Astrokids

This is a very hard question, as it happened so long ago that nobody existed yet, and there is very little evidence to tell us for sure! So I can’t tell you a definite answer, only the leading theory which I copied from www.kidsastronomy.com.

How Did The Solar System form?

Scientists believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter in this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle.

At the center of this spinning cloud, a small star begin to form. This star grew larger and larger, as it collected more of the dust and gas that were collapsing into it.

Further away from the star that was forming in the center were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun, while the smaller clumps became the planets, minor planets, moons, comets, and asteroids.

A Great Storm

Once ignited, the Sun’s powerful solar winds began to blow. These winds, which are made up of atomic particles being blown outward away from the Sun, slowly pushed the remaining gas and dust out of the Solar System.

With no more gas or dust, the planets, minor planets, moons, comets, and asteroids stopped growing. You may have noticed that the four inner planets are much smaller than the four outer planets. Why is that?

Because the inner planets are much closer to the Sun, they are located where the solar winds are stronger. As a result, the dust and gas from the inner Solar System was blown away much more quickly than it was from the outer Solar System. This gave the planets of the inner Solar System less time to grow.

Another important difference is that the outer planets are made up largely of gas, and water, while the inner planets are made up almost entirely out of rock and dust. This is due to the same reasons. As the outer planets grew larger, their gravity had time to accumulate massive amounts of gas, water, as well as dust.

Where Should We Colonise In Our Solar System?

Imagine that Earth is overcrowded. There isn’t enough room for all of us to live here. We will have to find another place in our solar system to live or else people will start to die!

… continue reading this entry.

The ‘Clever Cookies’ have completed their research and recommendations about space places to colonise. You can find their work here. We will let you know which place wins the race to be colonised first!

‘Tides’ are the way that the water level (usually in the ocean) goes up and down because of things in space – the moon and the sun. This is different to waves and surges caused by the weather.

In this picture you can see the same place, first at low tide, then high tide.

Basically,the moon’s gravity pulls the water towards it a little as a ‘bulge’, while at the same time, the way the Earth spins makes another bulge on the opposite side. These two bulges are the places where high tide happens. The other two sides of the planet will have lower water levels. These are where the low tide happens. As the Earth spins once each time, different parts of the world pass through the two bulges making the tides (for example once in the morning, once in the evening).

Here’s a little movie that might explain it better. If you try and watch it from school, you will need a teacher to log on for you, but it should work just fine from home!

THE night sky will sparkle with “falling stars” today and tomorrow as Earth passes through a trail of dusty debris from the Swift-Tuttle Comet, say scientists.

The light show, called the Perseid meteor shower, kicks off each year in late-July and increases in intensity, peaking a couple of weeks later.

On a clear night in a dark sky “you should see dozens of meteors per hour”, said Bill Cooke of NASA’s Meteoroid Environment Office.

East Asia is best placed to see the shower at its most intense moment, which is predicted for 4am AEST August 13, according to the US publication Sky and Telescope (skyandtelescope.com).

The meteors are also active for many days before and after this date, though the light reflected by a waning quarter moon may obstruct the view somewhat.

The Perseids occur when Earth runs into a trail of dust and pebbles deposited by the comet Swift-Tuttle in its 130-year orbit around the Sun.

This debris strikes the upper atmosphere at around 60km per second, a speed that causes it to burn up into a white-hot streaks. Bigger chunks can be seen as fireballs.

Meteor showers vary from year to year, depending on the amount of debris. In the early 1990s, there were several spectacular Perseid shows, with bursts of several hundred meteors per hour.

Meteors are named after the constellation from which they seem to appear – in this case, Perseus, a northern constellation lying east of Cassiopeia and north of Taurus.

FROM:  http://www.news.com.au/story/0,,25918247-1702,00.html

A comet is a ball of frozen rock, ice and dust from the furthest edges of our solar system – a ring of asteroids called the Kuiper Belt, or the Oort Cloud, which marks the very edge of our solar system. They orbit the sun, like planets do, but they are usually so far away we don’t see them, or only see them once.

When they get sucked in to the inner solar system, closer to the sun, they start to melt, leaving a beautiful tail. Some bits of rock fall off and turn into meteors or asteroids.  If a comet is travelling towards the Sun then the tail will follow behind, but if the comet is travelling away from the Sun the tail will be in front of the comet.

Many of our asteroids are actually ‘dead’ comets.

The lovely little sparkles we see in the sky at night, and the great big source of heat and light we call the Sun are the same thing. They are balls of gas or plasma which ’shine’ because of thermonuclear reactions inside them which release light and heat.

Stars change a lot during their lives. They begin as a protostar, turn into a T Tauri Star and then a Main Sequence Star, Red Dwarf, or Supergiant. As it ages it will become a Red Giant, and then a White Dwarf, or go supernova and become a neutron star or black hole.

T Tauri Star – As the protostar collapses, it starts to make energy and burn brightly. They stay this way for about 100 million years.

Main Sequence Star – These are ‘adult’ stars, like our Sun. They can be different size, mass, or brightness but are all changing the gas hydrogen into the gas helium, which makes lots of energy.

Red Dwarf Star – These are smaller, cooler Main Sequence Stars that can last up to 10 trillion years. Smaller again are brown dwarfs, and black dwarfs.

Supergiant Stars – These are the biggest stars which burn fast and have a short life of only a few million years. They will always end in a supernova!

Red Giant Star – At this stage, the star is starting to age and die. It won’t make new gas any more and will burn up all the leftover gas, which makes it grow bigger and bigger. It can get as big as 100 times bigger than it was as a Main Sequence Star! It will last only a few million years before it runs out of fuel.

White Dwarf – Once the star runs out of gas, it starts to collapse and cool down over hundreds of billions of years.

Neutron Stars and Black Holes – Large stars won’t become White Dwarfs. Instead, they will explode as a supernova and become a neutron star, or for really massive stars, the supernova will turn it into a black hole. Since neutron stars and black holes can’t yet be seen with Earth technology, here is a picture of the leftovers from a supernova.

In 2006, astronomers changed the definition of a planet. They did this mainly because they kept discovering things in our solar system which were bigger than Pluto. They didn’t believe these new things should be called planets, but since they were bigger than Pluto, it meant Pluto couldn’t be called a planet any more. Most of these objects were past Neptune in an area called the Kuiper Belt.

Now, to be a planet an object must:

• Orbit (go around) the sun
• Be big enough that it’s gravity will make it round shaped
• Have a clear orbit path with nothing else the same size at the same distance from the sun.

Dwarf planets only need to meet those first two points, but not the third. There are about 70 space objects in our solar system which may be called dwarf planets, but so far only 5 objects have been classified that way:

• Pluto - formerly thought of as a planet, with a moon (Charon) that shares it’s atmosphere, and 2 smaller moons. Named after the Greek god of the underworld.
• Ceres - the biggest object in the asteroid belt between Jupiter and Mars, it has been called a planet, comet, and an asteroid. Named after the Roman goddess of growing plants and harvest.
• Eris - first called Xena, after a TV show, it has one known moon called Dysnomia and is further out than the Kuiper belt. It’s discovery was the reason for the ‘dwarf planet’ classification to be made.  Named after the Greek goddess of strife and discord.
• Makemake - Part of the Kuiper belt, it has no moons and a reddish brown colour.  Named after a Polynesian creator god.
• Haumea - Part of the Kuiper belt, it has two moon called Hi’iaka and Namaka and a strange shape like a fat cigar. It was named after the Hawaiian goddess of childbirth.

Pluto is a dwarf planet (or plutoid) that usually orbits past the orbit of Neptune. It was classified as a dwarf planet in 2006; before that it was considered to be a planet, the smallest planet in our solar system. It has a moon called Charon.

WHAT ELSE CAN YOU DISCOVER ABOUT PLUTO (AND CHARON)? POST YOUR PLUTO (AND CHARON) FACTS IN THE COMMENTS BELOW.

Neptune is a giant, frigid planet with a hazy atmosphere and strong winds. This gas giant is orbited by 13 moons and narrow, faint rings arranged in clumps. Neptune’s blue colour is caused by the methane in its atmosphere.

WHAT ELSE CAN YOU DISCOVER ABOUT NEPTUNE? POST YOUR NEPTUNE FACTS IN THE COMMENTS BELOW.

Uranus is a huge, icy planet covered with clouds and is encircled by a belt of 11 rings and 22 known moons. Uranus’ blue color is caused by the methane in its atmosphere.

WHAT ELSE CAN YOU DISCOVER ABOUT URANUS? POST YOUR URANUS FACTS IN THE COMMENTS BELOW.

Saturn is the second-largest planet in our solar system. It has beautiful rings that are made mostly of ice chunks (and some rock) that range in size from the size of a fingernail to the size of a car.

WHAT ELSE CAN YOU DISCOVER ABOUT SATURN? POST YOUR SATURN FACTS IN THE COMMENTS BELOW.

Jupiter is the fifth and largest planet in our solar system. Its most prominent features are bands across its latitudes and a great red spot.

WHAT ELSE CAN YOU DISCOVER ABOUT JUPITER? POST YOUR JUPITER FACTS IN THE COMMENTS BELOW.

Mars, the red planet, is the fourth planet from the sun and the most Earth-like planet in our solar system. It is about half the size of Earth and has a dry, rocky surface and a very thin atmosphere.

WHAT ELSE CAN YOU DISCOVER ABOUT MARS? POST YOUR MARS FACTS IN THE COMMENTS BELOW.

Earth is a small, rocky planet which supports a variety of life! As far as we know, Earth is unique from all other planets in this respect.

WHAT ELSE CAN YOU DISCOVER ABOUT EARTH? POST YOUR EARTH FACTS IN THE COMMENTS BELOW.

Venus is a small, rocky planet blanketed in a thick layer of yellowish clouds. These clouds are not made of water (like the ones here on Earth). Instead, they are formed from a poison called sulfuric acid.

WHAT ELSE CAN YOU DISCOVER ABOUT VENUS? POST YOUR VENUS FACTS IN THE COMMENTS BELOW.

Mercury is a small, rocky planet – much like our Moon. It is covered with craters and has changed very little from when it was first formed. You can see Mercury with a pair of binoculars or even the naked eye. Because it is always very near the Sun, Mercury may be hard to see in early evening skies.

WHAT ELSE CAN YOU DISCOVER ABOUT MERCURY? POST YOUR MERCURY FACTS IN THE COMMENTS BELOW.

Like all the other planets in our Solar System, the Earth revolves around a medium-sized star. This star provides all the energy necessary to sustain life on Earth. Our Sun is not unique in the universe. It is a common middle-sized yellow star which scientists have named Sol. This is why our system of planets is called the Solar System.

WHAT ELSE CAN YOU DISCOVER ABOUT THE SUN? POST YOUR SUN FACTS IN THE COMMENTS BELOW.

Welcome, fellow astro-researchers!

I have just begun a new quest of discovery into the wonders of our solar system. It’s only early days yet, but perhaps, astrokids, you may be able to make use of my study notes in your own planetary research!

I can’t wait to hear about your discoveries, and to share my own! Good luck!

• NASA
• Nine Planets
• Astronomy for Kids
• National Geographic Science
• ESA Kids