Found 8 talks width keyword Earth

sara_seager_141023s
Thursday October 23, 2014
Prof. Sara Seager
MIT

Abstract

The discovery and characterization of exoplanets have the potential to offer the world one of the most impactful findings ever in the history of astronomy?the identification of life beyond Earth. Life can be inferred by the presence of atmospheric biosignature gases? Gases produced by life that can accumulate to detectable levels in an exoplanet atmosphere. Detection will be made by remote sensing by sophisticated space telescopes. The conviction that biosignature gases will actually be detected in the future is moderated by lessons learned from the dozens of exoplanet atmospheres studied in last decade, namely the difficulty in robustly identifying molecules, the possible interference of clouds, and the permanent limitations from a spectrum of spatially unresolved and globally mixed gases without direct surface observations. The vision for the path to assess the presence of life beyond Earth is being established.


john_houghton_140327s
Thursday March 27, 2014
Prof. John Houghton
Univ. of Oxford

Abstract

Because of the carbon dioxide emissions from fossil fuel burning, the Earth's atmosphere and oceans are warming through what is known as the "greenhouse effect". Big changes are on their way which we have not yet seen because of the time taken for the oceans to warm. It is essential that human communities prepare to adapt to these changes e.g. in sea level rise, severe heat waves, and a greater frequency of climate extremes.

The challenge to scientists is to learn enough about the complexities of the world's climate system to be able to project the climate's likely future.

The nations and peoples of the world need to recognise the urgency of the many actions that can - and must be taken.


francisco_gonzalez_posada_131120s
Wednesday November 20, 2013
Prof. Francisco González Posada

Abstract

Jorge Juan y Santacilia (Novelda, 1713; Madrid, 1773) participó en la expedición científica organizada por la Academia de Ciencias de París al Ecuador (Virreinato del Perú, entonces) para determinar 'definitivamente' la forma y tamaño de la Tierra, con la intención de resolver la perturbadora pugna científica entre los partidarios de las ideas de Descartes y Newton. A su regreso publicó con Antonio de Ulloa la obra, que se estableció como 'histórica', Observaciones astronómicas y físicas, que precedió a las referencias francesas. Con Louis Godin, académico francés director de la referida expedición científica, en la Academia de Caballeros Guardias Marinas de Cádiz, estableció el primer Observatorio Astronómico del sur de Europa (hoy Real Instituto y Observatorio Astronómico de la Armada, en San Fernando), y su discípulo José Celestino Mutis construiría en Santa Fe de Bogotá el primer Observatorio Astronómico de las Américas.


javier_licandro_130404s
Thursday April 4, 2013
Dr. Javier Licandro
IAC

Abstract

On February 15, while we were preparing to observe the close approach of the potentially hazardous asteroid (PHA) 2012 DA14 another small asteroid entered the Earth’s atmosphere over Russia. The object, of about 17m in diameter and  11.000 tons exploded in the atmosphere generating a bright flash, a powerful shock wave and small fragmentary meteorites. About 1500 people were injured because of the shock wave effects in the city of Chelyabinsk located east of the Ural Mountains and on the border of Europe and Asia. The more than 400 kilotons released suggest that this was largest asteroid that entered the Earth atmosphere since the 1908 Tunguska event.

The differences between the orbits of DA14 and the asteroid that caused the Chelyabinsk event showed that both objects are not related. The composition of the meteorite and the spectrum of DA14 we obtained with the GTC also support that.

In this talk I will resume all the information about the Chelyabinsk event and discuss the relevance of studying the near-Earth asteroids, in particular the PHAs, and present the main results of our study of asteroid DA14 (de León et al. 2013). I will also discuss the relevance of space mission studies on this objects and resume our participation in MarcoPolo-R and AIDA missions. 


seigo_miyamoto_valeri_tioukov_121022s
Monday October 22, 2012
Dr. Seigo Miyamoto, Dr. Valeri Tioukov
ERI, University of Tokyo, Japan
INFN, Napoli, Italy

Abstract

The origin and structure of the Earth's crust is still a major question. Current measurements of the nearby crust are based largely on seismic, gravimetric and electrical  techniques. In this talk, we introduce a novel method based on cosmic-ray muons to create a direct snapshot of the density profile within a volcano (and/or other geological features).  By measuring the muon
absorption along the different paths through an object (volcano, mountain, a fault, ...), one can deduce the density profile within the object. The major feature of this
technique makes possible for us to perform a tomographic measurement by placing two or more cosmic ray detection
systems around the object. Another strong point of this technique is the possibility to carry out fulltime monitoring, since  muons are incessantly arriving, recalling they are
the most numerous energetic charged particles at sea level.


enric_palle_bago_090612s
Friday June 12, 2009
Dr. Enric Pallé Bago
Instituto de Astrofísica de Canarias, Spain

Abstract

Of the 342 planets discovered so far orbiting other stars, 58 'transit' the stellar disk, meaning that they can be detected by a periodic decrease in the starlight flux. The light from the star passes through the atmosphere of the planet, and in a few cases the basic atmospheric composition of the planet can be estimated. As we get closer to finding analogues of Earth, an important consideration toward the characterization of exoplanetary atmospheres is what the transmission spectrum of our planet looks like. Here we report the optical and near-infrared transmission spectrum of the Earth, obtained during a lunar eclipse. Some biologically relevant atmospheric features that are weak in the reflected spectrum (such as ozone, molecular oxygen, water, carbon dioxide and methane) are much stronger in the transmission spectrum, and indeed stronger than predicted by modeling. We also find the fingerprints of the Earth's ionosphere and of the major atmospheric constituent, diatomic nitrogen (N2), which are missing in the reflected spectrum. Our results indicate that the technique of transit spectroscopy of rocky planets may be a very powerful tool for exoplanet atmospheric characterization, and is likely to provide the first detection of a habitable exobiosphere.

antonio_garcia_munoz_090305s
Sunday May 3, 2009
Dr. Antonio García Muñoz
Instituto de Astrofísica de Canarias, Spain

Abstract

There is a multitude of photochemical processes occurring in a planet's atmosphere. Some of these processes occur with an excess of energy and lead to products in the form of excited atoms, molecules and ions.In specific cases, these gases radiate at wavelengths that range from the UV to the NIR. Solar light is the ultimate cause of these airglow emissions, but traditionally one distinguishes between the day airglow (dayglow), and the night airglow (nightglow). The contribution of the Sun to the excitation of the emitting gas is more immediate in the day glow than in the nightglow. The airglow makes it possible to remotely investigate the chemical kinetics, energetic balance and dynamics of a planetary atmosphere. In the talk, I will go over some of the air glow missions that are known to exist in the atmospheres of the Earth, Mars and Venus. The examples illustrate some of my recent work, and include theoretical modelling and the interpretation of observational data. There is a long record of contributions to the nightglow from observations carried out at ground-based telescopes. I will briefly comment some of these.

humberto_campins_081007s
Tuesday October 7, 2008
Dr. Humberto Campins
University Central Florida, USA/ Instituto de Astrofísica de Canarias, Spain

Abstract

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.


« Newer Older »