WWK. We will know more about the study of celestial bodies and the wonder that originates beyond earths atmosphere. General idea of Astronomy What are celestial bodies? Examples What are nebulas? Examples Constellations The Universe: Cosmology and Galaxies.
WWK We will know more about the study of celestial bodies and the wonder that originates beyond earths atmosphere • General idea of Astronomy • What are celestial bodies? Examples • What are nebulas? Examples • Constellations • The Universe: Cosmology and Galaxies
“Astronomers study everything because everything is part of the universe.” • It combines many different subjects such as math, chemistry, biology, geology and physics. • Another name for an astronomer is an astrophysicists. “Astronomy is more than simply a mapping of stars and planets into outlines of gods and magical creatures. It is the scientific study of the contents of the entire universe- stars, planets, comets, asteroids, galaxies, and space and time- as well as its history.” Introduction to Astronomy
“Ceres is a celestial body that is by far the largest and most massive asteroid in the belt between Mars and Jupiter. It is approximately the size of Texas or 975km x 909km with a mass of 9.5 x 1020.” A celestial body is any natural body outside of the Earth. Some easy examples are the sun, moon and other planets. Celestial Bodies
Introduction: Examples: • The Latin word for “nebula” translates to “cloud”. Although this is what is translates to, a nebula is much more. It is an interstellar cloud in outer space that is made of: helium, hydrogen, gas, plasma and dust. Gravitational pull brings all these things together which later form what is known as a nebula. Nebulas
“Constellations are used in modern astronomy to internationally define an area of the celestial sphere, which is an imaginary sphere concentric with Earth and rotating on the same axis as Earth”. Traditionally, the term constellations refers to a pattern that is formed when imaginary lines are drawn in between stars close in proximity, forming an image. Constellations
Cosmology Galaxies “Galaxies are sprawling space systems composed of dust, gas and countless stars. The number of galaxies cannot be counted- the observable universe alone may contain 100 billion. Some of these distant systems are similar to our own Milky Way galaxy.” There are 3 types: Spiral (flat disk with bulging center and surrounding spiral arms), Elliptical (generally round but stretch longer around one axis than along the other) and Irregular (appear misshapen and lack distinct form, often because they are within the gravitational influence of other galaxies close by) • The study of the universe. • Modern cosmology is mainly the study of the Big Bang Theory. It brings together observational astronomy and particles physics. • “Cosmology is also connection to astronomy. However, they are contrasted in that while the former is concerned with the Universe as a whole, the latter deals with individual celestial objects.”
Vocabularycelestial body- This is any natural body outside of the Earthnebula- an interstellar cloud in outer space that is made up of helium, hydrogen, gas, plasma and dust.Cosmology- It brings together observational astronomy and particles physics
K.S What are some examples of all the subjects Astronomers need to be familiar with?
WWK We will know the contributions of scientists to the development of our understanding of the sciences of Space. Pre-Modern Astronomy Astronomy Basics Instruments Used Important Discoveries in Astronomy Cosmology and its Background
Ancient Civilizations such as the Harappans, Greeks, Mayans, and Chinese have studied the sky to predict the future, navigate, tell time and create calendars. They were religious based observations, but they formed the backbone of our modern day understanding of astronomy. • The Greeks were the first to begin to develop theories about the layout of the Universe • Observations of the moon led to the knowledge that the Earth was round, and not flat like previously assumed • Plato stated that the Universe was centered around Earth • Many thought that heaven was a giant bowl covering the Earth • The Chinese were rather advanced and tracked the planets carefully • They created the 365 day year around 484 BCE • They also followed a lunar calendar Pre-Modern
Astronomers, who are scientific observers of celestial bodies, have studied the sky above us for centuries. They have used a combination of math and physics to discover things such as • The origin of the Universe, such as the Big Bang Theory • Laws of Planetary Motion • The Solar System • The formation of stars • The existence of black holes • How the universe is centered around the sun • Thermal Radiation • What is Matter • The Theory of Relativity • The speed of Light • Dark Matter • The composition of the Universe Astronomy
Astronomers have used many tools to observe the universe. They date back centuries and have progressed from crude instruments to high tech computerized systems. • One of the first instruments developed by the Greeks, was the Armillary Sphere. It tracked the movement of objects against the celestial equator and the motion of the Sun and the Moon. • The Cross Staff was used before the invention of the telescope. It allowed astronomers to measure the distance between 2 stars. • The Quadrant was also used by the Greeks. It measured the altitude of celestial objects above the horizon. • The telescope was invented in 1608, and is now the most common and widely known astronomical instrument. There are 4 types: • Reflector: uses a mirror to collect light as a substitute for a lens • Refractor: collects light which can be viewed through an eye piece • Classical Cassegrain: the parabola shaped mirror conveys the light of the object to a focus near the top. Takes small pictures of the sky on photographic plates. • Radio: mirror is made of metal and reflects radio waves up to the primary focus Instruments
The Movement of Stars and Planets: This fundamental philosophy of astronomy was theorized in the ancient civilizations, though its hard to determine which one. • The Heliocentric Model: The idea that the Earth revolves around the Sun was theorized by Copernicus in 1543. He was the first to develop the math that could prove this theory. • Kepler’s Law: German astronomer Johannes Kepler was the first to discover that the planets revolved in an ellipses, instead of a perfect circle. This is helped astronomers figure out the distance between celestial objects. • Moons: Jupiter was the first planet discovered with a moon, other than Earth. Galileo discovered this in 1610, which changed how we viewed planets. • Herschel’s Map: From 1780 to 1834, William Herschel and his sister mapped the sky, charting thousands of nebulas and stars. They even discovered Uranus. • Theory of Relativity: Einstein proposed this theory in 1915, which states that mass can warp both space and time. • The Expanding Universe: Edwin Hubble in the 1920s discovered that there were other galaxies. He also tracked their movement and learned they are moving away from each other. • Radio Astronomy: Karl Janksy discovered radio waves coming from space, which we can use to see celestial objects far away that can’t be seen with other methods. Important Discoveries
Modern astronomers have now begun to theorize the origin of the Universe. This subject of study is called Cosmology, which looks at the evolution, structure, dynamics, and ultimate fate of the universe, as well as the natural laws that keep it in order. The most common and popular theory is the Big Bang, which states that the Universe is 13.78 billion years old and begun with a hot dense state that expanded and cooled to form subatomic particles and elements. Cosmology
Astronomer: A scientific observer of the celestial bodies Telescope: An optical instrument designed to view distant objects using an arrangement of lenses Cosmology: The study of the origin and evolution of the Universe Vocab
WWK You will know the formation and structure of Earth’s magnetic field, as well as it’s interaction with charged solar particles Bryson Wright
A freely suspended magnet always points in the North-South direction even in the absence of any other magnet. This suggests that the Earth itself behaves as a magnet which causes a freely suspended magnet (or magnetic needle) to point always in a particular direction: North and South. The shape of the Earth's magnetic field resembles that of a bar magnet of length one-fifth of the Earth's diameter buried at its center. Magnetic Axis and Geographic Axis
The South Pole of the Earth's magnet is in the geographical North because it attracts the North Pole of the suspended magnet and vice versa. Therefore, there is a magnetic S-pole near the geographical North, and a magnetic N-pole near the geographical South. The positions of the Earth's magnetic poles are not well defined on the globe; they are spread over an area. The axis of Earth's magnet and the geographical axis do not coincide. M.A. and G.A. continued…
At any location, the Earth's magnetic field can be represented by a three-dimensional vector. A typical procedure for measuring its direction is to use a compass to determine the direction of magnetic North. Its angle relative to true North is the declination or variation. Facing magnetic North, the angle the field makes with the horizontal is the inclination or dip. The intensity of the field is proportional to the force it exerts on a magnet. Background of the Magnetic Field
The dynamo effect is a geophysical theory that explains the origin of the Earth's main magnetic field in terms of a self sustaining dynamo. In this dynamo mechanism, fluid motion in the Earth's outer core moves conducting material across an already existing, weak magnetic field and generates an electric current. The electric current, in turn, produces a magnetic field that also interacts with the fluid motion to create a secondary magnetic field. Together, the two fields are stronger than the original and lie essentially along the axis of the Earth's rotation. The Dynamo Effect
The field lines defining the structure of the magnetic field are similar to those of a simple bar magnet. It is well known that the axis of the magnetic field is tipped with respect to the rotationaxis of the Earth. Thus, true north (defined by the direction to the north rotational pole) does not coincide with magnetic north (defined by the direction to the north magnetic pole) and compass directions must be corrected by fixed amounts at given points on the surface of the Earth to yield true directions. Structure
A magnetic field is made up of two unique quantities which physicists refer to as B and H. The academic concepts behind B and H are extremely difficult to explain to the layperson and aren't really relevant. Basically, B and H are both vector fields which interact with one another to create a magnetic field. This reaction can either be found in permanent magnetic field that are created by permanent magnets or by those which are created by electromagnets. Earth’s magnetic field creates a wall to protect us from charged solar particles from the sun. How it Works
Magnetic Field-The region surrounding a magnet, in which exerts a detectable force • Charged Solar Particles-High energy particles coming from the sun; discovered in the early 1940’s • Rotation-A circular movement of an object around a center Vocab Recap
What is the traditional device people use for determining magnetic North? K.S.
Madison McclurgUnit 13 period 2 WWK: We will know about the Giant Impact Hypothesis!
The Giant Impact Hypothesis is a hypothesis that approximately four and half billion years ago earth collided with an object the size of Mars. From this collision, the moon was created out of the left over debris.. The Giant Impact
There is little to no evidence on this mystery object, besides it being as big as Mars. This object is also known as Theia, which is a mythical Greek Titan who was the mother of the Goddess of the Moon (Selene). The other object
Supporting Facts This scientists' hypothesis is currently favored because of all the supporting evidence: 1.) The identical direction of the Earth's spin and the Moon's orbit 2.) The stable isotope ratios of the lunar and terrestrial rock are identical, which led scientist to believe the Moon and Earth have the same origin. 3.) The Moon has a very small iron core and lower density compared to the Earth, and the surface of the Moon was once molten. This is evidence of similar collisions in other star systems that results in debris disks.
Questioning the Hypothesis With such an impact, the energy is predicted to produce an ocean of magma by heating the earth, but scientists can not find evidence of planetary differentiation that heavier material sank into the Earth's surface. There are some other questions that have not been answered; like when the moon lost it's share of volatile elements and why Venus doesn't host a similar moon, even though it experienced a great impact during its formation.
George Darwin came up with the giant impact hypothesis that earth and moon had once been the same body. Darwin's hypothesis stated that “A molten moon had been spun from earth because of centrifugal forced” this became the dominant academic explanation. Father of the hypothesis
KS....... Who was the father of the Giant Impact Hypothesis?
Lindsey Morgan Unit 13 Period 2 WWK:Earth’s size and location in space, the moon’s relationship to our planet, who discovered the moon, what Aristarchus discovered, and how the moon affects Earth.
Earth’s Size and Location • Our planet’s size is measured in six different parameters. Mass: 5.9736×1024kg Volume: 1.083×1012 km3 Meandiameter: 12,742 km Surfacearea: 510,072,000 km2 Density: 5.515 g/cm3 Circumference: 40,041 km • Earth is known to be the fifth largest planet in our solar system, counting Pluto. • Earth is the third planet away from the sun, coming after Mercury and then Venus. It is located in one of the spiral arms of the Milky Way (the Orion Arm) , about 2/3 the way out from the center of our galaxy.
Earth and Moon Relationship • Our moon has 27% the diameter and 60% the density of Earth. It is in constant synchronous rotation with the our planet, and it is thought that it was created 4.5 billion years ago, not long after Earth’s creation. • The moon orbits Earth because of gravitational pull. It is known as the natural satellite of our planet. • The moon prevents Earth’s poles from destabilizing the Earth’s tilt, without this our weather would be dramatically different. It also acts as a “sweeper” of solar system debris such as small asteroids and meteoroids that could otherwise harm our planet.
Who Discovered the Moon? • It’s common to hear of references to who discovered certain planets in our solar system, but it is rare to hear of someone discovering the moon. This is because the moon was never actually discovered! • Because of the age of our planet, and the moon’s being so close to it, the moon has been here ever since the very first life forms were ever created on planet Earth. Therefore, any living creature with eyes that has ever lived has seen the moon. • It is quite probable, however, that early civilizations did not realize the different phases of the moon all came from the same object.
Aristarchus and His Discoveries • Aristarchus is an ancient Greek astronomer, and was the first to attempt at measuring the Earth’s distance from the moon and sun using angle measurements. Although his findings were off, his theory was impressive, especially for his time period which was around 310 BC to 230 BC. It is said that his method only failed in result because of the lack of advanced technology we now have to accurately measure. • He also attempted estimating our planet’s size, discovered that the Earth orbited the Sun, and that we were not the center of the universe. He also discovered the idea that stars were not just “dots of light” we see at night.
The Moon’s Affect On Earth • One of the most prominent ways the moon affects our planet is bytides, or the alternate rising and falling of the sea. These are created because of the moon and Earth’s attraction to each other, just like magnets are attracted to one another. • The moon is also responsible for stabilizing our axial tilt, which creates stability for our climate. • It has also contributed to workable metal deposits at the surface of our planet.
K.S. Which spiral arm of our galaxy is the Earth located in?