<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> In astronomy or planetary science, the frost line, also known as the snow line or ice line, is the particular distance in the solar nebula from the central protostar where it is cold enough for volatile compounds such as water, ammonia, methane, carbon dioxide, carbon monoxide to condense into solid ice grains . This condensation temperature depends on the volatile substance and the partial pressure of vapor in the protostar nebula . The actual temperature and distance for the snow line of water ice depend on the physical model used to calculate it and on the theoretical solar nebula model: </P> <Ul> <Li> 170 K at 2.7 AU (Hayashi, 1981) </Li> <Li> 143 K at 3.2 AU to 150 K at 3 AU (Podolak and Zucker, 2010) </Li> <Li> 3.1 AU (Martin and Livio, 2012) </Li> <Li> ≈ 150 K for μm - size grains and ≈ 200 K for km - size bodies (D'Angelo and Podolak, 2015) </Li> </Ul>

Line by line explanation of the cold within