|
News briefs
Hubble servicing: A Sky & Telescope article today, "Hubble Servicing: Robot to the Rescue?" and a Space.com April 5th report, "NASA Studies Robot Servicing of Hubble," both note that a robot mission to attach new batteries and gyroscopes outside the space telescope may be feasible, but replacing instruments inside would be far more difficult.
Readings: A Lawrence Journal-World article today, "Senator seeking asteroid defense," begins with, "Sen. Sam Brownback has taken on musical artists for their use of profanity, video game companies for their use of violence and researchers for their use of embryonic stem cells. Now he's taking on asteroids."
An article at TheFeature.com today says the Deep Impact mission will be first to test "various spacecraft file-sharing protocols" toward establishing the Interplanetary Internet (IPN). A milestone for IPN was reached with a February NASA-ESA test at Mars (see NASA 12 February 2004 news release).
|
Accretion theory: There is a fundamental problem in the theory about how the Sun's proto-planetary disk coalesced into planets. The theory is that dust grains came together to form increasingly larger objects, but this involves collision and, generally speaking, collisions cause deflection and disruption, not adhesion. A Sky & Telescope article yesterday, "Building Planets in Plastic Bags," tells about an informal show-and-tell science lesson broadcast from the International Space Station that led to an inadvertent revelation: The answer may be that the electrostatic environment in the solar nebula caused particles of different materials and sizes to stick together.
Ian Miller has another answer in a recent article at Astrobiology Magazine. He says "a hydraulic cement results" from "any mix" of carbonates, aluminum oxide, and silicon oxide when heated to 2000 K. This explains accretion, "gets water onto the rocky planets," and provides the origin of Earth's reducing atmosphere and biogenetic precursor materials.
|
