... The motion of a planet around the Sun or of a scientific satellite around Earth follows different equations (though a connection exists), but in many respect it resembles that of the stone. ... Kepler's law states: . ... Illustrating Kepler's 2nd law: . ... As an example, let the drawing on the right represent the orbit of an Earth satellite, and let AB and CD be the portions of the orbit covered in 3 hours near apogee and near perigee, respectively. ... Gravity can also provide energy. ...

... Low Polar Orbit . ... Different types of satellite orbits have different uses: while the synchronous orbit is best for communication satellites, Lagrangian point orbits help monitor the solar wind before it reaches Earth. ... Many spacecraft use such orbits, e.g. the US Air Force surveillance satellites of the DMSP series, or the series of French Earth-resources spacecraft SPOT . ... If the satellite then starts near a noon-midnight orbit, it will always pass near noon and near midnight. ...

... The fundamental internal FOS time interval is an FOS clock tick of 7.8125 ?sec duration, which is equal to 8 ticks of the HST 1.024 MHz clock. ... The engineering telemetry did record the so-called LINESTART time; that is, the precise time when the SDF told the FOS to commence sending data from the FOS memory to the SDF. ... FOS engineering telemetry, available only at STScI, provides all timing information at accuracy of FOS clock (7.8125 ?sec). ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

UFO Forum Message . Forums: . ... Post . ... It Really Is Relative . ... Post Message | ... If you are on the Earth the moon does not rotate around its own axis. ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Unless otherwise specified, web site content Copyright 1994-2016 John Huggins All Rights Reserved . Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Research areas . ... Events The Second All-Russian Research and Practical Conference 'Actual problems in Avionics Research: Theory, Service, Developments' . ... The Second All-Russian Research and Practical Conference 'Actual problems in Avionics Research: Theory, Service, Developments' "(AVIATOR) will take place at the Faculty of Aviation Equipment of the Military Educational and Scientific Centre of Air Force 'Air Force Academy named after Professor N. E. Zhukovskiy and Yu. ...

Astronomy Picture of the Day . A Gravity Map of Earth . ... 13.11.2001 . ... Credit: JPL , NASA Explanation: Is gravity the same over the surface of the Earth ? ... To better map Earth's gravity and hence better understand its interior and past, NASA plans to launch the Gravity Recovery and Climate (GRACE) satellite in February. ... U. Based on Astronomy Picture Of the Day . Publications with keywords: surface gravity - Earth . Publications with words: surface gravity - Earth . ...

... A document window is shown, with 8 lines (numbered 1 to 8), each 24px high. The text of the "outer" box (at the end of line 1, halfway into line 2, and halfway into line 3) is shifted upward 12px. The text of the "inner" box, thought shifted upward as well, has been relatively positioned so that it lies in its normal flow position at the end of line 2. ... The lines, as they appear in the image, contain: Start 1 Beginning of body contents. 2 of outer contents. Inner contents. ...

... Mindful of these biases, I can now explore the relations between the measured rotation periods and various other observables. The hypothesis behind monitoring stellar variability is that active stars have asymmetric spot distributions on their photospheres. ... They found that only stars with rotation periods greater than seven days show variations greater than 0.4 magnitudes at I. Bouvier et al . ... 1993a) demonstrated a relation between X--ray flux and spectral type in ZAMS stars. ...

The Second Cross-Border Schools Science Conference "Discover the Stars at Armagh", held on 29th and 30th April 2009 and organized by the Armagh Observatory and the Centre for Cross Border Studies was a great success. ... Over the two days of the conference, more than 250 students from schools as far away as Belfast, Dublin and Mullingar participated in a programme of activities lasting from approximately 10:00am to 3.00pm. ... Second Cross-Border Schools Science Conference . ...

On 6 may 2001 the azimuth was parked at az=214.4 degrees and the dome was at 19 degrees za with motors off and the brakes on. At 7:40:49 the azimuth started moving do to the wind. ... The operators began moving the dome downhill at azimuth 258 degrees. The dome was at 18 degrees by the time the azimuth stopped moving. The azimuth rail had been greased the previous week. ... The red shows the dome position during this time (the top red line is 19 degrees and the bottom one is 18 degrees). ...