The physical nature such as orbital distribution of asteroids is fundamental to understanding how our solar system has been evolved. The connection between Near-Earth Objects (NEOs) and Earth impactors such as meteorites and fireballs are still under debate, since there is no meteorite orbit whose parent NEO was identified. The orbital distribution of NEOs has been investigated by comprehensive sky surveys including Pan-STARRS (The Panoramic Survey Telescope And Rapid Response System). Here we focus on the Phaethon-Gemind complex detected by Pan-STARRS PS1 Prototype Telescope and our follow-up lightcurve observations.

Main belt comets (MBCs) are a class of newly discovered objects that exhibit comet-like appearances and yet are dynamically indistinguishable from ordinary main belt asteroids. The measured size and albedo of MBCs are similar to those of classical comets. At present, six MBCs have been discovered, namely 133P/Elst-Pizarro, 176P/LINEAR, 238P/Read, P/2008 R1, P/La Sagra and P/2006 VW139. The total number of active MBCs is estimated to be at the level of a few hundreds (Hsieh & Jewitt, 2006). Several explanations for the activity of MBCs have been suggested. These include impact ejection, sublimation and rotational instability. However, since renewed activity has been observed in 133P and 238P at successive perihelion passages, the most likely explanation may be a thermally-driven process - e.g sublimation of exposed surface ice. Although the proximity of MBCs to the Sun (r ~ 3 AU) makes the survival of surface ice improbable, thermal models have shown that water ice is thermally stable under a regolith layer a few meters thick. The study of MBCs has recently been complicated by the discoveries of two asteroid collisional events (P/2010 A2 (LINEAR) and (596) Scheila) in 2010, where comet-like dust coma/tail have been attributed to recent impacts. If MBCs are indeed icy, they represent the closest and the third established reservoir of comets (after the Oort cloud and the Kuiper belt). As such, they may have been an important source of water for the Earth's oceans. I will review the current state of MBC studies, present the latest observational results and discuss possible mechanisms that could produce the observed activity. I will also talk about current and future space missions that are dedicated or closely related to MBC studies.

We analyze the flux of new and evolved long-period comets (LPCs) reaching the Earth's neighborhood (perihelion distances q < 1.3 AU), their physical lifetimes, and their implications as regards to the amount of meteoritic matter that is being deposited in the near-Earth region. The flux of LPCs with q < 1.3 au is found to be of about 340 ± 40, brighter than absolute total magnitude 8.6 (radius R ~ 0.6 km) (Fernández and Sosa 2012). Bearing in mind that most of these comets disintegrate into meteoritic matter, this represents a large contribution to the interplanetary dust complex which requires an amount of matter of about 10 tons s−1 to keep it in steady state. These aspects, as well as the impact rate with Earth of meteoroids of LPC origin, will be discussed in this presentation.

An outline of Brian Marsden's work in the field of small-body solar-system astronomy was presented.

The IAU Meteor Shower Working List contains 369 showers, of which only 64 are considered established (per February 28, 2012). In this invited review, we will give an overview of international efforts to validate the remaining showers. We report on the showers that were validated in this triennium and proposed to receive the predicate “established" at the present General Assembly. The meteoroid orbit surveys characterize the meteoroid streams in terms of orbital elements and their dispersions, which is ground truth for efforts to identify their parent comets, study the fragmentation history of the (mostly dormant) comet population in the inner solar system, and understand the origin of the zodiacal cloud.

NEOs come close to the Earth's orbit so that any dust ejected from them, might be seen as a meteor shower. Orbits evolve rapidly, so that a similarity of orbits at one given time is not sufficient to prove a relationship, orbital evolution over a long time interval also has to be similar. Sporadic meteoroids can not be associated with a single parent body, they can only be classified as cometary or asteroidal. However, by considering one parameter criteria, many sporadics are not classified properly therefore two parameter approach was proposed.

Within a period of ~3 months there were two extended mission flybys of comets. Both encounters have provided an exciting new view of comet activity and volatile composition that is changing our paradigm of these small early solar system remnants. The EPOXI mission flew past the nucleus of comet 103P/Hartley 2 on 4 Nov. 2010. This small nucleus was known to be exceptionally active prior to the encounter, by virtue of a very large water production rate relative to its surface area. Both the encounter and ground-based data showed that comet Hartley 2fs perihelion activity was dominated by sub-surface CO2 outgassing rather than by water, suggesting our classic comet formation picture is not correct. The gas flow carried large grains (up to >10 cm in diameter) from the nucleus, and the icy grains contributed to the large observed water production. The CO2 abundance relative to water varies with rotation between 10-20% between the two lobes of the nucleus. The bi-lobed nucleus is rotating in an excited state, with a period that varied rapidly from ~16.5 hrs to longer than 18.5 hrs over 3 months. The nucleus morphology was different from that of other nuclei visited by space craft, with some regions of rough topography in which surface ice was visible. On 2011 Feb. 14 the Stardust-NExT spacecraft flew past the nucleus of comet 9P/Tempel 1, the target of the Deep Impact (DI) experiment in July 2005. The mission goal was to look at the nucleus after and intervening perihelion passage, extending the surface area imaged during the DI encounter and also image the 2005 impact site. The layering seen during the DI flyby was exhibited over the areas newly imaged in the NExT flyby, and it was found that 30% of the nucleus was covered by smooth deposits that were likely caused by eruption of subsurface materials. Although it has long been known that comets lose on average ~ a meter of their surface per perihelion passage, it was surprising to see that in the regions imaged by both DI and NExT there was little change in the surface photometric properties and morphology with the exception of the prominent smooth flow edges. As seen from both the spacecraft and ground-based campaign, the comet continued its trend of decreasing activity from previous perihelion passages. We will present highlights from both missions and discuss implications for formation scenarios.

Meteorites are some of the most important and valuable rocks available for scientific study. Approximately 43,000 meteorites are known on Earth and are egeologicalf samples of extraterrestrial bodies - meteorites are known to originate from asteroids, the Moon, Mars and possibly comets. With expanding exploration of our Solar System, meteorites provide the eground truthf to compare data collected by robotic missions with results gained from a variety of more accurate and precise techniques using laboratories on Earth. This talk will give an introduction to the history of meteorite science and the importance of meteorite collections to the field of meteoritics, planetary and solar system science. Curation of extraterrestrial samples is a particularly pertinent issue, especially with regards to particularly rare samples such as those from Mars like the recent Tissint meteorite. Future sample return missions to asteroids and Mars also pose siginificant challenges around the curation of these precious materials. Issues surrounding the curation of samples and how curation and curatorial actions can influence scientific studies will also be discussed.

Comets generally stay long in the sky and can be seen from many places on the surface of the Earth. We are interested in historical comets which were observed at plural sites. We have shown in a previous work (Tanikawa & Sôma, 2008) that in the seventh century, five comets were observed independently in China and Japan. From this fact and other data, we deduced that Japanese observational astronomy started in the seventh century. We know that, other than China and Japan, Korea and Vietnam had observational astronomy before the 9th century. We look for historical comets observed at plural sites by surveying the existing literature of respective countries. Examining the independence of the records, we provide a list of comets observed independently at plural sites. This strengthens the reliability of the records of comets. The list can be used for other purposes.

We have compiled and analyzed historical meter and meteor shower records in Korean, Chinese, and Japanese chronicles. We have confirmed the peaks of Perseids and an excess due to the mixture of Orionids, north-Taurids, or Leonids through the Monte-Carlo test from the Korean records. The peaks persist for almost one thousand years. We have also analyzed seasonal variation of sporadic meteors from Korean records. Major features in Chinese meteor shower records are quite consistent with those of Korean records, particularly for the last millennium. Japanese records also show Perseids feature and Orionids/north-Taurids/Leonids feature, although they are less prominent compared to those of Korean or Chinese records.

This paper outlines current achievements of the Hayabusa mission and future small body missions with an emphasis on scientific prospects by both remote sensing in the vicinity of target objects and retuned sample analyses of them. First, the Hayabusa spacecraft aimed as technology demonstration for the worldfs first deep space round trip and sample return from an asteroid and it was launched via the M-V rocket in May of 2003. Soon after the touchdown on Asteroid Itokawa, a sub-km, S-type NEO in November 2005, the spacecraft lost its attitude control due to the leak of RCS propellant; the communication link was lost for 46 days. While the ion engine thrusters reached their lifetime by November of 2009 owing to either of an ion source or neutralizers at each engine, a challenging combination of the neutralizer-A with the ion source-B was devised to resume the spacecraftfs propulsion. This enabled the spacecraft to have returned to the Australian desert on the Earth in June 2010. The sample return capsule (SRC) was successfully recovered and returned to Japan for initial inspection of the Itokawa samples. After the announcement of initial sample analysis results, international announcement of sample distributions has started in the spring of 2012. Following up the original Hayabusa mission, JAXA has approved the Hayabusa-2 project in 2011, an asteroid sample return mission to 1999 JU3, a sub-km, C-type NEO aiming for 2014-5 launch, 2018-9 remote sensing including artificial impactor excavation and 2020 Earth return of both surface and sub-surface samples of the asteroid. C-type asteroid is thought to be abundant in organic matters and hydrated compound, so it has important clues to solve the origin and evolution of the life. NASAfs OSIRIS-Rex and ESAfs Marco Polo-R missions are also carbonaceous asteroid sample return missions in 2010fs-2020fs. Cometary nucleus or/and D-type asteroid sample returns like Hayabusa-Mk-II concept are natural progression of this type of the endeavor. JAXAfs solar power sail mission aims for eventual rendezvous with Jovian Trojan asteroids, reservoir of D/P-type asteroids as either leftovers of Jupiter system formation or the second generation intruders from the Kuiper belt regions.

We analyze the orbital distribution of objects captured to near-Earth space from the flux of comets coming from the outer Solar system. For this purpose, we use the model of the cometary cloud developed earlier (Emelfyanenko, Asher, Bailey, 2007). This model is consistent with the broad dynamical characteristics of observed near-parabolic comets, short-period comets, Centaurs and high-eccentricity trans-Neptunian objects. We show that the observed distributions of both large and small near-Earth objects are different from the modeled distribution formed dynamically by the action of planetary perturbations. In particular, while the distributions of arguments of perihelion for observed Jupiter-family comets and modeled cometary asteroids follow a sinusoidal law with pronounced maxima around 0 and 180 degrees, it is not the case for observed cometary asteroids of any size. We conclude that there exist many unobserved extinct short-period comets among near-Earth objects of various sizes.

The study objects of our work were 91 TNO with diameters greater than 200 km. On the other hand, the paper used the data for 1048 and comets with aphelion and perihelion distances Q > 30 AU and q > 0.1AU, respectively, were observed until 2012. Short-perihelion comets (sporadic and concentrated in separate groups) were excluded from the analysis. If some comet split into several parties, we have taken data for only one fragment, which is marked with the letter A. Data for comets are taken from the catalog [4] and the individual Circulars International Astronomical Union, issued in period after 2008. The data for TNO, mostly borrowed from the website [5], as well as the issues of the same circulars.

Current status and prospects of further investigations are considered for: 1.Anomaly distribution of Na-atoms emission in the cometary heads; 2. Mechanisms of X-ray generation in comets; 3. Evolution of sungrazing comets near the Sun.

The distance between the pre-impact surface of Comet 9P/Tempel 1 and the upper border of the largest cavity with dust and gas under pressure excavated after the collision of the impact module of the Deep Impact spacecraft with the comet is estimated to be about 6 m if the diameter of the transient crater was about 200 m. This result suggests that cavities containing dust and gas under pressure located a few meters below surfaces of comets can be frequent.

We introduce a new data reduction method for Hayabusa/AMICA data to subtract a scattered light inside the optics. As the result, we obtained a map of space weathering on Itokawa for all available channels.

We investigated comets active at large heliocentric distances using observations obtained at the 6-m BTA telescope (SAO RAS, Russia). Long-slit and photometric modes of the focal reducer SCORPIO were used. Two of the comets, 29P/Schwassmann-Wachmann 1 (SW1) and C/2002 VQ94 (LINEAR) were observed to be emission rich. Detection of CO+ and N2 + emissions in the comae of these comets is evidence that they were formed in the outer regions of the Solar System or in a pre-solar interstellar cloud in a low temperature environment with T ~ 25K. The ratio of N2+/CO+ is equal to 0.011 and 0.027 for SW1 and LINEAR, respectively. Comet LINEAR is the most distant object in the Solar System (7.332 AU) for which CO+ and N2+ are measured. The photometric maximum of the isolated CO+ coma in comet LINEAR is shifted by 1.4 arcsec (7.44 × 103 km) relative to the photometric maximum of the dust coma. This shift deviates from the sunward direction by 63 degrees.

Visible 4-color simultaneous imager is being developed for a new 2-m telescope at Lulin observatory in Taiwan. The main task of this instrument is quick and efficient follow-up observations for large scale surveys, such as PS1 sky surveys. NCUcam-1 is one of unit cameras for this instrument. It is equipped with a new type of CCD chip, fully depleted CCD, and have superb sensitivity at the wavelength of 1 micron. Igneous asteroids exhibit prominent absorption feature around 1 micron due to minerals, and NCUcam-1 is able to deliver reliable taxonomic classifications. NCUcam-1 has achieved the first-light using 1-m telescope at Lulin in July 2011. Results of the characterization work for NCUcam-1 and tests observations of asteroids are reported. Upcoming plan for the study of pair asteroids search and identification is also presented.

Spectroscopic observations of evolved stars have shown signatures of aromatic and aliphatic compounds. This suggests that complex organics with chemical structures similar to those of insoluble organic matter (IOM) found in carbonaceous meteorites are made in stars. This raises the possibility that in addition to known pre-solar grains such as silicon carbide, organic star dust may also have traveled across the Galaxy to the Solar System.

Space-based and remote sensing observations reveal that regolith – a layer of loose unconsolidated material – is present on all asteroids, including very small, subkm-sized near- Earth asteroids (NEAs) such as (25143) Itokawa. Classically, regolith is believed to be produced by the ejecta of impact craters produced by small particles hitting asteroid surfaces. Such an explanation works for bodies whose gravity field is strong enough for substantial reaccretion of impact debris, but it fails to account for the ubiquitous presence of regolith also on small asteroids with weaker gravity. Several works have proposed that the thermal fatigue due to a huge number of day/night temperature cycles is a process that contributes to the formation of regolith on the Moon, Mercury, and on the NEA (433) Eros by fracturing boulders and rocks on their surfaces. However, this process lacks a demonstration: in order to study under which conditions rock cracking on NEAs occurs, we calculated typical temperature cycles for NEAs and we performed laboratory experiments of similar thermal cycling on meteorites taken as analogue of asteroid surface material. We will present results of these experiments and discuss their implications regarding regolith formation on asteroids.