Transcript
ASTRONOMYASTRONOMY
Where are we in the universe?
Where are we in the universe?
We live on Earth, the third planet of our
solar system.
We live on Earth, the third planet of our
solar system.
Our solar system is located in the Milky Way Galaxy, a
collection of 200 billion stars (together with their
solar systems).
Our solar system is located in the Milky Way Galaxy, a
collection of 200 billion stars (together with their
solar systems).
SPIRAL GALAXIES
SPIRAL GALAXIES
Spiral galaxies are galaxies with a central,
dense area and spiraling arms (which are often
sites of star formation).
Spiral galaxies are galaxies with a central,
dense area and spiraling arms (which are often
sites of star formation).
There are two types of spiral galaxies, "S" (normal
spiral) and the less common "SB" (barred
spiral, with an elongated center).
There are two types of spiral galaxies, "S" (normal
spiral) and the less common "SB" (barred
spiral, with an elongated center).
Normal SpiralNormal Spiral
Barred Spiral, with an elongated center
Barred Spiral, with an elongated center
Our Solar System
Our Solar System
Our solar system consists of the sun, planets, dwarf planets (or plutoids), moons, an asteroid
belt, comets, meteors, and other objects. The sun is the center of our solar system; the planets, over 61 moons, the asteroids, comets, meteoroids and other
rocks and gas all orbit the Sun.
Our solar system consists of the sun, planets, dwarf planets (or plutoids), moons, an asteroid
belt, comets, meteors, and other objects. The sun is the center of our solar system; the planets, over 61 moons, the asteroids, comets, meteoroids and other
rocks and gas all orbit the Sun.
The PlanetsThe Planets
The nine planets that orbit the sun are (in order from the
Sun): Mercury, Venus, Earth, Mars, Jupiter (the biggest
planet in our Solar System), Saturn (with large, orbiting
rings), Uranus, Neptune, and Pluto (a dwarf planet or
plutoid).
The nine planets that orbit the sun are (in order from the
Sun): Mercury, Venus, Earth, Mars, Jupiter (the biggest
planet in our Solar System), Saturn (with large, orbiting
rings), Uranus, Neptune, and Pluto (a dwarf planet or
plutoid).
A belt of asteroids (minor planets made of rock and metal) orbits
between Mars and Jupiter. These objects all orbit the sun in
roughly circular orbits that lie in the same plane, the ecliptic
(Pluto is an exception; this dwarf planet has an elliptical orbit tilted
over 17° from the ecliptic).
A belt of asteroids (minor planets made of rock and metal) orbits
between Mars and Jupiter. These objects all orbit the sun in
roughly circular orbits that lie in the same plane, the ecliptic
(Pluto is an exception; this dwarf planet has an elliptical orbit tilted
over 17° from the ecliptic).
The inner planets (those planets that orbit close to
the Sun) are quite different from the outer planets
(those planets that orbit far from the Sun).
The inner planets (those planets that orbit close to
the Sun) are quite different from the outer planets
(those planets that orbit far from the Sun).
The inner planets are: Mercury, Venus, Earth, and
Mars. They are relatively small, composed mostly of
rock, and have few or no moons.
The inner planets are: Mercury, Venus, Earth, and
Mars. They are relatively small, composed mostly of
rock, and have few or no moons.
The outer planets include: Jupiter, Saturn, Uranus, and
Neptune. They are mostly huge, mostly gaseous, ringed, and have many moons (plus
Pluto, which is a dwarf planet that has one large moon and
two small moons).
The outer planets include: Jupiter, Saturn, Uranus, and
Neptune. They are mostly huge, mostly gaseous, ringed, and have many moons (plus
Pluto, which is a dwarf planet that has one large moon and
two small moons).
Small BodiesSmall Bodies
There are other smaller object that orbit the Sun,
including asteroids, comets, meteoroids and dwarf
planets.
There are other smaller object that orbit the Sun,
including asteroids, comets, meteoroids and dwarf
planets.
Asteroids (also called minor planets) are rocky or metallic objects, most of which orbit the Sun in the asteroid belt between Mars and Jupiter.
Asteroids (also called minor planets) are rocky or metallic objects, most of which orbit the Sun in the asteroid belt between Mars and Jupiter.
Comets are small, icy bodies that orbit the sun. They have
very long tails.
Comets are small, icy bodies that orbit the sun. They have
very long tails.
Meteoroids are small bodies that travel through space.
They are stony and/or metallic and are smaller than asteroids. Most are very tiny.
Meteoroids are small bodies that travel through space.
They are stony and/or metallic and are smaller than asteroids. Most are very tiny.
The Sun The Sun
Our sun is a star located at the center of our Solar System. It is a huge,
spinning ball of hot gas and nuclear reactions that lights up the Earth and provides us
with heat
Our sun is a star located at the center of our Solar System. It is a huge,
spinning ball of hot gas and nuclear reactions that lights up the Earth and provides us
with heat
HOW FAR AWAY IS THE SUN?
HOW FAR AWAY IS THE SUN?
Our sun is a medium-sized yellow star that is 93,026,724
miles (149,680,000 km or 1 Astronomical Unit) from the
Earth.
Our sun is a medium-sized yellow star that is 93,026,724
miles (149,680,000 km or 1 Astronomical Unit) from the
Earth.
THE TEMPERATURE OF THE SUN
THE TEMPERATURE OF THE SUN
The Sun's core can reach 10 to 22.5 million°F. The surface temperature is approximately 9,900°F (5,500°C). The
outer atmosphere of the Sun (which we can see during a solar eclipse) gets
extremely hot again, up to 1.5 to 2 million degrees. At the center of big sunspots the
temperature can be as low as 7300 °F (4300 K, 4000 °C). The temperature of the
Sun is determined by measuring how much energy (both heat and light) it
emits.
The Sun's core can reach 10 to 22.5 million°F. The surface temperature is approximately 9,900°F (5,500°C). The
outer atmosphere of the Sun (which we can see during a solar eclipse) gets
extremely hot again, up to 1.5 to 2 million degrees. At the center of big sunspots the
temperature can be as low as 7300 °F (4300 K, 4000 °C). The temperature of the
Sun is determined by measuring how much energy (both heat and light) it
emits.
AGE OF THE SUNAGE OF THE SUN
The Sun formed 4.5 billion years ago, as the solar
system coalesced from a cloud of gas and dust.
The Sun formed 4.5 billion years ago, as the solar
system coalesced from a cloud of gas and dust.
STUDYING THE SUNSTUDYING THE SUN
Astronomers study the Sun using special instruments. Scientists
analyze how and why the amount of light from the Sun varies over time, the effect of the Sun's light on the Earth's climate, spectral lines, the
Sun's magnetic field, the solar wind, and many other solar phenomena. The outer regions of the Sun (the corona) are studied during solar
eclipses.
Astronomers study the Sun using special instruments. Scientists
analyze how and why the amount of light from the Sun varies over time, the effect of the Sun's light on the Earth's climate, spectral lines, the
Sun's magnetic field, the solar wind, and many other solar phenomena. The outer regions of the Sun (the corona) are studied during solar
eclipses.
STARSSTARS
Each star in the sky is an enormous glowing
ball of gas. Our sun is a medium-sized star.
Each star in the sky is an enormous glowing
ball of gas. Our sun is a medium-sized star.
Stars can live for billions of years.Stars can live for billions of years.
A star is born when an enormous cloud of hydrogen gas collapses until it is hot enough to
burn nuclear fuel (producing tremendous amounts heat and radiation). As the nuclear fuel
runs out (in about 5 billion years), the star expands and the core contracts, becoming a
giant star which eventually explodes and turns into a dim, cool object (a black dwarf, neutron
star, or black hole, depending on its initial mass). The largest stars have the shortest life
span (still billions of years); more massive stars burn hotter and faster than their smaller
counterparts (like the Sun).
A star is born when an enormous cloud of hydrogen gas collapses until it is hot enough to
burn nuclear fuel (producing tremendous amounts heat and radiation). As the nuclear fuel
runs out (in about 5 billion years), the star expands and the core contracts, becoming a
giant star which eventually explodes and turns into a dim, cool object (a black dwarf, neutron
star, or black hole, depending on its initial mass). The largest stars have the shortest life
span (still billions of years); more massive stars burn hotter and faster than their smaller
counterparts (like the Sun).
There are larger groups of stars, called clusters.There are larger groups of stars, called clusters.
WHY ARE STARS HOT AND BRIGHT?
WHY ARE STARS HOT AND BRIGHT?
Nuclear Fusion and Nucleosynthesis
Nuclear Fusion and Nucleosynthesis
Stars are giant nuclear reactors. In the center of stars, atoms are taken apart by
tremendous atomic collisions that alter the atomic structure and release an enormous
amount of energy. This makes stars hot and bright. In most stars, the primary reaction
converts hydrogen atoms into helium atoms, releasing an enormous amount of energy.
This reaction is called nuclear fusion because it fused the nuclei (center) of atoms
together, forming a new nucleus. The process of forming a new nucleus (and
element) is nucleosynthesis.
Stars are giant nuclear reactors. In the center of stars, atoms are taken apart by
tremendous atomic collisions that alter the atomic structure and release an enormous
amount of energy. This makes stars hot and bright. In most stars, the primary reaction
converts hydrogen atoms into helium atoms, releasing an enormous amount of energy.
This reaction is called nuclear fusion because it fused the nuclei (center) of atoms
together, forming a new nucleus. The process of forming a new nucleus (and
element) is nucleosynthesis.
WHAT IS THE CLOSEST STAR?
WHAT IS THE CLOSEST STAR?
The closest star to us is the sun! Other than that, the closest star is Proxima Centauri, aka Alpha Centauri C (the dimmest star in
the Alpha Centauri system). Proxima Centauri is 4.3 light-years from the Sun. It has an absolute magnitude of 15.5.
The closest star to us is the sun! Other than that, the closest star is Proxima Centauri, aka Alpha Centauri C (the dimmest star in
the Alpha Centauri system). Proxima Centauri is 4.3 light-years from the Sun. It has an absolute magnitude of 15.5.
WHY DO STARS TWINKLE?WHY DO STARS TWINKLE?
The scientific name for the twinkling of stars is stellar
scintillation (or astronomical scintillation). Stars twinkle when
we see them from the Earth's surface because we are viewing
them through thick layers of turbulent (moving) air in the
Earth's atmosphere.
The scientific name for the twinkling of stars is stellar
scintillation (or astronomical scintillation). Stars twinkle when
we see them from the Earth's surface because we are viewing
them through thick layers of turbulent (moving) air in the
Earth's atmosphere.
What is Astronomy?
What is Astronomy?
That's easy. Astronomy is the study of Outer
Space.
That's easy. Astronomy is the study of Outer
Space.
Why should we study Outer Space?
Why should we study Outer Space?
We study Outer Space because we are part
of it. That's right. You are part of outer
space, everything is.
We study Outer Space because we are part
of it. That's right. You are part of outer
space, everything is.
THAT’S ALL THANK YOU!THAT’S ALL
THANK YOU!
top related