Space Note 1 and 2

Astronomy

The study of the universe and the objects in it

Astromoner

Studies astromony

Celestial objects

Objects in the sky/space, not in our atmosphere

How long does light take to travel to us in real time

1.5 seconds

Solar system

The sun together with all the planets and other celestial objects. Its held by the sun's gravitation pull

Objects in our solar system

Planets, moons, comets, asteroids.

Moon

Smaller then the earth, has no atmosphere. Closest place towards us

Sun

A star, in the center of our solar system.

Stars

Hot ball of plasma and shines because of nuclear fusion

Nuclear fusion

The process in which the nuclei of atoms fuse and release huge amounts of energy

Inner planets

They are the smallest, up to mars and are rocky planets. Very close to the sun

Asteroid belt

Region of rocky debris that form a ring around the sun. Between Mars and jupiter. Sizes of asteroids range from sand particles to 1000km( s.korea size)

Outer planets

Giant, and made out of gas (gas giant). Jupiter to neptune

Other things in our solar system

Dwarf planets, moons, comets, dust, ice

Astronomical Unit (AU)

A measurement for large distances in space. Equal to the distance from the earth to the sun, or 150 million km.

Light years

A measurement for even larger distances outside our solar system. Equal to how fast light travels in a year. 9.46 trillion kilometers

Closest system to us

Centauri system.

Binary system

Solar system with 2 stars

Nebula

When a star forms

Supernova

When larger stars reach the end of their life cycle.

Galaxy

Contains stars, planets and dust. Galaxies with more dust produce more stars.

How do stars form

From dust and gases present in nebulae

Nebulae

Clouds of dust and gasses

Why do old galaxies not produce stars

Because the older galaxies have already used up all of their dust

Black hole

Forms when a massive star collapses at the end of their life cycle. The gravity is so strong that nothing can escape, even light and time

How do black holes increase in size

By absorbing mass of surrounding stars.

Singularity

Center of a blackhole that’s infinitely dense, gravity becomes infinite and law of physics stop applying

Supermassive blackhole

Massive blackhole. Every galaxy contains one.

Why are stars orbiting nothing in the milky way

They orbit nothing, which means it’s has to be a blackhole

Dark matter

Matter in the universe that is invisible. It does not emit or absorb light, or any kind of radiation

What is the universe made up of

Dark matter is 25%, celestial objects make up lest then 10% and the rest is dark energy.

How is most gravity produced

By dark matter

Star clusters

Concentration of stars in a small region of space

Two types of star clusters

Open and globular clusters

Open cluster

Contains 100s to 1000s of stars. Youngest star groups in a galaxy, still is forming and very spaced

Globular cluster

Contains 100,000s of stars. Together as a glob, in a spherical form because of the star groups. They are the older star groups

Types of galaxy shapes

1. Spiral and barred, 2. Elliptical 3. Irregular

Spiral and barred galaxies

Spiral shaped galaxies that look like a hand going out. Barred ones look the same except look like there’s a bar in the middle. The milky way is a barred galaxy

Central bulge

In the middle of a galaxy, a bump if you at the side. Mainly made up of older stars. New stars dont form in these because of lack of dust and gases

Why are older stars always closer together

They had more time to be affected by gravity

Galactic halo

Surrounds the central bulge, made up of individual stars.

Elliptical galaxies

A galaxy with a elliptical shape, like flattened sphere or football. These are the largest galaxies and contain little dust and no young stars cause they old

How are elliptical galaxies formed

When two sprial galaxies join together, can be barred. These spirals are almost perfect circles so they turn into ellipiods

Irregular galaxies

When the galaxies aren’t the other 2 types.

How do irregular galaxies form

When any type of galaxies collides together, or gets to close to a bigger galaxy which pulls its stars towards it.

Why do galaxies not actually collide

They collide with their gravity, and can merge. The stars dont collide because there’s so much empty space between the two galaxies

Galaxy clusters

Galaxies that are in groups, the milky way is in the local group

Super clusters

Galaxy clusters in groups. Things keep on clustering intill the size reaches a universe.