Geocentric Science

26 Articles About Astronomy & Deep Space

A Quick Review on Polaris

The North Star (Polaris) Polaris (the North Start) appears to remain stationary in the sky (because it is so far away). The other stars appear to rotate around Polaris. The altitude of Polaris = your latitude (for example, the latitude of New York City is about 40˚, and therefore the altitude of Polaris is 40˚)

Celestial Motion

Apparent Motion Celestial bodies such as the sun, the moon, planets, stars appear to rise in the EAST and set in the WEST. Celestial bodies appear to move due to Earth’s rotation.

Earth’s Layers

Refer to page 10 of the Earth Science Reference Tables As you read in The Formation of Earth article, the Earth’s layered structure is a result of differentiation. The diagram, Inferred Properties of Earth’s Interior (from the Earth Science Reference Tables), indicates the relationship between depth, density, pressure, and temperature. The middle diagram indicates the immense pressure in the Earth’s inner core. Therefore, as depth increases pressure increases. You might have experienced

Earth’s Magnetic Field

Particles of rock accreted together to create the early Earth. This young Earth looked extremely different from what it does today. Young Earth was a fiery planet; it was a rotating mass of hot gases and minerals, revolving around the Sun, which eventually began to cool and undergo differentiation (refer to The Formation of Earth, Earth’s Layers, and The not-so Solid Earth articles). Before the Earth underwent differentiation, there was a magnetic fields in the young Earth. As more rock accret

Earth’s Revolution

A Quick Review 360˚/365 days = 1˚/day Earth revolves around the sun counterclockwise 1 year to revolve (1 year to orbit the Sun)

Earth’s Rotation

A quick review 360˚/24 hours = 15˚/hour It takes the Earth 1 day to rotate on its axis The Earth rotates counterclockwise 15˚ of longitude = 1 hour Foucault Pendulum proves the Earth rotates!

Kepler's Second Law

Refer to the Equations on page 1 and the Solar System Data on page 15 of the Earth Science Reference Tables Law of Equal Areas - Opposite Segments are Equal in Area (Not Drawn to Scale) Planets do not move at a constant velocity. However, since Area #1 = Area #2, the planet will travel the same amount of area in equal periods of time. In order for this to occur, the planet must travel at different speeds throughout its orbit. Perihelion occurs when the planet is closest to the Sun and the

Luminosity and Temperature of Stars

Refer to the HR Diagram (Hertzsprung-Russell Diagram) (Characteristics of Stars chart) page 15 of the Earth Science Reference Tables This chart is also known as the HR Diagram. The HR Diagram is a plot of luminosity versus surface temperature of the stars. The points on the diagram represent stars. Most of the stars (about 90%) fall on the main sequence (this is not a place in space but is a relationship between temperature and luminosity). As temperature increases, energy emitted increases, r

Proving that the Universe is Expanding

Stationary Object Emitting Sound/Light The object emits wavelengths that are equal because object is NOT moving. Therefore, the same wavelength (same frequency) observed no matter where the observer is located. Object is Moving (Slower than the Speed of Sound/Light) All wavelengths are not equal and therefore different frequencies (pitches) will be observed (heard or seen). Position A: Object is moving away from the person; wavelength is long (low frequency, low pitch) and a red light is

Reasons for the Seasons

There are three factors that result in seasons: The Earth’s revolution around the Sun The Earth’s tilt on its axis Earth is always tilted towards Polaris Please note: the Earth’s distance from the sun does NOT influence the seasons (Earth’s orbit is nearly a circle, refer to the eccentricity value on page 15 of the Earth Science Reference Tables) Locations on the Earth’s surface receive different amounts of solar radiation (insolation) throughout the year. Places close to the Equ

Solar Wind and the Magnetosphere

Charged particles are continuously emitted from the Sun in the form of Solar Wind. The temperature and speed of the particles will determine the force the particles are ejected from the Sun. The Solar Winds could be extremely dangerous for Earth and all of its organisms. However, the Earth has a protection shield, known as the Magnetosphere (refer to the Earth’s Magnetic Field article). As the Solar Wind approaches Earth (or other planets that have a magnetic field, such as Jupiter and Saturn

Spectral/Emissions Lines and the Expanding Universe

Scientists learn about the radiation given off by space by using a spectrometer and measuring the radiation frequency of gases. This optical telescope can detect visible light. Each gas produces a certain line pattern, and this is considered the gas’ fingerprint. Each gas has its own line pattern (or fingerprint). For example, below are two sets of spectral lines. #1 represents lab spectral lines for hydrogen gas. #2 represents spectral lines of hydrogen gas from a distant galaxy. Lab and g

Star Trend Definitions and Concepts

Refer to the HR Diagram (Hertzsprung-Russell Diagram) (Characteristics of Stars chart) page 15 of the Earth Science Reference Tables Main sequence: a line on the HR diagram showing the patterns of stars when comparing luminosity and temperature and color Luminosity: absolute (actual) brightness of a star (distance is NOT important) Apparent brightness: the brightness that we observe (depends on size and distance) Massive stars: blue super giants, high luminosity, large stars, VERY hot, BLUE

The Apparent Path of the Sun

The Sun is not actually moving throughout the day, but it is a result of Earth’s rotation that causes the Sun to appear to move throughout the sky from east to west (regardless of one’s latitude). On the Equinoxes, the Sun always appears to rise directly in the east and sets directly in the west (on the Equinox only). Throughout the year, the sun will rise either north of east or south of east and will set either north of west or south of west. Depending on where the sun rises and sets, wil

The Big Bang Theory

The Dopper Effect shows that the Universe is expanding, and therefore the Universe must have been much smaller in the distant past. Today, scientists explain the formation of the Universe with the Big Bang Theory. A massive explosion occurred (The Big Bang), hurling the universe outwards in all directions. At this moment, time and space were created. When you look out into space, your perception of the movement of galaxies is really the Universe continuing to expand. In addition, elapsing time is

The Coriolis Effect

Refer to the diagrams Surface Ocean Currents on page 4 and the Planetary Wind and Moisture Belts in the Troposphereof the Earth Science Reference Tables Fluids, such as atmospheric winds and bodies of water, will flow from regions of high pressure to regions of low pressure on the Earth’s surface. Large-scale fluid systems will appear to move in a curved path due to the Earth’s rotation, the curvature of the Earth, and the differences in the rotational speed. If the Earth was not rotating,

The Doppler Effect

The Doppler Effect is a change in pitch (frequency) due to an object’s motion – the wavelength changes causing the pitch to change. As an object emits sound or light, and as the object moves towards or away from an observer, the wavelength changes. If an object is moving towards an observer, the wavelength will become shorter (higher pitched), creating a blueshift. Otherwise, if the object is moving away from an observer, the wavelength will become longer (a lower pitch), creating a reds

The Equinoxes

Equinox iss defined as “equal night”; therefore, on the Equinoxes, the Earth receives 12 hours of daylight and 12 hours of night. The Equinoxes occur midway between the ends of the Earth’s orbit (midway between the Winter Solstice to the Summer Solstice and from the Summer Solstice to the Winter Solstice). The Autumnal Equinox (Fall Equinox) occurs around September 22nd or September 23rd. The Vernal Equinox (Spring Equinox) occurs around March 20th or March 21st. The Sun’s rays hit the

The Formation of Earth

Refer to page 10 of the Earth Science Reference Tables Earth (as well as the other terrestrial planets) formed as rock and other space debris collided (accreted). The collisions provided a huge amount of energy and heated the planets. Many of the planets were mostly molten in their early stages. The Earth became layered through a process known as differentiation (the heavier, denser materials sank, and the lighter, less dense materials remained at the surface). The Earth’s layers are visible

The Life Cycle of a Massive Star

Refer to the HR Diagram (Hertzsprung-Russell Diagram) (Characteristics of Stars chart) page 15 of the Earth Science Reference Tables The formation of a very massive star (blue super giant) “Dust”, also known as nebulae, (the accumulation of dust and gases) comes together under the force of gravity to form a PROTOSTAR. The star is very massive, very hot, high energy, not stable, and “wants” to become stable (these stars will change most rapidly). The star undergoes a number o

The Life Cycle of an Average Star (Our Sun)

Refer to the HR Diagram (Hertzsprung-Russell Diagram) (Characteristics of Stars chart) page 15 of the Earth Science Reference Tables A star like our sun… it is AVERAGE in all aspects! “Dust” (gases and debris) come together under the force of gravity to form a PROTOSTAR The star has moderate mass, not very hot, moderate energy, and is relatively stable. Evolves and remains on the main sequence for about 10 billion years After about 10 billion years, the star becomes starts to evolve

The Milky Way Galaxy

Refer to the Solar System Data on page 15 of the Earth Science Reference Tables Our solar system consists of eight planets (refer to page 15 for the list of planets). The sun is the located at the center of our solar system, and each of the planets orbit around the sun. There are many stars and solar systems within our galaxy. We are part of the Milky Way Galaxy. The Milky Way is a spiral galaxy that consists of approximately 200 to 400 billion stars, and our solar system is located on one of

The Northern Lights

Are also known as Auroras or Aurora Borealis, which occur in high latitudes. Charged particles are emitted from the sun and are funneled into the upper atmosphere (known as the ionosphere) by the Earth’s magnetic field. The particles collide and their energy level changes. The color variation is the result of different elements being excited and returning to their ground state.

The not-so Solid Earth

Refer to page 10 of the Earth Science Reference Tables Although the Earth’s surface is composed mostly of water (the layer known as the hydrosphere), the Earth is composed of several distinct layers beneath the Earth’s surface. In the Formation of Earth article, you read about differentiation. The upper image of the Inferred Properties of Earth’s Interior shows the different layers of Earth’s structure: Lithosphere (continental and oceanic crust) Asthenosphere Stiffer mantle Outer

The Summer Solstice

As the Earth orbits (and remains tilted at the same angle towards Polaris), on June 21st or June 22nd, the Northern Hemisphere leans towards the Sun. As a result, the Tropic of Cancer (23.5º North) receives direct insolation. The Summer Solstice is the longest day of the year (greatest daylight hours). The Sun reaches its highest altitude at solar noon on the Summer Solstice at latitudes equal or greater than 23.5º North. The summer solstice marks the first day of summer. Solstice translates

The Winter Solstice

In the Northern Hemisphere the winter solstice is usually December 21st or December 22nd, and the Northern Hemisphere leans 23.5º away from the Sun. As a result, the Tropic of Capricorn (23.5º South) receives direct insolation. The Winter Solstice is the shortest day (fewest daylight hours) of the year. The Sun reaches its lowest altitude at solar noon on the Winter Solstice at latitudes equal or greater than 23.5º North. The winter solstice marks the first day of winter. Solstice translate