Star dust: greetings from deep space

Abstract

Dust is an essential component throughout space. Interstellar dust is the solid phase of interstellar matter from which stars and planets form. Cometary dust is the most pristine material from the early solar nebula. Huge dust clouds are observable, e.g., with the renewed Hubble Space Telescope. Cosmic dust is also attracted by the earth’s gravity and is deposited on the earth’s surface in estimated quantities of 30–1000 t daily. Space exposed surfaces, e.g., of space stations or space vehicles may be seriously eroded by cosmic dust hitting these surfaces. This has been extensively studied by secondary ion mass spectrometry, the key instrumentation for cosmic dust analysis and dust eroded surfaces in combination with scanning electron microscopy. The significance of material degradation of space exposed surfaces has been studied by a “Long Duration Exposure Facility” experiment managed by NASA. Another serious problem is the great amount of debris from older space installations in near-Earth Space. Measures of respective mitigation are outlined. Important chapters, e.g., on the International Space Station (ISS) and the Hubble Space Telescope (HST) refer to new respective information available. A further chapter describes asteroids with much larger “grain sizes” than cosmic dust. The eminent danger upon impact of asteroids on the Earth is outlined for most recent incidents (Tunguska and Chelyabinsk). Exciting missions, such as the Star Dust Mission and the Rosetta Mission, are shortly outlined. Finally, the speed of light and the incredible dimensions of the universe are discussed. This leads to the conclusion that manned space travel is very dangerous for man, and restricted to just the nearer part of our planetary system.