Educational Insights EI-5237 PlanetaryFeaturesChart, Interpreting the Planetary Features Chart

PlanetaryFeaturesChart

Planet	Symbol	Position	Average	Diameter	“Year”:Period	Average	“Day”: Time it	Atmosphere	Moons*	Temperature
		relative	distance		of time to	orbital	takes to
		to sun	from sun	at equator	orbit sun	speed	rotate on axis
			35,980,000 mi	3,031 mi		30 mi/sec		almost non-existent;		-279 to 801 ºF
Mercury		1st			88 Earth days		59 Earth days	trace amounts of	0
			(57,900,000 km)	(4,879 km)		(48 km/sec)				(-173 to 427 ºC)
								hydrogen and helium
			67,210,000 mi	7,521 mi		22 mi/sec		mostly carbon dioxide;		900 ºF average
Venus		2nd			224.7 Earth days		243 Earth days	sulfuric acid clouds obscure	0
			(108,200,000 km)	(12,104 km)		(35 km/sec)				(482 ºC average)
								view of surface
			92,960,000 mi	7,926 mi		18.5 mi/sec	23 hours,	78% nitrogen, 21% oxygen,		-129 to 136 ºF
Earth		3rd			365.26 Earth days			1% argon, carbon dioxide,	1
			(149,600,000 km)	(12,756 km)		(30 km/sec)	56 minutes			(-90 to 58 ºC)
								and trace gases
Mars		4th	141,700,000 mi	4,222 mi	1.88 Earth years	15 mi/sec	24 hours,	primarily carbon dioxide	2	-185 to 50 ºF
			(227,900,000 km)	(6,794 km)		(24 km/sec)	37 minutes			(-140 to 20 ºC)
			483,700,000 mi	88,846 mi		8 mi/sec	9 hours,	90% hydrogen		average cloud
Jupiter		5th			11.86 Earth years				60	temperature
			(778,300,000 km)	(142,980 km)		(13 km/sec)	51 minutes	10% helium
										-186 ºF (-121 ºC)
			888,200,000 mi	74,898 mi		6 mi/sec	10 hours,	97% hydrogen		average cloud
Saturn		6th			29.42 Earth years				33	temperature
			(1,429,400,000 km)	(120,540 km)		(10 km/sec)	39 minutes	3% helium
										-193 ºF (-125 ºC)
			1,786,500,000 mi	31,763 mi		4 mi/sec	17 hours,	83% hydrogen		average cloud
Uranus		7th			83.75 Earth years			15% helium	21	temperature
			(2,875,000,000 km)	(51,120 km)		(7 km/sec)	14 minutes
								2% methane		-193 ºF (-125 ºC)
			2,799,100,000 mi	30,800 mi		3 mi/sec	16 hours,	74% hydrogen		average cloud
Neptune		8th			164 Earth years			25% helium	11	temperature
			(4,504,400,000 km)	(49,500 km)		(5 km/sec)	7 minutes
								1% methane		-315 ºF (-193 ºC)
		Dwarf	3,676,200,000 mi	1,430 mi		3 mi/sec	6 Earth days,	methane gases frozen into		-387 to -369 ºF
Pluto					248 Earth years		9 hours,		1
		Planet	(5,915,800,000 km)	(2,300 km)		(5 km/sec)		ice for most of its orbit		(-233 to 223 ºC)
							18 minutes

*Scientists are constantly discovering new planetary moons and space objects. For the most up-to-date information, check one of NASA’s websites such as: http://nssdc.gsfc.nasa.gov

Interpreting the Planetary Features Chart

Both younger and older students can benefit from a discussion about the Planetary Features Chart. Duplicate this chart and distribute copies to the students. Begin your discussion by posing some simple riddles that students can answer by using the chart. For example, “I spin the fastest on my axis” (Jupiter), or “I’m the smallest planet” (Mercury). Then explore some of the topics below. Each begins with questions you might raise to get students thinking about the characteristics of the planets.

Which are the hottest planets? Where are they located?

Which are the coldest planets? Where are they located?

The planets closest to the sun tend to be the hottest. As you would expect, it gets very hot on Mercury, the planet closest to the sun. During Mercury’s night (which lasts 59 Earth days), however, it can be much colder than the lowest temperatures ever recorded on Earth. This is because Mercury has almost no atmosphere to hold in the heat and because the night lasts so long. Venus has an atmosphere much denser than Earth’s. Its thick atmosphere traps and holds the heat of the sun. Combined with its closeness to the sun, this makes Venus the most consistently hot planet with surface temperatures high enough to melt lead!

Which are the four smallest planets? What are they made of?

Which are the four biggest planets? What are they made of?

The four inner planets—Mercury, Venus, Earth, and Mars—are small and dense. They are made up of rocks and metals. Scientists call these terrestrial, or earth-like, planets.

Jupiter, Saturn, Uranus, and Neptune are often called the “gas giants.” They are made mostly of gases, liquid, and ice. They are made up mainly of the elements hydrogen and helium. Because they consist mostly of gas, they are much less dense than the inner planets. This means that they contain less matter per unit of volume . Saturn’s density is less than water. In fact, Saturn could float on a giant body of either fresh or salt water.

Very little is known about the dwarf planet, Pluto. Scientists believe it is made largely of ice.