Institute of Astronomy

Astronomy News

Is NASA doing enough to look for alien life?

17 June 2016 - 11:29am

A new study says Hubble's successor could spot alien life on three new exoplanets. Should NASA be doing more? Or is it right to focus on other priorities?

LIGO discovers new gravitational wave – and new era of astronomy

17 June 2016 - 11:29am

The detector's latest discovery means we are now firmly in a new era of astronomy – it matches up convingingly with what we already know about black holes

Fission and reconfiguration of bilobate comets as revealed by 67P/Churyumov–Gerasimenko

17 June 2016 - 11:26am

Fission and reconfiguration of bilobate comets as revealed by 67P/Churyumov–Gerasimenko

Nature 534, 7607 (2016). doi:10.1038/nature17670

Authors: Masatoshi Hirabayashi, Daniel J. Scheeres, Steven R. Chesley, Simone Marchi, Jay W. McMahon, Jordan Steckloff, Stefano Mottola, Shantanu P. Naidu & Timothy Bowling

The solid, central part of a comet—its nucleus—is subject to destructive processes, which cause nuclei to split at a rate of about 0.01 per year per comet. These destructive events are due to a range of possible thermophysical effects; however, the geophysical expressions of these effects are unknown. Separately, over two-thirds of comet nuclei that have been imaged at high resolution show bilobate shapes, including the nucleus of comet 67P/Churyumov–Gerasimenko (67P), visited by the Rosetta spacecraft. Analysis of the Rosetta observations suggests that 67P’s components were brought together at low speed after their separate formation. Here, we study the structure and dynamics of 67P’s nucleus. We find that sublimation torques have caused the nucleus to spin up in the past to form the large cracks observed on its neck. However, the chaotic evolution of its spin state has so far forestalled its splitting, although it should eventually reach a rapid enough spin rate to do so. Once this occurs, the separated components will be unable to escape each other; they will orbit each other for a time, ultimately undergoing a low-speed merger that will result in a new bilobate configuration. The components of four other imaged bilobate nuclei have volume ratios that are consistent with a similar reconfiguration cycle, pointing to such cycles as a fundamental process in the evolution of short-period comet nuclei. It has been shown that comets were not strong contributors to the so-called late heavy bombardment about 4 billion years ago. The reconfiguration process suggested here would preferentially decimate comet nuclei during migration to the inner solar system, perhaps explaining this lack of a substantial cometary flux.

France launches massive meteor-spotting network

17 June 2016 - 11:25am

France launches massive meteor-spotting network

Nature 534, 7607 (2016). http://www.nature.com/doifinder/10.1038/nature.2016.20070

Author: Traci Watson

Tracking space rocks that reach Earth will give insight into the early Solar System.

Unique meteorite from asteroid smash-up

16 June 2016 - 9:29am

Scientists identify a completely new type of meteorite that likely originated in a huge asteroid collision some 470 million years ago.

First Detection of Methyl Alcohol in a Planet-forming Disc

16 June 2016 - 9:26am
The organic molecule methyl alcohol (methanol) has been found by the Atacama Large Millimeter/Submillimeter Array (ALMA) in the TW Hydrae protoplanetary disc. This is the first such detection of the compound in a young planet-forming disc. Methanol is the only complex organic molecule as yet detected in discs that unambiguously derives from an icy form. Its detection helps astronomers understand the chemical processes that occur during the formation of planetary systems and that ultimately lead to the creation of the ingredients for life.

We have the technology to look for ET right now – why don’t we?

16 June 2016 - 9:24am

A new study says Hubble's successor could spot alien life on 3 new exoplanets. Should NASA be doing more? Or is it right to focus on other priorities?

Gluttonous Star May Hold Clues to Planet Formation

15 June 2016 - 10:26am

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In 1936, astronomers observed signs that the young star FU Orionis had begun gobbling material from its surrounding disk of gas and dust with a sudden voraciousness. During a three-month binge, as matter turned into energy, the star became 100 times brighter, heating the disk around it to temperatures of up to 12,000 degrees Fahrenheit. The brightening is the most extreme event of its kind that has been confirmed around a star the size of the sun, and may have implications for how stars and planets form. The intense baking of the star's surrounding disk likely changed its chemistry, permanently altering material that could one day turn into planets. FU Orionis is still devouring gas to this day, although not as quickly.

First mirror-image molecule found in interstellar space

15 June 2016 - 10:24am

A team of scientists has detected the first chiral molecule out in space – a key step toward understanding life's origins

Ocean worlds could host life under layers of high-pressure ice

15 June 2016 - 10:16am

Models of ice formation at high pressure suggest there could be habitable liquid water at the bottom of incredibly deep alien oceans

Black hole pairs spat out of mosh pits make gravitational waves

14 June 2016 - 9:08am

The pair of black holes responsible for the first ever detected gravitational wave may have been spat out of a mosh pit at the centre of a globular star cluster

Massive exoplanet’s close dance is making its star spin faster

13 June 2016 - 9:02am

Astronomers have discovered a massive planet on an orbit close enough to speed up the rotation of its star

Supernovae 2 million years ago may have changed human behaviour

10 June 2016 - 9:04am

Two nearby supernovae explosions may have increased cancer rates and changed the behaviour of early humans - but that's a pretty big may

LISA Pathfinder exceeds expectations

9 June 2016 - 9:16am

ESA's LISA Pathfinder mission has demonstrated the technology needed to build a space-based gravitational wave observatory.

Black Hole Fed by Cold Intergalactic Deluge

9 June 2016 - 9:15am
An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has witnessed a cosmic weather event that has never been seen before — a cluster of towering intergalactic gas clouds raining in on the supermassive black hole at the centre of a huge galaxy one billion light-years from Earth. The results will appear in the journal Nature on 9 June 2016.

Cloudy Days on Exoplanets May Hide Atmospheric Water

9 June 2016 - 9:14am

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Water is a hot topic in the study of exoplanets, including "hot Jupiters," whose masses are similar to that of Jupiter, but lie much closer to their parent star than Jupiter is to the sun. They are estimated to be a scorching 2,000 degrees Fahrenheit, meaning any water they host would take the form of water vapor.

Cold, clumpy accretion onto an active supermassive black hole

9 June 2016 - 9:13am

Cold, clumpy accretion onto an active supermassive black hole

Nature 534, 7606 (2016). doi:10.1038/nature17969

Authors: Grant R. Tremblay, J. B. Raymond Oonk, Françoise Combes, Philippe Salomé, Christopher, P. O’Dea, Stefi A. Baum, G. Mark Voit, Megan Donahue, Brian R. McNamara, Timothy A. Davis, Michael A. McDonald, Alastair C. Edge, Tracy E. Clarke, Roberto Galván-Madrid, Malcolm N. Bremer, Louise O. V. Edwards, Andrew C. Fabian, Stephen Hamer, Yuan Li, Anaëlle Maury, Helen R. Russell, Alice C. Quillen, C. Megan Urry, Jeremy S. Sanders & Michael W. Wise

Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds—a departure from the ‘hot mode’ accretion model—although unambiguous observational support for this prediction remains elusive. Here we report observations that reveal a cold, clumpy accretion flow towards a supermassive black hole fuel reservoir in the nucleus of the Abell 2597 Brightest Cluster Galaxy (BCG), a nearby (redshift z = 0.0821) giant elliptical galaxy surrounded by a dense halo of hot plasma. Under the right conditions, thermal instabilities produce a rain of cold clouds that fall towards the galaxy’s centre, sustaining star formation amid a kiloparsec-scale molecular nebula that is found at its core. The observations show that these cold clouds also fuel black hole accretion, revealing ‘shadows’ cast by the molecular clouds as they move inward at about 300 kilometres per second towards the active supermassive black hole, which serves as a bright backlight. Corroborating evidence from prior observations of warmer atomic gas at extremely high spatial resolution, along with simple arguments based on geometry and probability, indicate that these clouds are within the innermost hundred parsecs of the black hole, and falling closer towards it.

Astrophysics: Relativity passes black-hole test

9 June 2016 - 9:09am

Astrophysics: Relativity passes black-hole test

Nature 534, 7606 (2016). doi:10.1038/534154e

General relativity holds true, even under the extreme conditions of colliding black holes.In 2015, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) saw the first evidence of gravitational waves, which had been created by two merging black holes. Walter Del Pozzo at the University of

Flamingo stars turn pink when they gobble iron-rich planets

9 June 2016 - 9:08am

Consuming a metal-rich planet or two early in its life can change a star’s colour – making them the flamingos of space

Spongy minerals could explain why Mars gives off methane burps

9 June 2016 - 9:07am

Zeolites – volcanic minerals that easily trap and release gases – could be responsible for the burps of methane that occasionally come from the Red Planet