enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Orbit of Mars - Wikipedia

    en.wikipedia.org/wiki/Orbit_of_Mars

    Extra-close oppositions of Mars happen every 15 to 17 years, when we pass between Mars and the Sun around the time of its perihelion (closest point to the Sun in orbit). The minimum distance between Earth and Mars has been declining over the years, and in 2003 the minimum distance was 55.76 million km, nearer than any such encounter in almost ...

  3. Interplanetary spaceflight - Wikipedia

    en.wikipedia.org/wiki/Interplanetary_spaceflight

    Then, after intercepting Mars, it must change its speed by another 2.3 km/s in order to match Mars' orbital speed around the Sun and enter an orbit around it. [12] For comparison, launching a spacecraft into low Earth orbit requires a change in speed of about 9.5 km/s.

  4. Time travel - Wikipedia

    en.wikipedia.org/wiki/Time_travel

    Time travel is a concept in philosophy and fiction, particularly science fiction. In fiction, time travel is typically achieved through the use of a device known as a time machine. The idea of a time machine was popularized by H. G. Wells's 1895 novel The Time Machine. [1] It is uncertain whether time travel to the past would be physically ...

  5. Orbital speed - Wikipedia

    en.wikipedia.org/wiki/Orbital_speed

    In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter (the combined center of mass) or, if one body is much more massive than the other bodies of the system combined, its speed relative to the center of mass of the most massive body.

  6. Characteristic energy - Wikipedia

    en.wikipedia.org/wiki/Characteristic_energy

    The characteristic energy with respect to Sun was negative, and MAVEN – instead of heading to infinity – entered an elliptical orbit around the Sun. But the maximal velocity on the new orbit could be approximated to 33.5 km/s by assuming that it reached practical "infinity" at 3.5 km/s and that such Earth-bound "infinity" also moves with ...

  7. A Scientist Says Time Travel Is Possible With Ring Lasers - AOL

    www.aol.com/scientist-says-time-travel-possible...

    Ronald Mallett loves the concept of time travel. He has since he was a kid. At 77, the former University of Connecticut physics professor still isn’t backing down from his theory: A spinning ...

  8. Mental time travel - Wikipedia

    en.wikipedia.org/wiki/Mental_time_travel

    This is an example of mental time travel in animals. It was not a result of associative learning, that they actually chose the utensil instead of the food reward, since the scientists ran another experiment to account for that. Other examples, such as food caching by birds, may be examples of mental time travel in non-humans.

  9. Heliocentric orbit - Wikipedia

    en.wikipedia.org/wiki/Heliocentric_orbit

    A heliocentric orbit (also called circumsolar orbit) is an orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System, and the Sun itself are in such orbits, as are many artificial probes and pieces of debris. The moons of planets ...