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Moab Scale Model Solar System
The distance between the planets of our solar
system is hard to comprehend. By human standards
the distances are enormous and yet, when
compared to distances between stars in our galaxy,
the distance between planets seems small.
You’ve probably seen a model like this one.
This model of the Solar system is fun to look at
and it shows you the order of the planets, but it
has a big problem. It is not to scale.
The planets are bigger than they should be and
they are too close together. If this model was to
scale and the sun was the same size, the earth
would be about the size of a pin head.
Even the largest planet, Jupiter, would be
smaller than a gumball. The planets should also
be much farther away from the sun. For
example, Earth should be 35 feet away from the
sun.
This scale model solar system is designed to better
convey the enormous distances between the planets
compared to their relatively small proportional sizes.
Moab’s scale model of the solar system allows you to
take a stroll from one planet to the other. Although each
of the four inner planets (Mercury, Venus, Earth, and
Mars) can be walked to with relative ease, getting to
Pluto would involve a one-way hike of 9.5 miles!
According to project designer Sam Allen, the display is meant to
continue the theme started on East Center Street with Star Hall,
Sun Court and Moon Stone Gallery.
“I got the idea from the scale model solar system that was on
display in the stores along Main Street a few years ago. The
concept was fascinating to me.” said Allen.
Solar system project designer
Sam Allen stands at the center
of Moab’s Sun Court on the disk
representing the Sun, while
holding scale-model cutouts
representing Earth and Saturn.
The Moab City Council approved the project and planning and
community development director David Olsen was instrumental in
getting it done, Allen said, adding that special thanks are also due
to Rob Morris of the Clark Planetarium for help with the scale
calculations and NASA for the images used on the plaques.
The Sun is represented by a 142-inch diameter yellow disc at the
center of the Sun Court, an outdoor basketball court just east of the
historic Star Hall building. All of the distances and planet sizes are
scaled accordingly (1 inch equals approximately 10,000
kilometers).
<-- Sun
The locations of the inner planets are marked with plaques around
town and along the Mill Creek Parkway. A map is available at the
Grand County Public Library, where the plaque for Mercury also is
located.
Even at this small scale, the solar system is too big to fit inside
Moab City limits. The final plaque on the Mill Creek Parkway
represents Mars. The outer five planets are not represented by
plaques, but are denoted by their approximate locations along
Highway 191 south of town.
The relative sizes of the planets seem miniscule in light of the
sizable distances between them, Allen said, adding that the Earth is
only the size of a large marble or jawbreaker 1.3 inches in
diameter. Saturn is about the size of a basketball, and Jupiter
slightly larger than that. Uranus and Neptune are each about the
size of a softball or a large grapefruit. Tiny Pluto – demoted to
“dwarf planet” status last year - is nothing more than a pebble less
than a quarter of an inch across.
Sun
Start the tour at the Sun Court. The Yellow disc in the center of the
basketball court represents the sun.
The Sun is the closest star to Earth, at a mean distance from our
planet of 149.60 million kilometers (92.96 million miles). This
distance is known as an astronomical unit (abbreviated AU), and
sets the scale for measuring distances all across the solar system.
The Sun, a huge sphere of mostly ionized gas, supports life on
Earth.
Walk to the Library.
Mercury
The scale size of the planet Mercury is represented by a small
marble.
The small and rocky planet Mercury is the closest planet to the
Sun; it speeds around the Sun in a wildly elliptical (non-circular)
orbit that takes it as close as 47 million km and as far as 70 million
km from the Sun. Mercury completes a trip around the Sun every
88 days, speeding through space at nearly 50 km per second,
faster than any other planet. Because it is so close to the Sun,
temperatures on its surface can reach a scorching 467 degrees
Celsius. But because the planet has hardly any atmosphere to
keep it warm, nighttime temperatures can drop to a frigid -170
degrees Celsius.
Next walk to the
location of Venus.
Venus
It is at the southeast corner of the ball park, 300 E. 100 S. The
scale size of Venus is about the size of a quarter.
Venus and Earth are similar in size, mass, composition, and
distance from the Sun but, Venus has no ocean. Venus is covered
by thick, rapidly spinning clouds that trap surface heat, creating a
scorched greenhouse-like world with temperatures hot enough to
melt lead and pressure so intense that standing on Venus would
feel like the pressure felt 900 meters deep in Earth's oceans. These
clouds reflect sunlight in addition to trapping heat. Because Venus
reflects so much sunlight, it is usually the brightest planet in the
sky.
Now walk by the
bridge in the Cross
Trails Park. This is
the location of
Earth.
Earth
Earth is a little larger than Venus, but the scale size is still pretty
close to the size of a quarter.
Earth, our home planet, is the only planet in our solar system
known to harbor life. All of the things we need to survive are
provided under a thin layer of atmosphere that separates us from
the uninhabitable void of space. Earth is the third planet from the
Sun and the fifth largest in the solar system. Earth's diameter is just
a few hundred kilometers larger than that of Venus. The four
seasons are a result of Earth's axis of rotation being tilted more
than 23 degrees.
Follow the path
and go through
the tunnel under
300 South Street.
When you get out
of the tunnel on
the south side
you are about to
the orbit of Mars.
Mars
At this scale Mars is about the size of a dime.
Mars is a small rocky body. Its surface has been changed by
volcanism, impacts from other bodies, movements of its crust, and
atmospheric effects such as dust storms. It has polar ice caps that
grow and recede with the change of seasons; areas of layered soils
near the Martian poles suggest that the planet's climate has
changed more than once, perhaps caused by a regular change in
the planet's orbit.
Even at this small scale, the solar system is too big to fit inside
Moab City limits.
The outer five planets are not represented by plaques, but are
denoted by their approximate locations along Highway 191 south of
town.
For the rest of the tour you will need to ride in a vehicle. Drive
South out of town on Highway 191 and look for the small green
signs along the side of the road. These are mile markers. They
are placed every mile along the highway. The approximate
locations of the outer planets are represented by the nearest mile
marker.
Jupiter would be at mile marker 124
(near the Farm & City feed store).
Jupiter, mile marker 124.
Jupiter is the most massive planet in our solar system. Its scale
dimension is about the size of a 14” beach ball. Jupiter resembles
a star in composition. In fact, if it had been about eighty times more
massive, it would have become a star rather than a planet.
Saturn is close to mile marker 123 (by Grand Rental Center and
Moab 4x4 Outpost)
Saturn, mile marker 123.
Saturn is surrounded by thin, flat rings. Saturn is made mostly of
hydrogen and helium. Its volume is 755 times greater than that of
Earth. At this scale it is a little larger than a basketball. Winds in the
upper atmosphere reach 500 meters per second in the equatorial
region. These super-fast winds, combined with heat rising from
within the planet's interior, cause the yellow and gold bands visible
in the atmosphere.
Uranus is approximately at mile marker 121 near the KOA
Kampground and Spanish Trail Arena).
Uranus, mile marker 121.
Uranus is a gas giant with no solid surface.
It has some of the brightest clouds in the
outer solar system and 11 rings. Its scale
size is comparable to a large grapefruit.
The first planet found with the aid of a
telescope, Uranus was discovered in 1781
by astronomer William Herschel. The
seventh planet from the Sun is so distant
that it takes 84 years to complete one
orbit. Its scale size is about the size of a
large grapefruit or a softball.
Neptune is near mile marker 118,
by LeGrand Johnson’s.
Neptune, mile marker 118.
Neptune was the first planet located through mathematical
predictions rather than through regular observations of the sky.
Nearly 4.5 billion kilometers from the Sun, Neptune orbits the Sun
once every 165 years. It is invisible to the naked eye because of its
extreme distance from Earth. It is a little smaller than Uranus, so its
scale size is also about the size of a large grapefruit or a softball.
Pluto is close to mile marker 116, about two miles south of Old
Airport Road.
Pluto, mile marker 116.
Pluto was discovered in 1930. It was known as the most distant
planet from the Sun until August 24, 2006 when the International
Astronomical Union (IAU) formally downgraded Pluto to a dwarf
planet. Pluto takes 248 years to orbit the Sun. At this scale it is
about the size of a pea.
At this same scale, the nearest star in our
galaxy, Alpha Centauri, would be 65,044
miles away, too far to represent on any
earthly scale (this distance is more than
two and a half times around the equator
of the Earth).