Infrared Survey Explorer (WISE).

VIDEO: Time-lapse of the Milky Way from Great Barrier Island, New Zealand

MILKY WAY
A galaxy is a large group of stars, gas and dust held together by gravity.

There are many galaxies.

The Milky Way is the galaxy the Earth, the Sun and the rest of our solar system is a part of.

The name describes how it looks from Earth: a pale, milky band of light across the sky.

From Earth, the Milky Way looks like a band because we are looking at its disc shape from within.

It is thought to contain 100 billion stars.

All the stars we see in the night sky are from the Milky Way.

GLOSSARY

  • warped: twisted out of shape
  • pulsating: expanding and contracting
  • torque: force that causes rotation
  • rotational: using or relating to a circular movement around a centre
  • misshapen: out of shape

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QUICK QUIZ

  1. What shape did we previously believe the Milky Way was?
  2. What shape do we now know it is?
  3. How many stars did the scientists chart?
  4. Is the shape of the Milky Way staying the same or changing?
  5. What is in a galaxy?

LISTEN TO THIS STORY

CLASSROOM ACTIVITIES
1. Create Your Own Milky Way
Using the information from the Kids News article, create your own representation of the Milky Way Galaxy. Some ideas may include:

3D model

Digital representation on computer

Artwork

Labelled diagram

Be sure to include all the facts about what galaxy looks like and what it contains.

Time: allow 45 minutes to complete this activity
Curriculum Links: Science, Visual Arts, Digital Technologies, English

2. Extension
Further research the NASA Wide-field Infrared Survey Explorer and other images it provides for space research. Work with a partner to discuss the best way to research this and the most reliable websites for accurate information.

Time: allow 20 minutes to complete this activity
Curriculum Links: English, Science, Personal and Social

VCOP ACTIVITY
With a partner see if you can you identify all the doing words/verbs in this text. Highlight them in yellow and then make a list of them all down your page. Now see if you and your partner can come up with a synonym for the chosen verb. Make sure it still makes sense in the context it was taken from.

Try to replace some of the original verbs with your synonyms and discuss if any are better and why.

HAVE YOUR SAY: What would you call our home galaxy if it wasn’t called the Milky Way? Why?
No one-word answers. Use full sentences to explain your thinking.

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