... 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). ...

... How much brighter is the Sun as viewed from the planet Mercury as compared to Earth ? ... Actually, all of these questions can be answered through a very simple mathematical relationship known as the inverse square law. ... As the distance from the Sun increases the surface area of the sphere grows by the square of the distance. ... Common sense tells us that the Sun will be brighter and the inverse square law tells us how much brighter. ... gr = 0.912 G or 91.2% gravity felt at Earth's surface. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Moon . ... Earth Satellites . ... By admin October 4, 2012 Posted in: Moon . A tiny second moon.This is Phobos (27 km across) seen over Mars by ESA's Mars Express (Image credit:ESA) . ... They concluded that at any given time Earth probably has a second moon. ... But, just perhaps, briefly the Earth had a second natural satellite seen by thousands of people.Remember the spectacular fireball witnessed over the UK and Ireland on 21 September 2012 ? ...

... Recent Topics . ... MAO main . ... The third-order space-by-time relation . ... Тема: The third-order space-by-time relation . ... The mass m experiences a gravity force toward the sun and . ... will experience the Coriolis force or Coriolis acceleration. ... differentiated space-by-time twice and discovered equation2. ... time differentiation of space-by-time. ... to be described by differentiated forces. ... third-order space-by-time relation. ... understand the third-order space-by-time relation....

Pre-launch timing calibration standards Eckhard Kendziorra IAA TЭbingen Crab pulse profile measured with EPIC pn Lessons learned from XMM-Newton Relative timing of EPIC pn verified pre-launch (but only for relatively short intervals, relative timing verified shortly after launch but second jumps of experiment clock only detected after launch Absolute timing for EPIC pn NOT verified ...

... Reference ID: GPS . Driver ID: GPS-TRAK . ... This driver supports the Trak 8820 GPS Station Clock. ... For best accuracy, this radio requires the tty_clk line discipline, which captures a timestamp at the * on-time character of the timecode. ... In operation, this driver sends a RQTS\r request to the radio at initialization in order to put it in continuous time output mode. ... When enabled by the flag4 fudge flag, every received timecode is written as-is to the clockstats file. time1 time . ...

Precession of the Ecliptic . The relation of the celestial equator and poles to the ecliptic and its poles is complicated by the fact that the ecliptic is not stationary. ... The Precession of the Equinoxes . ... Because the equinoxes precess, moving westward along the ecliptic opposite the apparent eastward progress of the Sun during the year, they advance to meet the Sun. ... It has been decreasing from a peak of about 24 some 8,000 years ago toward a low of about 22 some 13,000 years hence. ...

In ancient times the solar system was thought to be the whole Universe, so the study of planetary motions was cosmology. ... The planets other than the Moon and Sun generally move West to East through the stars, but occasionally stop and move in the opposite direction ( retrograde motion). In order to explain the retrograde motion of the planets, the geocentric model of the Solar System shown above puts the planets on small circles called epicycles . ...

... The first column shows the kinematical diagrams, where is the angle between the line of sight on the object and the vector of rotation about Z -axis, and V S is objects line-of-sight velocity relative to an observer at rest at the position of the Sun. The straight lines are regression fits, whose slopes yield the subsystem’s rotation rate. The second column shows the relations between metallicity and distance from the Galactic plane. ... privious figure | next figure . ...

THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON NOVEMBER 2015 HAS MADE Wnov. = 37.1, 63.2 (new) THAT GIVES FOR 75 MONTHS (2015, APRIL) DEVELOPMENT CURRENT 24 CYCLE OF SOLAR ACTIVITY THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*may = 45.6; 76.0 - in new system; W*apr. = 49.3; 78.9 - in new system; - On July 1, 2015 Centre in Brussels moved to a new system of cal- culation the relative number of sunspots and practically all of the values were replaced throughout the numbered series of Wolf numbers (see link). ...