Ch 1. The Earth And The Universe Flashcards
Earth was formed how many billion years ago ?
4.5 billion years ago
Who gave Big Bang Theory and in which year ?
Georges Lemaitre in 1931
Big Bang took place how many years ago ?
13.8 billion years ago
Nearest galaxy to our Milky Way is ?
Andromeda Galaxy
The Black hole of Milky Way is called ?
Saggitarius A* (or) AY Star
What are the Inner planets/Solid planets/Terrestrial planets of the Solar System ?
Mercury, Venus, Earth and Mars
What are the Outer planets/Gaseous planets/Jovian planets of the Solar System ?
Jupiter, Saturn, Uranus and Neptune - The Gas Giants
What is the surface temperature of the Sun ?
6000°C
What is the interior temperature of the Sun ?
20 Mn.°C
What is Heliosphere ?
The volumn of space constrained by the sun’s magnetic feild is known as the heliosphere
What are solar winds ?
These are the storms of electrically charged gas blowing outward from the sun in every direction
What is Parker spiral ?
The Sun’s rotation causes the magnetic feild streamlines to assume a spiral shape, known as the Parker Spiral
The inner planets are made of ________ elements
Iron, Silicon, Magnesium, Sulfur, Aluminium, Calcium and Nickel
Who declared that Pluto is a Dwarf planet and in which year ?
International Astronomical Union (IAU), in 2006
Which planet is called Earth’s twin ?
Venus
Which planet is called Morning star and Evening star ?
Venus
Largest volcano and the tallest mountain in the solar system is ?
Olympus Mons
Largest moon of Jupiter is ?
Ganymede
The moons of Mars are ?
Phobos and Deimos
Largest moon of Saturn is ?
Titan
Which planets are called the ice giants ?
Uranus and Neptune
Which planets are called the twins of the outer solar system ?
Uranus and Neptune
Period of revolution of Mercury is ?
88 days
Period of revolution of Venus is ?
225 days
Period of revolution of Mars is ?
2 years
Period of revolution of Jupiter is ?
12 years
Period of revolution of Saturn is ?
29 years
Period of revolution of Uranus is ?
84 years
Period of revolution of Neptune is ?
165 years
what is a meteoroid ?
Rocky or metallic fragment of an asteroid, comet or planet
What is a meteor ?
Streak of light seen when a meteoroid heats up in the atmosphere
What is a meteorite ?
meteor fragment that reaches the ground
What is a comet ?
Icy body surrounded by frozen gases. It orbits the Sun
What is Kuiper Belt ?
It is a circumstellar disc in the outer Solar System. It’s one of the places where comets come from.
What are the three largest asteroids ?
Ceres, Pallas and Vesta
What are asteroids?
Rocky body smaller than a planet that orbits the Sun (does not orbit planet like a moon)
Who first predicted the existence of Black holes and in which year ?
Albert Einstein with his general theory of relativity in 1916
Halley’s comet can be seen for every ____ years and it was last seen in ?
75-79 years, 1986
Equatorial circumference (in miles) of the Earth is ?
24,897 miles
Who made the first voyage around the world and in which years ?
Sir Ferdinand Magellan in 1519 - 22
what is revolution speed of the Earth ?
30 Km/sec
What is the rotation speed of the Earth at the equator ?
460 m/sec
When is the Winter and Summer Solstice ?
22nd December and 21st June
When is Spring equinox and Autumn equinox ?
21st March and 21st September
When is Perihelion and Aphelion ?
Early January and early July
Average distance between two latitudes is ?
69 miles
Distance between two longitudes at the equator is ?
69 miles
How many degrees (longitudes) are covered in one hour of Earth’s rotation ?
15