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10 Cards in this Set
- Front
- Back
- 3rd side (hint)
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ASTRONOMY |
The study of the universe and the celestial bodies, gas and dust within it. It includes observations and theories about the solar system, the stars, the galaxies and the general structure of space. |
Universe, celestial bodies |
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UNIVERSE |
The sum total of all matter and energy that exists or has existed both in space and time.The totality of everything that exists, including all matter and energy, the planets, the stars, galaxies and the contents of intergalactic space. |
Sum total of all matter and energy,Totality of everything |
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ASTRONOMICAL SYSTEM OF UNITS |
A system of measurements developed for use in astronomy and was adopted by the International Astronomical Union (IAU) in 1976 and has been significantly updated in 1994 and 2009. It is a tri dimensional system, in that it defines units of length, mass and time only. |
Tri- dimensional (length, mass and time), adopter in 1976, updated in 1994, 2009 |
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Astronomical unit of Time |
The Astronomical unit of time is the day, defined as 86400seconds. 365.25days make up one Julian year. It is denoted by D in astronomy. |
Day, 86400 seconds, 365.25 |
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Astronomical Unit of mass |
The solar mass (1.98892×10 ration power 30 kg) is a standard way to express mass in astronomy, used to describe the masses of other stars and galaxies. It is equal to the mass of sun. |
Solar mass, 1.98892×10 ratio power 30 |
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Astronomical unit of length |
An AU is defined as the average distance between the Earth and the Sun and it is approximately 150million kms or exactly 149,597,870, 700 metres. Astronomical unit, light year and parsec are the units for measuring huge distances. |
Average distance between earth and the sun |
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Light Year |
A light year is the distance that light can travel in one year in a vacuum, which is about 5.8×10 power 12miles or 63,240AU or 9.46053×10 power 12 kms. |
Light, Distance, one year in vacuum |
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PARSEC |
A unit of distance that is equal to 3.26 light years or 3.085678×10 power 13 kilometres. It is the distance at which a star would have parallax of 1sec or arc. |
Unit of distance, 13 kms |
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Origin of the Universe |
The Big Bang theory is the leading explanation about how the universe began. At its simplest, it talks about the universe as we know it starting with a small singularity, then inflating over the next 13.7 billion years to the cosmos that we know today. Much of what we understand about the Big Bang theory comes from mathematical theory and models because current instruments don't allow astronomers to peer back at the universe's birth. |
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Big Bang Theory |
Most astronomers believe that the universe began in a Big Bang about 13.7 billion years ago. At that time, the entire universe was in a bubble that was thousands of times smaller than a pinhead and it was named as singularity. It was hotter and denser than anything we can imagine. Then it suddenly exploded. The universe that we know was born. Time, space and matter all began with a Big Bang. In a fraction of a second, the universe grew from smaller than a single atom to bigger than a galaxy and kept on growing at fantastic rate and is still expanding. |
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