(adsbygoogle = window.adsbygoogle || []).push({}); This is to inform you about what we currently know about space!

*Star Systems and Galaxies

Galaxies- are groups of stars

We live in a galaxy called the Milky Way. Its named that because of its milky white appearance in the night sky.

The Milky Way appears as a straight line in the night sky, because we live "on: the edge and are looking "in" toward the center of the spiral.

There are around 200 billion stars in the Milky Way and it is approximately 100,000 light years across. All of the glowing white stuff are stars and there is probably a large black hole at the glowing hot center of the galaxy!

It takes the Sun 200,000,000 years to revolve around the Milky Way!

Most stars come in pairs or "systems" and are called Binary Stars

Eclipsing Binary stars move around each other and their gravity induced spin gives them away.

Many stars belong to larger groupings called star clusters.

Open Clusters have a loose, disorganized appearance and contain a few thousand stars.

Globular Clusters are large groupings of older stars. Some contain more than a million stars.

Not all of the bright objects we see in the night sky are stars. Some of the objects are galaxies or groups of billions of stars that are just far away. All of the stars we can see are in the Milky Way. We have to look through the stars to see other galaxies. Kind of like looking through a car windshield that has rain drops on it.

Andromeda is our closest neighboring galaxy. It is a spiral galaxy that is 2.2 million light years away. Even so, you can see it with your naked eye if you where to look!

*Earth's Physical Properties

Actually the Earth is sphere.
There are a few reasons we know... 1.) 3rd Century B.C. Aristotle saw the Earth's shadow on the moon during an eclipse. 2.) Early sailors saw the mast of ships returning to port, before the hull. 3.) We have actual photos from satellites.

Measurable properties....

Diameter - If you measure a flat picture of the Earth from space, it is "fatter" across the equator than it is from pole to pole! This is called an oblate sphere.

Circumference - or all the way around the Earth is 39,843 km or 24,000 miles!

Density - the mass of all of the "stuff" that makes up Earth divided by its volume is equal to .52 g/cm^3. It is dense because it is mainly small, rocky and solid.

Earth's axis is tilted about 23.5 degrees off of vertical.
The Earth spins on its axis. This is called rotation. It takes 23 hours and 56 minutes to go around once. We call this Earth's day.

The Earth also goes around or "orbits" the Sun. This motion is called revolution. It takes 365 days 6 hours and 9 minutes to go around once. We call this Earth's year.

The distance from the Earth to the Sun can be used to help measure the distances to other things in our Solar System. It is called one astronomical unit. It equals 93,000,000 million miles or 149,600,000 kilometers.

The Earth also behaves like one big magnet. This magnetic field is caused because the Earth's core rotates. It is tilted 11.5 degrees beyond the axis. Interaction between molecules coming off of the Sun (the solar wind) interacts with the magnetic field causing two things happen. The magnetic field causes the Aurora Borealis or northern lights and even radio interference. Energy from the Sun interacts with the Earth's atmosphere. This Solar Wind is what causes the Aurora Borealis!

*Earth's Seasons

Near the equator, sunlight strikes Earth's surface more directly and is less spread out than near the poles.

This is different heating causes some areas of the Earth to be warmer and some to be colder.

Solstices occur twice a year, when the tilt of the Earth's axis is oriented directly towards or away from the Sun, causing the Sun to appear to reach its northernmost and southernmost extremes. When the Sun is directly in line with Earth's equator, it is called an Equinox which also occur twice a year.

So, Earth has seasons because it is tilted as it revolves around the sun.

*Observing the Solar System

The ancient Greeks were the first culture to really try to "map out" a picture of what our solar system looks like.

We know the names of the planets based on the names that the Romans gave them.

At the time they knew of only six planets.... Mercury, Venus, Earth, Mars, Jupiter, and Saturn...

The Greeks called them "wonderers" which means "wanderers".

140 AD

Ptolemy - came up with the first cosmological model for our solar system.

In Ptolemy's geocentric system, Earth is at the center of the revolving planets and stars.

Nicholas Copernicus, a Polis Priest developed the heliocentric model of the solar system.

Late 1500s

Danish astronomer Tycho Brahe made 20 years worth of very accurate observations.

His observations lead to very accurate sky charts for the motions of the heavens.

Tycho Brahe's assistant Kepler figured out the shape of Mars' orbit. it was indeed not a circle but a flattened out oval called an ellipse. This finalized how the planets actually moved in space.

1610

Galileo Galilei built the first crude telescope.

His observations of Jupiter's Moons and Venus' phases helped him to deduce that the geocentric model must be wrong.

Theses observations began the end of the geocentric model of the solar system.

Adding more later. :wtf:

I have to say.. there's a few spelling mistakes.. But space.. you cant learn space.. Its got infinite number of things to learn. Theres so much to learn. it will take the average human a lifetime to understand how everything about it works. To learn about space.. You gotta learn about earth first.. And once you have done that, you will easily be able to point out planets that could.. 1 day.. Be humanity's hope for life.

Yes I know, I have lots more, but I need my question answered which is at the bottom of the post. Read it. & I fixed the spelling errors, thanks.

If you add more on space I suggest you add time, as their connected. As well as gravity, etc...

You just just hit the Insert new Page button.

I hate space it make me think to much... i wish i new everything about it kay:

We hardly know anything about space, stars... we hardly know anything about stars it's all still theory and visual understanding. We are like a fetus when it comes to our knowledge of space.

Ok, but this will give you a breif idea of what we know know. (Once I add more) Theres no need to dislike.

---------- Post added at 08:43 PM ---------- Previous post was at 08:38 PM ----------



On Safari, when I click it, it does nothing. And on Internet Explorer and Firefox, it doesn't even show up.

I disliked because of the threads poor construction, if you are going to make an informational thread, write out all the information first then copy and paste it back into thread and make the edits necessary.

You on the other hand disliked my comment simply because I disliked your thread, if you would fix your thread up, I tend to remove dislikes and add a thanks instead. (If you have ever paid attention to me on these forums).

Disliking a post simply as a said point of revenge is childish, especially when it is in relations to the thread and is a properly thought post.

Also, no need to make a comment simply because I disliked your thread, it does nothing to you.

What do you mean fix it up? Theres nothing wrong with it, and im trying to add more but the insert new page button isn't working for me. Also, if you don't like it, just keep it to yourself then. Simple as that.