Category Astronomy/Space

This highly shocked zircon, from the Vredefort Dome in South Africa, shows thin, red bands that are a hallmark of meteorite impact. Photo: Aaron Cavosie

A study of zircons from a gigantic meteorite impact in South Africa casts doubt on the methods used to date lunar impacts. Durable crystals zircons are used to date some of the earliest and most dramatic cataclysms of the solar system. One is the super-duty collision that ejected material from Earth to form the moon roughly 50 million years after Earth formed. Another is the late heavy bombardment, a wave of impacts that may have created hellish surface conditions on the young Earth, about 4 billion years ago.

Both events are widely accepted but unproven, so geoscientists are eager for more details and better dates...

Proposed 15 yrs ago, the bounded L2 curvature conjecture has finally been proved by a group of 3 researchers at the Laboratoire Jacques-Louis Lions (CNRS / UPMC / Université Paris Diderot) and Princeton University. It provides a potentially minimal framework in which it is possible to solve the Einstein equations, which in turn could be a critical step toward the proof of major conjectures, such as Penrose’s cosmic censorship conjectures. This work has appeared in Inventiones Mathematicae Oct14

Even though this yr marks its 100th anniversary, Albert Einstein’s theory of general relativity still holds its share of mysteries. This theory of gravitation stipulates that matter curves spacetime in proportion to the mass of the object...

Cartoon illustration. Credit: Christine Daniloff/MIT

Fueling up on the moon could lighten cargo by 68% on the journey to Mars. Previous studies have suggested that lunar soil and water ice in certain craters of the moon may be mined and converted to fuel.

The group developed a model to determine the best route to Mars, assuming availability of resources and fuel-generating infrastructure on the moon. They found the most mass-efficient path involves launching a crew from Earth with just enough fuel to get into orbit around Earth. A fuel-producing plant on the surface of the moon would then launch tankers of fuel into space, where they would enter gravitational orbit...