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Earth and Space 6-8 / Week 08 / Monday
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Week 08 · How Big: Sizes and Properties

Monday

How big is big?
// Reading the planets as a data table
⏱ about 20 min

Monday: How Big Is Big?

Rocket sets the Earth ball on the Sky Deck table and holds up his hands, far apart. "Jupiter is this much bigger. Maybe."

"Guess a number," Raven says. "How many Earths wide?"

"Three?" Rocket says. Raven checks the NASA page. "Eleven. Jupiter is eleven times wider than Earth."

Rocket stares at the ball. "Then Jupiter would not fit on this table. And the Sun?"

Nova hovers over the ball, her light making a tiny bright dot on it. "The Sun is about 1.4 million kilometers across," she says.

"Compared to Earth's 12,756," Raven adds. "What do you notice?" Rocket whistles. "The Sun would not fit in the yard."

Rocket, Raven and Nova at the Sky Deck table by a window. Rocket holds his hands wide apart above a small ball for Earth. Raven holds a sheet of paper with circles drawn on it and a ruler. Nova the companion drone hovers above with her light making a bright dot on the ball.

From distances to sizes

Last week you walked the distances between the planets. This week you read their sizes and other properties.

The Next Generation Science Standards ask you to analyze data to find the scale properties of objects in the solar system.

Scale properties include an object's size, its layers and its surface features. You start with size.

Diameter is the distance straight across a planet through its center. The NASA Planetary Fact Sheet lists it in kilometers.

Earth, Jupiter and the Sun

Earth's diameter is 12,756 kilometers. NASA says Earth is the biggest of the terrestrial planets and the fifth largest planet overall.

Jupiter's diameter is 142,984 kilometers. NASA says Jupiter is 11 times wider than Earth.

The Sun is the largest object in our solar system. NASA gives its diameter as about 1.4 million kilometers.

NASA adds that it would take 1.3 million Earths to fill the Sun's volume. More than 330,000 Earths would be needed to match its mass.

ObjectDiameter (km)Compared with Earth
Earth12,7561
Jupiter142,984about 11 times wider
The Sunabout 1,400,000about 110 times wider
SIZE WORDS
  • Read the question.
  • Tap your answer.
What is a planet's diameter?
About how many times wider than Earth is Jupiter?
Which is the largest object in our solar system?
StatementTrue or false?
Earth is the biggest of the terrestrial planets.?
Jupiter is about three times wider than Earth.?
It would take about 1.3 million Earths to fill the Sun's volume.?
The Sun is smaller than Jupiter.?
WHY THIS EXERCISESize is the first scale property the standard asks you to compare.
What is Earth's diameter in kilometers on the NASA fact sheet? Type the number.
WHY THIS EXERCISEEvery size comparison this week starts from this number.
Try it
On paper, make a circle 1 centimeter across for Earth. Beside it, mark how wide 11 centimeters is. That line is Jupiter's width.
Write whether Rocket's guess of three was close.
For a grown-up
This week your student cuts paper circles to scale with scissors. A string circle on the floor stands for the Sun.
Please supervise the scissors and keep the string flat on the floor, never around anyone.
The facts this week come from the NASA Planetary Fact Sheet at nssdc.gsfc.nasa.gov, NASA at science.nasa.gov and OpenStax Astronomy at openstax.org.
Try this
Find a round object about 1 centimeter across, like a small bead, and one about 11 centimeters across, like a bowl.
Set them side by side. Write which stands for Earth and which for Jupiter.
Draw Earth as a small circle. Draw Jupiter beside it eleven times as wide. Write both diameters under them.

Good start. Tomorrow the eight planets sort themselves into two families: small and rocky, or giant and gassy.