After being in print for twenty years, the Chronological Encyclopedia of Discoveries in Space, covering everything that was learned on every single space mission in the 20th century, has finally gone out of print.
Behind The Black, c/o Robert Zimmerman
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"Useful to space buffs and generalists, comprehensive but readable, Bob Zimmerman's Encyclopedia belongs front and center on everyone's bookshelf." -- Mike Collins, Apollo 11 astronaut
"The Chronological Encylopedia of Discoveries in Space is no passionless compendium of information. Robert Zimmerman's fact-filled reports, which cover virtually every spacecraft or probe to have ventured into the heavens, relate the scientific and technical adventure of space exploration enthusiastically and with authority." -- American Scientist
Part of a gas cloud, being ripped apart by the super massive black hole at the center of the Milky Way, has already swung past the black hole.
“The ionised gas at the head of the cloud is now stretched over more than 150 light-hours (about 160 billion kilometres) at the pericentre of the orbit around the black hole, with the closest approach being about 25 light-hours (or a bit more than 25 billion kilometres)”, explains Stefan Gillessen from MPE, who led the observing team. “The pericentre approach however is not a singular event but rather a process that will be stretching over a period of at least one year.”
The black hole, dubbed Sagittarius A* (pronounced A-star), is more than 4 billion times the mass of our Sun, but emits very little energy for its size. (Most super massive black holes emit energy as they swallow the mass around them.) Astronomers are hoping that they will see some action when it eats this cloud sometime next year.