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Near-Earth asteroid
Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earth's orbit. Some NEAs' orbits intersect Earth's so they pose a collision danger. On the other hand, NEAs are most easily ... > more -
Rocket engine
A rocket engine is a reaction engine that can be used for spacecraft propulsion as well as terrestrial uses, such as missiles. Rocket engines take their reaction mass from within the vehicle and form ... > more -
Buzz Aldrin
Colonel Buzz Aldrin, Sc.D (born January 20, 1930 as Edwin Eugene Aldrin, Jr.) is an American pilot and astronaut who became the second human to set foot on the Moon (after Neil Armstrong) during the ... > more -
Chandra X-ray Observatory
Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the ... > more -
Carl Sagan
Dr Carl Edward Sagan (November 9, 1934 - December 20, 1996) was an American astronomer, astrobiologist and highly successful science popularizer. He pioneered exobiology and promoted the Search for ... > more -
Geomagnetic reversal
A geomagnetic reversal is a change in the orientation of Earth's magnetic field such that the positions of magnetic north and magnetic south become interchanged. The Earth's magnetic north pole is ... > more
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