Scientists think that this may be what our solar system looked like at the end of its main planetary formation phase. The diameter of the cleared inner region is about 100 A.U., slightly larger than our own solar system. The hole in the doughnut-shaped disc is typical of what would be left by a moving celestial body, offering indirect evidence that a planet has been formed. In April 1998 a team of U.S. astronomers reported finding a massive concentration of water vapor within the Orion molecular cloud, a giant interstellar gas cloud located near the Orion nebula. This gas cloud, which is a trillion miles across, generates enough water molecules in a single day to fill the Earth's oceans 60 times over.
Researchers believe the cloud provides an important clue to the origin of water in the solar system.
Eventually, the water vapor in the cloud will freeze, turning into small ice particles. Similar ice particles are thought to have been present within the gas cloud from which our solar system formed. A Saharan Stonehenge Scientists have confirmed that an assembly of huge stone slabs in Egypt's Sahara Desert is the oldest known astronomical alignment of megaliths in the world. Known as Nabta, the site is 6,500 to 6,000 years old, predating Stonehenge and similar prehistoric sites by about 1,000 years. Some of the slabs are nine feet high.