Asked by tibi29 to Anna, Daniel, Denise, Jesse on 26 Jun 2014.
Keywords: earth, life, stelar dust
Satellite observations suggest that 100-300 tonnes of cosmic dust enter the atmosphere each day. This figure tallies with the rate of accumulation in polar ice cores and deep-sea sediments of rare elements linked to cosmic dust, such as iridium and osmium. However, measurements in the earth’s atmosphere indicate that the input could be as low as 5 tonnes per day. These measurements include meteor radar observations, laser observations of the sodium and iron atoms from evaporating dust in the upper atmosphere, and measurements by high altitude aircraft of meteoritic iron in the lower stratosphere.
I am not entirely sure how it affects life on Earth, but I did read once that it had an effect on climate change.
Hope it helps! 🙂
regarding the amount I think Denise already gave quite an extensive answer. Regarding how it can affect life..well, as far as I know one of the theories about the origin of life on Earth involves some living organisms arriving on Earth from space, travelling on meteorites or maybe on large particles in dust. There is absolutely no proof of this, but it is still a fascinating theory. If it can affect life now? I don’t know if it can directly affect life in general, but for sure it affects the lives of astronomers, as it obscures a lot of light coming from stars or other objects they want to observe. I did a small research, and I found that if the dust wasn’t there in our galaxy, we would be able to see most of the 400 billion or so stars in the Milky Way rather than just a few million. Imagine what an amazing night sky!
I am not familiar with this topic, but I found some interesting information. It turns out that space is not really empty. There is cosmic dust that formed from the remains of planetary formation, collisions of asteroids, and explosions of stars as supernovas (stellar dust). The stellar dust is older than the age of the Solar System because they formed from an explosion of another star far away from us.
It turns out that the amount of stellar dust that enters the Earth every year is unknown. It is estimated that about 5 to 300 tones enter the Earth every year. However, the answer to your question is an active area of research.
We want to know how much it enters the Earth because it could have an effect on Earth’s climate. When these particles enter the Earth’s atmosphere at high speed, they will heat to high temperature as the collide with gases in the atmosphere. Many will disintegrate in the atmosphere, others of larger size reach Earth’s surface and oceans. Some scientists think that the dust creates clouds high in the atmosphere (and could reflect sunlight causing cooling of the atmosphere). Others see the contribution of iron from these particles to our oceans and surface.
I think that the impact on life today is not much if any, and the impact has the potential to be higher to the atmosphere. Now, whether life ever came from space on one of those particles, survived crashing into the Earth and survived, that I don’t know.
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