Our solar system is an immense place, filled with vast expanses of seemingly empty space separating planets. Even Voyager 1, humanity’s most distant spacecraft, launched over four decades ago, remains within the Sun’s gravitational reach. As of February 1, 2020, Voyager 1 was approximately 13.8 billion miles (22.2 billion kilometers) from the Sun—nearly four times the average distance between the Sun and Pluto. These numbers are so large they can be difficult to truly grasp.
To put these astronomical distances into perspective, scientists have devised clever methods to bring the solar system “down to Earth.” One such method is shrinking the solar system to the size of a familiar American football field. Imagine the Sun as just a dime placed on the goal line. In this scaled-down model, the distant planet Neptune would be a staggering 60 yards away.
The sheer scale of our solar system makes it challenging to represent effectively on paper or even a website. To simplify these immense measurements, astronomers use the Astronomical Unit, or AU.
Understanding the Astronomical Unit (AU): Earth’s Distance from the Sun
Scientists realized early on that constantly writing out enormous numbers was inefficient. Thus, the Astronomical Unit (AU) was established. One AU is defined as the average distance from the Sun to the Earth, approximately 93 million miles (150 million kilometers). To travel just one AU by airplane, even at a speed of 400 mph (644 kilometers per hour), would take over 20 years for a one-way trip. This single unit of measurement simplifies the daunting distances within our solar system.
To truly comprehend these distances, let’s revisit the football field analogy.
Visualizing Solar System Distances: A Football Field Model
Imagine the Sun, the largest object in our solar system, reduced to a ball about two-thirds of an inch (17 millimeters) in diameter—roughly the size of a U.S. dime coin—positioned at the goal line of a football field. On this scale, the planets become incredibly small and spread out across the field.
Even the inner, rocky planets—Mercury, Venus, Earth, and Mars—are reduced to mere grains of sand. They would be completely overshadowed by a common flea, which is approximately 3 millimeters long.
Mercury, the closest planet to the Sun, would be located just under a yard from the end zone, at 0.8 yards to be precise. In reality, Mercury’s average distance from the Sun is about 35 million miles (58 million kilometers), or 0.4 AU. Scaled down, Mercury’s diameter would be as tiny as the point of a needle.
Venus follows at 1.4 yards from the end zone. The actual average distance from the Sun to Venus is about 67 million miles (108 million kilometers), or 0.7 AU. Its size on this football field scale would be about 0.15 millimeters.
Then comes Earth, our home, located at the 2-yard line. Slightly larger than Venus, Earth would measure about 0.16 millimeters on this scale.
Football field at the three-yard line, illustrating the relative distances of the inner planets from the Sun in a scaled solar system model.
On this football field model, Earth and the inner planets reside within the first three yards of the goal line.
Earth’s “Goldilocks Zone”: The Perfect Distance for Life
Just as a quarterback aims to position their team close to the touchdown zone, Earth benefits immensely from its position in the solar system. Our planet resides at the ideal distance from the Sun, within what scientists call the “Goldilocks Zone,” where conditions are “just right” for liquid water and life to flourish. Venus is too hot, and Mars is too cold, but Earth’s distance provides the perfect balance.
As mentioned earlier, Earth’s average distance from the Sun is 1 AU, or approximately 93 million miles (150 million kilometers).
Mars, the next planet out, is situated at the 3-yard line on our football field. The Red Planet is, on average, about 142 million miles (228 million kilometers) from the Sun, or 1.5 AU. On our scale, Mars would be about 0.08 millimeters in size.
Beyond Mars lies the asteroid belt, primarily located between 4 and 8-yard lines on our football field. In real terms, this translates to an average distance of roughly 186 million to 372 million miles (300 million to 600 million kilometers) from the Sun, or 2 to 4 AU. These asteroids, if visible at all on this scale, would appear as microscopic specks. In fact, the combined mass of all known asteroids in our solar system is less than 10% of Earth’s Moon’s mass.
Even Jupiter, the largest planet in our solar system, remains relatively close on this scale, located at the 10.5-yard line.
Jupiter is positioned at the 10.5-yard line, averaging 484 million miles (778 million kilometers) from the Sun, or 5.2 AU. On our football field, Jupiter spans nearly 1.75 millimeters in diameter, roughly the thickness of a U.S. quarter.
Saturn is further out at the 19-yard line. This ringed planet is about 887 million miles (1.4 billion kilometers) from the Sun, or 9.5 AU. Saturn’s size on this scale is 1.47 millimeters.
Uranus, at 38 yards from the end zone, is where an interplanetary field goal kicker might be needed in our analogy. This gas giant is about 1.8 billion miles (2.9 billion kilometers) from the Sun—19 AU. Only one spacecraft has ever visited Uranus, highlighting the immense distances involved. On our scale, Uranus, at 0.62 millimeters, is just slightly smaller than the letter “R” on a penny.
Neptune marks the outer reaches of our scaled football field solar system. It is 60 yards from the goal line, at the opposing 40-yard line. In reality, Neptune averages 2.8 billion miles (4.5 billion kilometers) or 30 AU from the Sun. Slightly smaller than Uranus, Neptune measures 0.6 millimeters on this scale.
Football field at the opposing 40-yard line, showing the scaled position of Neptune and the outer solar system planets.
Dwarf planet Pluto is even further out, nearing the opposing team’s end zone, around 79 yards from the Sun, or 3.7 billion miles (5.9 billion kilometers) on average—39.5 AU.
On this football field scale, Voyager 1 has long since left the playing field, venturing far beyond the stadium parking lot.
Voyager 1 continues its journey away from the Sun at a rate of about 3.5 AU per year, or roughly 326 million miles (525 million kilometers) annually.
The vastness of space is truly mind-boggling.
A model of the Voyager spacecraft, highlighting its remarkable journey beyond our solar system and into interstellar space.
Even at our reduced football field scale, Voyager 1 is far beyond the stadium, emphasizing the incredible distances involved in space exploration and just how far the sun is from Earth in the grand scheme of our solar system and beyond.
