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What makes thunder and lightning? – Weather science

By | 2017-08-20T17:49:37+00:00 August 20th, 2017|Physics|

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 [...]

Supernova – Space – Astronomy

By | 2017-08-19T09:23:22+00:00 August 19th, 2017|Physics|

Supernova from space (thanks to NASA and the Hubble Telescope) 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. Red giant stars have a lot of gravity pulling them inward. Normally they don't collapse inward because the nuclear fusion going on inside them pushes energy outward. That [...]

What are stars made of? Astronomy, physics

By | 2017-10-14T16:41:05+00:00 August 19th, 2017|Physics|

The sun from space 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. Stars formed big clumps of hydrogen and a few helium atoms, the simplest kinds of atoms, and [...]

What are planets? Astronomy – Space science

By | 2017-08-19T01:34:27+00:00 August 19th, 2017|Physics|

The planet Venus from space 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 are made out of the recycled atoms [...]

What is a nebula? Space and astronomy

By | 2017-08-19T01:15:01+00:00 August 19th, 2017|Physics|

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 [...]

The Moon – Astronomy – Physics

By | 2017-08-19T01:10:14+00:00 August 19th, 2017|Physics|

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 [...]

Meteors – Shooting stars – Astronomy

By | 2017-08-18T18:32:54+00:00 August 18th, 2017|History|

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 [...]

Main sequence stars – Astronomy

By | 2017-08-18T17:56:46+00:00 August 18th, 2017|Physics|

A starry sky with the Milky Way galaxy(thanks to Bernd Nies) Nine out of ten stars that you see in the sky are main-sequence stars, and our sun is one of them. Most main-sequence stars probably started out as brown dwarfs, and then succeeded in getting enough mass together to begin a nuclear fusion reaction inside them. It's the energy from this [...]

Jupiter – Planets – Astronomy

By | 2017-08-18T17:46:33+00:00 August 18th, 2017|Physics|

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 [...]