On the Moon
- No air means no wind or rain to wear the surface away
- Days can reach about 120 °C (250 °F); nights fall below −170 °C (−275 °F)
- Micrometeoroids and sunlight slowly age what remains
- Footprints and wheel tracks can outlast generations
THE SCIENCE CARRIES ON
Science it made possible.
Every ending left
something to learn.
01 / MOON
The Moon is drifting away.
Apollo's laser mirrors measured its slow retreat: about 3.8 cm each year.
→ Moon Story 302 / MOONThe Moon has moonquakes and layers.
For years, Apollo seismometers listened beneath the stillness.
→ Moon Story 403 / MOONObjects fall at the same rate without air.
A hammer and a feather touched down together.
→ Moon Story 704 / MOONWater ice hides in dark lunar craters.
LCROSS and orbiters found traces of ice in shadow.
→ Moon Story 605 / MARSMars once had water.
Spirit, Opportunity, Curiosity and Perseverance each found a piece of that story.
→ Mars Stories 3, 4, 8, 906 / MARSMars has a liquid core and quakes.
InSight listened through the red planet's quiet.
→ Mars Story 607 / MARSIce lies just below the Martian arctic soil.
Phoenix brushed the red dust aside and found ice.
→ Mars Story 508 / MARSYou can fly on Mars.
Ingenuity lifted into the Martian sky 72 times.
→ Mars Story 709 / MARSSome ancient Martian rocks might hold clues to life.
Perseverance is still reading the rocks, one sample at a time.
→ Mars Story 9! A possible sign of life is not proof. Scientists need more evidence, which is why these samples matter.
TWO WORLDS, DIFFERENT CLOCKS
Why do things last on
the Moon but not on Mars?
On Mars
- Thin air, with winds strong enough to lift and move dust
- Dust can dim solar panels and starve a rover of power, as it did Opportunity and InSight
- At some sites, winter cold ended Phoenix's short season
- Changing seasons bring changing sunlight
On the Moon, it's mostly time. On Mars, it's dust, cold and sunlight.
01
MISSION MATH
MISSION MATH
WHY LEAVE THINGS BEHIND?
Why leave
things behind?
Space is a costly road with no roadside stop. Each kilogram needs fuel to leave Earth, and a return journey asks for still more. Bringing a rover home would mean carrying another rocket to Mars and back. So missions carry home what matters most, like rocks, and leave their machines beneath another sky.
Apollo crews returned with 382 kg (842 lb) of Moon rocks. Tools, cameras and even a rover stayed behind, saving room and weight for the journey home.
NOT FORGOTTEN
Why old hardware still matters.
It keeps teaching us.
Viking, Apollo and rover data still offer new questions to study.
Some still answer.
Apollo's laser mirrors return light from Earth-bound observatories.
These are places in history.
Many people believe the Apollo sites should be treated like museums. In 2011, NASA published recommendations asking future visitors to protect the historic hardware.
The past helps shape what comes next.
Artemis II flew around the Moon in April 2026. Lessons from Apollo, robotic landers and orbiters like LRO helped plan the journey.
CHAPTER 04 / YOUR TURN TO EXPLORE
Ready to test
what the worlds taught us?
Take the mission quiz, browse the field guide and carry these questions with you.
Enter the Field Guide →