Investigation IV

IV. Stormy Mars: Dust Gets In My Eyes

(Finding Out About Dust Storms On Mars)

	Look at Mars Temperatures with Clear Atmosphere: Cool! What season is it in the northern hemisphere? _____________ How do you know? __________________________________________________________
	What is the surface temperature range (lowest to highest) for 15 °N on a clear day? (A ruler is helpful on the screen) _____________________ What is the atmosphere temperature range? ______________________
	Look at Mars Temperatures With Dusty Atmosphere: Dust Gets In My Eyes. What hemisphere is experiencing summer? _____________ How do you know? ____________________________________________________
	What is the surface temperature range (lowest to highest) for 60°S on a dusty day? _____________________ What is the range for the atmosphere? ___________________________
	Describe the differences in surface temperatures for a clear and dusty day. _______________________________________________________ Do the same for atmosphere temperatures. ____________________________________
	What might account for the higher temperatures when dust is present in the atmosphere? See Seasons in Mars Stats. __________________________________________________________
	What are the nighttime temperatures on Mars like? ____________________________________________________ How does the size of the particles in the atmosphere affect the Martian nighttime temperatures? __________________
	The orbit of Mars is more elliptical than the orbit of Earth. The distance from Mars to the sun varies by 20%. In the drawing below, which hemisphere is experiencing summer when Mars is closest to the sun? ______________
	What might explain the production of storms? See Seasons in Mars Stats for help. __________________________________________________________
	Use Martian Seasonal Temperatures:It's Not The Heat, It's Not The Humidity. The numbers represent the degree positions of Mars in its orbit. (360 degrees would make one Martian year.) When did a dust storm begin in the southern hemisphere? ______________ How do you know? _________________________________________________________
	Each degree represents slightly less than 2 Mars' days. About how long did the storm last? ________________ (Some storm!)
	Look at the orbit view (upper left) in Mars: All Sun All The Time? Is it likely that there are dust storms today on Mars? ________ Explain your answer. ___________________________________________________
	Look at these photos of Mars from Mars Global Surveyor. Based on what you have learned, explain why these two photos look so different. __________________________________________________________
	What Martian features are visible in the photos from June and July, 2001? __________________________________________________________
	Now let’s compare Mars dust storms to Earth’s. How are these images of Mars and Earth similar? Different? __________________________________________________________
	Mars is regularly windy, even if there is no global windstorm. One common feature on Mars is the dust devil. Dust devils are little whirlwinds of wind that pick up dust. Look at the photograph of dust devils. The dark marks are the tracks left by the dust devils. In this image is there a pattern to the dust devil direction? __________ What is the direction (let’s assume North is up)? ___________
	Read more about Martian dust devils. Where might we find these on Earth? __________________________________________________________
	Another feature that results from Martian wind is the sand dune. Examine the dunes. What direction is the wind blowing? (Assume North is up) How can you tell? ____________________________ Sketch a profile of the dune (how it would look if you could slice it through the center from left to right and look at the cut section).
	Read about the types of Earth sand dunes and compare them to dunes of Nili Patera, Syrtis Major, on Mars. What types of dunes are these Martian ones? ____________________ Under what conditions do they form? ____________________ Where on Earth are these commonly found? ____________________
	Got 3-D glasses? Check out this Martian dune in 3-D for fun!

Want to be a Martian Sun-Times reporter? Write a story using the facts you have learned in this lesson. Choose one of the styles of reporting that your teacher gave you. Email it to us!