Aozora’s Weblog

Dec. 12, 2008 — By the time cosmic rays hit Earth, they have journeyed through so many magnetic fields and other perturbations that they arrive nearly uniformly from all directions.

So when a detector in New Mexico began registering streams of charged particles coming from the general direction of the Orion nebula and about 500 light-years from Earth — a neighbor by astronomical measures — scientists took note.

“I can’t tell you what it is, but I can tell you what it isn’t,” said University of Maryland physicist Jordan Goodman, “It isn’t a statistical fluctuation in our data. It’s not an error.”

Scientists aren’t sure what causes cosmic rays, which are charged particles, namely protons and electrons, moving at high speeds due to unknown events. The list of candidates includes supernova explosions and quasars.

Black Hole A black hole is a region of space whose gravitational force is so strong that nothing can escape from it. A black hole is invisible because it even traps light. The fundamental descriptions of black holes are based on equations in the theory of general relativity developed by the German-born physicist Albert Einstein. The theory was published in 1916.

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It certainly captures the imagination: a star passing silently by our solar system knocks a deadly barrage of comets towards Earth. However, recent simulations by one group of researchers has shown that these star-induced comet showers may not be as dramatic as once thought.
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Three astronauts and a Constellation Program aerospace engineer began a 10-day NASA mission in the ocean depths off the Florida coast Aug. 6. They tested lunar exploration concepts and a suite of long-duration spaceflight medical objectives.

Veteran space flyer and aquanaut Nicholas Patrick lead the undersea mission aboard the National Oceanic and Atmospheric Administration (NOAA) Aquarius Underwater Laboratory. NASA Astronaut Richard Arnold, Japan Aerospace Exploration Agency (JAXA) Astronaut Satoshi Furukawa and systems integration engineer Christopher Gerty completed the crew.

During the NASA Extreme Environment Mission Operations 13 (NEEMO 13), the crew conducted a variety of undersea “moon walks” to test concepts for future lunar exploration using advanced navigation and communication equipment.

“This crew will work much more independently from the mission control team than on previous missions,” said NEEMO Project Manager Bill Todd of the United Space Alliance at NASA’s Johnson Space Center in Houston. “This autonomous mode of operation will encourage the crew to make real-time decisions about daily operations similar to what we think will be necessary for lunar and Mars missions. The idea is to show how procedures and training for future missions can be adapted, considering the reduced direct communication with Mission Control those crews will encounter.”

A team of internationally renowned astronomers and researchers have found a way to make “unbelievably large” telescopes on the Moon.

“It’s so simple,” says Ermanno F. Borra, physics professor at the Optics Laboratory of Laval University in Quebec, Canada. “Isaac Newton knew that any liquid, if put into a shallow container and set spinning, naturally assumes a parabolic shape—the same shape needed by a telescope mirror to bring starlight to a focus. This could be the key to making a giant lunar observatory.”

Borra, who has been studying liquid-mirror telescopes since 1992, and Simon P. “Pete” Worden, now director of NASA Ames Research Center, are members of a team taking the idea for a spin.

On Earth, a liquid mirror can be made quite smooth and perfect if it its container is kept exactly horizontal and rests on a low-vibration low-friction air bearing that is spun by a synchronous motor having one stable speed. “It doesn’t need to spin very fast,” says Borra. “The rim of a 4-meter–diameter mirror—the largest I’ve made in my lab—travels only 3 miles per hour, about the speed of a brisk walk. In the low gravity of the Moon, it would spin even slower.”

Most liquid-mirror telescopes on Earth have used mercury. Mercury remains molten at room temperature, and it reflects about 75 percent of incoming light, almost as good as silver. The biggest liquid-mirror telescope on Earth, the Large Zenith Telescope operated by the University of British Columbia in Canada, is 6 meters across—a diameter 20 percent larger than the famous 200-inch mirror of the Hale telescope at Palomar Observatory in California. Yet when completed in 2005, the Canadian Palomar-class liquid-mirror telescope cost less than $1 million to build—only a few percent the cost of a solid-mirror telescope of the same diameter–and, for that matter, only a sixth of Palomar’s original cost in 1948.

Those economics are making astronomers sit up and begin noodling out plans for a lunar observatory.

“Our study started when I was still an astronomy professor at the University of Arizona before I came to NASA in 2006,” Worden recalls. “The real appeal of this approach is that we could get an unbelievably large telescope on the Moon.”

Plenty of books have been written about living in space, but they tend to concentrate on the past experience of people who have stayed in orbit. These people have nearly all been in the unusual situation of doing scientific research. And they have all undergone extensive selection and training, because going to orbit is so expensive today that it would be very wasteful if they were ill or failed to do some of their planned work. And so they’ve mostly been very busy all the time. So most books don’t say much about how it will be for people to live in space for fun, for example in an orbiting  hotel.

Some astronauts have complained about being in zero G because it makes their work difficult. Objects like screwdrivers and screws don’t stay still but float around. You can’t use your body’s weight to hold things down – you have to brace yourself against something rigid, and so on. It would be easier to do their experiments on the ground.