Purpose: Mars has always been a planet of interest for many people, including scientists, science-fiction writers and space explorers. The first telescope observation of the Red Planet by Galileo Galilei in 1609 opened up a new world of astronomy. Writers began producing their imaginative stories about Mars, including Gulliver’s Travels by Jonathan Swift in 1726. In the story, astronomers discover two moons orbiting the planet. However, Mars’ two moons, Phobos and Deimos, were not actually discovered until 1877. Today, scientists are looking to Mars to understand how life formed in our solar system and hope to one day send humans to explore its surface.

This activity, designed for in-class or virtual learning, encourages students to design an exploratory mission that will answer basic scientific questions about Mars. The students will discuss how the data collected by their missions might be used to plan for eventual human-crewed missions.

Procedural overview: After reading “To rehearse Perseverance’s mission, scientists pretended to be a Mars rover” and “The Perseverance rover caps off a month of Mars launches,” students will research past, current and upcoming Mars missions to determine what has been learned about Mars and what has been proposed for future missions. In class, students will discuss their findings and determine what still needs to be learned about the environment of Mars and how those findings might influence future human exploration of the planet. Students will divide into groups to determine which scientific questions they want to tackle, and then they will design exploratory missions to Mars to answer those questions.

Approximate class time: 45 minutes to one hour

Supplies:

Computer with internet access
Virtual space for remote discussions and data sharing
Mission to Mars student worksheet

Directions for teachers:

In this activity, students will learn what goes into planning a scientific mission to Mars. Students will research some basic properties of Mars and then investigate past and current Mars missions to determine what scientists hoped to study, how they planned to conduct research on these topics and what has been learned from the missions. Students will then use this information to design exploratory Mars missions of their own. These exploratory missions should target specific scientific questions and be designed in such a way that answers to those questions could be obtained. The students should be able to explain how they want to design their mission and why, and note which instruments they will include on the mission and what kinds of scientists they will need to complete their mission. Students will discuss how their mission could be used to help develop a future human-crewed mission to Mars.

A bonus activity could involve a second day to allow students to practice planning and delivering a presentation.

This activity can be done in the classroom or in a virtual-learning environment. Discussions can be conducted via Zoom, Skype or other suitable chat programs, while data can be shared via e-mail or through Google Docs, Sheets or Slides. To save time, students could do their research on prior missions as homework, and then the class could discuss findings collectively before dividing into groups to design the missions. A second option would be to group the students for the discussion and mission design.

Background

Here are some facts about Mars before you get started: Mars is the fourth planet from the sun, with an average distance of 2.09 x 10⁸ km between the two bodies. Mars is a rocky planet with a thin atmosphere composed primarily of carbon dioxide (95.1%) and small amounts of nitrogen (2.59%), argon (1.94%), oxygen (0.161%) and carbon monoxide (0.058%). The rest of the atmosphere is composed of water vapor and a few other trace elements. Although the Martian atmosphere is about one-hundredth the thickness of Earth’s atmosphere, it still forms clouds and experiences winds, including winds strong enough to shroud the entire planet in dust storms. But because the atmospheric pressure on Mars is much less than it is on Earth (6 to 7 millibars on average, compared with 1,013 millibars at sea level on Earth), the storms are much less intense.

Mars has a radius of 3,389.5 km, just over half of Earth’s radius (6,371 km), and it has a surface gravity about one-third of Earth’s. A day on Mars is about 40 minutes longer than a day on Earth, but Mars’ year is much longer — approximately 687 Earth days. The difference in their orbits brings Mars and Earth within their shortest distance of each other about every 26 months, providing an ideal mission launch window.

While there is no known liquid water on Mars’ surface, evidence strongly suggests that surface water may once have been plentiful. Today, scientists believe that the polar ice caps on Mars are made of a high percentage of water ice and that liquid water may be present beneath the surface.

Mars is the most widely explored planet in the solar system, except for Earth, and is the only planet that has been explored with rovers. Each mission to Mars has focused on a specific question or research area. Some missions have focused on small, localized regions to study minerals, soil composition and weather, while others have focused on bigger areas to study large-scale weather patterns, climate and geologic features.

You can also ask students to read about Mars on their own using the following or similar resources:

https://solarsystem.nasa.gov/planets/mars/overview/
https://www.nasa.gov/mission_pages/mars/main/index.html
https://www.nasa.gov/mission_pages/mars/missions/index-past.html
https://www.planetary.org/space-missions/every-mars-mission
https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-mars-58.html
https://solarsystem.nasa.gov/planets/mars/overview/
https://www.planetary.org/worlds/mars

The Background questions on the Mission to Mars student worksheet (questions and sample answers below) will help students complete their initial research on the planet.

1. Research the following properties of Mars:

Mass	6.42 x 1023 kg
Radius	3389.5 km
Day length (in Earth hours)	24 hours 37 minutes
Year length (in Earth days)	686.9 Earth days
Average distance from the sun	2.09 x 108 km
Surface gravity	3.71 m/s2
Temperature range	about –153° Celsius at the poles to about 20° Celsius at the equator
Moons (number and their names)	2; Phobos and Deimos
Atmospheric composition	95.1% carbon dioxide, 2.59% nitrogen, 1.94% argon, 0.16% oxygen, traces of carbon monoxide, water, nitrogen oxide, neon and krypton

2. What are some key geographic features on Mars?

Olympus Mons is the largest shield volcano in the solar system. Valles Marineris is a rift that looks similar to the Grand Canyon on Earth, but it is much longer and deeper. The northern hemisphere is smooth and has lower elevations than the southern hemisphere, which is primarily made up of heavily cratered highlands.

3. What is the surface gravity on Earth? How does that compare with the surface gravity on Mars?

Earth’s surface gravity is 9.8 m/s². Mars’ surface gravity is about one-third of Earth’s.

4. How does Mars’ atmospheric composition compare with Earth’s? How would this affect astronauts living on Mars?

The atmosphere on Mars is mostly carbon dioxide, whereas the atmosphere on Earth is primarily nitrogen and oxygen. Because humans need oxygen to breathe, astronauts would need oxygen tanks and suits similar to the ones astronauts wear when they are in space.

5. Like Earth, Mars also experiences seasons due to its ~25 degree axial tilt. How do the seasons compare between Earth and Mars?

The axial tilt of Mars is similar to Earth’s 23.5 degree tilt, and it also experiences spring, summer, winter and fall. But because Mars is farther away from the Sun, its seasons are longer than Earth’s, about 142–194 days per season compared with Earth’s 89–93 days per season.

6. Based on what you researched about Mars, do you think Mars can support human life using only the natural resources available on the planet? Explain why or why not.

There are no natural resources that we know of on Mars that could support humans. Water may exist in the polar caps or deep below the surface, which would require advanced machinery to dig out. The atmosphere is not suitable for humans to breathe, so astronauts would require oxygen. Based on what current missions find in the soil, nutrients from Earth may need to be added to allow crops to grow. There are also no known fuel sources for heating or electricity on the surface of the planet. Solar panels from Earth would be needed to harvest energy from the sun. The only building material that we know of on Mars’ surface is rock.

7. What natural hazards on Mars do you think pose risks for future astronauts?

Extreme cold temperatures, longer winters, lack of oxygen, dust storms, exposure to radiation and lack of natural shelters would all be natural hazards astronauts could face on Mars.

Mission research

Like any good scientists, your students will want to perform some research on other Mars missions before meeting with their group to discuss their plans. They can start by looking through old articles at Science News and Science News for Students to learn more about current and past Mars missions, including “To rehearse Perseverance’s mission, scientists pretended to be a Mars rover” and “The Perseverance rover caps off a month of Mars launches.” They can use additional sources such as NASA for more information to answer the Mission research questions on the Mission to Mars student worksheet (questions and sample answers below).  

1. Write some notes about previous and current Mars missions. Include details about the purpose of the missions, the scientific instruments, equipment and spacecraft (rover, lander, orbiter or flyby) used and key discoveries from the missions.

Answers will vary.

2. What are some key details from past and current Mars missions that can be used to help design human-crewed missions to Mars?

Answers will vary.

3. Based on your research, what would you be interested in studying about Mars during your Mars mission?

I’d be interested in studying more about the overall climate of Mars and especially any microclimates around areas that are of interest for human explorers. Understanding the overall climate and weather patterns in a specific location can be applied to designing the proper equipment for human explorers to bring to Mars.

4. If no data existed for what you want to study on Mars, what other types of existing data could you use to help plan your part of the mission and understand what you are looking for?

I could research data about the atmospheric composition based on Earth observations, the variation in distance from the sun throughout the Martian year and variations in solar luminosity based on solar cycles. Knowing the properties of the molecules that make up the atmosphere would allow me to determine how the varying amount of solar radiation falling on a specific area of Mars’ surface affects the surface temperature.

5. Astronomers are not the only ones who study other planets in the solar system. For example, geologists, mineralogists, biologists, meteorologists and engineers are some other types of scientists who work together to design, plan and build missions to Mars. What are some examples of what these scientists study that will benefit the missions?

Geologists can study rock formations, mountains and craters. Mineralogists can study the types of minerals on the planets and how they formed. Biologists can look for chemical signatures that indicate life in rock and soil samples. Meteorologists can study the atmospheres of the planets. Engineers study the landscape to design a rover that can traverse the area.

Group discussion

In either whole-class discussion or in groups, have students talk about what they learned from their background research about Mars missions. Remind them to include insights from missions that “failed.” You can use the following questions, which also appear on the Mission to Mars student worksheet, to lead your students through this discussion about their research.

1. What were the primary purposes of past and current missions to Mars?

Answers will vary and may include conducting geologic surveys and learning about atmospheric conditions or soil composition, which serve the larger purposes of studying how humans could survive on Mars and searching for evidence of past and current life.

2. What do you notice about the number of mission failures versus the number of successes? How are the failed exploratory missions valuable to teams studying Mars?

There is a high percentage of failures, at least 50 percent. Lessons can be learned from each of the failed exploratory missions by understanding what caused the failure so it can be fixed or prevented from happening in later missions that will include humans.

3. Discuss a successful Mars mission. What was the goal of the mission? What area of Mars was researched? What spacecraft and instrumentation did the mission require?

Curiosity was launched by NASA in the United Sates in November 2011. Curiosity is a rover designed to explore habitable environments. It landed in Gale crater on Mars in August 2012. Many instruments were included on the rover, including cameras, spectrometers, radiation detectors, an environmental sensor and an atmospheric sensor.

4. Discuss a failed Mars mission. What was the intended mission? Why did it fail?

Schiaparelli EDM lander launched with the ExoMars trace gas orbiter in March 2016 from Kazakhstan in a joint European-Russian mission. It failed when the parachute was shed from the lander too early, causing the lander to crash into Mars’ surface.

5. Do the Mars missions focus on answering one specific question or lots of different questions? Why do you think this is?

The Mars missions each have their own questions to answer rather than seeking to answer many questions about the planet. This allows mission planners to focus on the instruments that will get the most comprehensive and detailed dataset that will help answer the posed questions. If a mission were to try to juggle too many projects, it would probably be unable to carry all the instruments needed to answer all of the questions that came up. This would be like trying to do all of your schoolwork at once rather than focusing on one subject at a time.

Discuss with your students the focus of a few Mars missions. For instance, the Perseverance rover (launched July 2020) will study rock samples and the mineralogy at Jezero crater; the Hope orbiter (launched July 2020) will study weather patterns; the Tianwen-1 mission, containing an orbiter, rover and lander (launched July 2020), will look for past and current signs of life. These examples will help students understand that scientists and engineers decide which question or group of related questions they want to answer when planning their missions, and address why the student groups should focus their Mars missions on answering one specific question.

Planning the mission

Ask student groups to decide which focused question(s) they would like their exploratory Mars missions to study, and remind them to use the Mission to Mars student worksheet (questions and sample answers appear below) to complete their work. If the students need prompts, ask them open-ended questions such as “What resources does Earth provide that Mars does not?” or “What will astronauts need in order to survive on Mars?”

1. What is the primary question or goal of your team’s mission to Mars?

We want to learn more about localized climate variations on Mars.

2. How will the data from your mission benefit planning for human missions to Mars?

Knowing the long-term climate conditions and seasonal changes will help in the planning for human-crewed missions. It will be important to know how sunlight, weather and temperature will change while the astronauts are on Mars for two Earth years awaiting the next possible return launch. For example, understanding the atmospheric conditions can help the engineers properly design or refine the parachute deployment or the amount of reverse thrust needed for the landing of the spacecraft. The amount of solar variance and temperatures throughout the year can be used to help design a habitat that can use solar power as much as possible and provide heating and cooling throughout the Martian year. The climate data can also be used to help design suits that will protect the explorers as they travel outside the habitat.

3. What measurements will your mission need to make in order to answer your team’s question?

Our mission will need to measure the temperature, atmospheric pressure, wind speed and direction, amount of solar radiation, visibility, cloud cover and atmospheric composition.

4. Based on the measurements your team is interested in taking on Mars, what types of scientific instruments and equipment will you need? Use your research on past and current Mars missions to guide your thinking.

For our lander, we would need to include a variety of weather instruments, including wind sensors, pressure gauges, sensors to measure atmospheric composition, thermometers and cameras that take pictures of the sky and the surrounding areas, such as a fisheye camera, and solar panels to measure the amount of solar radiation.

5. Select the kinds of experts you will need for your team’s mission. Feel free to add more types of experts if your team thinks they will be needed.

Computer scientist	Biologist	Chemist	Physicist
Astronomer	Mathematician	Geologist	Biochemist
Statistician	Microbiologist	Volcanologist	Meteorologist
Mechanical engineer	Chemical engineer	Medical doctor	Virologist

6. Why will you need these particular experts? What will they do?

We will need meteorologists to help design the instruments the mission requires; computer scientists, mechanical engineers and physicists to help plan and launch the mission; computer scientists to ensure the data gets sent back to Earth; meteorologists and astronomers to study the data.

7. Select the type of spacecraft your study will require.

Lander

Rover

Orbiter

Flyby

8. Why will this type of spacecraft be best for your team’s mission?

A lander will be best for this mission because even on Earth most weather stations are static, so that they can gather data to determine patterns in one particular area. By installing a permanent weather station on Mars, especially in an area that is of interest for human exploration, we will be better able to understand the microclimate and the weather patterns of that particular location.

9. What are the potential challenges your team will need to overcome to measure useful data?

A special coating will need to be added to all of the instruments to protect them from dust and from the possible corrosive effects of the Martian atmosphere. Also, the location of our lander on Mars will be relevant, since landing on a mountain or in a canyon could affect both temperatures and wind currents.

Bonus

If you want your students to practice making scientific presentations, they can work in their groups to create slideshows or posters of their missions.