An astronaut in low Earth orbit moves in (approximately) a big circle extending around the Earth. ... That can be interpreted as stating that in the astronaut's frame of reference, all bodies are subject to two forces, gravity and the centrifugal force, and the two are in perfect balance, adding up to zero. ... Wheel-shaped space . ... The science-fiction film "2001: A Space Odyssey" featured spinning space station, whose rotation provided the crew with "artificial gravity." ...

... 22.Reference Frames . ... To derive the motion of a penny dropped inside an airliner moving at 600 miles/hr (about 1000 km/hr)--should we calculate it with respect to the interior of the airliner, or with respect to the ground? ... And if a similar penny is let go inside an orbiting spaceship--should its motion be calculated relative to the interior of the spaceship, or relative to the Earth outside? ... How do observations differ in the two frames--the airliner cabin and the Earth? ...

... Gravity is responsible for keeping your feet on the ground and keeping the Earth and all other planets in our Solar System in their orbits around the Sun. ... Einstein's theory of gravity, known as the theory of General Relativity. This suggested that gravity is actually the curving of the fabric of the Universe, known as 'spacetime', around objects. For instance, a very heavy star warps the space around it, causing a deep well in the fabric, and pulling in anything that comes too close. ...

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... Bad Astronomy . ... Every few months, one of a series of questions comes up on the USENET group sci.astro involving tides, or the rotation of the Moon, or the recession of the Moon from the Earth. ... Why the Moon's rotation period is the same as the length of time it takes to orbit the Earth (same as number 1, but phrased differently). ... But when this happens, the time it takes for the Earth to rotate once will be slowed to exactly the same time it takes for the Moon to go around the Earth once! ...

Every body is held together by two forces, its self-gravitation and its internal strength due to molecular bonding. ... A few of these cases have been obviously attributable to the tidal forces of Jupiter (Comet Brooks 2 and Comet Shoemaker-Levy 9) or the Sun (the Kreutz comet family), while other splittings have to be attributed to less obvious causes. ... They always approach the Sun to within 3 million kilometers (1.9 million miles) or less, and some have actually hit the Sun. ...

... Snug in the payload section was GLAST, the Gamma-ray Large Area Space Telescope, now in orbit around planet Earth. Phoenix and the Snow Queen . ... A flat, smooth, shiny feature dubbed the Snow Queen is near the top of this color mosaic of the surface beneath the Phoenix Mars Lander. ... To help find out, the Phoenix Lander Phoenix Lander which arrived on Mars two weeks ago has attempted to place a scoop of soil in Phoenix's Thermal and Evolved-Gas Analyzer (TEGA). ... Two Armed Spiral Milky Way . ...

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... This talk focuses on exploring the connection between Ly absorbers and galaxies. The theorist view of gas in the low z universe is based on the filamentary structures that are evident in simulations based on the CDM paradigm. ... The observer's view of gas in the low-z universe is based on the Ly absorbers which have column densities as low as 10 cm , while galaxies are at column densities of 10 cm . ... The absorber has N cm . ... Can examine LSS defined by gas-rich galaxies around absorbers. ...

We present new images of the reflection nebula surrounding the R Coronae Borealis Star, UW Centauri. ... Instead, the morphology of the nebula appears to change as different parts are illuminated by light from the central star that is modulated by shifting thick dust clouds near its surface. ... In this way, the central star acts like a lighthouse shining through holes in the dust clouds and lighting up different portions of the nebula. ... ADS Citation Query . citations = 21 . ...

What happens to a star heavier than five solar masses? ... Stars about ten solar masses probably behave like our five solar mass star until they reach the end of core-helium burning. ... The Crab nebula was formed after a massive explosion ripped a star apart in 1054. ... Today, the glowing outer layers of the star are still rushing away from a tiny star in the centre. ... An incredible explosion rips through the outer layers of the star, releasing colossal amounts of energy in a supernova explosion. ...

Журнал ПОВЕРХНОСТЬ публикует оригинальные статьи и обзоры по наиболее актуальным проблемам изучения поверхностных явлений. ... Редакция журнала 'Поверхность. ... Англоязычная версия журнала Journal of Surface Investigation . X-Ray, Synchrotron and Neutron Techniques выходит 6 раз в год . The Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques ( Poverkhnost '. ... X-ray, Synchrotron and Neutron Techniques is abstracted and/or indexed in (Impact Factor 0.359): . ...

... 2013 July 31 . 130 Years of Earth Surface Temperatures . Image Credit: GISS , NASA . Explanation: How has the surface temperature of Earth been changing? ... On average, the display demonstrates that the temperature on Earth has increased by nearly one degree Celsius over the past 130 years, and many of the warmest years on record have occurred only recently. ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . NASA Web Privacy Policy and Important Notices . ...

... Ronald J. Garan, Jr. COLONEL, U.S. AIR FORCE, RET.) NASA Astronaut (Former) . ... ORGANIZATIONS: Society of Experimental Test Pilots, Engineers Without Borders, Association of Space Explorers, Member of the Launch.org Council, and Founder of the Manna Energy Foundation. ... In 1991, Garan was reassigned to the U.S. Air Force Weapons School, Nellis Air Force Base, Nevada, where he served as an F-16 Weapons School Instructor Pilot, Flight Commander and Assistant Operations Officer. ...

... The SDSS 2.5-m primary mirror is supported in a manner similar to the Apache Point Observatory 3.5-m telescope primary. ... The axial support is provided by 48 air pistons. The pistons have the same diameter thereby applying equal forces with the same air pressure. ... Each group supports a 120њ sector of the mirror. ... Figure 1: CAD drawing showing the 2.5-m primary mirror and the locations of actuators (green circles) These actuators apply forces (10*cos2 N) to correct astigmatism. ...

Radio Observations of PSR B1259-63 Around Periastron . ... Abstract The recent periastron passage of the pulsar PSR B1259-63 around its companion star SS2883 gave a unique opportunity to study the characteristics of the disc of a Be star. We report here on extensive multifrequency radio observations of the pulsar from 1993 August to 1994 October which show large changes in its flux density, linear polarization, dispersion measure (DM) and rotation measure (RM), often on short time-scales. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . ... Moon . ... Comets and Asteroids . ... What changed our view of Chariklo is the discovery of a ring system around it, the first such feature found around a Solar System body smaller than a gas giant planet. ... Almost certainly the rings were born when a collision with a smaller asteroid blasted millions of tonnes of debris off CharikloтАЩs surface. ... A ring system detected around the Centaur (10199) Chariklo (Braga-Rigas et al.) ...

... The fact that the Sun is a gas, however, lets different regions pass by one another fluidly. ... This differential rotation has interesting ramifications for the Sun's magnetic field. ... This bizarre distortion of the magnetic field results in active phenomena on the surface of the Sun. ... Magnetic instabilities in the solar field cause short, violent ejections of gas called solar flares-the most explosive events on the Sun. ... The Sun can also be viewed safely through special types of filters. ...

... You can see the exit, it is only a few yards away. ... Play Information * Episode and Level # : E1M1 Single Player : Yes Cooperative 2-4 Player : Yes Deathmatch 2-4 Player : Yes Difficulty Settings : Yes New Sounds : One New Graphics : Yes New Music : No Demos Replaced : None * Construction * Base : New level from scratch Editor(s) used : DEU521 * BSP11x * DMGRAP11 Known Bugs : None (I hope) * Permissions * Authors MAY use this level as a base to build additional levels. ...

... Precisely one month ago, on 11 July 2009, the last active area of the new solar cycle disappeared from the surface of the Sun. Over the 30 days following this, neither observers on Earth nor devices in space have been able to detect the emergence of any sunspots. ... Therefore, it seems that our star has once again returned to a state of deep solar "winter", following several sparks of activity in May-June 2009. ... To date, this period has lasted 30 days. ...