MAANASI What do we know about the Earth Solar System and Universe?

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MAANASI What do we know about the Earth Solar System and Universe?

Black Holes

Scientists estimate there are ten million to 1 billion black holes in the milky way alone. (science.nasa.gov)

Black Holes aren't in the Solar System. There are in space. A Black Hole, is a region of spacetime, where gravity is extremely strong that nothing can escape from it. "The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. (Wikipedia)

Reasons Humans had For Studying Space

In general, humans don't like not knowing things. We are adventurous and want to find answers. So we make up our own stories and theories as to why things are there and how they happened. In this case, it's for the Universe.

Many cultures had theories on how the universe was made.

First Nations, Metis and Inuit cultures made their own theories/explanations for the formation of the Solar System and Universe. Season wheels have been found to depict annual changes. Harvest and planting for crops. When to hunt and cultivate fish stocks.

Ptolomy: Earth is spherical as not everyone records a solar eclipse at the same time. Planets orbits are complex epicycles.

Around the 11th century. Islamic astronomers confirmed the idea of The Earth being the centre of the Universe. Explained more about epicycles.

Ancient Greeks Identified that objects in the sky appear with predictable regularity. Was thought the solar system was spherical. The Moon was reflecting off of the light of the Sun.

Also believed the Moon is closer to the Earth than the Sun. Comets are formed by collisions of planets. Motions of planets are controlled by the mind. (Anaxagoras) Motion of planets is caused by a fire at the centre of the Universe. The Moon, Sun and planets orbit the Earth. (Study of Pythagorus)

Chinese had two theories. One: Earth is within heaven, heaven acts like a lid. Two: Earth floats on the water heaven contains.

Ancient Babylonians believed the universe revolved around heaven and Earth.

Bronze age cultures made a bronze disc the represent the cosmos. Nebra sky disc had a crescent Moon, Sun, 32 stars and 3 arcs describing the sunset and sunrise in summer and winter.

Ancient Mayans has studied the phases of the Moon. recurrence of eclipses, and appearance of Venus. And carefully calculated phases of Pleiades, the Sun, Moon, Venus, Jupiter, Mars and Saturn.

Make up their own theories and stories. There were many conceptions of the universe held by different civilizations and cultures.

Glooscap: Indigenous believed that Glooscap made the world habitable for humans by arranging and creating landforms, giving animals their attributes, and eliminating monsters.

Union of two beings: In Taoist, Prakrti and Brahman stories.

From pre-existing materials: As in the Norse and Babylonian

Supreme Creator: One being created all that is known> In Judeo-Christian, Egyptian, Aztec, and Buddhist.

Great Egg: In Finnish, Chinese and Indian stories, they believed that the Universe hatched from one egg.

Sun

The Sun's size is massive. One million Earths can fit into the Sun.

Composition: In terms of atoms. The Sun is composed of 91% Hydrogen and 8.9% helium. In terms of mass. The Sun is about 70.6% Hydrogen and 27.4% helium.

Moon

Earth, Moon and Sun are held together by Gravity.

Has 8 Phases: In which are a result from the angle the moon makes with the sun. The phases of the Moon depend on how much of the Sun's light is covering the Moon.

These phases also have spiritual meanings. Eg. Waning crescent. The Moon must wax (grow larger) and wane (grow slimmer). Cycle repeats every month.

New Moon: When none of the Sun's light is covering the Moon.

Full Moon: When all of the Sun's light is covering the Moon.

The moon reflects the Sun's light. It doesn't have a light of it's own. So it's a natural satellite.

Theory on how it was formed: A Mars-sized body hit Earth, and made a debris-ring that slowly collected into a single natural satellite. However, there are many beliefs on how the Moon was made.

Earth

Earth is one of the rocky planets. So it is believed that it was formed by the process of accretion from the densest chunks of matter.

Earth is the third planet that orbits the sun. The Moon orbits the earth. It is the only astronomical planet known to have life.

Universe

"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." -Douglas Adams

The universe is expanding by the day.

Everything in space is in the universe.

Universe is extremely massive. The earth and planets are so tiny compared to the size of the Universe.

The universe is believed to have formed due to the Big Bang. Which is the universe expanding from singularity 14 billion years ago.

Star

Death of Star: When a star has burned all of its Hydrogen fuel, it becomes a Red Giant. Which can be millions of metres across, large enough to swallow Mercury and Venus. "After puffing off its outer layers, the star collapses to form a very dense white dwarf." (www.esa.int)

This gravity causes regions of greater density to form within the nebula over time. Dense regions continue to pull gas from less dense regions for 10 million years. This forms a protostar.

Protostar: Mass and gravity of the protostar increase, so it becomes a tightly packed sphere of matter drawing more matter into its core. The force of gravity eventually causes the atoms in the core of the protostar to become tightly packed that the pressure in the core rises, and nuclear fusion begins.

They form by parts of nebulas collapsing on themselves. When a certain density is reached, gravitational forces pull the gas and dust particles making clumps form in the main cloud of the nebula.

Comet

Appear every 5-10 years.

Outgassing: When the comet begins to release gases. Which produces a visible atmosphere or coma.

"Cosmic snowballs of frozen gases., rock and dust that orbit the sun." (asteroids-comets-and-meteors)

Natural Sattelite

A natural satellite, is a body that orbits another body (planet/dwarf planet) in space. (oxfordlanguages)

Artificial Satellite

An artificial satellite, is an artificial body placed in orbit around the Earth tot collect information or for communication. (oxfordlanguages)

Celestial Objects within the Solar System

Celestial Objects: Or astronomical bodies. Stuff that fills empty space of the Universe. It can be Planets, Stars, Moons. But there's other celestial objects in the universe.

Properties: They can be glowing. Such as stars, and galaxies. Celestial objects come in different sizes. Galaxies will be much bigger than stars.

Location, Appearance, Motion: Stars move. They are so far away, so their appearance won't show their movement. They appear as tiny glowing specks in the night sky.

Examples: -Planetary Systems -Nebulae -Star Clusters -Galaxies

Astronomical Phenomena:

Examples: -Eclipse -Stars forming -Supernova explosions

How they can be best observed from Earth: A lot of celestial objects can be observed from Earth by looking at the sky.

Solar System

Solar Nebula Theory-How the solar system was formed. Sun was formed like any other star. In planetary nebulae a lot of other material is there. Dust, Ice, Rock. called the protoplanetary disk. Just as the sun forms, accretion occurs.

Evidence: Most of the planets aside from Venus and Uranus rotate in the same direction. All planets can be found orbiting the Sun on the same flat plane. Rocky planets and asteroids have a similar cross section. Observations of distance planetary nebula show the same stages of formation. Computer simulations based on observed data create a solar system almost identical to the existing one.

Problems with the Model: Cannot yet be explained how material pulled towards a star or planetesimal loses enough momentum to change its orbit.

Explanation of the mechanism of how particle clumps turn into planetesimals is unclear. Timescale for formation of the gas giants are unclear. Gas giants can migrate inwards as they interact with the protoplanetary disk.

Planets Formation: Process of accretion from densest chunks formed four of the planets. Mercury, Venus, Earth, Mars. When planetesimals reach about 1 km in diameter, they begin to accrete each each other, and continue growing larger. Estimated there were only 100 or so planetesimals in our solar system, when it began to form. Other 4 larger planets formed from gases, which are much less dense, therefore found much further away from the Sun than the rocky ones. Process of formation is fairly the same.

Major Components: Other than planets, the solar system consists of -Sun -Moon -Comets -Dozens of Moons -Millions of asteroids -Dwarf Planets. eg. Pluto

A lot of solar system models show the planets very close together. In comparison to how massive the universe is, the planets are very small and far away from each other.

The Solar System has eight planets: -Mercury -Venus -Earth -Mars -Jupiter -Saturn -Uranus -Neptune All orbit the Sun.