Universe 7&8 Flashcards
No of solar eclipse a yr
1-2
Mercury also called
Budh
When was universe formed
20 billion yrs ago
No of stars in Milky Way is
100 billion stars, 10^11
Largest moon of Uranus
Titania
Largest moon of Neptune
Triton
Name the five largest moons
Ganymede,titan,Callisto,lo,moon,triton
Light yr
9.46 x 10^12 km
No of moons for Saturn
53- confirmed,9- unconfirmed
Sun gravity …….. times that of 🌏
28
Neptune also called
Varun
Saturn also called
Shani
Comets are found in
Oort belt
Asteroids location
Between mars and Jupiter
No of stars in ursa major, Orion, Cygnus
7,7,5
Venus also called
Shukra
Name 4 satellites discovered by gallileo
Ganymede,Callisto,lo,europa
Main element in mercury
Iron
No of rings in Saturn
3
Uranus size
64 earths
D- 4x that of earth
Largest asteroid
Ceres has a diameter of 1000 km
No of satellites for Neptune
13- confirmed,1- unconfirmed
2 types of lunar eclipse
Penumbral and umbral lunar eclipse
Asteroids are also called
Minor planets
Colour of Uranus and why it’s caused
Blue green,hydrogen and methane
Mercury revolution
88 days
Spinning neutron star
Pulsar
Largest moon of Jupiter
Ganymede
Clouds of Venus are made of
Sulphuric acid
Distance between earth and sun
150 crore km,8.3min
2moons of mars
Phobos and Deimos
Meteors are ……. like objects
Stone
Diameter and mass of mars in comparison to 🌏
D- more than half
Mass-one tenth
Largest moon of Saturn
Titan
Distance of Sirius and alpha centaury from earth
8.7,4.3
No of moons for Jupiter
50- confirmed,17- unconfirmed
Galleys comet appears every ……………yr last seen in ……………… yr
76,1986
No of satellites for Uranus
27
Composition of sun
Hydrogen-93% , helium-5%, heavier elements-2%
Layers of sun from in to out
Core,radioactive zone,convective zone,photosphere,chromosphere,corona
Uranus also called
Arun
Lunar month or sidereal month( time taken by moon to complete one revolution around earth )
27.3 days
Lunar phase or synodic month
29 . 5 days
Observable universe length is
93 billion light yrs
Mass of sun in the solar system
98%
The temperature of the core of the sun is
15 million °c
Surface is 5600 °c
4 types of solar eclipse
Total
Annular
Partial
Hybrid
In total solar eclipse
Sun is completely covered by moon
In annular solar eclipse
The moon is farther away from earth compared to total eclipse , so a bright ring of sunlight is visible
In partial solar eclipse
Sun is partially covered by moon . Covered by penumbral part
What do you mean by magnitude of a solar eclipse
The fraction of part of the sun covered by the moon
Depending on where you are how can you determine an eclipse
If you are in the umbra of moon’s shadow
- total solar eclipse etc.
If you are in umbra of the moon’s shadow
Total solar eclipse
If you are in penumbra of moons shadow
Partial solar eclipse
Total lunar eclipse?
When moon is entirely covered by the umbra of the umbra of the earth
Partial lunar eclipse ?
Only part of the moon is covered by the earths umbra, rest covered by the penumbra
Penumbral lunar eclipse?
the penumbra covers all or part of the Moon, the umbra misses it.
No of galaxies in universe
100 billion
No of stars in galaxies
100 billion
Jovian planets
Jupiter , Saturn , Uranus, Neptune
4 types of satellites based on the type of orbit they are in
Low Earth
Sun-synchronous
Geosynchronous
Geostationary
Geosynchronous satellites
Those satellites placed into orbit so that their period of rotation exactly matches the Earth’s rotation.
Geostationary satellites
Are geosynchronous satellites but follows the equatorial plane of earth
Low earth orbit satellites
For military purposes goes round the eart in 90 minutes
Albert Einstein discovered relation between space and time and discovered the space time continuum
More the space covered the smaller is the rate at which time travels.
It means for an object at rest time will move at a very fast rate and
For a object at motion time will move slowly
If the motion of an object reaches the speed of light
The time will slow down until time stops flowing for the object
And if the speed increases speed of light you will travel to the past
How is flow of time affected by gravity
Stronger the gravitational pull slower the time flows
How can you travel to the past if you can’t reach speed of light
Then through wormholes which connect different space time continuum
How can you travel to the future
By revolving around a place with lot of gravity like black holes and coming back to earth . As for the object travelling around the black hole time will flow very slowly due to the gravity
Expansion of the universe is accelerated by an unknown force called
dark energy
Radiation from black hole
Hawking radiation
The alpha centauri star star system consists of 3 stars -
Alpha Centauri A
Alpha Centauri B (A and B form binary stars)
Alpha Centauri C or called Proxima Centauri
1 parsec is is
3.26 light years
Blue stars are more hot than yellow stars, which is more hot than red stars?
The more hot an object the higher is the frequency of its radiation
1 parsec
3.26 light yrs
One Light minute
18 x 10 raised to 6 km
Sun’s surface temp
6000 °C
Why do stars twinkle
This is because we look at stars through air which is constantly blowing , so we receive their light as unsteady and they appear to twinkle.
Pole star also called
Polaris or Dhruva tara
Pole star always points to the
North
Time taken by light to reach earth
8.3 minutes
Distance btw Earth and Sun
149,400,000 km
Approx 150 million km
Alpha centauri and Earth distance
4.3 light yrs = 40.678 x 10*12
No of galaxies in universe
100 billion (10*11)
Each galaxy has how many stars
100 billion stars
Total no of stars in universe
10*22
Who divided galaxies into 3 categories
Hubble
Hubble ?
American astronomer
3 categories of galaxies
Spiral
Elliptical
Irregular
Spiral galaxies diameter
20,000 to 100,000 light yrs
80% of the total no of galaxies are …… in shape
Spiral
Spiral galaxies have a well defined …. and a large ………… composed of stars
Nucleus
Spheroidal halo
18% of the total no of galaxies are …….. in shape
Elliptical
Elliptical galaxies are divided into …. categories based on ………
8
Flattening
The categories are E0 to E7.
E0 galaxies are nearly spherical
E7 galaxies are highly flattened
Elliptical galaxies are less …… than spherical galaxies
Luminous.
This is because they are mostly composed of red and yellow stars.
Irregular galaxies form … % of the total no of galaxies
2%
In irregular galaxies there are
Lot of dust and blue stars
Milky Way comes from
A Greek word Gala
Diameter of Milky Way galaxy
10*5 light yrs
Central thickness of Milky Way galaxy
10*4 light yrs
Sun is situated at a distance of ……. from the centre of the Milky Way galaxy
2.7 x 10*4 light yrs
Thickness of the Milky Way disc near the sun
1000 light yrs
Interstellar matter
Dust and gases filled between the stars in galaxies
90% of interstellar matter is
Hydrogen (H2)
Mass of Milky Way galaxy
3 x 10*41 kg
All stars complete one revolution through the galactic centre of the Milky Way in
300 x 10*6 years
No of constellations that we know
88
One of the largest star of Orion
Betalgeuse
Orion visible during
Winters in northern hemisphere
Rusa major is visible during
Summers
Rusa minor vs Ursa Major
Ursa minor -
Stars more close and less bright
Last star is the pole star itself
Ursa Minor is visible in
Summers
Cassiopeia is visible in the
Northern hemisphere in winter in early part of night.
No of Moons for different planets
Mars - 2 Jupiter - 63 Saturn - 34 Uranus - 27 Neptune - 13
Mass and diameter comparison of moon and earth
Mass - 1/4
Mass - 1/81
Distance btw Earth and moon
3,84,400
Time taken by the moon to revolve around the Earth
27 days and 7 hrs.
……….. after every new moon day is the full moon day
2 weeks
First Indian satelite
Aryabhatta
Big Bang occurred
15 million yrs ago
Largest asteroid
Ceres whose diameter is 1003 km
Scorpius has how many stars
7
Scorpius visible during
Summers
Brightest star in Orión constellation
Rigel
Betelgeuse is also called
Alpha Oris
Comet’s orbit shape
Elliptical
The belt of the Orion points to the star
Sirius
Ursa Major also called
Vrihat Septarishi
2nd densest planet after Earth
Mars
Dwarf planets e.g.
Ceres
Eris
MakeMake
Haumea
Neptune completes one revolution in
165 yrs
Speed of Neptune’s winds
2000 km/hr
Mars temperature
-120 to 25°C
First spacecraft to visit Mars
Mariner 4 in 1965
In ancient times Venus was thought as 2 different bodies
Eosphorus - morning star
Hesperus - evening star
Saturn was first visited by
NASA’s Pioneer 11 in 1979
Rings of Saturn were made of
Ice and dust.(3)
Uranus revolution period
84 yrs
No of rings for Uranus
13
Brightest ring of Uranus
Epsilon ring
Diameter comparison of Sun and earth
109 times more
Mass comparison of Sun and earth
333,000 times as heavy as Earth
Sunspots have a temp of
4000°C
Areas on surface of the sun where hot gases shoot outward
Prominences
Venus reflects ….. of the light
3/4
Most common planet that appears in east before sunrise and west before sunset
Venus
Saturn’s rings were first observed by
Galileo Galilee
Name comet means
A hairy star
Tail of comets could be as long as
800 million km
Solstices
Spring - 21 March
Summer - 21 June
Autumn - 23 September
Winter - 22 December
1 hectare is how many acres
2.5 acres (approx.)
Distance btw Mercury and Sun
58 million km
Sun present age
5 billion yrs old and is expected to live for another 5 billion yrs
1 hectare is how many acres
2.5 acres (approx.)
Distance btw Mercury and Sun
58 million km
Sun present age
5 billion yrs old and is expected to live for another 5 billion yrs
Diameter of moon
3.475 km
