From dust growth to the formation of our own Earth

Hauyu Liu^1*

¹天文及天文物理學研究所, 中央研究院, 台北市, Taiwan

* Presenter:Hauyu Liu, email:hyliu@asiaa.sinica.edu.tw

Terrestrial planets such as the Earth and Mars are made of interstellar dust. Over the last three decades, it has been considered that water-ice-coating is the key to making the interstellar dust grains sticky enough for coagulating efficiently, allowing the sub-micron-sized grains to eventually grow to kilometer-sized bodies and then become self-gravitating. A major problem in this scenario is how to remove water (by ~99.8%) in the end. My new Atacama Large Millimeter Array (ALMA) and Jansky Very Large Array (JVLA) observations recently demonstrated that the bare silicate grains (potentially mixed with refractory organics) in the protoplanetary disk are in fact stickier than the water-ice-coated grains, which is opposite to the previous understanding. This transformational result may represent a crucial step towards the understanding of how to produce 1-10000 km sized solid bodies that have similar compositions with the Earth, Mars, and the Solar System asteroids which are seriously deficient in water.

Keywords: Planet-formation, Dust-grain-growth, ALMA, Jansky Very Large Array, Cradle-of-life