Atmospheric entry

Atmospheric entry is the movement of an object into and through the gases of a planet's atmosphere from outer space. There are two main types of atmospheric entry: uncontrolled entry, such as in the entry of astronomical objects, space debris or bolides; and controlled entry, such as the entry (or reentry) of technology capable of being navigated or following a predetermined course.

Atmospheric drag and aerodynamic heating can cause atmospheric breakup capable of completely disintegrating smaller objects. These forces may cause objects with lower compressive strength to explode.

For Earth, atmospheric entry occurs above the Kármán Line at an altitude of more than 100 km (62 mi.) above the surface, while at Venus atmospheric entry occurs at 250 km (155 mi.) and at Mars atmospheric entry at about 80 km (50 mi.). Uncontrolled, objects accelerate through the atmosphere at extreme velocities under the influence of Earth's gravity. Most controlled objects enter at hypersonic speeds due to their suborbital (e.g., ICBM reentry vehicles), orbital (e.g., the Space Shuttle), or unbounded (e.g., meteors) trajectories. Various advanced technologies have been developed to enable atmospheric reentry and flight at extreme velocities. An alternative low velocity method of controlled atmospheric entry is buoyancy which is suitable for planetary entry where thick atmospheres, strong gravity or both factors complicate high-velocity hyperbolic entry, such as the atmospheres of Venus, Titan and the gas giants.

List of The Dead Zone episodes

The following is a list of episodes from the USA Network original series The Dead Zone. The series debuted on June 16, 2002.

Series overview

Episodes

Season 1: 2002

Season 2: 2003

Season 3: 2004

Season 4: 2005

Season 5: 2006

Season 6: 2007

References

Reentry (neural circuitry)

Reentry is a neural structuring of the brain, specifically in humans, which is hypothesized to allow for widely distributed groups of neurons to achieve integrated and synchronized firing, which is proposed to be a requirement for consciousness, as outlined by Gerald Edelman and Giulio Tononi in their book A Universe of Consciousness (2000).

See also

References

External links