Antarctic Study Shows How Much Space Dust Hits Earth Every Year

Further down for "dust" and not just meteorites:

> between 4,000 and 6,700 metric tons of space dust falls to Earth each year

> The total dust mass input before atmospheric entry is estimated at 15,000 tons/yr (from the study itself)

Where it came from:

> The team found that more than 60 percent of the dust probably originated from Jupiter family comets, which are herded into orbital periods of less than 20 years by the giant planet’s gravitational influence. About 20 percent of the dust likely came from the main asteroid belt. (yes that leaves 20% unexplained)

How reliable is it:

> ...a geologist at the U.S. Naval Research Laboratory, who was not involved in the research, is impressed by the study but cautions that its estimate cannot be the final word.

Tiny sample size, methodology but also randomness had a big influence. A study that improves upon previous ones and is just one of many more to come. As always, a headline of something taken randomly by a press office from a long line of study points that actually need to be looked at in context and together. It does seem to give a good estimate about the order of magnitude to a casual reader like me though.

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I admit even after reading through some details I can't say if the first number is part of the second, or if I need to add them? They do talk about "meteorites and dust", so they counted two separate things? On the other hand, the first number for "meteorites" has the dust in the same sentence ("With clean sampling techniques and accurate ages for dust deposits, the researchers calculated around 5,200 metric tons of micrometeorites fall to Earth every year"). I'm confused. Maybe I should not have started with the article but with the actual study.

Reading that study (linked in the article), the 5,200 is a complicated product of a lot of measurements and statistics (you see it in the abstract already) - and they say "dust" in the context of that number.

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Given that both numbers are close and the uncertainty is large I won't spend any more time trying to figure it out, the magnitude is the same and it's all I think one can take away from this as a casual reader. The really interesting stuff probably only interests few and is all the many many details of how they did it exactly, for example "The errors are derived assuming that the number of influx particles follows Poisson statistics" => from the study, one of hundreds of important details that the linked article compresses into something easier to read, but with quite a bit of information loss.