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Post by momof6 on Sept 10, 2004 17:21:12 GMT -5
This month we will be studying the planet Mercury.
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Post by momof6 on Sept 30, 2004 22:52:00 GMT -5
MERCURY By Sharon Fabian
-------------------------------------------------------------------------------- 1 Mercury is an extreme planet. It is the fastest of all the planets. It is one of the hottest planets, and it is also one of the coldest! It may be the site of the largest crash in the history of the solar system. Mercury may also have the strangest view of the sun in the whole universe! 2 Mercury zooms around the sun at a speed of 48 kilometers per second, or half as fast as the Earth travels. 3 At certain times and places, Mercury's surface temperature can rise to twice the temperature inside an oven when you are baking a cake. On the other hand, in the shadow of its North Pole craters, Mercury has ice like our North Pole does. 4 Since Mercury is so close to the sun, we have never been able to see it in any detail. Even with the most powerful telescope, Mercury looks like a blurry white ball. It wasn't until 1974 that we really began to learn about Mercury. In 1974 and 1975, Mariner 10 flew by Mercury three times and sent back about 12,000 images. 5 These pictures combined to give a map of about 45% of Mercury's surface, and what they show us is a planet covered with craters, much like our moon. Mercury's largest land feature is the Caloris Basin, a crater formed by a collision with a meteorite long ago. The size of the Caloris Basin, about 1350 kilometers in diameter, suggests that this may have been the largest impact ever. In fact, the impact was so intense, that scientists think it sent shock waves through the center of Mercury, causing strange landforms to appear on the opposite side of the planet. These landforms, nicknamed "weird terrain," look like nothing we have seen anywhere else except on the moon. 6 Around some of Mercury's larger craters are secondary craters, formed when rocks from Mercury's surface were thrown up by the impact, and then fell back to Mercury, causing craters of their own. 7 Mercury also has craters that appear to have shiny rays radiating out from their centers. These rays were probably formed from tiny specks of rock and dust thrown out by the impact. Since Mercury has almost no atmosphere, the specks fell straight back down and settled around their crater in a neat geometric pattern. The tiny specks of rock reflect Mercury's bright sunlight, and give the rays their bright shiny look. 8 Here is the strangest thing of all about Mercury. If you could stand on the surface of Mercury, your view of the sun would be unbelievable! First the sun might start to rise; then it would speed up and begin to get larger. Then it would stop, reverse its direction, stop again, and then continue on its way! If you could take your eyes away from this sight for a minute, you would notice that the stars in the background were zipping along at three times the speed of the sun. An extreme view, for sure. 9 Since Mercury is such an extreme little planet, what would we really learn from exploring it? Would it be worth the effort to spend the millions of dollars to send up another spacecraft to explore Mercury? NASA seems to think so, because even though Mercury is a planet of extremes, in some ways it is like Earth. Mercury may have gone through many of the same stages that Earth has gone through over the past few billion years. So, beginning in 2004, the Messenger spacecraft will begin its explorations of Mercury. Messenger will map the rest of the planet, and it will study what the planet is made of. It will take measurements of Mercury's magnetic fields and look for facts about the planet's interior. Why? If scientists can learn more about Mercury, maybe those facts will also help them draw conclusions about planet Earth. By studying Mercury, scientists hope to learn more about how the earth was formed and how it has changed over its lifetime. Maybe the extreme little planet called Mercury will teach us more about our home planet, Earth.
Copyright © 2004 edHelper --------------------------------------------------------------------------------
Name _____________________________ Date ___________________ Mercury
1. Mercury is the _____ planet. Hottest Fastest Largest None of the above 2. Scientists used a powerful telescope to discover the Caloris Crater on Mercury. False True 3. The landforms on Mercury called "weird terrain" are located _____. At the North Pole Around large craters On the side of the planet opposite a large crater In the Caloris Crater 4. Messenger is the name of one of Mercury's moons. False True 5. Mercury has an "extreme" view of _____. Pluto The sun Earth The moon 6. Which happened last. Scientists tried to see Mercury through telescopes. The spacecraft Mariner 10 explored Mercury. The planet Mercury was formed. The spacecraft Messenger explored Mercury. 7. This article is mainly about _____. A planet that is more like earth than any other planet An unusual planet and what we can learn from it Planets and stars The Messenger spacecraft 8. The word collision in paragraph 5 means about the same thing as _____. Crash Crater Landing Planet
Mercury - Answer Key
1 Fastest 2 False 3 On the side of the planet opposite a large crater 4 False 5 The sun 6 The spacecraft Messenger explored Mercury. 7 An unusual planet and what we can learn from it 8 Crash
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Post by momof6 on Sept 30, 2004 22:54:14 GMT -5
Name _____________________________ Date ___________________
Mercury Word Search
Find each of the following words.
SECOND SMALLEST ROCKY 88 DAYS REVOLUTION CRATERS HYDROGEN IRON CORE NO SEASONS NO MOON 58.6 DAYS ROTATION ELLIPTICAL ORBIT MERCURY HELIUM THIN ATMOSPHERE CLOSEST TO SUN
E T T C E H R T M O N O S E A S O N S S C A A N O U T N R O C K Y T 8 8 D A Y S R O T A T I O N S E C I O M N E O A N T Y T H I N A T M O S P H E R E T T T O L O O E I G C I H L H E L I U M C R A T E R S R O E O U T U R R O H 8 R T S N I F O U R S E A S O N S T S O P C C K R N I E T O O U A N L E D O S L Y O 6 L D O . U E D O L E T O E L L I P T I C A L O R B I T E B A A A T R R Y R C M I S E C O N D S M A L L E S T T C R S R L Y A H I C C M N H O T A S O O S T T 8 8 D A Y S R E V O L U T I O N N C M N I O Y C Y P U C O E O T R E N U C I N O O E C E E L R S N N N R T R Y H N C L O S E S T T O S U N N N H O N E M O O N O A S 8 H L M E R L 5 8 . 6 D A Y S R E V O L U T I O N I 8 O E C A C O 5 8 . 6 D A Y S R O T A T I O N L T A S R S T O R C I S N S N A E N I D C Y T V I T H R D
Answer Key SECOND SMALLEST ROCKY 88 DAYS REVOLUTION CRATERS HYDROGEN IRON CORE NO SEASONS NO MOON 58.6 DAYS ROTATION ELLIPTICAL ORBIT MERCURY HELIUM THIN ATMOSPHERE CLOSEST TO SUN
E N O S E A S O N S N R O C K Y M E O T H I N A T M O S P H E R E E G C H E L I U M C R A T E R S R O N C R N O U D O O E L L I P T I C A L O R B I T R Y R M S E C O N D S M A L L E S T Y H I 8 8 D A Y S R E V O L U T I O N N C L O S E S T T O S U N 5 8 . 6 D A Y S R O T A T I O N
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Post by momof6 on Sept 30, 2004 23:01:18 GMT -5
©abcteach Planet Report
This report form can be used for elementary age students. Older students can use the more detailed report form found on the planet study thread. --------------------------------------------------------------------------------
Name __________________ Date ___________________
Name of Planet ________________________
Position from the sun ____________________
Report:
_____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________
What was the most interesting fact you researched about your planet?
_____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________
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Post by momof6 on Sept 30, 2004 23:07:53 GMT -5
GENERAL INFORMATION ON MERCURY
Mercury is the planet closest to the Sun in our Solar System. This small, rocky planet has almost no atmosphere. Mercury has a very elliptical orbit and a huge range in temperature. During the long daytime (which lasts 58.65 Earth days or almost an entire Mercurian year, which is 88 days long), the temperature is hotter than an oven; during the long night (the same length), the temperature is colder than a freezer.
Mercury is so close to the Sun that you can only see it near sunrise or sunset.
Craters on the surface of Mercury. Mercury is a heavily cratered planet; its surface is similar to the surface of our Moon. Cratering on Mercury triggered volcanic eruptions that filled much of the surrounding area. Mercury does have a magnetic field (probably generated by a partly-liquid iron core).
SIZE Mercury is about 3,031 miles (4,878 km) in diameter. It is the second-smallest planet in our Solar System (after tiny Pluto). Mercury is a bit over one third of the diameter of the Earth. Mercury is only slightly larger than the Earth's moon.
MASS AND GRAVITY Mercury's mass is about 3.3 x 1023 kg. This is about 1/20th of the mass of the Earth.
The gravity on Mercury is 38% of the gravity on Earth. A 100 pound person on Mercury would weigh 38 pounds. To calculate your weight on Mercury, just multiply your weight by 0.38 (or go the planetary weight calculator) ATMOSPHERE Mercury's thin atmosphere consist of trace amounts of hydrogen and helium. The atmospheric pressure is only about 1 x 10-9 millibars; this is a tiny fraction (about 2 trillionths) of the atmospheric pressure on Earth.
Since the atmosphere is so slight, the sky would appear pitch black (except for the sun, stars, and other planets, when visible), even during the day. Also, there is no "greenhouse effect" on Mercury. When the sun sets, the temperature drops very quickly since the atmosphere does not help retain the heat.
MERCURY'S ORBIT AND DISTANCE FROM THE SUN Mercury is closest planet to our Sun and the fastest moving planet in our Solar System. Mercury is just over a third as far from the sun as the Earth is; it is 0.387 A.U. from the sun (on average). Mercury's orbit is very eccentric; at aphelion (the point in the orbit farthest from the sun) Mercury is 70 million km from the sun, at perihelion Mercury is 46 million km from the sun.
There are no seasons on Mercury. Seasons are caused by the tilt of the axis relative to the planet's orbit. Since Mercury's axis is directly perpendicular to its motion (not tilted), it has no seasons.
If you were on the surface of Mercury, the Sun would look almost three times as big as it does from Earth!
TEMPERATURE RANGE Mercury has a huge range in temperatures. Its surface ranges in temperature from -270°F to 800°F (-168°C to 427°C). During the very long daytime (88 Earth-days long), the temperatures are very high (the second-highest in the Solar System - only Venus is hotter); during the long night, the thin atmosphere lets the heat dissipate, and the temperature drops quickly.
MOONS Mercury has no moons
SPACECRAFT VISITS Mercury was visited by NASA's Mariner 10 in 1973 and 1974. Under half of Mercury's surface was mapped by this spacecraft.
MERCURY'S NAME AND SYMBOL
Mercury was named after Mercury, the mythical Roman winged messenger and escort of dead souls to the underworld. It was named for the speedy Mercury because it is the fastest-moving planet.
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Post by momof6 on Sept 30, 2004 23:18:50 GMT -5
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Post by momof6 on Sept 30, 2004 23:34:57 GMT -5
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Post by momof6 on Sept 30, 2004 23:36:49 GMT -5
INSIDE MERCURY
Crust: Mercury has a thick crust that is composed mostly of silicate rocks. Mercury may have small ice caps at its north and south poles; this ice stays frozen inside deep craters that are shaded from sunlight.
Mantle: Beneath the crust it is a mantle (also made of silicate rocks) that is hundreds of kilometers thick.
Core: At the center of Mercury is a partly-molten iron core about 2,300 miles (7,500 km) in diameter (almost half of the diameter of Mercury). This core accounts for about 80% of Mercury's mass. This core generates a magnetic field (which is how we know that Mercury has an iron core).
Density: Mercury has a density of 5,430 kg/m3, slightly less than that of Earth. Mercury is the second-densest planet in the solar system (after Earth) because of its large iron core.
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Post by momof6 on Sept 30, 2004 23:38:28 GMT -5
Lesson for older students.
Draw and label the planet Mercury using the information from the above post.
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Post by momof6 on Sept 30, 2004 23:46:18 GMT -5
LENGTH OF A DAY AND YEAR ON MERCURY
Mercury revolves around the sun very quickly, but rotates around its axis very, very slowly. One day on Mercury (sunrise to sunrise) is longer than one year on Mercury (one orbit around the Sun).
Mercurian Year: A year on Mercury takes 87.97 Earth days; it takes 87.97 Earth days for Mercury to orbit the sun once.
Mercurian Sidereal Day: Each sidereal day on Mercury takes 58.65 Earth days; it takes Mercury 58.65 days (2/3's of its year) to rotate around its axis once. One day on Mercury seems to last two Mercurian years (or 176 Earth days), i.e., sunrise to sunrise. It is daytime for one Mercurian year, and nighttime for one Mercurian year. (It used to be thought that Mercury always kept the same side side towards the sun, but this is not true.)
A point on Mercury that is directly facing the Sun will point in the same direction after one rotation (59 days = 2/3 of Mercury's orbital period), but that point will no longer be facing the Sun. That point will return to the same position in three rotations of the planet during which it will orbit the sun twice (or 176 Earth days).
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Post by momof6 on Sept 30, 2004 23:49:06 GMT -5
QUIZ ON MERCURY
1. Is Mercury composed of rock or gases?_________________
2. Since Mercury is close to the Sun, it gets very hot. Does it ever get cold? _____________________
3. Does Mercury have a thick or thin atmosphere? __________________
4. Is Mercury closer to the size of the Earth or our moon? __________________
5. If you stood on the surface of Mercury, what color would the sky be? _____________________
6. We have four seasons on Earth. Are there any seasons on Mercury? ______________
7. How many moons does Mercury have?_______________________
8. Would a person feel very light or very heavy on the surface of Mercury? ___________________
9. Is Mercury the smallest planet in the Solar System? ______________________
10. Is the surface of Mercury covered with craters, molten iron, or oceans? ___________________
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Post by momof6 on Sept 30, 2004 23:52:06 GMT -5
Fill in the blanks using words from the word bank
Word Bank: moving sunset Venus heat moons temperature closest Sun atmosphere Pluto Mercury surface axis sky Seasons
Mercury is the planet _________________________ to the Sun in our Solar System and the fastest _________________________ planet in our Solar System. It is the second-hottest planet in our Solar System (only _________________________ is hotter). Mercury is so close to the _________________________ that from Earth, you can only see it near sunrise or _________________________. Mercury has no _________________________. Mercury was named after Mercury, the mythical Roman winged messenger. This small, rocky planet has almost no atmosphere. Since the atmosphere is so slight, the _________________________ would appear pitch black (except for the sun, stars, and other planets, when visible), even during the day. If you were on the surface of _________________________, the Sun would look almost three times as big as it does from Earth! Also, there is no "greenhouse effect" on Mercury. When the Sun sets, the temperature drops very quickly since the _________________________ does not help retain the _________________________.
Mercury has a very elliptical orbit and a huge range in temperature. During the long daytime (which lasts 88 Earth days or an entire Mercurian year), the _________________________ is hotter than an oven; during the long night (the same length), the temperature is colder than a freezer.
Mercury is about 3,031 miles (4,878 km) in diameter. It is the second-smallest planet in our Solar System (only _________________________ is smaller). Mercury is only slightly larger than our moon. Mercury is a heavily cratered planet; its surface is similar to the _________________________ of the Earth's moon.
There are no seasons on Mercury. _________________________ are caused by the tilt of the axis relative to the planet's orbit. Since Mercury's _________________________ is directly perpendicular to its motion (it is not tilted), it has no seasons.
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