Earth 2.0 – have we found a replacement?

Fancy jetting off somewhere new and exotic for your holidays this year? How about the newest, most expensive option out there?

Proxima b is your newly discovered, closest neighbouring habitable planet. Only 4.25 light years away, this rocky planet orbits our nearest star, Proxima Centuri. With a mass 1.3 times that of Earth, and a surface temperature which may, hopefully, if there’s an atmosphere, allow liquid water oceans to form, this planet may just be visit-able. A year long holiday on this planet is the perfect length – it lasts only 11.2 Earth days, excluding the 70,000 years of travel on modern spacecraft each way.

Okay, so the average surface temperature could be anything from…

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Mapping the stars

The biggest ever map of the sky has been created. It includes the location and brightness of 1,142,000 stars, and two million of these also have their motion across the sky mapped.

Pictures from ESA’s Gaia satellite have been compiled by a team of 450 scientists and software engineers. The satellite is half way through its five year mission to collect data on billions of stars in the Milky Way, just 1% of all the stars in the galaxy. The pictures come from the first 14 months of the mission.

Soon, the team will…

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A lumpy model for a lumpy universe

Computer models are used for all sorts of applications, from designing cars to predicting the weather. They are even used to simulate the whole universe, to work out how it was born, and what might happen next. Until now, the universe has been modelled using numerical simulations, which are quick and simple, but limited by the assumptions they make and their use of Newtonian gravity instead of Einstein’s general relativity.

A typical numerical simulation assumes that the universe is isotropic and homogeneous, meaning that all of its matter is distributed evenly throughout. This is true on a large scale, but on smaller scales the matter is gathered into clusters of galaxies and dark matter, and the rest of space is empty. This means that expansion of the universe occurs at different rates in different places – spots dense with matter will be pulled closer together by their gravity and expand slower, and empty spaces will expand unhindered (28% faster than the average rate of expansion!).

Two sets of code have now been written independently using…

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Meteorites solve a mystery of life?

In the lab, two chemical products are normally made. The product is a racemic mixture, meaning that it is composed of molecules which are structurally identical, but which are mirror images of each other. Mysteriously, in biological processes, only one of these mirror images is made.

The pair of mirror molecules are called enantiomers, and arise from the chirality of the molecule. If a molecule is chiral, its mirror image is not superimposable onto the original molecule. A reaction gives one or both mirror images, which are labelled right handed (D enantiomers) or left handed (L enantiomers). In nature, normally only the right handed version of any sugars, and the left handed enantiomer of any amino acids is made, allowing the reactions within the body to be so selective.

But where does this homochirality come from? Analysis…

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