The Search for Distant Objects in the Solar System Using Spacewatch

We have completed a low-inclination ecliptic survey for distant and slow-moving bright objects in the outer solar system. This survey used data taken over 34 months by the University of Arizona's Spacewatch Project based at Steward Observatory, Kitt Peak. Spacewatch revisits the same sky area every three to seven nights in order to track cohorts of main-belt asteroids. This survey used a multiple-night detection scheme to extend our rate sensitivity to as low as 0.012 arcsec hr-1. When combined with our plate scale and flux sensitivity (V21), this survey was sensitive to Mars-sized objects out to 300 AU and Jupiter-sized planets out to 1200 AU. The survey covered approximately 8000 deg2 of raw sky, mostly within 10° of the ecliptic but away from the Galactic center. An automated motion-detection program was modified for this multinight search and processed approximately 2 terabytes of imagery into motion candidates. This survey discovered 2003 MW12, currently the tenth largest classical Kuiper Belt object. In addition, several known large Kuiper Belt objects and Centaurs were detected, and the detections were used with a model of our observational biases to make population estimates as a check on our survey efficiency. We found no large objects at low inclinations despite having sufficient sensitivity in both flux and rate to see them out as far as 1200 AU. For low inclinations, we can rule out more than one to two Pluto-sized objects out to 100 AU and one to two Mars-sized objects to 200 AU.

Cool (Free!) Astronomy-related Software:
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Celestia: (GET THIS ONE! -- m_f) A real-time space simulation that lets you experience our universe in three dimensions. Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy. All travel in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across. A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit.
Sky Screen Saver: Shows the sky above any location on Earth, including stars (from the Yale Bright Star Catalogue of more than 9000 stars to the 7th magnitude), the Moon in its correct phase and position in the sky, and the position of the Sun and all the planets in the sky.
Outlines, boundaries, and names of constellations can be displayed, as well as names and Bayer/Flamsteed designations of stars brighter than a given threshold. A database of more than 500 deep-sky objects, including all the Messier objects and bright NGC objects can be plotted to a given magnitude. The ecliptic and celestial equator can be plotted, complete with co-ordinates.
Home Planet: A comprehensive astronomy / space / satellite-tracking package for Microsoft Windows 95/98/Me and Windows NT 4.0/2000/XP and above. Selected features:
- An earth map, showing day and night regions, location of the Moon and current phase, and position of a selected earth satellite. Earth maps can be customised and extended.Hposition and phase data for the Sun and Moon.
- Panel showing positions of planets and a selected asteroid or comet, both geocentric and from the observer's location.
- A sky map, based on either the Yale Bright Star Catalogue or the 256,000 star SAO catalogue, including rendering of spectral types, planets, earth satellites, asteroids and comets.
- Databases of the orbital elements of 5632 asteroids and principal periodic comets are included, allowing selection of any for tracking.
- A telescope window which can be aimed by clicking in the sky map or telescope itself, by entering coordinates, or by selecting an object in the Object Catalogue.
- A horizon window which shows the view toward the horizon at any given azimuth.
- Object Catalogue allows archiving images, sounds, and tabular data about celestial objects.
- Orrery allows viewing the solar system, including a selected asteroid or comet, from any vantage point in space, in a variety of projections.
- Satellite tracking panel. Select an Earth satellite from a database of two-line elements, and see its current position and altitude.
- View Earth From panel allows you to view a texture-mapped image of the Earth as seen from the Sun, Moon, a selected Earth satellite, above the observing location, or the antisolar point.
- Satellite database selection allows maintenance of multiple lists of satellites, for example TV broadcast, ham radio, low orbit, etc.
Cartes du Ciel Sky Charts: Enables you to draw sky charts, making use of the data in 16 catalogs of stars and nebulae. In addition the position of planets, asteroids and comets are shown.
SETI@Home: A scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). You can participate by running a free program that downloads and analyzes radio telescope data.

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