Ice and Seek

Overview

In this two-part activity, students begin exploration of ice on planets and moons in our solar system by building an understanding that there are different types of ices. As teams, the students examine three types of ice- dry ice, alcohol ice, and water ice. They identify the ices based on clues then match the type of ice to the appropriate planet or moon on which it occurs.

Materials

• 3 (6-8 ounce) clear plastic cups per station
• Isopropyl alcohol
• 1 small piece of dry ice per station
• 1 metal spoon per station
• 1 thermometer per station
• 1 magnifying glass per station
• 3 plates per station (can be paper or plastic or metal)
• 1 set of small gloves per station (garden/work gloves – not rubber or latex)
• Prepared ices #1 and #2 per station (directions for how to make in Before the Lesson section.
• 1 Ice and Seek Lab Sheet per student
• 1 pencil per student
• 1 Planetary Ice Data Set for each student group, or post one throughout the classroom
• 1 Ice Across the Solar System sheet for each student

This activity is adapted from The Lunar and Planetary Institute

Explanation

"Ice" is a term used by planetary scientists to refer to substances that are common liquids (or gases) under Earth's surface conditions but occur as solids- frozen- in other places in our solar system. Examples are ammonia ice and carbon dioxide or dry ice. Different substances "freeze" — become solid — at very different temperatures. For example, the freezing point of water (H₂O) is 0°C (32°F) and the temperature at which carbon dioxide (CO₂) forms a solid on our planet (dry ice) is –78°C (–109°F).

Directions

Before the Lesson - How to Prepare

• Gather all the needed materials and create the number of stations needed based on the number of students participating, we suggest no more then 3-4 students per group.
• At least a day in advance, prepare the ices:
  
  1. Fill one cup per group with a mixture of ½ water and ½ alcohol; label cups with the number 1.
  2. Fill one cup per group with water; label cups with the number 2.
  3. Hint- if you will cut the bottom off the ices once frozen you can write your numbers up side down and then place your ice upside down for the activity.
  4. Freeze these containers.
  5. Dry ice can be purchased the day before as well; wrap it tightly in newspaper and place it in a freezer. Some will sublimate overnight, so consider purchasing a little extra. Handle the dry ice carefully, as it is cold enough to cause frostbite to exposed skin. You can use a hammer and a chisel to chunk your dry ice into smaller pieces.
• At each ice station place a plate, metal spoon, thermometer, magnifying glass, and a set of gloves. Put a label with the number 3 in front or on the plate.
• When your ices are frozen use a scissors or razor blade to cut off the bottom of the cup (this helps students when they are measuring the ices temperature.
• Immediately prior to the activity, place one of the previously prepared cups of water ice and alcohol ice at each station and using tongs or gloves place a piece of dry ice on each plate.

Activity Directions

1. Divide the students into teams of 3 or 4 (3 is ideal). Explain that at each station students will examine different types of ice that occur on other places in our solar system. Based on the clues they will receive; their mission is to discover the identities of these ices.
2. Have the students examine the Ice and Seek Lab Sheet (download below) clues and instructions.
3. Review with the students how they should conduct their investigation. Reinforce the importance of proper handling of the ices! Dry ice can cause frostbite. Don’t tell them one ice is dry ice, but make sure they will follow instructions completely to remain safe.
4. At each station students should:
   • Record the ice sample number on their Lab sheet.
   • Carefully examine the ice using the tools provided at the station.
   • What temperature is the ice? Students should use gloves and the thermometer to take the temperature of the ices, placing the thermometer under each ice, and waiting a minute to obtain results. It would be good to instruct students to take turns doing this together as a team, allowing each student to obtain the temperature of one ice.
   • Note: The temperatures the students collect will be warmer than the temperatures of the ice; the air temperature in the room in contact with the thermometer will cause a warmer reading.
   • How hard is the ice? Students should use the metal spoon to test for hardness by scraping and/or poking the ices, remembering not to ever touch the ices with their hands.
   • Does the ice affect metal? They should press the metal spoon on the ice and observe what — if anything — happens.
   • Note: When gas is trapped between the metal and dry ice the  ice "squeaks" due to the sublimation and causes the metal to vibrate.
   • What other tools can they use to examine the ice? Remind the students to use their eyes and noses. Their senses are some of the most important tools they, as scientists, have!
5. Once students are done with their Ice stations, remove the ices and discuss their observations. Ask the students if they noticed what looked like smoke coming from the dry ice. Explain that dry ice is actually frozen carbon dioxide (CO2). Carbon dioxide is a very common gas. It is what we exhale when we breathe and what plants need to survive. When a substance changes directly from a solid like dry ice into a gas, we call the process sublimation. Dry ice, under Earth's normal surface conditions, does not melt into a liquid, it sublimates — or turns directly into a gas. What looked like smoke was really cold carbon dioxide gas sublimating from the ice. Water ice can do the same thing; in very cold conditions, like those in Antarctica, water ice can sublimate — turn directly into water vapor.
6. After discussing the types of ices, distribute a Planetary Ice Data Ice Data set (download below) to each student group and an Across the Solar System sheet (download below) to each student. Have students work as a team to look at the information found on the planetary ice data sheets, their mission will be to identify, which planets and moons have ice and what type of ice it is, filling out their Across the Solar System worksheet. Remind students that not all the planetary bodies have ice, and some may have more than one type of ice in more than one place!
7. Alternatively, you could post each planet and moon data set in a location throughout the classroom and invite the student groups to travel as a team to each image, read the information about that planet, moon, or comet, then record on their sheets whether that planetary body has ice and, if so, where and what type of ice it is. Remind them that not all the planetary bodies have ice, and some may have more than one type of ice in more than one place!
8. After all the teams have examined the ice and each child has completed his or her Ice Across the Solar System sheet, gather the group together and discuss what they have learned.