How did this question arise?

It dates back to the opposition of Mars in August 2003. An opposition occurs when a planet outside the orbit of Earth (that is Mars and beyond) is opposite the Sun in the sky. From Earth the planet therefore is visible all night, reaching maximum elevation at midnight. More importantly for observers the planet is at its closest to Earth so also appears at its brightest. Due to the elliptical orbit of planets, some oppositions bring them closer to Earth than others. This is particularly the case with Mars as its orbit is lightly more elliptical than the other planets.

The email doing the rounds mentions August 27 but omits the year so it is easily recycled year after year. Rather than dismissing the email out of hand though, use it as a timely, useful exercise in critical thinking and investigation in the classroom. Don’t answer the student questions, get them to think how they can go about finding out if it is true, where Mars will be in the sky, how far away it will be and how large it will appear. This is a great Problem-Based-Learning exercise. It draws on several skills and blends reading with simulations, some ratios and mathematics and modelling.

Several sites have background on the hoax email and the misconceptions:

• ABC Science page on the Mars email
• Universe Today page on the topic
• Phil Plait’s Bad Astronomy site (excellent coverage of many misconceptions and hoaxes)
• Snopes page

Free programs such as the open-source Stellarium are also a great way to let students explore what the sky will look like in late August.

Exploring this email could easily take up one or more lesson but will be time well spent in developing students’ questioning and thinking skills. Let me know if you try it.