relative size of the sun/stars. the sun…is a star!! the sun is a star, just like those we can see...
TRANSCRIPT
Relative size of the sun/stars
The SUN…is a star!!The Sun is a star, just like those we can see in the night sky. As stars go, it is an "average" star. Because it is so much closer to us than the other stars, it appears much brighter. During the daytime, the Sun's light covers up the light from the other stars. Earth is almost 150 million kilometers from the Sun. Light from the Sun takes about eight minutes to reach us. The nearest star to our solar system is Alpha Centauri. Light from this star takes over four years to reach us.
the sun…
Layers of the sun
Layers of the sun1. Core- The Sun's nuclear "furnace,"
where fusion reactions initially combine hydrogen atoms to produce helium, yielding energy in the process.
2. Radiative Zone- Energy moves through a surrounding envelope of gas toward the Sun's surface.
3. Convection Zone- Big "bubbles" of hot gas transport energy to the surface.
4. Photosphere- The Sun's visible surface.
5. Sunspot- A magnetic "storm" on the Sun's surface.
6. Solar Flare- An eruption of hot gas that can extend thousands of miles into space.
7. Corona-The Sun's outer atmosphere, which is heated by the magnetic field to millions of degrees.
The Photosphere
The chromosphere
The corona
Solar flare on the corona
Aurora…..what is this caused by?
Earth’sMagnetic field and the Van
Allen Belts
The Planets
Planets
• Have elliptical orbit around sun• Gravity: force of attraction between 2 objects that
depends on mass and distance apart (larger mass = stronger force; longer distance = less force)
Terrestrial Planets
• 4 inner planets that have a rocky surface & relative size of Earth (Mercury, Venus, Earth & Mars)
Jovian Planets (gas giants)
• Outer 4 planets that are more gaseous and lack solid surfaces
• Thick atmospheres rich in H and He
Elliptical orbit:
Asteroid belt
Asteroids
Asteroids
• Located in the asteroid belt between Mars and Jupiter
• 1000’s of rocky objects left over from the formation of the solar system orbiting the sun
• Range from a few km to over a 1000 km in diameter
Meteoroids
• If asteroids collide and break apart meteoroids are created.
• These fly around our solar system until collision or orbited
It’s a shooting star??….no it’s actually a Meteor!!
• Meteoroids that enter Earth’s atmosphere is called a meteor…aka shooting star!!
Meteorite
-If the fragment reaches Earth surface it is called a meteorite
-These can cause impact craters.
Breakdown…
• Meteoroid-fragment flying in space
• Meteor-streak left from fragments entering Earth’s atmosphere and burning.
• Meteorite-fragment strikes Earth’s surface.
Impact Craters evidence
Meteor crater, AZ
These travel to Earth at about 20 km/s
• Meteor Crater in Arizona is one of the best known examples of an impact crater on Earth. The crater is 1.2 kilometers in diameter and 200 meters deep. It formed approximately 49,000 years ago when an iron meteorite that was roughly the size of a school bus struck the Arizona desert east of what is now Flagstaff.
Extinction of the dinosaurs?? By a 14-18 km in diameter meteorite?
• As of 2002, fewer than 200 impact structures are recognized on Earth. Like the Moon, the Earth must have been struck innumerable times by asteroids and comets over its history. Most craters on Earth have been destroyed by erosion. A particularly large crater formed near Chicxulub, Mexico, about 65 million years ago. This impact event is thought by many scientists to be responsible for the extinction of the dinosaurs.
How come the Moon’s craters don’t erode?
What’s wrong with this picture?
Nordlingen, Germany, Is this town built in an impact crater??
Impact Crater Structure
Solar Eclipse
Solar Eclipse
• Occurs when the moon passes directly between the sun and earth and blocks the view of the sun
When is the next solar eclipse??...Will this be you?
http://sunearth.gsfc.nasa.gov/eclipse/solar.html• Next time for us? 2038
Most people are lucky if they see a solar eclipse just once in their lifetime. Any one spot on earth only experiences an eclipse every 400 years. However people do travel great lengths to see them.
Lunar Eclipse
• Occurs when the moon passes through the Earth’s shadow. Only occurs during a full moon.
Lunar Eclipse
Early Earth
• A magma ball• Slowly started to cool and crust.• Outgassing from volcanoes/magma occurred-
contributes to atmosphere
Outgassing from Early Earth
• The gases that accumulated were those we still find coming out of volcanoes:– Water vapor (H2O)– Hydrogen chloride (HCl) – Carbon Monoxide (CO) – Carbon Dioxide (CO2) – Nitrogen (N2)– Methane (CH4) – Ammonia (NH4)
– Hydrogen Cyanide (HCN)
Iron Catastrophe
• Occurred about 500 my after Earth’s creation.
• Responsible for the creation of the magnetosphere.
• Elements/compounds on Earth started to order themselves by density.
• The denser material (iron) drifted towards the core of Earth and the less dense material (silicates) went towards the surface of Earth.– Called Differentiation-layering
according to density.
The moon…• The moon is believed to be
about 4 byo• Created from a planetismal
impact• The crash caused debris to
fly in space and orbit Earth• Over time the debris
condensed to form the moon.
• Moon was a lot closer but is slowly moving away (about 1inch/year)
• Evidence: Moon rock is younger than asteroids and oldest Earth rocks
• The moon rotates once about every 27 days, and revolves once about every 27 days. So every time the moon goes around Earth it turns around one time. That is why the moon always looks the same - we only ever see one side of it! Another strange thing is that if we lived on the Moon and thought of days and years the same way we do on Earth, a day AND a year would be the same length! Since the rotation and revolution times are the same, the length of a day and the length of a year are identical.
The moon…
• Rotation- 27 days
• Revolution- 27 days– Years and days are the same length!
• The moon has an orbital plane 5 degrees above Earth’s plane– This is why we can see it.
Phases of the moon
• The phase of the moon depends upon its revolutionary position.
• Full and New moon- occurs when sun, Earth and moon in alignment.
• Half moons-occur when sun, Earth and moon are at right angle.
• Waxing-phases before full moon
• Waning-phases after full moon.
Kepler’s Laws of Planetary Motion
• Johannes Kepler (1571-1630) -studied orbits of planets.
• 1. The Law of the Orbits: All planets move in elliptical orbits, with the sun at one focus.
Kepler’s Laws of Planetary Motion
• 2. The Law of the Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.
• 3. Law of the Periods: The square of the period of any planet is proportional to the cube of the semi-major axis of its orbit.