Astronomy

Kaitlyn McElveen

The Sun

• The Sun is a yellow medium-sized and medium-hot star.

• It is composed of gases, mainly hydrogen. It also contains helium which is formed from two hydrogens.

• The Sun has 5 layers which are: the core, radiative zone, convective zone, photosphere, and chromosphere.

• It is the center of our solar system.

• The Sun was estimated to be born 4 billion years ago!

• Sun prominences are arks of gas that spews out of the Sun.

• Sun spots are dark spots that are cooler than the rest of the Sun.

The Sun CONT’D• Spicules are jets of gas that leaps from the Sun. • The Sun also has solar flares, which are magnetic storms that

releases tons of gas into its atmosphere.• How the Sun formed:

1. Explosion occurs from the death of another star.2. The energy from the explosion made hydrogen and helium

fuse together into a compact object.3. The Sun was formed.

• Effects on Earth: 1. Important for life. 2. Warms the planet. 3. Controls weather patterns. 4. Harms the skin with UV radiation. 5. Serious cable interferences; knocks out power grids on

satellites

The Sun CONT’D

Mercury• Mercury is the first planet and is closest to our

Sun.• It has little to no atmosphere.• Mercury is composed of rock and iron and is

part of the inner planets (rocky planets before

the asteroid belt).• It is a extremely hot planet, but note that it is

not the hottest.• Temperatures reach 800°F during the day and

reach 300° F during the night.• At most, Mercury is 70 million miles away from

the Sun.

Venus

• Venus is the second planet is nearly the size of Earth, giving it the nickname “Earth’s Twin.”

• Venus has a thick atmosphere, composed of mainly carbon dioxide.

• It is the hottest planet in our solar system.• Venus rotates slowly. It takes 255 Earth days

to rotate once on its axis.• Venus is highly volcanic.• Venus takes 243 days to revolve the Sun.

Earth, Our Home

• Earth is estimated to be 4.5 million

years old.

• Earth’s astrological name is Terra.

• It is about 93 miles away from the

Sun.

• It is composed of tectonic plates,

allowing the planet to refresh

itself.

• These plates appear from massive

heat and energy coming from the

core.

• The Earth revolves around the Sun

every 365.25 days.

• The Earth rotates every 23 hours

and 54 minutes.

• Earth is closest to the Sun in

January and farthest in July, due to

its elliptical shaped orbit.

• Earth is the only known planet

able to sustain life and have liquid

water.

• There is no accepted theory of how

Earth came to be.

• Seasons on Earth occur from its 23.5 degree tilt.

• For example, when it is winter in the Northern Hemisphere, it’s summer in the Southern Hemisphere

• The angle of sunlight hitting Earth determines the season.

Seasons on Earth

The Moon

• The moon was estimated to be formed 20-30 million years after Earth.

• It is composed of similar materials of Earth’s crust. • It is about 2,168 miles in diameter.• The moon is estimated to be about 238,000 miles

away from Earth and moves 38mm away from Earth each year.

• It orbits Earth every 29.5 days.• Gravity from the moon impacts Earth’s tides.• Since the Earth drags the moon along with it, it slows

its rotation down and the rate slows 15 milliseconds a year.

• The moon has no atmosphere.• It has many craters, revealing it’s been hit numerous

times by meteoroids

The Moon Cont’d• The moonlight is actually

sunlight reflecting off of the moon’s surface.

• The moon was thought to be created from a piece of Earth from a meteoroid.

• The moon’s orbit is tilted.• Another theory, the most

accepted theory, was that a dwarf planet named Thea collided with Earth, destroying Thea. Then, parts of the collision got caught up in Earth’s orbit, creating what is now our moon.

Phases of the Moon

• New moon: phase in which you see no part of the moon.• Waxing crescent: ¼ of the moon is visible; it is gradually

increasing in visibility• First Quarter (or half moon): ½ of the moon is visible, first half

moon throughout phases• Waxing gibbous: ¾ of the moon is visible• Full moon: whole moon is visible• Waning gibbous: ¾ of the moon is visible; begins to decrease• Third Quarter: ½ of the moon is visible; still decreasing• Waning crescent: ¼ of the moon is visible• New moon: completely dark and phases begin all over again• You do not see all the phases of the moon at the same time. You:

1. Never see a crescent moon at midnight.2. Never see last quarter moon at sunset.3. Never see a full moon during the day.

Tides

• The moon controls the tides on Earth. • There are two high and low tides in a

single day.• There are two different types of tides

during a month; Neap tide and Spring tide.

• Neap tide occurs during First and Third Quarter.

• Spring tide occurs during Full and New Moon.

Lunar and Solar Eclipses

• Solar eclipses occur when the moon is between the Earth and Sun.

• Lunar eclipses occur when the Earth is between the moon and Sun.

• Each can be classified in three ways; Partial eclipse, total eclipse, and annular eclipse.

• Partial eclipse: a portion of it is blocked• Total eclipse: blocks it entirely• Annular eclipse: furthest point in orbit• Solar eclipses are uncommon, but lunar eclipses happen

more often.• The phases of an eclipse, in order, are First Contact, Second

Contact, Bailey’s Beads, Diamond Ring, Corona, Totality, and the Ending Contacts.

• During lunar eclipse, the parts of it are: the penumbra, umbra, Sun, Moon, and Earth.

Lunar and Solar Eclipses Cont’d

Mars

• Mars has a predominately carbon dioxide and an atmosphere thinner than Earth’s.

• Martian days last a little over 24 hours.• It contains ice caps similar to those on Earth.• Temperatures are cold ranging from a chilly -200° to

80°F.• Mars’s surfaces is made up of huge canyon and

rusty colored ground.• What causes its ground to be that color is the iron

oxide in it.• Mars has no surface water.• It’s weather is erratic. Sometimes the winds blow at

tremendous speeds.

Asteroid Belt

• The Asteroid Belt is in between Mars and Jupiter.

• It separates the inner and outer planets.

• It is not as densely packed as many believe.

• Some scientists believe that the Asteroid Belt’s asteroids were once pieces of ancient planets.

Jupiter

• Jupiter orbits the Sun every 12 years.• Its atmosphere has raging winds.• A well-known, over 300 year old storm, has raged

on Jupiter. People call this storm the Great Red Spot.

• It takes up 71% of the solar system’s planetary mass.

• Jupiter has a metal core 4 times the size of Earth.• It is a gas planet.• It is the largest and fifth planet from the Sun.• Jupiter is the first outer planet.• Jupiter has thin rings.

Saturn

• Saturn is the sixth planet and is yet, another gas planet.

• It is well-known, mainly by its thick band of rings.• It is nearly 886 million miles away from the Sun.• Saturn has a rocky core, but its atmosphere

consists of liquid metallic hydrogen.• A rotation at the equator takes 10 hours and 14

minutes.• It is a very hot planet and tends to send off more

energy than it even receives.• Saturn has raging winds and a massive magnetic

field.

Uranus

• Uranus is the seventh planet in our solar system.• It spins sideways. The most accepted theory of how

Uranus became tilted the way it did was that a space object collided the planet and the impact tilted the axis.

• The tilt is nearly 98°.• For a full revolution around the Sun, it takes 84

years.• Uranus has 13 rings, 2 of them are a bit farther

than the others.• The moons revolve Uranus the opposite way of the

other moons in the solar system.• Uranus is also considered a gas planet.

Neptune

• Neptune orbits the Sun every 165 years.• Its days last 16 hours.• Similar to Jupiter’s Great Red Spot, it has a

raging storm called the Great Dark Spot.• The atmosphere is mainly made up of

hydrogen, helium, methane, and ammonia.• Neptune is 4 times the size of Earth.• Strong winds that reach over 400 mph.• Neptune is also another gas planet and ends

the outer planets.

Pluto and Other Dwarf Planets

•Pluto planetary title was removed

because it didn’t meet one of the

following criteria.1. Orbits the Sun: Pluto does orbit the Sun.2. Be spherical: Pluto is shaped

like of a sphere.3. Cleared its entire orbital neighborhood: Pluto did not meet this because there’s still many objects in its path that it hasn’t cleared.

• Because it didn’t meet criteria 3, they decided to call Pluto and other similar space objects ‘plutoids’ or ‘dwarf planets.’

• Pluto, along with many others, lie in the Kuiper Belt.

• The Kuiper Belt consists of many space objects and is right at the breach of our solar system.

Pluto and Other Dwarf Planets Cont’dPluto and Other Dwarf Planets Cont’d

Major Moons of Other Planets

• Mercury: No moons• Venus: No moons• Earth: 1 moon ( Luna )• Mars: 2 moons ( Phobos and Deimos )• Jupiter: 63 moons (IO, Europa, Ganymede, and

Callisto)• Saturn: 61 moons ( Titan and Rhea )• Uranus: 27 moons ( Cordelia and Ophehia )• Neptune: 13 moons ( Triton )• The list above contains how many moons they

have and the major moons of each.

Galaxies• There are 3 types of galaxies;

spiral, elliptical, and irregular galaxies.

• Elliptical galaxies a densely-packed, oval- shaped galaxies with little to no dust clouds.

• Spiral galaxies have bulging nucleus’ with at least two arms. They contain great clouds of gas and dust.

• Irregular galaxies are the least common. The stars are spread out unevenly and there is no distinct shape.

• We live in the Milky Way galaxy, which is a spiral galaxy.

Asteroids, Meteoroids, and Comets

• Comets are icy, glowing objects.

• Comets measure from meters to kilometers in diameter.

• Meteoroids are smaller than asteroids and comets.

• When a meteoroid enters Earth’s atmosphere, it becomes

a meteor.

• Once it passes through Earth’s

atmosphere and hits the surface,

it is called a meteorite.

• Asteroids are the largest of the

space objects and they do not glow.

• They can also get caught in orbit.

Asteroid Belt•The Asteroid Belt is in between the inner and outer planets.•This belt contains

a number of asteroids, which have been caught up in orbit.

Gravitational forces, Mass and Distance

• Mass is the amount of matter in an object. Most objects mass is measured in kilograms.

• Weight is the amount of gravity pulling down the mass of an object. This is typically measured in newtons.

• Weight measurements differ on different planets, depending on the gravitational pull.

• Distance is the extent of two objects and places. They’re usually measured in kilometers.

• 2 Rules of Universal Gravitation:1. Gravitational force increases as the

mass of an object increases.2. Gravitational force decreases as

the distance between two objects increases.

Light Years

• Light years don’t measure the speed light travels. It is actually a measurement of how far light can travel in a year, so it is measuring distance.

• The stellar parallax is the difference of direction of two widely spread objects to an observer.

Space Technology

• One tool to study space are telescopes.• There are two types of telescopes; the optical

telescopes and the radio telescopes.• Optical telescopes can be divided into two groups;

refracting and reflecting.• Refracting telescopes uses double convex lenses.• Reflecting telescopes use concave mirrors. An example

of a reflecting telescope is the Hubble Space Telescope.• Radio telescopes study radio waves that travel through

space and easily travel through atmospheres.

• Another tool used to study space is satellites. These tools are objects that can revolve around another object.

• They are controlled by gravity.• There are two types of satellites; communication

satellites and scientific satellites.• Communication satellites provide signal for radio and

TV.• Scientific satellites are used to monitor weather.• Spectroscopes are also another type of space

technology. • They usually use light waves to measure how hot and

the composition of an object.• Spectroscopes are used for planets, galaxies, and stars.

Space Technology Cont’d

• Lastly, a space technology are also space probes.

• Space probes can travel to, on, and from planets.

• They are used to gather information to send back to Earth.

• Space probes can travel the farthest into the solar system than any other space instrument known.

• An example of a space probe is Pioneer 10, which passed Jupiter.

Space Technology Cont’d Pt.2

Some Pretty Interesting Facts

• Did you know? Pluto is also the name of a pet of a popular Disney character.

• Did you know? Pluto’s name was suggested by a young girl who at the moment was studying Greek mythology. She thought that the planet was dark and suggested the god of the underworld, Pluto.

• Did you know? Our solar system is estimated to be 15 trillion kilometers wide.

• Did you know? Scientists believe our solar system formed when a nebula flattened.

• Did you know? Scientists believe that Andromeda consumed another galaxy. They think this from its double center. Scientists think one day it’ll consume the Milky Way!

• Did you know? Venus was named after the Roman goddess of love and beauty.