Solar System: Sun, Earth and Moon

Earth’s size and shape The earth is sphere. Aristotle made three observations: Objects fall straight down Earth’s shadow is curved People see different stars

Earth

Gravity The attractive force between two objects Depends on the masses and distance between two objects. How does the pull of gravity indicate that the Earth’s shape is spherical?

Earths properties: Diameter Pole to Pole12,714 km Diameter through equator12,756 km Circumference poles40,008 km Circumference equator40,008 km Mass5.98 X kg Avg distance from sun149,600,000km Avg distance from moon384,400 km Period of rotation23hr 56 min Period of revolution365 days, 6h,9min

Earth’s magnetic field Hypothesized that the strong rotation of the earth and the movement in the core set up the magnetic field The magnetic poles are 11.5* off from the physical poles. The wander due to the movement of the Earths crust and mantle

Magnetic fields mgres?q=earths+magnetic +poles&hl=en&sa

Magnetosphere An area in the Earth’s magnetic field that deflects harmful radiation coming from the sun as solar wind These collide with atoms in the atmosphere causing the aurora borealis or aurora australis

Earth’s Orbit ellipse

Earth Is a planet Suports life Has lower CO2 than Venus but trapped CO2 may contribute to green house effect Ocean absorbs CO2

If the magnetic field was not there to protect us what would happen to the earth?

The Sun and Earth: seasons The earth moves in two ways: Rotation: the earth spinning like a top around its axis. 24 hours or one day Revolution: The earth traveling around the sun. It takes one years 365 ¼ days

Rotation of the earth

Revolution of the earth

Where the sunlight hits the earth slanted Direct slanted

Seasons Seasons are caused by the tilt of the Earth’s axis as it moves around the sun. The amount of sunlight depends on the Latitude that the sunlight is directly hitting.

Solstices Solstices occur twice a year on the days that the sun appears directly overhead at latitude 23.5 north or 23.5 south. Remember the un tilts 23.5 degrees off of the axis. Northern Hemisphere: Summer solstice on June 21 st. The Northern Hemisphere is tilted toward the sun. The longest day in the North and the shortest in the South. North- Summer, South-Winter.

Solstice Winter solstice occurs on December 21 six months after the Summer Solstice. The Northern Hemisphere is tilted away from the sun and receives the least amount of light. Shortest day in the North and Longest day in the South. North-Winter, South-Summer

VLA Very Large Array (VLA)Dedicated in 1980, the Very Large Array (VLA) has been an extraordinarily productive scientific instrument. Astronomers from around the world use it to study objects from our Solar System to the edges of the known Universe, billions of light- years from the Earth.The telescope array consists of twenty-seven, 230-ton, 25-meter diameter dish antennas that together they comprise a single radio telescope system.The VLA has made key observations of black holes and protoplanetary disks around young stars, discovered magnetic filaments and traced complex gas motions at the Milky Way's center, probed the Universe's cosmological parameters, and provided new knowledge about the physical mechanisms that produce radio

Image courtesy of NRAO/AUI

EVLA emission.The VLA is now being transformed into a new research instrument: the Expanded Very Large Array (EVLA). By 2012, new state-of-the-art electronics and software will have completely transformed the VLA into the EVLA, a much more capable research tool with more than ten times the VLA's sensitivity. Reinvigorated by new technologies, the EVLA will push the frontiers of science and knowledge for decades to come.The Very Large Array Visitors Center is 50 miles west of Socorro, New Mexico on U.S. Highway 60. From U.S. 60, turn South on NM 52, then West on the VLA access road, which is well marked. Signs will point you to the Visitor Center.