gravity

/Tag: gravity
20 08, 2017

What makes thunder and lightning? – Weather science

By |2018-04-24T15:20:20-07:00August 20th, 2017|Physics|0 Comments

A bolt of lightning in the sky Hot air and cold air are constantly moving around the Earth, as the hot air rises and the cold air sinks - that's what makes wind. Sometimes as this airmoves around, it gets more exciting than just wind, though. A thunderstorm begins when the wind picks up a lot of water from the [...]

19 08, 2017

Supernova – Space – Astronomy

By |2018-05-31T11:49:31-07:00August 19th, 2017|Physics|0 Comments

Supernova from space (thanks to NASA and the Hubble Telescope) What is a supernova? Supernovas are exploding stars. Red giant stars explode when they have used up their hydrogen and helium fuel, and converted most of their atoms to iron atoms. A red giant star explodes Red giant stars have a lot of gravity pulling them inward. Normally they don't collapse inward because the nuclear [...]

19 08, 2017

What are stars made of? Astronomy, physics

By |2018-05-31T11:49:32-07:00August 19th, 2017|Physics|0 Comments

What are stars made of? This is just one of the stars: the sun from space The first stars The earliest stars probably formed only a few hundred thousand years after the Big Bang that started the universe - maybe about 13.5 billion years ago. Stars are the oldest big objects in the Universe. (More [...]

19 08, 2017

What are planets? Astronomy – Space science

By |2018-09-10T17:46:23-07:00August 19th, 2017|Physics|0 Comments

What are planets? The planet Venus from space Before there were planets For several hundred million years after the Big Bang, there were no planets, only stars. Planets couldn't form until the first stars ran out of fuel and exploded into supernovas, about 14 billion years ago. The supernovas spewed out thousands of tons of carbon, oxygen, iron and other elements into space. Planets [...]

19 08, 2017

What is a nebula? Space and astronomy

By |2018-05-31T11:49:30-07:00August 19th, 2017|Physics|0 Comments

The Eagle Nebula A nebula is a bunch of atoms and molecules floating in outer space, like a cloud of dust. More than one nebula are called nebulae, because -ae is the plural ending in Latin, just as -s is the plural ending in English. Nebula is the Latin word for a cloud. The earliest nebulae formed just [...]

19 08, 2017

The Moon – Astronomy – Physics

By |2018-05-31T11:49:27-07:00August 19th, 2017|Physics|0 Comments

Earth's moon (about 239,000 miles from Earth) (That's almost ten times as far as going all the way around the Earth) Nobody knows exactly how the moon formed, but this is one possibility. After the planet Earth formed (along with the other planets), about four and a half billion years ago, during the Hadean Eon, there were [...]

18 08, 2017

Meteors – Shooting stars – Astronomy

By |2018-05-31T11:49:25-07:00August 18th, 2017|History|0 Comments

Lyrid meteor shower Meteors or meteorites are bits of rock (like granite) and ice - usually a mixture of rock and iron and nickel but sometimes just rock or just iron - from out in space that get sucked into the gravity of the Earth and fall through our atmosphere to the ground. Usually this is because a comet has passed close enough to the Earth for [...]

18 08, 2017

What is mass? Physics

By |2018-05-31T11:49:29-07:00August 18th, 2017|Physics|0 Comments

This truck has a lot of mass. Mass is a measure of the number of atoms in an object combined with the density of those atoms. Usually people measure mass in kilograms. You can tell how much mass something has by measuring how hard it is to get that thing to change directions or slow down. If you're driving a [...]

18 08, 2017

Main sequence stars – Astronomy

By |2018-05-31T11:49:32-07:00August 18th, 2017|Physics|0 Comments

Main sequence stars: A starry sky with the Milky Way galaxy (thanks to Bernd Nies) What is a main sequence star? Nine out of ten stars that you see in the sky are main-sequence stars, and our sun is one of them. (More about the sun) Most main-sequence stars probably started out as brown dwarfs, and then succeeded [...]

18 08, 2017

Jupiter – Planets – Astronomy

By |2018-05-31T11:49:17-07:00August 18th, 2017|Physics|0 Comments

Jupiter from space Jupiter (named after the Roman god Jupiter) is the next planet further out from our Sun after Mars. But Jupiter is much, much further away from the Sun than Mars is. If the Sun were the size of a penny, then Earth would be about six feet away from the Sun. And Mars would be about ten [...]