This, ladies and gentlemen, is the beginning of commercial space travel.
Read about it here.
Aurora Borealis as seen from the International Space Staion
What would happen if I drilled a tunnel through the center of the Earth and jumped into it?
Although it would be impossible to do this on earth, you actually could do this on the moon. The moon has a cold core and it also doesn’t have any oceans or groundwater to mess things up. In addition, the moon has no atmosphere, so the tunnel would have a nice vacuum in it that eliminates aerodynamic drag.
So, imagine that the tunnel through the moon is 20 feet (7 meters) in diameter. Down one side is a ladder. If you were to climb down the ladder, what you would find is that your weight decreases. Gravity is caused by objects attracting one another with their mass (see Question 232). As you descend into the tunnel, more and more of the moon’s mass is above you, so it attracts you upward. Once you climbed down to the center of the moon you would be weightless. The mass of the moon is all around you and attracting you equally, so it all cancels out and you would feel weightless.
If you were to actually leap into the tunnel and allow yourself to fall, you would accelerate toward the center to a very high speed. Then you would zoom through the center and start decelerating. You would eventually stop when you reached the tunnel’s lip on the other side of the moon, and then you would start falling back down the tunnel in the other direction. You would oscillate back and forth like this forever. If you could do this on earth, one amazing effect would be the ease of travel. The diameter of the earth is about 12,700 kilometers (7,800 miles). If you drilled the tunnel straight through the center and could create a vacuum inside, anything you dropped into the tunnel would reach the other side of the planet in just 42 minutes! ________
The Solar System, from a different perspective
There are 10^11 stars in the galaxy. That used to be a huge number. But it’s only a hundred billion. It’s less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.
— Richard Feynman
The threat of Space Debris
Yesterday marked a momentous day in U.S. history as NASA launched its final space shuttle, ending a 30-year era. Four astronauts—commander Chris Ferguson, pilot Doug Hurley and mission specialists Rex Walheim and Sandy Magnus—are leading the 12-day Atlantis mission, the 135th and final flight of the storied space shuttle program. After Atlantis returns to Earth, NASA will officially retire the program and shift its focus to developing next-generation crew exploration vehicles (CEV) capable of carrying crew and cargoes to Earth’s orbit, the moon and Mars. But just days before the Atlantis launch, something unexpected made headlines. Rocketing past the International Space Station at 29,000 miles per hour, a piece of space debris came only 1,100 feet away from a collision, forcing crew members to take refuge in two space capsules reserved for an emergency escape.
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