Universe
How old is the universe?
The most recent estimates put the age of the universe at between 13 and 20 billion years.
What is a star?
A star is a gigantic, luminous ball of heated gas, or plasma, held together by gravity.
Can a star turn into a planet?
Yes, a star can turn into a planet, but this transformation only happens for a very particular type of star known as a brown dwarf.
Can you buy a planet?
No, people cannot legally buy planets.
Do all planets have moons
Most of the major planets ( except Mercury and Venus ) have moons.
How big is the universe?
The latest estimates say it is about 156 billion light years across. Since one light year equals about 6 trillion miles.
How many stars are visible in the night sky?
Astronomers have calculated that about 6,000 stars should be seen from the darkest locations.
What planet is made of diamonds?
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How many moons are there?
Earth has one moon, and there are more than 200 moons in our solar system.
Which planet rotates fastest?
Jupiter is the fastest spinning planet in our Solar System rotating on average once in just under 10 hours.
When did the universe begin?
The universe began about 14 billion years ago from an infinitely small, dense, and hot state that expanded rapidly.
What is the brightest star in the sky?
The brightest star visible in the night sky is Sirius, located in the constellation Canis Major.
What planet is full of water?
It is Earth. The only astronomical object known to have bodies of liquid water on its surface.
Why is Mars so hot?
Mars is about 50 million miles farther away from the Sun than Earth. That means it gets a lot less light and heat to keep it warm.
How many planets have been discovered?
More than 4,000 exoplanets have been discovered and are considered "confirmed".
How will the universe end?
It will continue to expand until all of the stars eventually burn out. Eventually, matter will decompose and all that will be left is a cold, dark void. That may sound depressing, but it will take at least 100 trillion years.
How long do stars live?
The life cycles of stars differ greatly and depend mostly on the star's size. Large stars burn their fuel faster while smaller stars burn it more slowly.
What does it rain on Venus?
It does rain sulfuric acid on Venus, nut not on the surface, rather at 25 km high in the atmosphere.
How old is the Earth?
Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years.
What was the first planet discovered?
The first new planet discovered was Uranus.
How many galaxies are there in the universe?
The most recent estimates by astronomers suggest that there are about 200 billion galaxies in the known universe.
Why do stars seem to twinkle?
The twinkling of stars is caused by instability of our atmosphere.
Which is the smallest planet?
Mercury is the smallest planet in our solar system - only slightly larger than Earth's Moon.
Can human live without the Sun?
All plants would die and all animals that rely on plants for food, including humans would die, too.
Why is Earth called a blue planet?
Planet Earth has been called the "Blue Planet" due to the abundant water on its surface.