by Chris Peterson » Sat Feb 04, 2012 3:22 pm
Boomer12k wrote:Well...OK....I am going to put the myth that there are no stupid questions to the test....
"Pressure from Sunlight", and "Solar Wind"....they appear to do the same thing...but evidently are NOT the same thing? :?
Because are not both going "OUTWARD" from the sun? So should not both tails be pointing at least more or less in the same direction?
Or does it have to do with the masses and density of the materials in each tail? The denser dust tends to follow the comet, while IONS, are affected outward from the sun...
Shouldn't they BOTH be affected outward?
The solar wind consists of charged particles leaving the Sun at relatively low speed compared with the speed of light. Solar radiation is photons, which of course do travel at the speed of light. They are completely different things. Both the solar wind and solar radiation move outwards.
Dust ejected from the comet is massive, and in the absence of other forces would simply continue in orbit with the nucleus, spreading slowly forwards and back depending on the direction it was ejected. Radiation pressure, and to a lesser extent solar wind, do slow down the dust, which moves it outward and results in a tail substantially along (and behind) the orbit of the nucleus. Lighter dust is pushed more outwards, heavier dust stays closer to the original orbit. The dust tail never points directly away from the Sun, but lies on some angle between that and the comet's orbit. The situation with gas coming from the comet is different. Being very low mass, it is strongly affected by the solar wind (but not much by solar radiation), so it blows almost directly away from the Sun.
[quote="Boomer12k"]Well...OK....I am going to put the myth that there are no stupid questions to the test....
"Pressure from Sunlight", and "Solar Wind"....they appear to do the same thing...but evidently are NOT the same thing? :?
Because are not both going "OUTWARD" from the sun? So should not both tails be pointing at least more or less in the same direction?
Or does it have to do with the masses and density of the materials in each tail? The denser dust tends to follow the comet, while IONS, are affected outward from the sun...
Shouldn't they BOTH be affected outward?[/quote]
The solar wind consists of charged particles leaving the Sun at relatively low speed compared with the speed of light. Solar radiation is photons, which of course do travel at the speed of light. They are completely different things. Both the solar wind and solar radiation move outwards.
Dust ejected from the comet is massive, and in the absence of other forces would simply continue in orbit with the nucleus, spreading slowly forwards and back depending on the direction it was ejected. Radiation pressure, and to a lesser extent solar wind, do slow down the dust, which moves it outward and results in a tail substantially along (and behind) the orbit of the nucleus. Lighter dust is pushed more outwards, heavier dust stays closer to the original orbit. The dust tail never points directly away from the Sun, but lies on some angle between that and the comet's orbit. The situation with gas coming from the comet is different. Being very low mass, it is strongly affected by the solar wind (but not much by solar radiation), so it blows almost directly away from the Sun.