Asteroids

I think writing about asteroids would sound fun right now. So I'm writing this...
Asteroids are small bodies in our solar-system, that are said to be the leftovers from the formation 4.6 billion years ago. They are rocky objects & have a wide variety of shapes. Some are round, others rather irregular. Their sizes also vary (up to a few hundreds of kilometers across, but most are much smaller).
More than 100,000 asteroids in our solar-system lie in the Asteroid Belt, which is located between Mars & Jupiter. There are many asteroids there. If there weren't any asteroids, the space between these two planets would be greater than the space between any other planets next to each other.
Scientists claim that asteroids (especially the ones in the Asteroid Belt) are the remains of a planet in our solar-system that's already gone now. Thousands of the biggest asteroids have names today.
Eventhough the chances are very small that an asteroid will collide with Earth, they still come close to Earth, like Hermes (came as close as to 777,000 km from the Earth). Anything might happen at any time!

The Solar-System

Here, I decided not to write as much as my previous entries. I will just write about the solar-system as a whole.
The Solar-System as a whole, consists of eight planets and their 172 known moons, asteroids, comets, dust & gas.. And of course, also the dwarf planets & their moons, and other flying bodies.... xp
Most of the bodies of our solar-system travel around the Sun along nearly circular paths, also known as orbits. They all travel in an anti-clockwise direction when you see the whole solar-system from above.
This formation of this solar-system began billions of years ago (that's a VERY long time if you think about it!).. It began when dust & gases came together to form the Sun & other bodies in our solar-system.

Makemake

Makemake is the fourth official dwarf planet here. It was officially called a dwarf planet in July 2005, just about two months before Haumea. It is also a large KBO. Like other planets that orbit our solar-system from the edge, it is also icy & cold (temperature of about -240°C). Because it is vary far away, it also needs a very long time to orbit the Sun once (nearly 310 years!).. O.O And clearly therefore, it is also usually farther from the Sun than Pluto.

It is smaller than Pluto & Eris and its diameter is only between 1,300 km to 1,900 km. That is about three quarters of the size of Pluto. But astronomers haven't discovered any moons for Makemake yet. This is a bit odd, because other large KBO objects have at least one moon. Makemake may be covered with ice, that is made of methane & maybe ethane too.

The surface of this planet is bright, something you would expect from a surface of ice.. But it is also kind of red in colour, which you wouldn't expect....

It may also have an atmosphere (some of the time). When this dwarf planet come closer to the Sun in its orbit, it warms up. This may cause the methane & ethane gases then to form an atmosphere. When it gets further from the Sun, Makemake may cool down. Then the gases would fall onto its surface as 'snow'.. So, the atmosphere's gone again! BUT again, this is only theory. Scientists aren't sure if this happens. This might also happen to Pluto.. Who knows, right?

Like Haumea, it is also named after a god, but not a Hawaiian one. This time, it's a god from the mythology of the Rapa Nui people of the Easter Island (the place with the 'world wonder' statues). He is the god of fertility & the creator of humans in the mythology. As you know, July 2005 is also not long after Easter 2005, therefore, astronomers nicknamed it "Easterbunny" :-0 This is funny ^.^ So, when they had to choose an official name for this planet, they decided to name it after a character from the mythology of Easter Island.

Makemake, with Pluto & Eris (not Ceres!), is also called a "plutoid". These are dwarf planets, like Pluto, that orbit the Sun from beyond the planet of Neptune. Ceres orbits the Sun before Jupiter.

Haumea

Haumea is the fifth official dwarf planet in our solar-system. The four before it are Pluto, Eris, Ceres & Makemake. It was classified as a dwarf planet in September 2008. It is a large Kuiper Belt Object (KBO). It was labelled 2003 EL61.
Haumea is also very cold & icy (the temperature is about -241°C). It orbits the Sun from the far edge of the solar-system too & it takes 285 Earth years to orbit it just once. Usually it is farther from the Sun than Pluto.

Haumea is smaller than Pluto & Eris and it has an odd shape... This odd shape is because the planet is spinning so fast that it is pulled into an ellipsoid (a 3D ellipse). Haumea is 1,960 km across measured from the farthest ends & only about half of that (996 km) from the nearest points across. Therefore also, the days on Haumea are very short. They are less than 4 hours on Earth! It is also dense, which means, most of it is probably just made up of rocks.
Most of the other KBOs probably has more ice on them than Haumea. It has two known moons (like Mars), which were both discovered in 2005. They are called Hi'iaka & Namaka.

Astronomers think that Haumea crashed with another object a long time ago. That would be another reason for the weird shape & also why it spins so fast. The collision might also have caused much ice on Haumea to fly away, so there is less ice now. Its moons may be just some leftovers from the crash.
There are two different groups that might get the credit for discovering this planet. One groups is led by Mike Brown of the California Institute of Technology. The other group is led by José Luis Ortiz Moreno from the Sierra Nevada Observatory in Spain. Haumea was discovered between March 2003 & July 2005. Before it was called Haumea, while it was still coded, it was given the nickname "Santa" by Brown's group because they discovered it around Christmas 2004.
In the Hawaiian mythology, Haumea is the goddess of fertility & childbirth. She had three children named Hi'iaka (Hawaiian sea goddess), Namaka (goddess of hula dancers) & Pele (Hawaiian goddess of volcano & fire). This is where the two names of its moons come from.

Eris

Eris is the largest know dwarf planet in our solar-system. It is also one of the first 3 objects categorized as a 'dwarf planet', with Pluto & Ceres. Eris was first recognized in January 2005. Some astronomers called Eris our "tenth planet" when it was first discovered (in 2003 by Michael Brown, Chad Trujillo, and David Rabinowitz). But after discussions, they decided to have a new category for objects like Eris. It is similar to Pluto, because it is a large sphere of ice & rock.

The temporary name of Eris was "2003 UB(313)", because 2003 was the year they first discovered Eris, and then nicknamed "Xena" before it was called Eris. Eris has a moon called Dysnomia. Before that, it also had a nickname -> "Gabrielle".

The diameter of Eris is about 2,500 km (1,553 miles - a little bit bigger than Pluto), but we can't be sure of it's exact size, because it is too far to see clearly, even with the world's best telescopes!

Here is a picture, so you can see the position of Eris:

Eris' orbit is not like the orbit of other planets or dwarf planets, because its orbit is like a flattened circle. Eris takes 557 years to fully orbit the Sun just once! The surface temperature on Eris is about -250°C..! Cold, isn't it?

Ceres

Ceres is the largest asteroid in the main Asteroid Belt. It was classified as a 'dwarf planet' in 2006, alound with Pluto & Eris. Ceres was discoved by the Italian astronomer (and monk) Guiseppe Piazzi.




The diameter of Ceres is about 975 km (605 miles - about the size in the picture). It is much bigger than the other objects & bodies of the main asteroid belt & contains about a third of the belt's total mass. It orbits the Sun once every 4.6 Earth years. As you already know, its orbit lies between Mars & Jupiter, because it is part of the asteroid belt. A day on Ceres is about 9 hours on Earth, because the asteroid turns on its axis once every 9 hours.

What's the difference between a normal & a dwarf planet?

As many of you may ask, what is actually the difference between a normal planet and dwarf planets??
Here I will tell you that it is a matter of size, with dwarf planets being smaller..

Then you might ask, how big must a planet be to be categorized 'regular' or 'normal' and not 'dwarf??
It's not just the size that matters, but it is also based on different facts.. For example, the history of the object in the solar-system & other properties of the object.

But both, regular & dwarf planets, need to be big enough so that their gravity can form them into a shape of spheres. This means, we can't even call normal asteroids, which are irregular in shape, a dwarf planet. Here, normal planets also have a greater gravity force than dwarf planets.

Dwarf Planets

Now, I will start talking about dwarf planets.. Eventhough I don't know a lot about them.
Dwarf planets are middle-sized bodies in our solar-system. These are little planets and big asteroids. The small bodies are things such as comets & asteroids. The larger planets are the ones I have explained before (except Pluto)..
There are 5 dwarf planets that are already official. As you know Pluto is included. The other dwarf planets are Ceres (the largest asteroid in the asteroid belt between Mars & Jupiter), Eris, Makemake & Haumea. Pluto, Makemake & Haumea orbit the sun from the Kuiper Belt (like the asteroid belt, just outside the outer planets - an icy band of frozen planetoids on the edge of our solar-system). Eris is also a Trans-Neptunian Object (TNO - objects beyond Neptune), but it is further away from the sun than the others.
The term 'dwarf planet' was approved by the International Astronomical Union (IAU) in 2006.

Pluto

As you know Pluto is the smallest and furthest Planet in our Solar-System. Now Pluto isn't called a planet anymore, but a 'Dwarf-Planet'. Pluto is the only Planet that has not been visited by a Spacecraft from Earth. Pluto is a Double Planet. A Double Planet is a Planet that has only one Moon. The Planet and the Moon are orbiting each other. The Moon always faces Pluto on the same side. Pluto always faces its Moon with same side. Moon’s and Pluto’s size are very similar. The Moon is nearly as big as the Planet. To be a Double Planet, the Planet has to be/need to be/need to have: The Planet is only allowed to have one Moon. The size Moon has to be nearly the size of the Planet. They has to face the same face every time. To do that: the Planet has to spin once in the same time as its Moon orbits the Planet once.

Here you can see that Pluto is not much bigger that its Moon.
Some people say that Pluto isn’t a Planet. Pluto is just a Moon from Neptune that got out of its gravitational pull. Other people think Pluto and it Moon is part of the Kuiper Belt. The Kuiper Belt is named after the Astronomer called Gerard Kuiper Those people call them “Super-Comets” or “Ice Dwarfs”. On Pluto there’s only a little of Sun’s heat, there. So, that means that Pluto is mostly made of Ice. Pluto was found in the same way as Neptune was found. The movement of Uranus. This time not Uranus’s movement, Neptune’s movement. Pluto was discovered in 1930 by Clyde Tombaugh. Clyde looked at millions of photographs. Until he found one looking more like a Planet. I don’t think I need to tell you again that, Pluto is not always the furthest from the Sun.

Facts:

Symbol:

Colour: Grey
Diameter: 2,301 km (1,430 miles, 0.18 x Earth’s)
Mass: .013x10^24 kilograms (0.002 x Earth's)
Density: 1,750 kg/m^3
Minimum distance from the Sun: 4.34 billion km (2.7 billion miles)
Maximum distance from the Sun: 7.4 billion km (4.6 billion miles)
Minimum distance from Earth: 4.34 billion km (2.7 billion miles)
Roman and Greek Names: Pluto and Hades

Surface:

Time taken to spin once: 6 days 9hrs (6.4 days)
Temperature: -218°C (360°F)- -229°C (-380°F)
Time taken to go around the Sun once: 248 Years
Moon(s): 1 named, 0 coded & all together 1 Moon. - Charon.

Neptune

Neptune is also just made out of water. Neptune has four Rings. They are called Galle, Leverrier, Plateau & Adams. Nobody can see Neptune’s Rings.

This is the only image I could find on the Internet of Neptune with its Rings (eventhough it's not the real Neptune, only a picture).
Astronomers didn’t look around the skies with their telescopes to find Neptune. It was just that Uranus wasn’t moving it’s orbit around the Sun, the way that Astronomers expected it to. This made the Astronomers come to the Idea, that there was another Planet behind Uranus. French and British mathematicians worked out where Neptune should be found. In 1846 Neptune was discovered by a German Astronomer. Neptune is also made out of hydrogen, helium and methane. This time the methane gives the colour Blue. The winds in Neptune goes up to 600 meters per hour. That is much faster than a Hurricane on Earth. Neptune has a very strange Moon called Triton. Triton is the largest Moon of Uranus. That is not the strange thing. The strange thing about it is that it is the only Moon of any Planet, that orbits in the opposite direction from left. The direction that every Planet in our Solar-System moves (except for one). There is a sign that there may be life, in the past. Europa, the Moon from Jupiter, also gives a sign for life. Triton and Europa may have been warm enough for life. They contain liquid water underneath their Surfaces. As we know there are some animals on our Planet that live on the North and South Pole. Such as Polar Bears, Penguins and Seals. There may be living creatures on Triton and Europa under the Icy Surface.

Facts:

Symbol:

Colour: Blue
Diameter: 49,493 km (30,760 miles, 3.8 x Earth’s)
Mass: 102.4x10^24 kilograms (17.2 x Earth's)
Density: 1,638 kg/m^3
Minimum distance from the Sun: 4.46 billion km (2.77 billion miles)
Maximum distance from the Sun: 4.54 billion km (2.82 billion miles)
Minimum distance from Earth: 4.3 billion km (2.68 billion miles)
Roman and Greek Names: Neptune and Poseidon

Surface:

Time taken to spin once: 19hrs 12min (17.24hrs)
Temperature: -210°C (346°F)- -218°C (-360°F)
Time taken to go around the Sun once: 165 YearsMoon(s): 8 named, 5 coded & all together 13 Moons. I only list the ones without codes. Coded: S/year N(for Neptune)number (one: first, two: second, …) - Despina, Galatea, Larissa, Naiad, Nereid, Proteus, Thalassa & Triton.

The Discovery of Uranus

Here, I will write a little story about the discovery of Uranus (it's true).. Enjoy!

For some centuries, people knew only five Planets in this Solar-System, except for Earth --- Mercury, Venus, Mars, Jupiter and Saturn. In 1781, there was a musician and amateur Astronomer named William Herschel. He was looking at the stars with a telescope, which he made himself, when he found a dim object. He saw it for years. Then, he thought, it must be a Planet. Uranus was like Jupiter and Saturn it has no solid Surface. It is made of hydrogen, helium and methane. Methane gives Uranus that blue-greenish colour. Before we come to what Mr. Herschel found out about the Planet’s Surface, I’ll tell you about the two Moons that he discovered. There are two types of Moons for that Planet. There are Icy Moons and Small Moons. I’ll tell you only about one Moon that he discovered. Well he didn’t really discovere it. It was G. Kuiper who discovered Miranda. I don’t know the two Moons that Mr. Herschel discovered. The Moon I am going to tell you about is called Miranda. Miranda is the smallest Moon of that Planet. It belongs to the Icy Moons group. It has ice cliffs that is 12 miles high and 300 miles across. Miranda looks like as if it has been broken in the past, and put itself together again. It has left very strange and unusual patterns. Now it’s the Planet’s Surface turn. As you go deeper to the Planet’s Surface, you’ll see that there is only water. I don’t know why the water is not frozen. As you go deeper in that great, big ocean it gets warmer. If you get near the center of the Planet it is very hot. Hotter than boiling water.

Uranus

Uranus is one of the Giant Planets, but the smallest Giant Planet. Uranus also have faint Rings (more than one), not Ring. Uranus has nine faint rings. Not one faint Ring (like Jupiter has). The furthest ring is the thickest Ring of all. as you know, Uranus may be a star because. It has so many Rings that it can be a Solar-System by it self. Uranus is the star and the Rings around it can be the orbiting lines. The Rings of Uranus are dark, that is nothing, such as Saturn’s, which are very bright.

On this picture we can only see tree Rings. This picture is also too dark, for the normal Uranus.
Uranus is a very odd Planet. It doesn’t sit like other Planets with the North Pole North, and the South Pole South. It doesn’t sit on the South Pole. It sits on its side (middle line, Equator). That means the North and South Pole of Uranus is sticking of the side.

Facts:
Symbol:

Colour: Blue-Green
Diameter: 51,488 km (32,000 miles, 31 x Earth’s)
Mass: 86.8x10^24 kilograms (14.5 x Earth's)
Density: 1,270 kg/m^3
Minimum distance from the Sun: 2.7 billion km (1.7 billion miles)
Maximum distance from the Sun: 3 billion km (1.87 billion miles)
Minimum distance from Earth: 2.57 billion km (1.6 billion miles)
Roman and Greek Names: Uranus and Uranus
Surface:

Time taken to spin once: 17hrs 14min (17.24hrs)
Temperature: -200°C (-328°F) - -210°C (-346°F)
Time taken to go around the Sun once: 84 years and 4 days
Moon(s): 21 named, 6 coded & all together 27 Moons. I only list the ones without codes. Coded: S/year U(for Uranus)number (one: first, two: second, …) - Ariel, Belinda, Bianca, Caliban, Cordelia, Cressida, Desdemona, Juliet, Miranda, Oberon, Ophelia, Portia, Prospero, Puck, Rosalind, Satebos, Stephano, Sycorax, Titania, Trinculo & Umbriel.