- Watching the sun, moon, and star movements become a way to identify when to plant, crops, when to harvest, and when it was time to plan for other events.
- Ancient civilizations used celestial cycles of motion as clocks and calendars. The change of position of the Big Bang towards the North Star over a period of 24 hours shows how the Big Dipper can be used to help you track of time. As well as it changes its position in the sky according to the season of the year.
- The stone pillars of Stonehenge were positioned so they could be used to follow t movement of the Sun and moon with the seasons of the year.
- It seems impossible to know anything about the actual distance to any given star. Distance without a referent point can be measured in terms of angels or time. The unit of astronomical distance that light travels in one year, about 9.5 x 10^12 km (about 6 x 10^12 miles.)
Origin of Star
- Stars are born from swirling clouds of hydrogen gas in the deep space between other stars, which we call a nebulae. The cloud gas atoms begins to condense by gravitational attraction to a protostar, an accumulation of gas that will become star.
- It takes around 17 millions of years for a nebulae to form into a protostar until a star is born, and the star then continues for the next 10 billion years.
- As an average star, the sun converts about 1.4 x 10^17 kg of matter to energy every year as hydrogen nuclei are fused to produce helium. The Sun was born about 5 billion years ago and has sufficient hydrogen in the core to continue shining for another 4 or 5 billion years.
- Higher temperatures mean increased kinetic energy, which results in increased numbers of collisions between hydrogen nuclei with the end result being an increased number of fusion reactions.
- is a gigantic explosion in which a massive star collapses and its outer layers are blasted into space.
- produces a brilliant light in the sky that may last for months before it begins to dim as the new elements that were created during the life of the star diffuses into space.
- is the very small (10 to 20 km diameter), superdense remains of a supernova with a center core of pure neutrons.
- is a very strongly magnetized neutron star that emits a uniform series of equally spaced electromagnetic pulses. If a neutron star is spinning, it is called a pulsar.
- If the theoretical limit is reached, nothing can stop the collapse, and the collapsed star will become so dense that even light cannot escape. The star will now be a black hole.
- A galaxy is an extremely large collection of stars bound together by mutual gravitational attraction. The Milky Way contains an estimated 100 billion to 200 billion stars.
Canis Major Dwarf
- Closest to the Milky Way Galaxy
- 42,000 light years away
- They are generally the most distant objects observed in the universe, and they emit tremendous amounts of electromagnetic radiation (energy) at all wavelengths.
- Starlike sources of energy that are located in the centre of galaxies.
- Minor planets
- Simply left over debris from the formation of the solar system.
- Mostly found at the Kuiper’s Belt in between Jupiter and Mars.
- Small interplanetary metallic stony objects that range in size from a fraction of a millimeter to about a hundred meter. They are probably the remains of comets and fragments of shattered asteroid.
- A relatively small object that is composed of dust and ice and that revolves about the sun in a highly elliptical orbit. As a comet near the sun, some of the surface vaporizes to form a gaseous head and a long tail.
Asteroids and Comets
Comparisons of Asteroid and Meteors
Earth in Space
- The shape of Earth is a slightly pear-shaped, slightly lopsided oblate spheroid.
- Earth moves constantly around the sun in a slightly elliptical orbit that requires an average of one year for one complete circuit.
- The movement around the sun is called a revolution, and all point’s on Earth’s orbit lie in a plane of the ecliptic.
- Rotation is the spinning of Earth around an imaginary line through the geographic poles called Earth’s axis.
Seasons of the Year
- Summer Solstice – June 22
- Winter Solstice – December 22
- Spring Solstice – March 21
- Autumnal Equinox – September 23
- Solstice – “Sun stand still”
- Equinoxes – “equal nights”
- The Earth has 1 moon that revolves around it. It is a satellite of Earth which takes around 29 1/2 days, almost a month, for the moon to move (revolve) around the Earth.
- The moon does not make any light of its own. The lighted parts that we see are called phases. The moon reflects light from the sun.
- As the moon moves around the Earth, it looks like it has different shapes, which changes every time it changes its position revolving around the Earth.
- New Moon
- Waxing Crescent
- First Quarter
- Waxing Gibbous
- Full Moon
- Waning Gibous
- Last Quarter
- Waning Crescent
EARTH SYSTEM SCIENCE
- The study of the interactions between and among events and Earth’s spheres.
- It studies the flow of matter and energy in and out of the Earth’s open systems, or Spheres.
Types of Spheres
- Atmosphere – a gaseous sphere and it envelopes the Earth. Consists of a mixture of gases composed primarily of nitrogen, oxygen, carbon dioxide, argon, and water vapor.
- Hydrsphere – all of the water on Earth. 71% of the earth is covered by water and only 29% is terra firma.
- Lithosphere – the Earth’s solid surface, often called the crust of the earth. It includes continental and oceanic crust as well as the various layers of the Earth’s interior.
- Biosphere – all life on Earth, including man, and all organisms. The life zone on our planet distinguishes our planets from the others in the solar system.
- Cryosphere – the portion of the Earth’s surface where water is in a solid form. Snow or ice: includes glaciers, ice, shelves, snow, icebergs, and arctic climatology.
- Anthrosphere – man and his direct ancestors, hominids. The human population, it’s buildings, dams, and other constructions.
- a change in one sphere results in changes in others, called an event. And this series of event, is similar to a chain reaction of cataclysm for spheres involved.
What are these events about?
- Natural events – earthquake, hurricane, forest fires
- Human caused events – oil spill, air pollution, construction
- It has some global implications.
- Helps people predict outcomes.
- Preparation for natural disasters
- Environmental impacts of human activities.
- Advances in technology have allowed scientists to study the Earth in a variety of different ways.
- Satellites and space craft allow us to view, photograph and map Earth from Space.
- Submersibles and ships allow us to view, photograph and map the ocean floor.
- Buoys and other monitoring devices provide us with data related to events such as tsunamis and earthquakes.
- Powerful computer programs called GIS (Geographic Information Systems) help scientists organize, layer and interpret huge amounts of data in order to study how the Earth changes over time.
- Using data from modern technology, scientists can create complex representations of how Earth “works”. These representations of Earth processes are called models.
- Interactions among the Earth’s spheres change the spheres to differing degrees.
- These impacts can be single events, temporary changes, or ongoing changes.
- Bill Tillery. Physical Science. 10th Edition.
- Shipman. Physical Science.