Uncategorized

A limiting factor for the survival of life in a changing environment is the intracellular production of reactive oxygen species. These can damage the building blocks of life (DNA, proteins, lipids) through oxidation. All organisms, including microbial extremophiles, have developed mechanisms to quench the reactivity of oxygen species or avoid their production. Not surprisingly, these same molecules are drivers for evolution.

At the present time, Mars is a dry and cold planet. Surface ice is unstable for more than one season outside the polar regions, and the atmosphere is so cold or so dry that the presence of liquid water, never detected, is unlikely anywhere on the surface.

It is often said that mathematics is a universal language that we could use to make contact with another intelligence. But is that really the case? Or is this just a disguised version of anthropocentrism?

Although they are relatively frequent as free-floating objects, brown dwarfs are scarcely found as companions to solar-type stars. The paucity of brown dwarfs in close-orbits first noticed by radial velocity surveys has led to the concept of the "brown dwarf desert".

One of major advances of string theory in recent years was an understanding that vacuum solutions with potentially viable four-dimensional cosmology come in a plethora of an incredibly large and rich 'landscape' of string theory vacua. The number of possible vacua and, in turn, types of Universes, may exceed 10 to the power 1000.

Common wisdom holds that, in order for a terrestrial planet to have life, it's helpful to have a Jupiter-like planet in the system to shield against inbound comets. How well does Jupiter do that really? Common wisdom held until recently that it would be an impossible for an icy object like Ceres to exist within the inner Solar System. From where did the ice come? Common wisdom held until recently that the Centaur asteroids and Kuiper Belt objects were dynamically distinct. Are they?

Marking the 100th anniversary of teams led by Roald Amundsen and Robert Scott reaching the South Pole, science historian Edward Larson will reexamine their so-called Race to the Pole in light of their objectives. Amundsen and his men focused exclusively on reaching the pole and succeeded brilliantly. Scott and his men had multiple objectives, which included conducting a broad array of scientific research by teams of researchers that fanned out across the region. Larson will retell the story of these expeditions in context and contrast it with the conventional wisdom about them.

With the retirement of the Space Shuttle this past summer the United States entered a new era, one in which U.S. astronauts will be flying only aboard the Russian Soyuz vehicle in order to access Low Earth Orbit and the International Space Station. California headquartered Space Exploration Technologies (SpaceX) has developed and twice launched a brand new launch vehicle (Falcon9), as well as launched and recovered a space capsule designed for humans (Dragon). SpaceX will soon begin delivering cargo, and ultimately plans on launching crew, to the International Space Station from U.S. soil.