We present the results of experiments performed in the Padua simulators of planetary environments, named LISA, used to study the limits of bacterial life on the planet Mars. The survival of Bacillus strains for some hours in Martian environment is briefly discussed.

Currently the only technique sensitive to Earth mass planets around nearby stars (that are too close for microlensing) is the monitoring of the transit time variations of the transiting extrasolar planets. We search for additional planets in the systems of the hot-Neptune GJ-436 b, and the hot-Jupiter XO-1 b, using high cadence observations in the J and KS bands, with the SofI and ISAAC instruments from La Silla Paranal Observatory. New high-precision transit timing measurements were used to derive new ephemeris. No statistically significant timing deviations were detected. We demonstrate that the high cadence ground based near-infrared observations are successful in constraining the mean transit time to 30 sec, and are a viable alternative to space missions.

We used the method of Silva & Cruz (2006), which distinguishes between planetary and stellar companions by fitting transit light curves, to select the most promising CoRoT candidates to be monitored with radial-velocity measurements. Testing this method on the light curves of confirmed CoRoT exoplanetary systems shows that the estimated radius for such planets is smaller than 2 RJup, while for most of the light curves in which no planet has been detected, the secondary companion has an estimated radius larger than 2 RJup. We present preliminary results concerning other light curves for which no planet has been detected yet.

An important factor in estimating the likelihood of life elsewhere in the Universe is determining the stability of a planet's orbit. A significant fraction of stars like the Sun occur in binary systems which often has a considerable effect on the stability of any planets in such a system. In an effort to determine the stability of planets in binary star systems, we conducted a numerical simulation survey of several mass ratios and initial conditions. We then estimated the stability of the planetary orbit using a method that utilizes the hodograph to determine the effective eccentricity of the planetary orbit. We found that this method can serve as an orbital stability criterion for the planet.

In this paper we present an application of Bayesian model comparison to the radial velocity measurements of suspected extra-solar planetary system host star.

We present recent results of our ongoing multiplicity study of exoplanet host stars.

The atmospheres of close-in Extrasolar Giant Planets (EGPs) experience important stellar radiation, raising the question of the heat redistribution around the planetary surface and of the importance of photochemistry effects for their spectral properties. They experience mass loss via quasi-thermal escape of their lightest elements. They rotate and experience tidal effects. Model atmospheres struggle to include even part of this complexity. Some address the dynamics of the atmospheres as a whole (3D) as subjected to rotation, or as patches of the surface (wind studies), compromising on the details of the composition and radiative/convective properties. Others solve the composition and radiative/convective properties, compromising on dynamical effects such as rotation. In this paper, we review existing model atmospheres for EGPs, and present the first high spatial resolution local (as opposed to global) 2/3D radiation hydrodynamic simulations of EGP atmospheres including dust cloud formation.

The search for life in the universe relies on defining the limits for life and finding suitable conditions for its origin and evolution elsewhere. From the biological perspective, a conservative approach uses life on earth to set constraints on the environments in which life can live. Conditions for the origin of life, even on earth, cannot yet be defined with certainty. Thus, we will describe what is known about conditions for the origin of life and limits to life on earth as a template for life elsewhere, with a particular emphasis on such physical and chemical parameters as temperature, pH, salinity, desiccation and radiation. But, other life forms could exist, thus extending the theoretical possibility for life elsewhere. Yet, this potential is not limitless, and so constraints for life in the universe will be suggested.

To prepare future observations of terrestrial planets and the detection of life, we search for life on the planet Earth seen as a point source. Observations of Earthshine is a convenient way to see Earth as a remote planet. The vegetation reflectance spectrum presents a sharp edge in the near infrared: the Vegetation Red Edge. Observational programs in progress are described, particularly our observations at the Concordia station in Antarctica.

Glycolaldehyde is the simplest of the monosaccharide sugars and is directly linked to the origins of life. We report on the detection of glycolaldehyde (CH2OHCHO) towards the hot molecular core G31.41+0.31 through observations with the IRAM PdBI (Plateau de Bure Interferomter) at 1.4, 2.1, and 2.9 mm.

We describe the LWARD program on dM stars and habitability in their environment.

We performed numerical simulations to study the secular orbital evolution and dynamical structure of the quintuplet planetary system 55 Cancri using the self-consistent orbital solutions of Fischer et al. (2008).

Despite the number of known exoplanets increasing on an almost weekly basis, the question as to whether exoplanets host moons remains unanswered. Exomoons could be potential seats for life, as well as improving our understanding of planetary formation and celestial mechanics. Here we summarize our findings from an investigation into how detectable habitable-zone exomoons are with Kepler-class photometry.

We report on a statistical study of models for the formation of habitable planets.

We report on mid-infrared (8–13 μm) spectroscopic observations of eight FU Orionis type objects and discuss a qualitative initial mineralogical analysis.

In this study, we model the internal structure of CoRoT-7b, considered as a typical extrasolar terrestrial planet, using mass and energy balance constraints. Our results suggest that the deep interior is predominantly composed of dry silicate rock, similar to the Earth's Moon. A central iron core, if present, would be relatively small and less massive (<15 wt.% of the planet's total mass) as compared to the Earth's (core mass fraction 32.6 wt.%). Furthermore, a partly molten near-surface magma ocean could be maintained, provided surface temperatures were high enough and the rock component mainly composed of Earth-like mineral phase assemblages.

After their formation, and for almost 0.5 Gyr, Mars and Earth evolved in the same manner. On Earth, life occured very early, around 3.6 Gy ago. Then, the hypothesis that life might have occured also on Mars, and be extinct, is not unrealistic. If this is true, then complex molecules could be present, representing an early state of life-building blocks. Missions to Mars (Viking 1-2, Phoenix) have carried instruments capable to search for molecular indicators, although up to now, no positive detection has been obtained. Future missions to Mars (MSL-NASA, Exomars-ESA) will use enhanced experiments to try to end this quest.

The Kepler Mission successfully launched March 6, 2009, beginning its 3.5-year mission to determine the frequency of Earth-size planets in the habitable zones of late-type stars. The brightnesses of over 100,000 stars are currently being monitored for transit events with an expected differential photometric precision of 20 ppm at V=12 for a 6.5-hour transit. The same targets will be observed continuously over the mission duration in order to broaden the detection space to orbital periods comparable to that of Earth. This paper provides an overview of the selection and prioritization criteria used to choose the stars that Kepler is observing from the > 4.5 million objects in the 100 square degree field of view. The characteristics of the Kepler targets are described as well as the implications for detectability of planets in the habitable zone smaller than 2R⊕.

The SIM Lite Astrometric Observatory is an optical astrometry mission for detection of Earth-like planets and investigation of dark matter, galaxy assembly, black holes etc. SIM Lite is a minimum system that performs the full NRC recommenced SIM science programs. This paper summarize the latest status and progresse of the SIM Lite space mission.

In its all-sky survey, the ESA global astrometry mission Gaia will perform high-precision astrometry and photometry for 1 billion stars down to V = 20 mag. The data collected in the Gaia catalogue, to be published by the end of the next decade, will likely revolutionize our understanding of many aspects of stellar and Galactic astrophysics. One of the relevant areas in which the Gaia observations will have great impact is the astrophysics of planetary systems. This summary focuses on a) the complex technical problems related to and challenges inherent in correctly modelling the signals of planetary systems present in measurements collected with a space-borne observatory poised to carry out precision astrometry at the micro-arcsecond (μas) level, and b) on the potential of Gaia μas astrometry for important contributions to the astrophysics of planetary systems.