According to a new international study, most (>80 percent) of the water inside the Moon was delivered by asteroids similar to carbonaceous chondritic meteorites during the early lunar evolution, approximately 4.5—4.3 billion years ago. A similar delivery of water to the Earth would have been occurring within this same interval of time.
The final primary mirror segment is installed on NASA’s James Webb Space Telescope. Once in space and fully deployed, the 18 hexagonal-shaped mirror segments will work together as one large 6.5-metre mirror. The crowning mirror installation marks an important milestone in the assembly of what will be the biggest and most powerful space telescope ever launched.