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Evidence is building that a large world lurks far beyond Pluto and the Kuiper Belt. The race to find it is on. We were going cross-eyed searching for faint, slow-moving [...]

In our solar system's earliest days, the giant-planet region was home to a vast number of small objects. These bodies, similar to today's asteroids and comet nuclei, skipped around among [...]

Many bodies likely lurk in the sprawling emptiness that fringes our solar system. Where are they, and how did they get there? In 1781 William Herschel discovered Uranus, the first [...]

This article discusses the discovery and investigation of "irregular" satellites. These satellites follow planets in large, elliptical orbits, in contrast with standard satellites such as the Earth's moon which usually have tight, circular, equatorial orbits. A wave of theoretical work surrounding the movements of these celestial bodies has resulted from their discovery with the use of advanced digital detectors. INSET: Watchers of the Skies.

The article discusses the importance of Trojan asteroids in the solar system. It examines the locations and characteristics of the Trojans along with the formation and evolution of the planets. It notes that Trojans are named after mythological characters from the Trojan War wherein the leading region is the Greek camp and the objects are named after participants of the Greek side of the war.

We have been systematically monitoring a large sample of bright Kuiper Beltobjects for possible light variations due to rotational and phase angle effects.Here we report on three objects, 2003 AZ84, (24835) 1995 SM55and (55636) 2002 TX300observed to have measurable rotational lightcurveswith peak-to-peak amplitudes of 0.14 ± 0.03, 0.19 ± 0.05 and 0.08 ± 0.02magnitudes and single-peaked periods of 6.71 ± 0.05, 4.04 ± 0.03 and8.12 ± 0.08 hours, respectively. We observed a further ten objects whichshowed no rotational photometric variation within measurement uncertainties.In addition, we find that the lightcurve of 1995 SM55may have a variableamplitude. We discuss this peculiar object as well as our observations of the reportedlyvariable Kuiper Belt object (19308) 1996 TO66. Finally, we continue to find the phase functions of the Kuiper Belt objects to be very steep and linear, to firstorder, with a median slope of 0.16 ± 0.01 magnitudes per degree in the phaseangle range 0 to 2 degrees.

Active asteroids behave dynamically like asteroids but display comet-like comae. These objects are poorly understood, with only about 30 identified to date. We have conducted one of the deepest systematic searches for asteroid activity by making use of deep images from the Dark Energy Camera (DECam) ideally suited to the task. We looked for activity indicators among 11,703 unique asteroids extracted from 35,640 images. We detected three previously identified active asteroids ((62412), (1) Ceres and (779) Nina), though only (62412) showed signs of activity. Our activity occurrence rate of 1 in 11,703 is consistent with the prevailing 1 in 10,000 activity occurrence rate estimate. Our proof of concept demonstrates (1) our novel informatics approach can locate active asteroids and (2) DECam data are well-suited to the search for active asteroids.

We present a new near-infrared photometric system for detection of water ice and methane ice in the solar system. The system consists of two medium-band filters in the K-band region of the near-infrared, which are sensitive to water ice and methane ice, plus continuum observations in the J band and Y band. The primary purpose of this system is to distinguish between three basic types of Kuiper Belt Objects (KBOs)--those rich in water ice, those rich in methane ice, and those with little absorbance. In this work, we present proof-of-concept observations of 51 KBOs using our filter system, 21 of which have never been observed in the near-infrared spectroscopically. We show that our custom photometric system is consistent with previous spectroscopic observations while reducing telescope observing time by a factor of [?]3. We use our filters to identify Haumea collisional family members, which are thought to be collisional remnants of a much larger body and are characterized by large fractions of water ice on their surfaces. We add 2009 YE7 to the Haumea collisional family based on our water ice band observations (J - H2O = -1.03 +- 0.27) which indicate a high amount of water ice absorption, our calculated proper orbital elements, and the neutral optical colors we measured, V - R = 0.38 +- 0.04, which are all consistent with the rest of the Haumea family. We identify several objects dynamically similar to Haumea as being distinct from the Haumea family as they do not have water ice on their surfaces. In addition, we find that only the largest KBOs have methane ice, and Haumea itself has significantly less water ice absorption than the smaller Haumea family members. We find no evidence for other families in the Kuiper Belt.