Category Astronomy/Space

Yasha Neiman grapples with complex conundrums in quantum gravity on a daily basis. Credit: OIST

A new perspective bridges two approaches to understanding quantum gravity. “As we learn more, reality becomes ever more subtle; the absolute becomes relative, the fixed becomes dynamical, the definite is laden with uncertainty,” writes physicist Yasha Neiman. A professor and head of the Quantum Gravity Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), he grapples with this conundrum on a daily basis. Quantum gravity, Neiman’s branch of physics, aims to unify quantum mechanics, which describes nature at the scale of atoms and subatomic particles, with Einstein’s theory of General Relativity – the modern theory of gravitation as curvature of space and time...

A potential interstellar dust track (circled) in Stardust’s aerogel collector. Credit: UC Berkeley/Andrew Westphal

More samples of comets are urgently required to better understand the early history of the solar system, say researchers analyzing comet dust brought back to Earth by NASA’s Stardust mission in 2006. The dust particles are from Comet 81P/Wild (also known as Wild 2) and date to the beginning of the solar system, containing clues about its earliest history. “The future of Stardust science”, which is a paper published in June 2017 in the journal Meteoritics & Planetary Science, summarizes the roughly 150 scientific publications based on Stardust science...

This large, fuzzy-looking galaxy is so diffuse that astronomers call it a ‘see-through’ galaxy because they can clearly see distant galaxies behind it. The ghostly object, catalogued as NGC 1052-DF2, doesn’t have a noticeable central region, or even spiral arms and a disk, typical features of a spiral galaxy. But it doesn’t look like an elliptical galaxy, either. Even its globular clusters are oddballs: they are twice as large as typical stellar groupings seen in other galaxies. All of these oddities pale in comparison to the weirdest aspect of this galaxy: NGC 1052-DF2 is missing most, if not all, of its dark matter. Credit: NASA, ESA, and P. van Dokkum (Yale University)

Galaxies and dark matter go together like peanut butter and jelly. You typically don’t find one without the other...

Surface of Mercury – credit: NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State University

A hot, metallic, Earth-sized planet with a density similar to Mercury – situated 339 million light years away – has been detected and characterised by a global team of astronomers, including the University of Warwick. Named K2-229b, the planet is almost 20% larger than Earth but has a mass which is over 2.5X greater – and reaches a dayside temperature of over 2000°C (2330 Kelvin). It finds itself very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits this star every fourteen hours.

Using the K2 telescope, Dr Armstrong and colleagues employed the D...