The Myth of Mars

http://www.lcsd.gov.hk/CE/Museum/Space/StarShine/AstroEvent/MarsAtOpposition/e_starshine_ae_mao.htm

It seems that every summer since 2003 there is an exciting announcement that "Mars will be as large as the FULL MOON!" and "No living human has ever seen this before or will ever see it again!"

This summer the story says that Thursday, August 27 is that day- the first day of Astronomy class! How exciting! Unfortunately, it's just not true and everyone from Snopes to NASA can explain why.

So let me join in on debunking this story.

Planets orbit the sun not in circles but ellipses (off-centered ovals) and they orbit at different speeds. So as they orbit, the planets "pass" each other regularly, and they are both on the same side of the sun. And the distance between them varies, depending upon what part of the oval they are on. So while it is true that in 2003 (August 27, actually) the Earth and Mars were closer than they had been in 60,000 years, they weren't that much closer than they get every 15 years or so- and every two years they are "closer than usual". This is called perihelic opposition, and the closest the two planets can get to each other is 35 million miles, but it might be as much as around 60 million miles.

So while Mars can get within about 35 million miles of the earth every couple of decades, and it can get quite bright, it will never look as large as a full moon. It's just too far away.

First Homework Assignment!

First Homework Assignment!

Homework 8-27-08 DUE BY MONDAY AUGUST 31 2009
Read the introduction to your textbook, pages 2-11.
Choose ONE of the following questions and answer it thoroughly. This is your first homework, and with it you are making a first impression upon your teacher. Use your best written English to answer the question. Demonstrate your ability to communicate. Your grade will be based on your quality of expression; there is no “right” or “wrong” answer. Show me the best writing of which you are capable.YOUR RESPONSE SHOULD BE ADDED AS A COMMENT TO THIS BLOG.
1. It has been suggested that the universe may be 15 billion years old. The introduction of your textbook defines a light year as the distance traveled by light on one year. Light travels at about 3 x 10^5 kilometers (km) per second. Explain how this information could be used to predict that the universe must be smaller than 2 x 10^26 km across.
2. The Bible states in Joshua 10:12-13 that “…the sun stood still and the moon stopped, till the nation avenged itself on its enemies, as it is written in the book of Jashar. The sun stopped in the middle of the sky and delayed going down about a full day.” (Scripture taken from the Holy Bible, New International Version, 1984, International Bible Society, Colorado Springs, CO. Used by permission.) Is there any conflict between believing the biblical account of the sun stopping in the sky and the structure of our solar system as described in the introduction of your textbook?

3. One reason that many people are interested in astronomy is the possibility that life exists beyond the earth. With particular reference to the description of the scientific method, what sort of evidence (not including actually meeting an alien!) do you feel would be required to make a strong claim that life probably exists elsewhere?