Download 100 Earth Science Facts

100 Earth Science Facts
1. The Sun is the center of our Solar system. (Heliocentric)
2. Long ago, most people believed that the planets and sun revolved around the Earth. (Geocentric)
3. Most scientists believe the universe began with a Big Bang and it is still expanding.
4. Our solar system contains 1 star (the sun), 8 planets, and numerous comets, asteroids, meteoroids and
moons.
5. The Inner planets (in order from the sun) are Mercury, Venus, Earth, and Mars.
6. The outer planets (in order from the sun) are Jupiter, Saturn, Uranus, and Neptune.
7. The inner planets are small and solid and the outer planets are big and made of gas.
8. Pluto is not considered a planet any longer because of its small size and tilted orbit.
9. Jupiter is the largest of the gas giants) outer planets) and Earth is the largest of the Inner planets.
10. Interesting features found on the planets are Jupiter’s red spot, canyons and extinct volcanoes on Mars,
and an active volcano on Jupiter’s moon Io.
11. Mercury has no atmosphere. Earth has an atmosphere mainly of nitrogen (78%) and oxygen (21%). Mars
has a very thin atmosphere.
12. The outer planet’s atmosphere is made primarily of hydrogen and helium.
13. All objects in the sky (sun, moon, stars) seem to rise in the east and set in the west.
14. All objects in our solar system revolve (orbit) around the sun because of the sun’s great amount of gravity.
15. Asteroids are found between the orbits of Mars and Jupiter. Meteoroids are smaller pieces of asteroids
that float about in space. Our gravity may send them crashing to Earth.
16. During a solar eclipse, the moon is in between the Earth and sun.
17. A solar eclipse can only happen when the moon is new and a lunar eclipse can only happen when the
moon is full.
18. It takes about 1 month for the moon to rotate and revolve.
19. The Earth rotates once a day and revolves once a year.
20 Another name for revolve is orbit and another name for rotate is spin.
21. The inner planets revolve around the sun faster than the outer planets. (They don’t have as far to go.)
22. How fast a planet rotates determines how long its day and night will be. This, along with its distance from
the sun, will also determine how hot or how cold the planet is.
23. The Earth is closer to the Sun in the winter than in the summer, so our seasons are not caused by the
distance between the Sun-Earth, but rather the Earth’s tilt.
24. The seasons are reversed below the equator. (Ex. Summer here=winter in Australia.)
25. As you go deeper inside the Earth, it gets hotter and its composition becomes denser.
26. Oxygen and silicon are common elements found in the Earth’s crust and iron and nickel are more common
as you go deeper down toward the core.
27. The Earth’s lithospheric plates are in constant motion. This movement causes the continents and the
seafloor to move in different directions.
28. The movement of the Earth’s plates causes earthquakes, volcanoes, tsunamis, trenches, and mountain
building.
29. The most active region of plate movement on the Earth is an area around the Pacific Ocean called the Ring
of Fire.
30. Flour, milk, eggs, sugar, and butter are to cake as minerals are to rocks.
31. Rocks are classified by how they formed. The 3 types of rock are igneous, sedimentary, and metamorphic.
32. Rocks that form from lava or magma are called igneous rock.
33. Rocks that form at or near the Earth’s surface are called sedimentary rock. Most rocks that you find on
the ground are sedimentary.
34. Whenever sediments get compacted and cemented together, these sediments turn in to a rock known
as sedimentary rock. Whenever rock is exposed to extreme heat and pressure, it can turn into a
different type of rock called metamorphic rock.
35. Wind, water, ice, sunlight and gravity can all cause rock to physically weather into small fragments
called sediments. This process is called weathering.
36. Sedimentary rock is known for being soft and having layers.
37. If a rock cools slowly, such as from magma inside the Earth, there will be large grains or crystals visible
in the rock. This is called intrusive igneous rock.
38. If a rock cools quickly, such as from air or water on the surface, then this is called extrusive igneous
rock.
39. The continual process by which new rock forms from old rock material is called the rock cycle. This
process normally takes a very long time.
40. Erosion happens after weathering. It is when the sediment is removed or taken away, like a stream
taking sediment into the ocean.
41. Whenever this sediment comes to a stop, it is laid down or deposited in low places. This is called
deposition. This sediment will likely later become a sedimentary rock.
42. Fossils help scientist to understand the age of rocks and how the Earth’s surface and climate have
changed over time.
43. The fossil record supports the belief that the continents have not always been where they are today.
This includes fossils from tropical plants that have been found in places that are cold today.
44. Soil is a mixture of organic (use to be alive) and inorganic (never has been alive) material.
45. Examples of organic material found in soil include leaves, sticks, and dead plants/ animals. Inorganic
material in the soil would be weathered rocks and minerals.
46. Rocks that are smooth and rounded have most likely been tumbled in a river or creek at some time.
47. Contour plowing, terracing, and no-till farming can all help to control erosion.
48. A natural resource is any natural material used by humans. Examples are water, petroleum, minerals,
forest, and animals.
49. A renewable resource is one that can be replaced at the same rate it is used up. Trees and fresh water
are 2 examples.
50. A non-renewable resource is one that forms at a rate much slower than the rate it is consumed (used up).
Examples are coal and petroleum.
51. The sun is the major source of energy on Earth.
52. Water falling over a dam creates hydroelectric energy.
53. Burning fossil fuels, like coal and natural gas, produces energy but can also cause problems to our
environment.
54. Precipitation can become acidic (acid rain) if it mixes in with polluting chemicals in the atmosphere. This
acid rain can kill vegetation and damage buildings.
55. Nuclear energy is clean burning but it does produce radioactive waste.
56. Neither solar nor wind energy produce pollution, but neither one is very reliable. They only work if the sun
is shining or the wind is blowing.
57. The Law of Superposition says that the deeper you dig down in the ground, the older the fossils are that
you find, unless the ground has been disturbed.
58. The water cycle is the never-ending movement of water between the ocean, atmosphere, and land. No
water is every gained (created) or lost (destroyed) from this cycle.
59. Evaporation is turning water from a liquid to a gas (vapor). This happens faster whenever it is warm.
60. Condensation is the opposite of evaporation. It is when water goes from a gas back to a liquid. The air
mass must get colder for this to happen.
61. Dew on the grass, your bathroom mirror fogging up after a hot shower, and your glass of ice tea
“sweating” on a warm day are examples of condensation.
62. In the water cycle diagram, condensation takes place inside the clouds where the air has cooled.
63. Warm air can hold more water vapor than cold air. This is why the moisture falls out of clouds. It is much
colder higher up in the air than on the surface.
64. Whenever the air can hold no more water, it falls out in the form of precipitation.
65. There are 4 forms of precipitation: rain, snow, sleet, and hail.
66. Fresh water includes all water found on Earth that is not in the oceans.
67. Places that we get fresh water from are the ground (groundwater), rivers, lakes, and glaciers.
68. Most of the Earth’s surface (71%) is covered by water. 97% of this water is salty (oceans) and is
undrinkable. 3% is considered fresh.
69. Most of our fresh water is frozen and unavailable for us to use. This is why we need to protect our fresh
water, one of our most important natural resources.
70. As your altitude increases, the air pressure and temperature decreases.
71. Land and water absorb and lose heat at different rates.
72. This is why some places like Florida are cooler than Georgia in the summer and warmer in the winter. The
ocean warms Florida in the winter and cools it off in the summer.
73. Convection is the movement of matter due to differences in density.
74. This happens in the atmosphere (warm air rises, cool air sinks), in the mantle (magma rising), and in the
oceans (cold water currents sinking).
75. The greenhouse effect is when water and carbon dioxide in the air traps the heat, making it very warm.
This happens on Venus and on the Earth, to a smaller degree.
76. Some scientists believe the Earth’s temperatures are increasing each year. This is called global warming.
Things that could be causing this are our burning of fossil fuels (gas, coal) and deforestation (cutting down our
carbon dioxide consuming trees).
77. Wind is caused by a difference in air pressure between 2 places.
78. Cold air weighs more (has more pressure) than warm air. This is why the wind always blows in between 2
places that have different temperatures.
79. Since air and water absorb heat at different rates (see #71), the wind always blows at places like the
beach, lakes, and mountaintops.
80. Humidity refers to water vapor in the air.
81. Air pressure refers to how much the air is pressing down on you. We measure air pressure with an
instrument called a barometer.
82. An H on a weather map stands for High Pressure. This is a sign of good or heavenly weather.
83. An L on a weather map stands for Low Pressure. This is a sign of rain, storms, or lousy weather
84. A north wind brings cold, dry air and a south wind brings warm, moist air.
85. A west wind brings a dry wind with good weather and an east wind brings stormy weather.
86. Clouds are classified by their height, or altitude.
87. Stratus clouds are thick, gray, low clouds and may bring rain. Fog is a stratus cloud.
88. Cumulus clouds are mid-level clouds that are puffy like cotton balls. These clouds are common in the
summer and are a sign of good weather.
89. A L on a weather map stands for Low Pressure. This is a sign of rain, storms, or lousy weather
90. Frost is frozen dew.
91. We live in an area of the atmosphere called the troposphere.
92. The weather in the U.S. generally moves from the west to the east.
93. The wind is what causes surfaces currents in the ocean.
94.There are also currents below the surface currents on the ocean floor. They usually move in the opposite
direction, setting up a convection cycle.
95. A falling barometer means that rain and storms are on the way.
96. Weather is what we are having today (hot, cold, stormy).
97.Climate is the average of all weather conditions over a 10 year period. Just because it is raining in a desert
today does not mean that it has a rainy climate.
98. Our atmosphere is made up of 79% nitrogen and 21% oxygen.
99. Ozone in our upper atmosphere absorbs most of the sun’s harmful ultraviolet radiation that tans our skin
and causes skin cancer.
100. Whenever it is humid outside (the air is full of water vapor), sweat cannot evaporate off of our skin
because the air is already full of water. Our sweat does not evaporate, we do not cool off, and it feels hotter
than the temperature really is.