5 Facts About Space
Space captivates children’s imaginations like few other topics. The vastness of the universe, the mystery of distant planets, and the wonder of stars twinkling in the night sky spark curiosity and questions that lead naturally to scientific thinking. For teachers and parents, space provides excellent opportunities to teach physics, scale, scientific observation, and how scientists gather evidence about phenomena we cannot directly experience.
This comprehensive guide explores five essential facts about space, providing educators and families with accurate information, curriculum connections, and practical activities that bring the cosmos to life in classrooms and homes.
Introduction to Space
Space, also called outer space, is the vast expanse beyond Earth’s atmosphere where planets, stars, galaxies, and other celestial objects exist. Unlike Earth’s surface with its air, water, and life, space is mostly empty—a near-perfect vacuum with extremely low density of particles.
Space begins approximately 100 kilometres above Earth’s surface at the Kármán line, the internationally recognised boundary between Earth’s atmosphere and outer space. Beyond this point, the atmosphere becomes so thin that conventional aircraft cannot generate enough lift to fly, and only spacecraft can operate.
The universe contains everything that exists—all matter, energy, planets, stars, galaxies, and the space between them. Scientists estimate the observable universe spans about 93 billion light-years in diameter, though the entire universe may extend far beyond what we can observe.
“Teaching about space connects children to the grandest questions humans can ask—where did we come from, are we alone, what lies beyond our world? These questions naturally lead to scientific inquiry, mathematical thinking, and the wonder that drives lifelong learning,” says Michelle Connolly, founder of LearningMole and former classroom teacher with 16 years of experience.
Understanding space helps children grasp their place in the universe, appreciate Earth’s uniqueness, and develop scientific literacy about topics from gravity and light to the scale of astronomical distances.
Five Amazing Space Facts
Fact 1: Space Is Completely Silent
Sound requires a medium—solid, liquid, or gas—to travel through because sound waves move by causing particles to vibrate. When you speak, your vocal cords create vibrations that travel through air molecules, eventually reaching someone’s ear where they’re detected as sound.
Space, however, is nearly a perfect vacuum with extremely few particles. Without sufficient particles to vibrate and carry sound waves, sound cannot travel through space. This means space is completely silent—no explosions, engine roars, or voices can be heard as they would in Earth’s atmosphere.
This fact surprises many children whose ideas about space come from films showing loud spaceship engines and noisy explosions. These dramatic sound effects, while entertaining, are scientifically inaccurate. In reality, astronauts communicate through radio waves, which unlike sound can travel through the vacuum of space as electromagnetic radiation.
Inside spacecraft or space stations, sound works normally because air fills these pressurised environments. Astronauts hear each other speak, equipment hum, and objects clank just as they would on Earth. But outside in the vacuum of space itself, absolute silence reigns.
Scientific principle: This fact teaches about sound as a mechanical wave requiring a medium for transmission, distinguishing it from electromagnetic waves like light and radio that can travel through vacuum.
Classroom application: Demonstrate sound transmission by creating a simple “telephone” from two cups and string. Discuss what happens if the string goes slack (no sound transmission) and relate this to how lack of particles in space prevents sound travel. Compare with light, which we can see from distant stars despite the vacuum of space.
For older pupils, explore how different media affect sound speed and quality. Sound travels faster through water than air and faster still through solids. This reinforces understanding of how particle density and proximity affect wave transmission—concepts directly relevant to understanding why space is silent.
Fact 2: The Sun Contains 99.86% of Our Solar System’s Mass
The Sun dominates our solar system not just by its light and heat but by its sheer mass. This enormous star contains approximately 99.86% of all matter in the solar system, with planets, moons, asteroids, comets, and everything else accounting for just 0.14%.
To put this in perspective, the Sun’s mass equals about 333,000 Earths. You could fit roughly 1.3 million Earths inside the Sun’s volume. Jupiter, the solar system’s largest planet, contains most of the remaining 0.14% of mass not in the Sun—all other planets, moons, and objects share the tiny fraction Jupiter doesn’t claim.
This massive concentration of matter gives the Sun tremendous gravitational pull that governs the entire solar system. Every planet orbits the Sun because its gravity constantly pulls on them, preventing them from flying off into space. The Sun’s gravity reaches beyond Neptune, influencing objects in the distant Kuiper Belt and Oort Cloud billions of kilometres away.
The Sun generates energy through nuclear fusion in its core, where tremendous pressure and temperature (about 15 million degrees Celsius) force hydrogen atoms to fuse into helium, releasing enormous energy that eventually reaches Earth as light and heat. This process converts roughly 4 million tonnes of matter into energy every second, yet the Sun has enough hydrogen to continue burning for approximately another 5 billion years.
Scientific principle: This fact teaches about mass, gravity, nuclear fusion, and how gravitational forces determine orbital motion and solar system structure.
Classroom application: Create a scaled model of the solar system showing relative sizes. Use a beach ball for the Sun and various smaller balls for planets—pupils immediately visualise how the Sun dwarfs everything else. Discuss why this size and mass difference matters for understanding gravity and orbits.
Calculate how many Earths could fit inside the Sun by comparing volumes, applying mathematical concepts to astronomical contexts. For Key Stage 3 pupils, introduce calculations about gravitational force decreasing with distance, explaining why distant planets orbit more slowly than inner planets.
Fact 3: One Day on Venus Is Longer Than One Year on Venus
This seemingly impossible fact results from Venus’s unique rotation characteristics. A “day” measures how long a planet takes to rotate once on its axis, while a “year” measures how long it takes to orbit the Sun.
Venus rotates extremely slowly and in the opposite direction from most planets—a phenomenon called retrograde rotation. One complete rotation takes about 243 Earth days. However, Venus orbits the Sun relatively quickly, completing one orbit in approximately 225 Earth days.
This means a Venusian year (225 Earth days) is actually shorter than a Venusian day (243 Earth days)—a mind-bending concept for children to grasp. Even stranger, Venus’s retrograde rotation means the Sun rises in the west and sets in the east, opposite to Earth’s sunrise and sunset directions.
Scientists aren’t entirely certain why Venus rotates this way. Theories suggest a massive collision early in the solar system’s history might have knocked Venus sideways, or perhaps gravitational interactions with the Sun and other planets gradually slowed and reversed its rotation over billions of years.
Venus’s slow rotation affects its climate dramatically. The long days and nights contribute to extreme temperature variations, though Venus’s thick atmosphere (95% carbon dioxide) distributes heat so effectively that temperatures remain scorching hot—around 465°C—on both day and night sides, making Venus the hottest planet in our solar system despite Mercury being closer to the Sun.
Scientific principle: This fact teaches about planetary rotation versus orbital revolution, relative motion, and how different measurements of time depend on perspective and motion.
Classroom application: Use globes and lamps to demonstrate Earth’s rotation (day/night) and revolution (yearly orbit), then model Venus’s unusual rotation pattern. Have pupils physically act out these motions, with one child being the Sun while another rotates slowly backwards while orbiting.
Create timelines comparing Earth days/years to Venus days/years, developing understanding of scale and relative time measurements. Discuss why we define “day” and “year” based on rotation and orbit—introducing the concept that time measurements depend on motion and position.
Fact 4: Footprints on the Moon Will Last for Millions of Years
When Apollo astronauts walked on the Moon between 1969 and 1972, they left footprints, tracks, and equipment that remain virtually unchanged over 50 years later. These marks will persist for millions of years because the Moon lacks several features that erase evidence on Earth.
The Moon has no atmosphere, which means:
- No wind to blow dust and erase tracks
- No rain to wash away marks
- No rivers or flowing water to reshape the surface
- No weathering from atmospheric gases
Without an atmosphere, the Moon also lacks life—no plants, animals, bacteria, or fungi to disturb the surface. No geological activity like plate tectonics reshuffles the Moon’s crust. The Moon is geologically “dead,” with no volcanic eruptions, earthquakes, or mountain-building processes actively reshaping its surface.
The only forces that will eventually erase these footprints are micrometeorite impacts (tiny space rocks constantly bombarding the lunar surface) and slow degradation from solar radiation and extreme temperature swings between lunar day and night. These processes operate so gradually that Apollo landing sites will remain recognisable for millions of years.
This permanence of human marks on the Moon creates a poignant legacy. Long after buildings on Earth crumble and human-made objects decay, footprints on another world will silently testify to humanity’s first steps beyond our planet.
Scientific principle: This fact teaches about weathering and erosion, atmospheric processes, geological activity, and how different environments affect preservation of evidence.
Classroom application: Compare environments where evidence persists versus erodes quickly. Create “footprints” in sand, soil, and other materials, then subject them to wind (fan), water (spray), and movement (shaking), observing how quickly marks disappear. Discuss what makes the Moon different.
Examine photographs of Apollo landing sites taken by lunar orbiters decades after missions, identifying still-visible equipment, footprints, and rover tracks. This teaches about evidence, scientific observation, and how we study places we cannot directly visit.
Fact 5: There Are More Stars in the Universe Than Grains of Sand on All Earth’s Beaches
This extraordinary fact illustrates the universe’s almost incomprehensible scale. Scientists estimate the observable universe contains approximately 200 billion trillion stars (that’s 200,000,000,000,000,000,000,000 or 2 × 10²³ stars).
To put this in perspective, researchers estimate all of Earth’s beaches and deserts combined contain roughly 7.5 quintillion grains of sand (7,500,000,000,000,000,000 or 7.5 × 10¹⁸ grains). This means the universe contains roughly 10,000 times more stars than sand grains on Earth.
Each star is a sun, many with their own planetary systems. Our Milky Way galaxy alone contains an estimated 100-400 billion stars. The observable universe contains at least 2 trillion galaxies, each with billions to trillions of stars.
These numbers stretch beyond everyday comprehension, yet they’re based on careful scientific observation and calculation. Astronomers count galaxies visible in deep-space images, estimate stars per galaxy based on brightness and mass, then multiply to reach total estimates—acknowledging substantial uncertainty given the universe’s vastness.
This staggering number of stars implies countless planets, increasing the probability that life exists elsewhere in the universe. While we’ve only confirmed a few thousand exoplanets (planets orbiting other stars), mathematical probability suggests billions of potentially habitable worlds exist in our galaxy alone.
Scientific principle: This fact teaches about scale, estimation, scientific notation, probability, and astronomical observation methods.
Classroom application: Practise estimation skills by calculating sand grains in a small sample, then scaling up to estimate beach totals. Compare with star number estimates, introducing scientific notation for handling extremely large numbers.
Create visualisations showing scale—if one sand grain represented the Sun, how far would the nearest star be? This introduces astronomical distances and scale in tangible terms. Discuss why scientists use light-years (distance light travels in one year) rather than kilometres for astronomical measurements.
Understanding Our Solar System
Our solar system consists of the Sun, eight planets, their moons, and countless smaller objects including asteroids, comets, and dwarf planets. Understanding its structure and scale provides context for Earth’s place in space.
The Planets
Inner rocky planets (Mercury, Venus, Earth, Mars): These small, dense planets with solid surfaces orbit relatively close to the Sun. They formed from heavier elements that remained solid in the early solar system’s inner region where temperatures were higher.
Outer gas giants (Jupiter, Saturn): These enormous planets consist mainly of hydrogen and helium without solid surfaces. Their distance from the Sun allowed lighter gases to condense during planetary formation.
Ice giants (Uranus, Neptune): These planets contain more water, methane, and ammonia ices than the gas giants, with different internal structures despite similar appearances.
Moons and Other Objects
Over 200 moons orbit planets in our solar system, from tiny irregular rocks to substantial worlds like Jupiter’s Ganymede (larger than Mercury) and Saturn’s Titan (with its own atmosphere and liquid methane lakes).
The asteroid belt between Mars and Jupiter contains millions of rocky objects from boulder-sized to Ceres (nearly 1,000 km diameter, classified as a dwarf planet). Comets, icy bodies from the outer solar system, develop spectacular tails when approaching the Sun as ice vaporises.
Scale and Distance
The solar system’s scale challenges comprehension. If the Sun were a football, Earth would be a peppercorn about 26 metres away, and Neptune would be a large pea 800 metres distant. The nearest star would be another football in Australia if the Sun were a football in London—illustrating the vast emptiness between stars.
Space Exploration
Humanity’s journey into space began barely 60 years ago but has dramatically expanded our knowledge of the universe while inspiring technological advancement.
Historic Achievements
1957: Soviet Union launches Sputnik 1, the first artificial satellite, beginning the space age.
1961: Soviet cosmonaut Yuri Gagarin becomes the first human in space, orbiting Earth once.
1969: American astronauts Neil Armstrong and Buzz Aldrin walk on the Moon during Apollo 11 mission—humanity’s first steps on another world.
1971: Soviet Union launches first space station (Salyut 1), beginning permanent human presence in space.
1990: Hubble Space Telescope launches, revolutionising astronomy with unprecedented deep-space images.
1998: International Space Station construction begins—ongoing international collaboration in space.
2012: Curiosity rover lands on Mars, conducting sophisticated geological and atmospheric research.
2020s: Commercial spaceflight expands with private companies launching satellites, cargo, and astronauts.
Why Explore Space?
Space exploration drives technological innovation in computing, materials science, medicine, and communications. GPS satellites, weather forecasting, global communications, and Earth observation all depend on space technology.
Scientific benefits include understanding Earth’s climate better by studying other planets, searching for life beyond Earth, understanding the universe’s origin and structure, and preparing for potential future threats like asteroid impacts.
Space exploration inspires children toward science, technology, engineering, and mathematics careers while demonstrating international cooperation and human capability to overcome extraordinary challenges.
Teaching Space in the Classroom
Space topics appear throughout science curriculum, offering opportunities for engaging cross-curricular teaching.
Cross-Curricular Connections
Science: Space teaches physics concepts including gravity, light, forces, energy, and states of matter. Understanding planets, stars, and the solar system addresses Earth and space science objectives across key stages.
Mathematics: Astronomical distances, planetary sizes, orbital periods, and rocket trajectories apply mathematical concepts including scale, ratio, measurement, geometry, and problem-solving in authentic contexts.
Geography: Earth’s place in space, seasons resulting from axial tilt and orbit, day and night from rotation, and how space observation supports weather forecasting and climate monitoring connect space to geographical understanding.
Design and Technology: Designing spacecraft, rovers, or space stations teaches about problem-solving within constraints, testing and evaluation, and how form follows function in extreme environments.
English: Reading non-fiction texts about space, writing creative narratives set in space, learning scientific vocabulary, and researching astronomers or astronauts develops literacy through engaging content.
Art: Creating space-themed artwork, designing mission patches, observing and drawing the Moon’s phases, or producing scale models develops creative skills alongside scientific understanding.
Age-Appropriate Activities
Key Stage 1 (Ages 5-7): Observe the Moon’s changing appearance over a month, learn names of planets, understand day/night results from Earth’s rotation, and explore simple concepts about space being different from Earth.
Key Stage 2 (Ages 7-11): Study the solar system’s structure, understand gravity’s role in planetary motion, learn how ideas about space have changed through history, and investigate shadows and Earth’s movement.
Key Stage 3 (Ages 11-14): Explore forces in space including gravity, light years and astronomical distances, life cycles of stars, and the universe’s origin and structure.
Practical Space Activities
Create scale models showing relative planet sizes or distances, though both cannot be accurately modelled simultaneously at manageable scales. Track the Moon’s phases through drawings or photographs over a lunar month. Build and launch simple rockets using balloons or film canisters with fizzing tablets. Observe planets visible with naked eye or simple telescopes.
LearningMole’s video resources bring space concepts to life with animations showing planetary motion, scale comparisons making enormous distances comprehensible, and explanations connecting abstract space concepts to concrete examples children understand.
Educational Resources for Teaching About Space
LearningMole provides comprehensive resources supporting engaging space education across primary and secondary year groups.
Video Library
Our space videos feature clear explanations of complex concepts, stunning imagery from space missions and telescopes, animations demonstrating planetary motion and scale, and content aligned with curriculum objectives across key stages.
Videos address common misconceptions about space while building accurate understanding through visual demonstrations that make abstract concepts concrete.
Downloadable Resources
Printable materials include planet fact files, solar system diagrams, Moon phase observation sheets, space-themed comprehension passages, mathematical problems using astronomical data, and complete lesson plans with differentiated activities.
These resources save planning time while ensuring scientific accuracy and curriculum alignment, avoiding the misconceptions present in some general space materials.
Interactive Activities
Digital activities allow pupils to explore the solar system virtually, compare planet characteristics, calculate astronomical distances using scale, sequence space exploration milestones, and test knowledge through engaging quizzes.
Conclusion: The Wonder of Space
Space captivates imaginations while teaching fundamental scientific concepts about our universe. From the silence of the vacuum to the incomprehensible number of stars, from Venus’s peculiar rotation to the permanence of lunar footprints, space facts simultaneously humble us with the universe’s vastness and inspire us with humanity’s growing capability to explore and understand the cosmos.
Teaching about space develops scientific literacy, mathematical thinking, and the curiosity that drives learning across subjects. Children who understand Earth’s place in space gain perspective on our planet’s uniqueness and fragility while appreciating the extraordinary universe we inhabit.
LearningMole’s comprehensive space resources support teachers and parents in bringing the cosmos to life through accurate information, engaging activities, and curriculum-aligned materials suitable for diverse educational settings.
Whether observing the Moon through a telescope, calculating how long light takes to reach Earth from distant stars, or imagining future Mars missions, studying space opens minds to possibilities while grounding understanding in scientific evidence and mathematical reasoning.
Explore LearningMole’s complete space collection including solar system videos, planet comparison activities, astronomy lessons, and cross-curricular resources. Our subscription service provides teachers and families with expertly designed materials that make learning about space both educational and awe-inspiring.