UNIT 1: Origin And Understanding Of Universe Flashcards
One of the earliest and famous hypothesis was given by German philosopher
Immanuel Kant
In 1796 what theory was given by a Mathematician_____________ and what did the theory state
Nebular Hypothesis
Laplace
Sun was rotating, slowly and the formation of planets was associated with a cloud of material related to a youthful sun.
A wandering star approached the sun. A material was extended in cigar shape and got separated from the solar surface. With the moving of the passing star, that separated material from the solar surface continued to revolve around the sun and then got condensed slowly forming the planets;
Who, When, who all supported it, what were the arguments called and why
Chamberlain, Moulton
1900
Sir James Jeans, Sir Harold Jeffery
“Binary theories”-the arguments considered a companion to the sun to have been coexisting, an these arguments are called binary theories
Later, who are revised the nebular hypothesis when and what was it
Otto Schmidt in Russia and Carl Weizacar in Germany, 1950
They argued that the sun was surrounded by a solar nebula containing mostly hydrogen, helium and dust. It also argued that a disk-shaped cloud was formed due tot he friction and collision of particles, and the planets were formed through the process of accretion. However, later scientists took up the problems of the origin of the entire universe and not just that of the earth or the planets.
Who and when provided the evidence suggesting that the universe is expanding or we can say that the distance between the galaxies were found to be increasing, as the time crosses, galaxies will further move apart.
1920 Edwin Hubble
What are the three stages of Big Bang theory
- “Tiny ball “ (singular atom) at one place, which had infinite temperature and density, and an unimaginably small volume
- It exploded. First atom began to form within the first three minutes
- The temperature dropped to 4500K within 300,000 years and the atomic matter emerged
When did Big Bang take place
13.7 Billion years ago
What is an alternative Bigbang theory
Hoyle’s concept of steady state
Why was Hoyle’s concept of steady state regected
Cause it proposed that the universe would be of the same size at any given point of time
Evidence that proves that the Universe is expanding
- Redshift of the objects in the universe
- Hubble law
- The presence of Cosmic Microwave background
Redshift of the objects in the universe
Movement of objects relative to us is measured using the Doppler shift. Done by measuring the frequency of the objects. Light also has a Doppler shift.
Light coming towards us: blue shift
Light going away from us: red shift
Hubble law
This law suggests that the velocity of recession is proportional to the distance of the galaxy from us. Astronomer, Edwin Hubble measured in 1929, the velocities of a large selections of galaxies and found that the majority of galaxies are moving away from us.
Cosmic Microwave background
According to the Bigbang, theory, the early universe was a very hot place and the gas within it get cool, as it expands. This means there should be radiation, meaning the leftover heat from the Big Bang, called the “cosmic microwave background”, or CMB all over the universe. Thus, the existence of the CMB radiation was observed in 1965 by Arno Penzias and Robert Wilson. Presently, the the temperature of the CMB radiation is at 2.725degrees above absolute zero
The existence of CMB was observed in ____ by______. Presently the CMB radiation is at _______
1965
Arno Penzias, Robert Wilson
2.725˚ above absolute zero
_____________ gave rise to gravitational forces
Density differences
Hydrogen gas started accumulating as a huge cloud called
Nebula
Nebula——> ______————> __________———->
Localised clumps of gas
Dense gaseous bodies
Stars
When was stars formed
5-6 billion years ago
Individual galaxies have diameters ranging from
80,000-150,000 light years
What are the types of Galaxies
3 types
- Elliptical galaxies: spheroid or an elongated sphere shape; two dimensional
- Spiral galaxies: Bulge, disk or halo; Milky Way
- Irregular galaxy: No regular shape; asymmetrical
The condensation of gas cloud develops as small circular objects around the core. With the help of the process of cohesion, these small circular objects develop into ________ which comprises a large number of small bodies
Planetesimals
When was the solar system formed
9 billion years ago; 4.5 billion years ago; conflicting sources
Stages in which solar system was formed
- Supernova
- Solar Nebula
- Formation of the sun
- Formation of other planets
Solar system comprises of
- Planets
- Dwarf planets
- Moons
- Asteroids
- Comets
- Meteoroids
Terrestrial plants Jovian planets
First four
Last four
When was Pluto deemed as a Dwarf planet and by whom?
International Astronomical Union
August 24, 2006
Difference between the terrestrial and Jovian planets
When was sun formed and how far is it
5-6 billion years ago
150 million km
How long can sun go further
5 billion years
Layers of the sun
Mercury is not the hottest because
It does not have the atmosphere
Mercury does not have any moons and it takes____ days to complete one rotation and ___ days for one revolution
59
88
Which is the densest planet in the solar system
Earth
Which is the second densest planet in the solar system
Mercury
Size of mercury is _____ of earth
1/3
Mercury has the smallest ______ and ________ of its orbit is the largest of all planets
Tilt
Eccentricity
Mercury has ______ instead of atmosphere and it mainly contains of
Thin exosphere
Oxygen, sodium, hydrogen, helium and potassium
______ is the sixth largest planet
Venus
_______ is the hottest and brightest planet of the solar system and why
Venus
Because its full of carbon di oxide and clouds made up of sulfuric acid
_____ is considered to be an active planet and why
Venus
it has volcanoes
_______is called earth’s twin and why
Venus
Similar in size and density
Which rotates from east-west
Venus, mercury
Uranus too but it rotates on its side
Which planets does not have moon
Mercury and Venus
Venus completes one revolution in
225 days
Venus completes one rotation in
243 days
Which is the fifth largest planet in the solar system
Earth
Water covers _____ percentage of earth’s surface
71
Earth’s atmosphere is composed of
77-nitrogen
21-oxygen
Traces of argon, carbon di oxide and water
Earth revolution
356+1/4 days
Why does earth have seasons
23.5˚angle tilt
Which is the second smallest planet
Mars
_______ is like a cold desert, and half the size of earth
Mars
Why is mars called red planet
Rusty iron
Mars where does water exist
Thin clouds and icy dirt
Whats Mars atmosphere made of?
Carbon di oxide, nitrogen, and argon
______ mass is less than 10 times of the earth
Mars
The Axis of rotation of Mars is tilted at
25.2˚
What are the two moons of mars
Phobos and Deimos
Which is the biggest of the eight planets?
Jupiter
What is the biggest storm found on mars
Great Red Spot
Is Jupiter solid or gas
Its a giant planet, but without a solid surface and it may have a solid inner core
What is the mass of Jupiter relative to other planets?
The mass of the Jupiter is more than twice as that of all the other planets combined.
It has 318 times the mass than that of the Earth
Jupiter is the _______ brightest object after ________, _______, ________.
Fourth brightest object
Sun
The Moon
Venus
Atmosphere of Jupiter consists of
90% Hydrogen
10% Helium
Methane, water ammonia and rock
Jupiter has conformed _______ moon, and the largest one is called ________, which is also the biggest one in the solar system. The three other moons are _____, _________, and __________. All these four are called____________.
67 moons,
Ganymede
Io, Europa, Callisto
Galilean Moons
Why does Jupiter does not have seasons
Because its tilted only at an angel of 3.13˚
What are the bright ringlets of Saturn made of ?
Ice and rock
What is Saturn called
The Ringed Planet
______________ is the farthest planet that can still be viewed with the naked eye.
Saturn
How many moons does Saturn have?
150 moons
What is the largest moon of Saturn?
Titan
What is the second largest moon in the solar system?
Titan
What is the atmosphere of titan made of
Nitrogen
What angle is Saturn tilted at
27˚
Which planet of the solar system, have the lowest density
Saturn
What is the appearance of Saturn and why is it so
Yellow
Atmospheric layer composed of ammonia crystals. Below these crystals, there is a layer of clouds probably made up of water ice, and below that are the layers of sulfur ice and cold hydrogen mixtures.
_________ what are the regular storms experienced by Saturn
Great White Spot
Which is the third largest planet of the solar system?
Uranus
What is Uranus made up of
Small rocky center above which it has water, methane and ammonia fluids
What is Uranus’s atmosphere made of
Methane, hydrogen and Helium
Uranus: ________- in its atmosphere gives it a _______ colour.
Methane
Blue
Which is the only planet know to rotate on its side
Uranus
How many known moons does Uranus have
27 known moons
_________ diameter is 4 times as that of the Earth
Uranus
The Volume of Uranus is _____ times greater than that of the Earth
63
_________ takes the shortest time of all planets to complete one rotation and how much is it
Uranus
17 hours
______ has the coldest atmosphere
Uranus
________ and ______ are called ice giants
Uranus and Neptune
What is the fourth largest planet
Neptune
What planet has the same colour as that of Uranus
Neptune
Neptune has how many rings
6 rings
_________ planet has the highest density of all gas giants
Neptune
How many moons does Neptune have
14
What is the largest moon Neptune has
Triton
Where is asteroid belt located
between mars and Jupiter
Which is the only dwarf planet in the asteroid belt
Ceres
What are the four largest asteroids of the belt
Ceres, Vesta, Pallas, Hygeia
Meteorite
Meteoroid when it enters the earths atmosphere but does not completely burn up and hit the ground is called Meteorite
Which completely Burns are called meteors
What are comets made of
Frozen gases, rock and dust.
Called as snowballs
________ stretches away from the sun
Comet tail
Billions of comets are orbiting our Sun in the ______________ and _________________.
Kuiper Belt
Oort Cloud
Oort Cloud
It is an extended spherical shell of icy objects in the outermost stretch of the solar system. They are considered to be the source of origin of most of the long-period comets
Kuiper Belt
This is a region beyond the 8 planets in the Solar System, extending from the orbit of Neptune. It is like an asteroid belt, but at least 20 times as wide as 20 to 200 times as massive as that of an asteroid belt. Most of the Kuiper Belt objects are mode of frozen volatiles, such as methane , ammonia and water. The Kuiper Belt has three dwarf planets- Haumea, Pluto and Makemake.
What are the three dwarf planets Kuiper Belt has
Haumea, Pluto, and Makemake
How old is Earth
4.5 to 4.6 billion years ago
Which is the fifth largest planet of the solar system
Earth
Earth is the largest among terrestrial plants in terms of
Density, mass and diameter
Earth is of what shape
Gelid
Temperature inside the earth increased due to the
Gradual increase in density
Why does earth have crust, core and mantel
Heavier density elements sinked to the center
Moons gravitational pull, pulled the lighter materials upwards
Evolution of atmosphere
- Loss of primordial atmosphere because of the impact of solar winds
- Cooling of earth resulted in gases and water vapour
- Photosynthesis, volcanic eruptions, gases expelled from earth
Life began to evolve around
3800 million years ago
The process of photosynthesis began around
2500-3000 million years ago
Geological time scale
Moon is also known as
Luna
How is moon believed to be formed
“Giant impact”, “Giant Splat”
A body called their, thrice to the size of Mars collided with earth shortly after it was formed. It separated a part of the earth into space, which continued to orbit around the earth and took the form of moon about 4.44 billion years ago.
The diameter of moon is _____ to that of earth
Quarter
Moon completes revolution in about
27 days
Which is the fifth largest moon in the solar system?
Earth’s Moon
Which is the second brightest object in the sky (when seen from earth)
Moon
The time taken by the moon for successive new moons is ________days
29.5
Tides are caused by
Earth and the Moon
The terrain of moon is primarily made of two types:
A. The highlands that are heavily cratered
B. The Maria that is relatively smooth and younger. The Maria are huge impact craters on the moon’s surface, which comprise about 16% of the surface.
The moon has _____(atmosphere)
No
It is suggested that there might be some water ice in ______________
In deep craters near the South Pole of the Moon as well as the North Pole.
The crust of the moon is about ____________think on average
68km
Unlike earth, moon’s interior is no longer
Active
The moon’s surface mostly covered with a mixture of fine dust and rocky debris produced by meteor impacts called
Regality
