Stars and planets
Discussion
What's the difference?
My son asked me last night in front of a friend, I said that stars were planets. My friend insisted that planets are not visible to the human eye without magnification. I then asked if they were balls of ignited nuclear fuel, and he stack dumped. We all agreed that we don't know, and I have a disappointed son.
My son asked me last night in front of a friend, I said that stars were planets. My friend insisted that planets are not visible to the human eye without magnification. I then asked if they were balls of ignited nuclear fuel, and he stack dumped. We all agreed that we don't know, and I have a disappointed son.
Stars are balls of nuclear fusion reactions, mainly hydrogen and helium, but lots of other stuff too.
Planets are a mixture of heavier elements - orbiting stars. They are not the same!
Edited to add, Mercury, Venus, Mars, Jupiter and Saturn are all easily visible to the naked eye.
Planets are a mixture of heavier elements - orbiting stars. They are not the same!
Edited to add, Mercury, Venus, Mars, Jupiter and Saturn are all easily visible to the naked eye.
Edited by Puggit on Tuesday 20th January 15:23
MaxAndRuby said:
What's the difference?
My son asked me last night in front of a friend, I said that stars were planets. My friend insisted that planets are not visible to the human eye without magnification. I then asked if they were balls of ignited nuclear fuel, and he stack dumped. We all agreed that we don't know, and I have a disappointed son.
Huh? Are you serious? You said stars were planets?My son asked me last night in front of a friend, I said that stars were planets. My friend insisted that planets are not visible to the human eye without magnification. I then asked if they were balls of ignited nuclear fuel, and he stack dumped. We all agreed that we don't know, and I have a disappointed son.
Are you serious ?
Assuming you are: A main-sequence star is a burning sphere of gas (plasma) and usually produces visible light.
A planet usually orbits a star and doesn't produce light as it is not burning.
Some planets, like Jupiter, Saturn, Neptune and Uranus are composed of all or mainly gas but don't contain enough mass for gravity to collapse and compress the gas enough to trigger ignition. These 'gas giant' planets are essentially failed stars.
You can see planets with the naked eye due to starlight reflected off them. Venus can sometimes be seen clearly and is often mistaken for a very bright star. Mars can also be seen fairly easily and is identified by its faint red colour.
Assuming you are: A main-sequence star is a burning sphere of gas (plasma) and usually produces visible light.
A planet usually orbits a star and doesn't produce light as it is not burning.
Some planets, like Jupiter, Saturn, Neptune and Uranus are composed of all or mainly gas but don't contain enough mass for gravity to collapse and compress the gas enough to trigger ignition. These 'gas giant' planets are essentially failed stars.
You can see planets with the naked eye due to starlight reflected off them. Venus can sometimes be seen clearly and is often mistaken for a very bright star. Mars can also be seen fairly easily and is identified by its faint red colour.
Edited by lunarscope on Tuesday 20th January 15:31
Puggit said:
Stars are balls of nuclear fusion reactions, mainly hydrogen and helium, but lots of other stuff too.
Planets are a mixture of heavier elements - orbiting stars. They are not the same!
Edited to add, Mercury, Venus, Mars, Jupiter and Saturn are all easily visible to the naked eye.
Planets are a mixture of heavier elements - orbiting stars. They are not the same!
Edited to add, Mercury, Venus, Mars, Jupiter and Saturn are all easily visible to the naked eye.
Edited by Puggit on Tuesday 20th January 15:23
V8mate said:
Isn't our Sun a star?
And can't you see Venus with the naked eye?
Yes our sun is a star.And can't you see Venus with the naked eye?
The planets are only visible because of the reflected light from the sun.
Without the sun you would not be able to see them (we would not be here at all but that's incidental).
Puggit said:
Galileo said:
You'd be amazed at how many people know so little about the subject. I had to explain to Mrs g that the light coming from the moon was reflected from the sun. She thought it was self luminated.
Don't get on to moons, he's confused enough 
I sorry to suprise SOME people on here but even I know that stars are balls of different gasses which are burning and plants are more a solid compound, also if i remember correctly a Nova is when a star has exploded and is no longer able to burn can't remember what a super Nova is though.
Andy Mac said:
Puggit said:
Galileo said:
You'd be amazed at how many people know so little about the subject. I had to explain to Mrs g that the light coming from the moon was reflected from the sun. She thought it was self luminated.
Don't get on to moons, he's confused enough 
Moons are actually made of cheese and held up by string.
Edited by Galileo on Tuesday 20th January 15:41
that took me a second 
It does shock and amaze me that people manage to wend their way through Britain's education system and emerge out the other end not having a clue about some basic facts about the universe. Something is going wrong somewhere.
Stars are essentially balls of gas inside which temperatures and pressures are so high that nuclear fusion reaction are taking place on an ongoing basis. The tremendous light and energy being produced is what makes them shine.
Planets are smaller objects which, so far, seem to only orbit stars (although there is speculation that "loose" planets may wander between stars).
Planets come in a wide variety of shapes and sizes. The planet we are most familiar with is earth, which is esentially rocky with a molten core and a thin atmosphere. Similar planets to eartb are Mars and Venus (usually referred to as "terrestrial" planets), although even these exhibit wide variations in their sizes and atmospheres.
There are also "gas giant" planets, such as Jupiter and Saturn. These are MUCH bigger than the terrestrial planets and the bulk of their mass comes from having thick, dense atmospheres mainly consisting of hydrogen and methane.
Most of the planets in our solar system are visible to the naked eye. Indeed, thenaked eye planets were discovered and named thousands of years before the invention of the telescope. Mercury, Venus, Mars, Jupiter and Saturn are all fairly easilly visible. In fact, Venus is particularly bright at the moment and is very, very brilliant in the southern sky each night.
Stars do not emit visible light of their own. We see them because they reflect light from the sun.
Since 1995, over 300 planets have been found orbiting other stars although they have nearly all been found by the effect they have on their parent star rather than through direct observation.
Hope that clarifies matters.
Stars are essentially balls of gas inside which temperatures and pressures are so high that nuclear fusion reaction are taking place on an ongoing basis. The tremendous light and energy being produced is what makes them shine.
Planets are smaller objects which, so far, seem to only orbit stars (although there is speculation that "loose" planets may wander between stars).
Planets come in a wide variety of shapes and sizes. The planet we are most familiar with is earth, which is esentially rocky with a molten core and a thin atmosphere. Similar planets to eartb are Mars and Venus (usually referred to as "terrestrial" planets), although even these exhibit wide variations in their sizes and atmospheres.
There are also "gas giant" planets, such as Jupiter and Saturn. These are MUCH bigger than the terrestrial planets and the bulk of their mass comes from having thick, dense atmospheres mainly consisting of hydrogen and methane.
Most of the planets in our solar system are visible to the naked eye. Indeed, thenaked eye planets were discovered and named thousands of years before the invention of the telescope. Mercury, Venus, Mars, Jupiter and Saturn are all fairly easilly visible. In fact, Venus is particularly bright at the moment and is very, very brilliant in the southern sky each night.
Stars do not emit visible light of their own. We see them because they reflect light from the sun.
Since 1995, over 300 planets have been found orbiting other stars although they have nearly all been found by the effect they have on their parent star rather than through direct observation.
Hope that clarifies matters.
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