Education and
Public Engagement
at the Lunar and Planetary Institute
Explore! Life on Mars

Nurturing Life


During this 60–90-minute activity, children ages 8–13 explore what living things need to survive and thrive by creating and caring for a garden plot (outdoors where appropriate) or a container garden (indoors) at the program facility. The garden will be used to beautify the facility with plant life with many planting and landscaping options provided. Children will consider the requirements of living things, compare the surface conditions on Mars to those found on Earth, view images/video of a NASA Astrobiology Institute “garden” where astrobiologists are studying life under extreme conditions, and consider the similarities and differences in the type of life that would be possible on Mars as compared to their garden on Earth.

The icebreaker activity, Is It Alive?, may be conducted at the beginning to set the stage for a positive social experience and the deeper explorations of this activity. Optional:  Each child may use the corresponding Extreme-O-File activity pages of their observations, which may be combined with other module activity pages to complete their file.

What's the Point?

Tips for Engaging Girls in STEM:
  • Expose girls to female role models who have achieved in math and science in order to promote positive beliefs regarding women’s abilities. If possible, have female speakers share the science of astrobiology. This activity addresses this tip by providing activity pages and trading cards featuring female (and male) astrobiologists, as well as link to online resources for connecting with female scientists and role models. Suggestions and links to online video resources featuring interviews with female scientists are also included within the activity for those not able to arrange for an in-person presenter.
  • Foster girls’ long-term interest in math and science by choosing activities connecting math and science to careers (don’t reinforce existing gender stereotypes, and do choose activities that spark initial curiosity about content). This activity addresses this tip by providing a topic that most people are naturally interested in learning more about — the possibility of life elsewhere in the universe — in a context that is engaging (gardening). The corresponding activity pages, trading cards, and optional scientist involvement help to address this tip by providing a range of real-world examples of female scientists in the field of astrobiology (and its associated disciplines). Specifically, the activity resources present female scientists — in their own words — describing how they became interested in math and science, how they ended up their current role (astrobiology), and their advice for children interested in pursuing a career in math and science.



For each group of 3–4 children:

Suggested books

For each large group (maximum of 15 children per Facilitator):

Facilitator’s Note:  Recommended Plants and Seeds
It is important to use plants and/or seeds that are appropriate for your intended garden location (indoors or outdoors). Particular attention should be paid to the lighting, soil, and water conditions of the intended planting location. It is recommended that you research appropriate plants for your growing zone or consult a garden center/plant nursery/master gardener in your area. There are many options for your garden — it can be edible, hardy/drought tolerant (xeriscaping), flowers (for cutting), etc. Below you will find a list of recommended plants that may be suitable and readily available (seasonally) for many locations, growing zones, and gardening options.

  • Plants:
    • Vegetables (cucumber, pepper, pumpkin, etc. — annual, edible
    • Herbs (basil, thyme, parsley, mint, etc.) — annual, edible
    • Marigolds (flowering) – annual
    • Rounded Rectangle: Living Stones (Lithops) *An interesting plant option available at some garden centers or online.  Zinnia (flowering) — annual
    • Petunia (flowering) — annual
    • Cosmos (flowering) — annual
    • Daylilies (flowering) — perennial, zones 3–10
    • Hosta (flowering) — perennial, zones 3–9
    • Columbine (flowering) — perennial, zones 3–9
  • Seeds (annuals):
    • Balloon Flowers
    • Zinnia (cut flower)
    • Sunflower (edible)
    • Petunia (flowers)
    • Shasta Daisy (cut flowers)
    • Corn Flowers (cut flowers)
    • Cucumber (edible, climbing)
    • Basil (edible)
    • Sweet Peas (climbing)
  • Xeriscaping (see note below):
    • Jade Plant (Crassula argentea) cuttings — Indoor and zones 9a–11 outdoors
    • Hens and Chicks (Sempervivum) — Indoors and zones 3–11 outdoors
    • Silver Mound (Artmesia) — Indoors or zones 3–7 outdoors
    • Living Rock (Lithops spp. and Pleiospilos spp.) — Indoors and zones 9b–11 outdoors
      *Prefers very dry conditions!
    • Lavender (flowering, fragrant) — Indoor and zones 5–10 outdoors
    • Pansy (flowering) — Indoor and zones 2–11 outdoors
    • Sages (Salvia officinalis) — Zones 4–10 outdoors
    • Purple Coneflower (flowering) — Zones 3–9 outdoors
      *Draws many birds and butterflies

Note:  Xeriscaping is a form of gardening that utilizes very hardy, drought-tolerant plants. One of the main goals of xeriscaping is water conservation, but this is not the only advantage. Additional benefits of xeriscaping include less maintenance, no need for pesticides or fertilizers, increased property value, and increased wildlife habitat. Most regions have a variety of native plants that may be used in this type of landscaping. Garden centers, plant nurseries, and master gardeners are excellent sources of information regarding appropriate plant selection when planning a xeriscaped garden in your area. To learn more about xeriscaping, please visit eartheasy.

For each child:

Trading Cards (large file, 34 MB)
Trading Cards (small file, 7 MB)

For the facilitator:


Note: The live greenhouse feed can take a while to load and requires a Java plug–in.  Please test it out and plan accordingly before your program.

    • Optional: If you have difficulty in accessing the live NAI Greenhouse video feed, you may instead use this alternate resource, which features images and basic information about microbes and microbial mats of the variety grown and studied by scientists
Facilitator’s Note: A sandy soil mix may be purchased as a “succulent and cactus” mix at most garden centers. However, you may also create your own by following this easy (and less expensive) recipe:  Mix together equal amounts of peat moss, coarse sand, and perlite. Perlite is used to help prevent water loss and soil compaction. All these ingredients should be readily available at a garden center or hardware store.
Picture of 2-Liter soda pop bottle cut in half with the cut edges taped.    Picture of 2-Liter soda pop bottle, cut in half, edges taped, and fitted back together.
Example of a plastic bottle properly prepared for the take–home garden (option #3)

Facilitator’s Note:  How to Take Cuttings and Propagate a Jade Plant                              
Propagation of selected succulents like the jade plant, Crassula argentea, is done mainly with cuttings; either leaf or stem cuttings will work. Leaf cuttings are easier to work with but take much longer to become a “jade plant.”

Materials needed:  A sharp knife, liquid or powder rooting hormone (available at gardening and hardware stores), a pot, suitable soil, a parent plant (the plant from which you will take the cutting), an area where you can work, some paper towels or something to help clean up and on which to place cuttings. It is best to prepare cuttings before your program (day of).

Picture of Jade plant cutting, planted in a pot.

Instructions for propagating using a Leaf Cutting:

  1. Place soil in the pot or container you will be using for your new jade plant and water thoroughly, letting it drain while you prepare the rest of your items.
  2. Cut the leaves off the parent plant and set them aside on a paper towel to dry.
    (Do steps #1 and 2 before the program.)
  3. Give each child a leaf cutting.
  4. Have them dip the cut end into some rooting hormone, either liquid or powder. If using powder, you may need to moisten the stem to get the powder to stick).
  5. Have the children make a small hole in the dirt with a stick or their finger.
  6. Place the cutting into the hole, trying not to rub off too much of the rooting hormone in the process.
  7. Carefully press the dirt around the cutting.
  8. Place the planted cutting in a warm, shaded place for 3–4 weeks, and then gradually expose the plant to sunlight, moving it closer to full sun week by week. This allows the plant to develop a tolerance and increases the success of your plant. Explain to the children that it will take time, but that their leaf will develop roots and eventually grow into a jade plant that looks like the parent plant. Be sure to send plant care instructions home with the children if using with garden option #3.

Source: Jade plant care and propogation

Trading Cards (large file, 34 MB)
Trading Cards (small file, 7 MB)


Optional:  Conduct the Ice Breaker activity: Is It Alive? to set the stage for the deeper explorations of this activity and a positive social experience. 

1. Welcome the children and explain that today they will be learning about what life needs to survive and thrive and will discuss the possibility of life on Mars! By exploring what life needs and what conditions are like on Mars now and in the past, the children will work together to create a garden to both beautify the facility and share their experience with the community. Introduce the science of astrobiology – the search for life on other worlds. This activity will help them to understand why knowing what life needs is helpful to the scientists searching for it beyond Earth.

Hand out the Explore: Life on Mars? Scientist Spotlight Pages and Life on Mars? Trading cards. Give the children a few minutes to look over the scientist pages to learn more about astrobiology.

2. Optional: Introduce and discuss the “Extreme–O–File” Activity Pages. Explain that these pages will be used during the course of the activity.
Note: You may choose to substitute the Extreme-O-File Activity Pages with the Life on Mars? Scientist Trading Cards if desired.    

Trading Cards (large file, 34 MB)
Trading Cards (small file, 7 MB)  

Optional (time permitting): Invite/Arrange for an astrobiologist to visit and speak with your group in person.  Please see the “Preparation” section for suggestions.

Optional (time permitting): Play a short video of female scientists sharing what they do, such as NASA Aspire to Inspire

3. Discuss what life needs. Explain that in order for astrobiologists to detect life beyond Earth, they need to know what to look for — what life needs. Tell the children to pretend that they (the group) have been left out in the forest. They do not have anything with them.
Note: if the children have completed the icebreaker activity (Is It Alive?), then have them reflect on that experience here.

Summarize the 4 requirements for life:  Nutrients (food), water, warmth (energy), and shelter (stable environment). Post them on the wall with brightly colored paper or Post–it® notes so that the children may refer to them during the activity if needed. Optional: Have the children record the 4 requirements for life in their Extreme–O–File activity pages.

Facilitator’s Note:  What Does Life Need?
There are four main requirements that have been the focus of our search for life in the universe. Life as we know it needs an energy source, nutrients (something to eat or consume), protection from the elements, and liquid water. Scientists are looking for places in our solar system — and beyond — that have all the things that we know life needs.

Of the four identified necessities for life, the presence of liquid water is considered to be one of the most important and perhaps useful to scientists. Liquid water has been a focus in the search for life beyond Earth because, to date, we have only found living organisms where liquid water exists. Pure water is a liquid over a fairly wide range of temperatures — between 0°C (32°F) and 100°C (212°F). Under special circumstances, however, water can remain a liquid beyond this range. For example, at high pressures (like at the bottom of the ocean or deep in Earth’s crust), water can remain a liquid to higher temperatures. Similarly, saline water (water containing salt like our ocean water) has a lower freezing temperature, allowing it to remain a liquid at temperatures that are colder than the normal freezing point. Temperatures much above or below this normal range for liquid water, though, negatively affect the cellular structures of living organisms — potentially destroying them. The presence of water on a planetary body is one requirement for life to exist there (past or present), thus scientists are interested in identifying locations in the universe that possess water — especially liquid water — to better narrow their search for life beyond Earth!

For more information about the requirements of life, please refer to the Facilitator Background Information.

4. What is it like on Mars? Discuss the challenges that living things on Mars would face and describe that the children will use their understanding of life’s needs to create a garden.

Play the following video clips and then discuss, or as an alternate option, you may ask the children to browse through some non–fiction science books about Mars from your collection. Please see the module resource list for book suggestions.
Mars in a Minute: Is Mars Really Red?
Mars in a Minute: Is Mars Red Hot?

Note: If you have not previously completed the Mars by the Book activity, you may want to incorporate the non–fiction books and research from that activity here (time permitting). This will allow the children to discover what it is like on Mars for themselves instead of simply being told.

5. Discuss the similarities and differences of your garden compared to the life forms that could be on Mars. Hand out copies of the NAI Extremophile Trading Cards and have the children look at the images of Mars-like locations on Earth and the organisms that live there. Also have them look at the extremophile features in a set of Life on Mars? Trading Cards.

Trading Cards (large file, 34 MB)
Trading Cards (small file, 7 MB)  

Facilitator’s Note:
It is important for the children to understand the connections between their garden and the types of life that may have existed on Mars in the past. In particular, they are planting a garden with multicellular plants, but any possible life forms on Mars are likely much less evolved or complex (i.e., microbes) and not visible with the naked eye. Use the questions above to help them to picture the conditions on Mars, focusing their attention on what life needs. Use the NAI Extremophile Trading Cards to help them to understand the differences between the type of life that would be possible on Mars and the Earth analog. Explain to them that an analog is a place/organism on Earth that has some important similarities to the places/possible life forms on another planet, such as Mars. Analogs help scientists to understand how life may have developed on other planets and places, such as Mars.

Might There be Life on Mars?
Conditions on early Mars may have been much more like conditions on early Earth (geologically active, warmer, wetter, etc.). By understanding early life here on Earth (analogs), astrobiologists are hoping to discover how best to search for it elsewhere, such as on Mars. Scientists are using this understanding to narrow our search for life beyond Earth to those places that possess the requirements of life (e.g., liquid water, moderate temperatures, etc.).

All life as we know it requires liquid water, hence the interest in finding evidence of past liquid water on Mars, and understanding the history of this water. There is strong scientific evidence that liquid water once occurred on the surface of Mars, so it is possible that life could have become established. The first conclusive fossil evidence for life on Earth, in the form of fossil bacteria, occurs about 3.5 billion years ago — the time that the martian environment was changing from warmer and wetter to colder and drier. Microbial life on Earth probably existed before this time period, possibly becoming established after the period of intense asteroid bombardment was over, but there is no record of it. In short, it may have taken life up to a billion years to become established on Earth, although it may have happened more quickly, and so scientists consider this to be a reasonable timeline for Mars as well.

Given this start, and using Earth as a model, conditions on much of Mars would have been suitable for life for about 500 million years before the climate deteriorated. However, the features recording flooding events suggest that there were occasional warmer and wetter periods, and there may have been refuges for life, such as moist areas near warm volcanic regions. Given the harsh conditions, and lack of evidence, it is unlikely that life evolved into complex multicellular forms, like it did on Earth between 1 billion years and 500 million years ago.

Optional (time permitting):  Research how to grow a garden. Explain that they will use what they learn to help build a garden to beautify the library. Please allow 15–20 minutes to complete this step, keeping this in mind when planning your children’s program. Note:  This garden may use xeriscaping, a type of gardening that uses hardy, drought-tolerant plants, to help represent the harsh climate on Mars if desired.

7. Create a garden. Have the children work as a group to put their knowledge of life to the test by sustaining life in a garden!  Make sure to follow the planting instructions that came with your plants or seeds.  Conduct one or more of these options:

Garden Option #1:  Plant an outdoor garden on the grounds of the facility.  Discuss how your garden is related to life that would be possible on Mars. Work as a group, taking turns, to plant the garden. Make sure to water the new plants/seeds carefully after planting (with close adult supervision).

Garden Option #2:  Plant an indoor garden in a container(s). Discuss how your garden is related to life that would be possible on Mars. Work as a group, taking turns, to plant the garden. Make sure to water your new container garden after planting, using either a pitcher or watering can.

Garden Option #3:  Invite participants to construct a take-home garden in a bottle. Explain that their bottle will require all of the ingredients for life that were discussed, and they will be responsible for taking care of them at home. Give them a note card or label with plant care instructions. Optional:  Have the children record the directions for caring for their plant at home in their journal and show them the area in their journal for recording observations at home. Option #3 is recommended to be conducted in support (conclusion) of either option #1 or option #2, but may be used on its own if desired.

8. Discuss how the garden has the same needs as life that might exist — or have existed — on Mars in the past. They will be responsible for providing for the needs of their plants to take home and/or the garden at the library!

9. Discuss briefly how astrobiologists search on Mars for the same support for life that they created in their garden(s):  water, nutrients, shelter (or at least a stable environment), and energy.

In Conclusion

Summarize what life needs to survive (water, sunlight, warmth, nutrients) may have been present on Mars in the past. Today, astrobiologists are using their understanding of life on Earth to better understand life beyond our planet in places such as Mars, where it appears that the right ingredients for life may have been present (or may still be). While life was beginning on Earth, it may have also been present on Mars! Your garden is a reminder of life’s needs. However, the type of life in your garden is quite different — much more evolved and complex than what life forms on Mars would be. Any life on Mars would likely be simple, single-celled microbes, similar to the extremophiles that you discussed during the activity.


Create a poster as a group about your garden to put on display in the facility for your community. Using what you have learned and the Extreme-O-File astrobiology resources, have the children work as a group to create a poster describing the project to put on display. You may cut out and use parts of the activity pages and resources (make sure to have extra copies available for this purpose), as well as creating text and artwork to include on the poster. They should be sure to include the following:

Note:  You may want to have the children work in groups of 4–6 for each question to be addressed in the poster, and then bring all groups together to assemble it.