Planetary Sciences Programs

Participants in CS3 pursue many aspects of Planetary Sciences.




Interplanetary dust and particles from ejected from comets impact the Earth's atmosphere at a constant rate appearing in the form of meteors.  Occasionally, the Earth passes through a stream of material causing a meteor shower.  Sometimes a larger meteors (bolide) survive to hit the ground resulting in a meteorite.  CS3 participates in the study of these objects.



Near Earth Objects (NEO's)


On a regular basis, small asteroids approach the Earth, and even come inside the orbit of the Moon.  These objects are typically too small to do any damage and typically break up when they occasionally enter the atmosphere.  However, astronomers wish to know more about this class of objects.



Main Belt Asteroids


Main Belt asteroids are located between the orbits of Mars and Jupiter.  They comprise the bulk of the objects that amateur and professional astronomer like to study.  Thousands of lightcurves have been obtained, but strong observing biases have crept into the data.  Observers at CS3 have attempt to combat the biases by observing low numbered asteroids for which no period has been reported.  Inevitably, they turn out to be a slow rotating asteroid which was abandoned by previous researchers.



Trojan Asteroids


Jupiter Trojan Asteroids are a special class of objects that are trapped in Jupiter's orbit around the Sun, preceding or following Jupiter by 60 degrees.  These are ancient objects which may provide clues about the evolution of the Solar System.



Binary Asteroids


It was recently discovered that many asteroids have companions or satellites.  The study of these objects give important clues about the evolution of asteroids and the nature of the Solar System.



Shape Models


Only a small number of asteroids have been visited by spacecraft or imaged by radar telescopes.  One of the interesting aspects of asteroid research is the ability to create rough 3-D models of asteroids based upon their changes in brightness over time.  With enough lightcurves, a model can be developed which also gives information about its pole orientation and direction of spin.



The main tool CS3 uses for scientific measurements is photometry - the measurement of the brightness of an object.  By watching changes in brightness over time, observers can determine the rotational period, shape, surface roughness, if the object has a satellite, and the effects of the enivornment on its period and orbit.

Brightness measurements are often plotted into a lightcurve, with time on the horizontal axis and brightness on the vertical axis.  Brighter observations are at the top of the plot.  A typical asteroid is oblong in shape.  As it rotates, it presents a wide side to Earth twice each rotation making the plot appear like a sine wave.

A phased lightcurve of the Main Belt Asteroid 1318 Nerina.  Observations were obtained over three nights by Robert Stephens with his 0.3-m telescope in Rancho Cucamonga.  The asteroid rotates once every 2.5280 hours.