Education Technology

Comets and Coronal Mass Ejections

Activity Overview

The aim of this investigation is to determine the distance a comet moves in a period of time, thus determining the speed of a comet as it approaches the Sun. The comet’s speed will also be compared with the speed of a coronal mass ejection (CME) from the Sun. Digital technology and Pythagoras’ theorem will be used throughout.


ACMNA214 - Find the distance between two points located on a Cartesian plane using a range of strategies, including graphing software


  • Distance
  • Speed
  • Coordinates
  • Pythagoras

About the Lesson

A coronagraph is a telescopic attachment used to block out the Sun's glare so that nearby objects can be resolved. The coronagraph image overleaf was obtained from Solar and Heliospheric Observatory (SOHO) located at It represents Comet McNaught as it approached the Sun in early January 2007. The comet appears to be approaching the planet Mercury (the bright object in the foreground).

In this activity, students make a series of calculations to determine the distances travelled and the speeds of the comets as they pass by the sun.