... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

Observations of the "Face on Mars" and similar features by the Mars Global Surveyor Orbiter Camera . ... For example, using the latest Mars Digital Image Mosaic and the U. S. Geological Survey control network, the aforementioned "Pyramid" is located at 40.67 N, 9.62W. Using the Viking spacecraft tracking and engineering telemetry, the position is 40.71 N, 9.99 W. The difference, 0.04 deg latitude and 0.37 deg longitude, represents nearly 17 km on the ground, or 7X the size of the Pyramid. ...

... Current APO Weather . ... Search Site . ... Information for New Users . ... Technical Staff pages . Night Logs and Mailing Lists (maintained by APO) . ... Technical Documents and Database Search . ... Observer's Documentation and Procedures . ... Problem Reporting and APO Technical Documents Database Search . ... APO Drawing/Document Management Procedures . ... APO Technical Documents Database Search . Home Astrophysical Research Consortium . ... Mail Lists (maintained by APO) . ...

Operations in Point operations use the pointer to query sets about points, delete points in a set, and move points. In all cases where interaction is required, pressing the right mouse button with the pointer in the drawing area cancels the operation. ... Report on a point in a set . ... Press the left mouse button. ... Press Delete point with the left mouse button to activate. ... Move the pointer to the new location and press the left mouse button again to register the point's new location. ...

User Commands pointing-diff(1) NAME pointing-diff - Determine the great-circle distance between an SU and a specific sky point. SYNOPSIS: <program name> su=<sunit_id> ra2=<ra> dec2=<dec> where posi- tions are in decimal degrees INTRODUCTION: Determine the great-circle distance between an SU and a specific sky point. NOTES: Should enhance this tool to take 2 sus or 2 sky positions. ... AUTHOR I. Jordan SunOS 5.10 Last change: 15 AUG 2006 1 ...

... X-Ray Structural Analysis . ... The course introduces the basic principles of diffraction analysis of crystal atomic structure and the basic concepts of state-of-the-art atomic crystallography. ... X-ray crystal diffraction. тАЬGeometricalтАЭ theory of diffraction by three-dimensional scattering center grating. ... Systematic X-ray reflection extinction related to Bravais lattice type, screw axis, glide-reflection planes. €аFourier synthesis as a method of crystal atomic structure analysis. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Moon . Planets . ... Monthly Sky Notes . ... February . ... The ringed planet will be quite bright, but unlike Jupiter it will not be the brightest point of light in the sky, this accolade will return to Sirius which is the brightest star in our night sky in the constellation of Canis Major. ... Seven days later on February 18, the Moon will be in its full Moon phase. ... Tweets that mention Wonders of the February Night Sky | ... Astronotes . ...

. Next: Support Up: How to use Previous: New Users . љ MIDAS is used at many different sites on a large variety of configurations. The main part of this manual does not refer to special configurations or hardware devices. Site specific implementations and details of the local installation can be found in Appendix C of Volume A. Pascal Ballester . Tue Mar 28 16:52:29 MET DST 1995

... Astronomy . ... Requires various plug-ins to your browser to work right. [m,h] (A simpler version of this activity, to be done with printed paper versions of the image, can be found at: www.jpl.nasa.gov/galileo/sepo/educaton/europa/puzzle.html ) . ... Interesting activity, in which students use an inexpensive "stream tray" to simulate the flow of water on sandy terrain, compare their results to features seen in martian images, and then try to replicate some of the features seen on Mars. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2011 February 23 . The Solar System from MESSENGER . ... Nearly such a view was taken recently from the MESSENGER spacecraft currently orbiting the Sun from the distance of Mercury . ... MESSENGER, which has flown by Mercury three times now, is on schedule to enter orbit around the Solar System's innermost planet next month. ... About APOD | ...

... The Solar System from MESSENGER . ... The Sun's planets all appear as points of light, with the closest and largest planets appearing the brightest. Star Size Comparisons . ... To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over NeuchБtel, Switzerland. ... What's happened to these clouds? ... Spiral Galaxy NGC 2841 Close Up . ... Planetary Nebula Project . ... Inside the nebula lies an open cluster of bright young stars designated NGC 2244. ...

Lecture 15 Plan for Lecture Will complete derivation of Angular Diameter Distance and then go through a specific example-- Einstein de Sitter universe Then look at what it becomes in a ` flat ' universe (currently favoured) Then discuss velocities and the Hubble Law (actually derive this) And then specific examples of what the data on Luminosity distance seems to be saying about the dynamics of the universe Finally, a new topic -- horizons, in ... Also, k = 0 (for EdS) S () . ...

Next: Library, Archive and Historic Up: Buildings, Grounds, Library and Previous: Disposal of the Schmidt . Mark Bailey, Apostolos Christou and David Asher have developed ideas for a new outdoor exhibit in the Observatory grounds, called `The Human Orrery'. ... The position of the proposed new Library, Archive and Historic Scientific Instruments building is shown in outline. ... Next: Library, Archive and Historic Up: Buildings, Grounds, Library and Previous: Disposal of the Schmidt M.E. Bailey . ...

... connection points . ... The point P3 is the connection between the horizontal and vertical actuators and is the axis of rotation for the tail gunner motion. processing: survey/020204/reduc We can compute P3,P5 (the moveable points) in dome centerline coordinates if we have the actuator distances and we know the positions of the above connection points in dome centerline coordinates for a given position of the tertiary (say the nominal focus position).(see actuator distances to dome centerline ). ...

... 295, 2003 H. E. Payne, R. I. Jedrzejewski, and R. N. Hook, eds. The MAST Pointings Tables Pro ject Karen Levay, Paolo Padovani1 , Randall Thompson, Megan Donahue, Michael Corbin Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 Abstract. We have undertaken a pro ject to create a database of all HST imaging observations organized by position on the sky. ... Each sky region was called a "pointing." ... Users select the instrument pointings table they wish to search. ...

... The SIAM is used to point the satellite such that a nominal on-axis source position is imaged onto a specific point on the detectors. ... New angles for the SIAM are calculated from shifts of the pointing of the instrument given in parameter Instrument relative to the pointing obtained by using the SIAM that is specified by parameter siamset . ... Using this, the positions of 5 test sources in the FOV of the instrument are calculated. ... Source Number . Ra (arcmin) . Dec (arcmin) . ...

... Archives . ... X-ray summer school is on going. ... Recently I went to JSM 2007 and tried to attend talks about (bayesian) change point problems, which frequently appears in time series models, often found in economics. ... Tags: ARCH , Bayesian Block , challenges , change point problem , GARCH , light curves , summer school , X-ray . ... I received another type of changing point problem, defining a peak precisely, from a x-ray school student, who tried bayesian block but said it didn?t work. ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : The Moon only shows one face to us because it is not rotating. Better astronomy : The Moon only shows one face because it is rotating, once every time it revolves around the Earth. ... Place the Moon model on the table about 30 centimeters (one foot) away with the X facing the Earth model. ... You'll see that to keep the X facing the Earth model, you have to rotate the Moon model as it goes around the Earth model . ... 2008 Phil Plait. ...

SINGULAR POINTS IN THE SOLAR CHROMOSPHERE . ... In the structure of the solar chromosphere, containing information on the configuration of the magnetic field, we have found and identified all the main types of the singular points ( see Fig. 1 ), which are known as inherent features of the 2-D vector field. ... The main types of the singular points are the node, the focus, the center, and the saddle. ... Singular point of the focus type in the solar chromosphere. ...