Kuiper belt through the eyes of the artist
Cosmic dust accumulates daily in the Earth’s stratosphere. Moreover, for the year its number reaches 40,000 tons! Since the 1970s NASA representatives launch balloons into the sky to collect valuable samples for analysis.
It is important to understand that these particles in size reach only a few tens of micrometers. And the main sources of cosmic dust are the nearest comets and asteroids located closer to the Sun (the inner Solar system with an asteroid belt).
Outer and Kuiper Belt Sizing Comparison
However, a recent study showed that some samples of cosmic dust could have come from objects in the far Kuiper belt. And “far” means the distance to the Sun from 30 a. e and up to 55 a. e. This region is beyond the limit of Neptune’s orbital path. Therefore, scientists are surprised at the very thought that dust particles could overcome such great distances.
The analysis also showed that cosmic dust spent about 10 million years on the journey from the Kuiper belt to the Earth’s stratosphere. Now the spacecraft New Horizons is moving in the direction of the belt, which on January 1, 2019 flew past the 2014 MU69 object, 43.4 a away from our star. e. Video of the span of the New Horizons vehicle in front of the Ultima Thule:
We have no chance to return the samples from the Kuiper belt, but if the found dust particles really belong to this area, then we can get a rough idea of the composition of a distant region.
Thus, the analysis of dust particles (which presumably arrived from the Kuiper belt) showed that they appeared due to contact with liquid water. This is strange, because the Kuiper belt is considered too cold to have water in a liquid state. Perhaps it was all about collisions and warming up that caused the ice to melt.
To prove the arrival of samples from the Kuiper Belt, you need to collect and analyze a lot more material than the Lindsay Keller team and NASA planetary scientists will do in the near future.