Unit E: Science Exploration

Things in space

Nebula

• Nebulae are accumulations of gas and dust in space

• the attraction of particles causes the nebula to start collapsing into a small, rotating cloud

• If the core gets hot enough, it will start to glow. This is called a protostar, the first stage in a star’s formation

• soon it becomes hot enough to achieve fusion, creating a star

  

Star

• A star is a hot, glowing ball of gas (mainly hydrogen) that gives off a ton of light energy

• The colour of a star depends on its surface temperature. Very hot stars look blue. Cooler stars look red.

Constellation

• Constellations are grouping of stars we see as patterns in the night sky There are 88 rexognized constellations

• Ex. Big dipper, Orion, and Virgo

Planet

• Ancient people knew about 5 planets: Mercury, Venus, Mars, Jupiter, and Saturn (that’s all they could see and Earth wasn’t included becasue they believed it was the centre of the universe)

• Planet- means “wanderer” in Greek

• Over time, each planet moves in a weird way. This is called retrograde (the path a planet takes), but it’s just an optical illusion.

• In contrast, the stars move in a perfect circle

Moon

• The moon is a natural satellite that obrits a planet

• Our moon moves from east to wast across the skiy. This movement is called the ecliptic

• The moon had phases. It takes 28 days ti complete a cycle

Black hole

Solar wind and the Sun

• solar wind is charged particles released by the sun in every direction

• Earth is protected by solar wind with its magnetic field

• solar wind is known as the aurora borealis

• sunspots are spots on the sun that are darker. This is a result of the sun’s magnetic field that prevents heat from flowing to the surface

The Planets

1. Mercury- closest to the sun

2. Venus- the hottest planet

3. Earth -the only planet that can sustain life

4. Mars- - the red planet( from rust- iron III oxide)

5. Jupiter- the largest planet

6. Saturn- rings

7. Uranus- tilted axis

8. Neptune'

9. (not really) Pluto- classified as a planetoid

Inner planets

• The first 4 planets

• smaller, rockier in composition, and closer to the sun that the Jovian planets

Outer planets (Jovian-Jupiter)

• large, gaseous, and located great distance from the sun

The Protoplanet Hypothesis

The “protoplanet hypothesis” is a model for explaining the birth of solar systems. The process can be described in three steps:

1. A cloud of gas and dust in space begins swirling.

2. Most of the material (more than 90%) accumulates in the center, forming the Sun.

3. The remaining material accumulates in smaller clumps circling the center. These form the planets

Eclipses

• A solar eclipse is when the moon, passing between the sun and the earth, casts a shadow on earth

• A lunar eclipse occurs when Earth passes between the Sun and the Moon, casting its shadow over the Moon

Asteroids, Comets, and Meteors

• Asteroids are belts of small rocky or metallic bodies travelling in space

• Majority of them are found between the orbits of Mars and Jupiter

• Comets are objects made of dust and ice. They are pushed by solar wind and their tails glow when they get close to the sun

• Meteoroids are small or big pieces of rocks flying through space with no paticular path

• A meteriod becomes a meteor when its pulled into the Earths atmoshphere and the the ifrsction causes it to give off light

• A meteor becomes a meteorite when it hits Earth’s surface

Solstices and Equinoxes

• Winter solstice- December 21st (shortest day)

• Vernal equinox- March 21st (halfway to summer)

• SUmmer equinox- June 21st (longest day)

• Autumnal equinox- September 21st (halfway to winter)

Early Views of Space

The geocentric model of the universe

• The arth is at the center of the universe

• Every orbit is a perfect circle

• This was the model of Airistotle, ptolemy, and pythagoras

• it was believed that there was a dome of stars enclosing our solar system

The heliocentric model of the universe

• Sun at the center

• every orbit is eliptical (oval)

• This was the model of Coppernicus, Galileo. Kepler, and Newton

• Gailieos observations (and the conclusions he made)

1. Craters on the moon- celestial bodies are not perfect

2. Sunspots- the sun turns of its axis so maybe the earth does too.

3. Moon orbiting jupiter- not everything revolves around the earth

4. Phases of venus- venus orbits the sun so maybe the earth does too

Defending heliocentricity

• Galieo used his observations to defend copernicus’ theory

• The main point- celestial bodies (like earth) can orbit other celestial bdies

• followed by two astronomers Tycho Brahe and Johannes Kepler

Kepler’s Laws (techically Brahe’s, his teacher)

1. Planets move in elliptical orbits

2. The closer to the sun a planet is, the faster it will move

Discoveries

The Atronomical Unit

• 1 A.U = the distance between teh Earth and the Sun = 150,000,000 km

The Light Year

• 1 light year = the distance that light travels in a year = 9,460,728,000km= 63,240 A.U

• Speed of Light = 299,792 km/sec

• It takes 8 minutes fro light to travel from the Sun to the Earth

Astronomer tools

• Astrolabe- measured altitude

• cross-staff- measure the angle bewtween the moon nand any given star

Positions of Objects in Space

Azimuth

• Azimuth is direction(degrees)

• North = 0 degrees

• East = 90 degrees

• South = 180 degrees

• West = 270 degrees

• measured with a compass

Finding a celestial body in the sky

• Altitude is height- horizon = 0 degrees.

• Zenith (directly overhead) = 90 degrees

Rockets

Compiled of three components

1. structural components- the rockets itself, engines storage tanks, fins

2. fuel- liquid oxygen, liquid hydrogen, gasoline

3. payload- what its carrying- people water, air, food

Soviet Satellites

• October 4th 1957- first launched satellite, the Sputnik

• A month later a second space capsule was launched , carrying a small dog named Laika

IMPORTANT DATES TO REMEMBER

• First satellite- 1957

• Went to the moon and back-1969

Cool stuff

Microgravity- the condition which the gravitational forces are greatly reduced

Space shuttles- rockets used by space until 2011. They were re-usable

Ion drives- engines that use xenon fas instead of chemical fuel, The gas is electrically charged. Pros: lasts a long time and only rewuires a small amount of xenon gas. Cons: weak as hell

Solar sails- used to power spacecrafts. Pros- fast and saves on fuel. Cons- no power outside the solar system

Producing Water and Oxygen

Water- waste water is distlled and the steam is condensed into potable water

Oxygen- electrically electrocute water to seperate the elements. Hyfrogen is thrown overboard and oxygen is kept.

Dangers of Space

Environmental

• cosmic and solar radiation

• Extreme hot and cold

• meteors

Body changes

• Bones expand

• visual depth is affected

SATELLITES

Observation

• What satellites were mostly used for

• geosynchronous orbit (high orbit)

Remote sensing

• Low orbit

• take high resoloution of the earths surface

Communication

• low to medium orbit

• Ex. Satellite radio

GPS

• Global postitioning system

• geosynchronous (high) orbit

• requirea t least 4 satellietes to recieve an accurate calculation

Technology made for space used on earth

• Space food- baby and freeze-dried foods

• computer robotics- emergency response robots for use in dangerous situations (bombs)

• Simulation of space environment for space training- VR

  Refracting optical telescopes

• Optical telescopes uses visible light

• a refracting telescope had a objective lens that refracts light from the outside

• as well as an ocular lens that refracts light to the eye

• When multiple telescopes are used to view n object, it is called inferometry (we do this with our eyes)

  Reflecting telescope

• Has a primary and secondary mirror that capture light from outside

• and an eye eyes that refracts light to the eye