Nasa has developed "toy like" autonomous robots to carry out scientific surveys of treacherous areas of the Arctic and Antarctic.The SnoMotes robots are designed to operate in terrain deemed too dangerous for scientists.The devices can record data including barometric pressure,

NASA will hold a media teleconference on Thursday, July 24, at 1 p.m. EDT, to announce the first results from a fleet of five satellites that have discovered what powers sudden brightening and rapid movements of the Northern Lights, or

The heads of the International Space Station agencies from Canada, Europe, Japan, Russia and the United States met at European Space Agency Headquarters in Paris on July 17, 2008.

NASA Administrator Michael Griffin on Thursday announced that Rob Strain will be the next center director of NASA's Goddard Space Flight Center in Greenbelt, Md.

The Stationair is a Cessna (a Textron company) single-piston engine aircraft. The roots of the Stationair lie in the Cessna 210 model. In 1963 Cessna released a modified 210 (fixed landing gear and altered doors) as the Cessna 205; the

Several f(R) modified gravity models have been proposed which realize thecorrect cosmological evolution and satisfy solar system and laboratory tests.Although nonrelativistic stellar configurations can be constructed, we arguethat relativistic stars cannot be present in such f(R) theories. This problemappears due

We present and discuss the bounds from the energy conditions on a generalf(R) functional form in the framework of metric variational approach. As aconcrete application of the energy conditions to locally homogeneous andisotropic f(R)-cosmology, the recent estimated values of the

We investigate the future evolution of the dark energy universe in modifiedgravities, including $F(R)$-theory, string-inspired scalar-Gauss-Bonnet andmodified Gauss-Bonnet gravities and ideal fluid with inhomogeneous equation ofstate (EoS). Modified Friedmann-Robertson-Walker (FRW) dynamics for all thesetheories may be presented in universal form

We propose an extension of General Relativity with two different metrics. Toeach metric we define a Levi-Cevita connection and a curvature tensor. We thenconsider two types of fields, each of which moves according to one of themetrics and its connection.

We develop a theoretical framework that allows us to compare electromagnetismand gravitation in a fully covariant way. This new scenario does not rely onany kind of approximation nor associate objects with different operationalmeaning as it's sometime done in the literature.

We consider a loop-quantum gravity inspired modification of generalrelativity, where the Holst action is generalized by making the Barbero-Immirzi(BI) parameter a scalar field, whose value could be dynamically determined. Themodified theory leads to a non-zero torsion tensor that corrects the

A detailed study is presented of the counterrotating model (CRM) for genericelectrovacuum static axially symmetric relativistic thin disks without radialpressure. We find a general constraint over the counterrotating tangentialvelocities needed to cast the surface energy-momentum tensor of the disk as

Starting from the canonical phase space for discretised (4d) BF--theory, weimplement a canonical version of the simplicity constraints and construct phasespaces for simplicial geometries. Our construction allows us to study theconnection between different versions of Regge calculus and approaches usingconnection

We present the results of the first joint search for gravitational-wavebursts by the LIGO and GEO600 detectors. We search for bursts withcharacteristic central frequencies in the band 768 to 2048 Hz in the dataacquired between the 22nd of February and

Several approaches to the dynamics of loop quantum gravity involvediscretizing the equations of motion. The resulting discrete theories are knownto be problematic since the first class algebra of constraints of the continuumtheory becomes second class upon discretization. If one treats

From the similarity between null infinity and horizons, we show how to set upproper frames near generic isolated horizons. The asymptotic expansion andreference spin frame are used to study gravitational radiation near genericisolated horizons and it turns out that the