Found 8 talks width keyword comets

Simons Observatory (SO) is a new Cosmic Microwave Background telescope currently under construction in the Atacama Desert, close to ALMA and other recent CMB telescopes. It will have six small aperture (42cm) telescopes (SATs), and one large aperture (6m) telescope (LAT), observing at 30-280GHz (1-10mm) using transition edge sensors (TES) and kinetic inductance detectors (KIDs). As well as observing the polarisation of the CMB to unprecedented sensitivity, the LAT will perform a constant survey at higher angular resolution, enabling the systematic detection of transient sources in the submm, with large overlap of optical surveys such as LSST, DESI and DES. As well as giving an overview of SO, I summarise the types of transient sources that are expected to be seen by SO, including flaring stars, quasars, asteroids, and man-made satellites.

Series: XXVIII Canary Islands Winter School of Astrophysics: Solar System Exploration

Topic: Cometary Science and the Rosetta Mission.

Lecture 2: Rosetta, a voyage to a comet and to our origins.

In this second talk, Dr. Küppers gives an overview of the Rosetta mission, from its launch in 2004 until the end of the mission, in September 2016, only a month before the celebration of this Winter School. The talk includes information on the instruments on-board the spacecraft, the two fly-byes to asteroids Steins and Lutetia, and the results obtained from the observations of comet 67P/C-G. 

Series: XXVIII Canary Islands Winter School of Astrophysics: Solar System Exploration

Topic: Cometary Science and the Rosetta Mission.

Lecture 1: Comets and the Rosetta mission. 

Dr. Küppers gives a general overview on comets in the context of the formation of the Solar System, describing their physical, dynamical, and compositional properties. The speaker describes cometary missions that have been sent before the Rosetta mission and lists some of the most important cometary science questions that are still unsolved or under debated.

Understanding the composition and the nature of any asteroid approaching the Earth, and consequently potentially hazardous, is a matter of general interest, both scientific and practical. The potentially hazardous asteroid 1999 RQ36 is especially accessible to spacecraft and is the primary target of NASA's OSIRIS-REx sample return mission. Spectra of this asteroid point to the most primitive meteorites (CIs and CMs) as the most likely analogs. Asteroid (3200) Phaethon is also particularly interesting. Together with 2005 UD and 2001 YB5, is one of the only 3 near-Earth asteroids with associated meteor showers, which mostly come from comets. There is evidence of the presence of hydrated minerals on its surface, usually associated with organic material. Both asteroids are classified as "B". B-type asteroids are found mostly in the middle and outer main belt and are believed to be primitive and volatile-rich. We combine dynamical and spectral information to identify the most likely main-belt origin of these two objects.

Comets may have played an important role in depositing the organic matter that, between 4,6 and 3,6 billion of years ago, allowed the formation of life on the primordial Earth. Nowadays, many complex organic molecules are routinely observed in the gaseous component of the comae by radio and near-IR observations. However a large quantity of organic matter may be under the form of solid, either as organic grains or organics embedded in silicate grains. The Giotto mission to the 1P/Halley comet revealed for the first time the in-situ presence of organic grains, that accounted for almost 50% of the mass of organic matter in its coma. Remote detection of these organic grains in other comets is very difficult because they rapidly sublimate under the solar radiation and their spectroscopic signatures are hidden within those of the refractory cometary dust. In this talk I will give a short review on the organic matter in comets, I will describe a method for detecting organic grains in comets and I will present recent results.

The role of asteroids and comet impacts on the origin of Earth’s water and organic molecules is reviewed. Earth is believed to have formed dry, and magma oceans probably destroyed any primordial organics on Earth. The oldest clear evidence for water on Earth is about 3.85 Ga, right after the “Late Heavy Bombardment” (LHB). Asteroid and comet impacts during the LHB probably contributed significantly to Earth’s water and organic inventory. Evidence for this contribution is found in the D/H isotopic ratios of meteorites and comets. The abundance and variety of organic solids in asteroids and comets also point at a significant contribution to the organic inventory of the early Earth. However, the pieces of this puzzle do not all fit into a neat picture and several questions remain unanswered.

Radar observation of near-Earth asteroids (NEAs) reveal the size, shape, spin characteristics of the population of small bodies near the Earth. Although spacecraft missions may give higher resolution images, they are infrequent and expensive. Only through ground based observations can we hope to understand the diverse population of NEAs. Radar imaging reveals surface features and shape at up to 7.5-m resolution. We see a surprising variety of object shapes, which tells us about their formation and evolution. Binary NEAs are easily detected using radar regardless of viewing geometry, the characteristics of which have led to new ideas about NEA evolution and internal structure. Craters and other surface concavities are often visible in radar images, unlike lightcurve-based shape models. Although opportunities to observe comets with radar are rare, more than ten comet nuclei have been detected to date, three with high resolution imaging. Radar observations have played an important role in a number of key areas in small body science, some of which will be discussed in this talk.