Institute of Astronomy

Feed aggregator

Dancing in the dark: The search for the 'missing Universe'

Astronomy News - 17 March 2015 - 10:32am

Large Hadron Collider goes after dark matter

New lunar crater named after Earhart

Astronomy News - 17 March 2015 - 10:32am

Scientists discover a large crater on the Earth-facing side of the Moon - the first detection of its kind in at least a century.

Rosetta comet wind mystery 'solved'

Astronomy News - 17 March 2015 - 10:32am

Scientists from the Rosetta mission may have solved the puzzle of features on Comet 67P that look like they were produced by wind.

VIDEO: Dark matter's 'gang of four'

Astronomy News - 17 March 2015 - 10:31am

The Large Hadron Collider will put reputations on the line when it attempts to solve the mystery of dark matter.

Hubble Source Catalog: One-Stop Shopping for Astronomers

Astronomy News - 16 March 2015 - 10:29am

Get larger image formats

Astronomers at the Space Telescope Science Institute and the Johns Hopkins University, both in Baltimore, Maryland, have created a new master catalog of astronomical objects called the Hubble Source Catalog. The catalog provides one-stop shopping for measurements of objects observed with NASA's Hubble Space Telescope.

New Desktop Application Has Potential to Increase Asteroid Detection, Now Available to Public

Astronomy News - 16 March 2015 - 10:27am

A software application based on an algorithm created by a NASA challenge has the potential to increase the number of new asteroid discoveries by amateur astronomers.

NASA's Hubble Observations Suggest Underground Ocean on Jupiter's Largest Moon

Astronomy News - 13 March 2015 - 10:16am

Get larger image formats

Nearly 500 million miles from the Sun lies a moon orbiting Jupiter that is slightly larger than the planet Mercury and may contain more water than all of Earth's oceans. Temperatures are so cold, though, that water on the surface freezes as hard as rock and the ocean lies roughly 100 miles below the crust. Nevertheless, where there is water there could be life as we know it. Identifying liquid water on other worlds big or small is crucial in the search for habitable planets beyond Earth. Though the presence of an ocean on Ganymede has been long predicted based on theoretical models, NASA's Hubble Space Telescope found the best evidence for it. Hubble was used to watch aurorae glowing above the moon's icy surface. The aurorae are tied to the moon's magnetic field, which descends right down to the core of Ganymede. A saline ocean would influence the dynamics of the magnetic field as it interacts with Jupiter's own immense magnetic field, which engulfs Ganymede. Because telescopes can't look inside planets or moons, tracing the magnetic field through aurorae is a unique way to probe the interior of another world.

NASA’s Hubble Observations Suggest Underground Ocean on Jupiter's Largest Moon

Astronomy News - 13 March 2015 - 10:16am

NASA’s Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is thought to have more water than all the water on Earth's surface.

The UK's best solar eclipse this decade happens next Friday, 20 March! Everyone...

Astronomy News - 13 March 2015 - 10:15am
The UK's best solar eclipse this decade happens next Friday, 20 March!

Everyone in the UK will be able to see it - provided there's no cloud. Our booklet explains what you will be able to see and how to view the eclipse safely.

https://www.ras.org.uk/publications/other-publications/2577-how-to-observe-an-eclipse-safely


How to observe an eclipse safely
www.ras.org.uk
What is a solar eclipse, and how is it caused? What can members of the public expect to see, and how can they observe an eclipse safely?This booklet explains the answers to these questions and more.

Aurora reveals Jupiter moon's secret subsurface sea

Astronomy News - 13 March 2015 - 10:14am
Hubble Space Telescope images reveal Ganymede, the largest moon in the solar system, has a secret sea – just a day after a similar find on Saturn's moon Enceladus






Explosive eruptions rocked the youthful moon

Astronomy News - 13 March 2015 - 10:14am
The Chinese Jade Rabbit lunar rover reveals that the moon's geological history is complex and violent






'Best evidence' for Ganymede ocean

Astronomy News - 13 March 2015 - 10:13am

The Hubble telescope obtains compelling evidence that Ganymede - the largest moon in the Solar System - has an ocean beneath its icy crust.

VIDEO: Nasa films biggest solar flare of 2015

Astronomy News - 13 March 2015 - 10:13am

Nasa cameras have captured images of an X-class flare, the strongest category of Sun storm possible, and they are the first of its size in 2015.

Hot water activity on icy moon's seafloor

Astronomy News - 12 March 2015 - 10:17am

Tiny grains of rock detected by the international Cassini spacecraft orbiting Saturn point to hydrothermal activity on the seafloor of its icy moon Enceladus.

A Grand Extravaganza of New Stars

Astronomy News - 12 March 2015 - 10:14am
This dramatic landscape in the southern constellation of Ara (The Altar) is a treasure trove of celestial objects. Star clusters, emission nebulae and active star-forming regions are just some of the riches observed in this region lying some 4000 light-years from Earth. This beautiful new image is the most detailed view of this part of the sky so far, and was taken using the VLT Survey Telescope at ESO’s Paranal Observatory in Chile.

Get ready for next Friday, 20 March! UK skies set to dim in decade’s deepest sol...

Astronomy News - 12 March 2015 - 10:14am
Get ready for next Friday, 20 March! UK skies set to dim in decade’s deepest solar eclipse.

This is the best eclipse in the UK since 1999, and there won't be a better one until 2026. It will be visible everywhere in the UK that morning (unless there's cloud).

https://www.ras.org.uk/news-and-press/2599-uk-skies-set-to-dim-in-decade-s-deepest-solar-eclipse


UK skies set to dim in decade’s deepest solar eclipse
www.ras.org.uk
On 20 March a total eclipse of the Sun will take place, visible from the North Atlantic Ocean. Observers in the UK and Ireland will see a partial solar eclipse, with up to 97% of the Sun blocked out. This will be the deepest eclipse in the UK since 1

Undersea Jacuzzi may give life to Saturn's icy moon

Astronomy News - 12 March 2015 - 10:13am
Dust from Saturn's rings shows Enceladus could have hydrothermal vents similar to those on Earth at the bottom of its ice-covered sea






Spacecraft Data Suggest Saturn Moon's Ocean May Harbor Hydrothermal Activity

Astronomy News - 12 March 2015 - 10:11am

NASA's Cassini spacecraft has provided scientists the first clear evidence that Saturn’s moon Enceladus exhibits signs of present-day hydrothermal activity which may resemble that seen in the deep oceans on Earth. The implications of such activity on a world other than our planet open up unprecedented scientific possibilities.

Ongoing hydrothermal activities within Enceladus

Astronomy News - 12 March 2015 - 10:11am

Ongoing hydrothermal activities within Enceladus

Nature 519, 7542 (2015). doi:10.1038/nature14262

Authors: Hsiang-Wen Hsu, Frank Postberg, Yasuhito Sekine, Takazo Shibuya, Sascha Kempf, Mihály Horányi, Antal Juhász, Nicolas Altobelli, Katsuhiko Suzuki, Yuka Masaki, Tatsu Kuwatani, Shogo Tachibana, Sin-iti Sirono, Georg Moragas-Klostermeyer & Ralf Srama

Detection of sodium-salt-rich ice grains emitted from the plume of the Saturnian moon Enceladus suggests that the grains formed as frozen droplets from a liquid water reservoir that is, or has been, in contact with rock. Gravitational field measurements suggest a regional south polar subsurface ocean of about 10 kilometres thickness located beneath an ice crust 30 to 40 kilometres thick. These findings imply rock–water interactions in regions surrounding the core of Enceladus. The resulting chemical ‘footprints’ are expected to be preserved in the liquid and subsequently transported upwards to the near-surface plume sources, where they eventually would be ejected and could be measured by a spacecraft. Here we report an analysis of silicon-rich, nanometre-sized dust particles (so-called stream particles) that stand out from the water-ice-dominated objects characteristic of Saturn. We interpret these grains as nanometre-sized SiO2 (silica) particles, initially embedded in icy grains emitted from Enceladus’ subsurface waters and released by sputter erosion in Saturn’s E ring. The composition and the limited size range (2 to 8 nanometres in radius) of stream particles indicate ongoing high-temperature (>90 °C) hydrothermal reactions associated with global-scale geothermal activity that quickly transports hydrothermal products from the ocean floor at a depth of at least 40 kilometres up to the plume of Enceladus.

Regulation of star formation in giant galaxies by precipitation, feedback and conduction

Astronomy News - 12 March 2015 - 10:10am

Regulation of star formation in giant galaxies by precipitation, feedback and conduction

Nature 519, 7542 (2015). doi:10.1038/nature14167

Authors: G. M. Voit, M. Donahue, G. L. Bryan & M. McDonald

The Universe’s largest galaxies reside at the centres of galaxy clusters and are embedded in hot gas that, if left undisturbed, would cool quickly and create many more new stars than are actually observed. Cooling can be regulated by feedback from accretion of cooling gas onto the central black hole, but requires an accretion rate finely tuned to the thermodynamic state of the hot gas. Theoretical models in which cold clouds precipitate out of the hot gas via thermal instability and accrete onto the black hole exhibit the necessary tuning. Recent observational evidence shows that the abundance of cold gas in the centres of clusters increases rapidly near the predicted threshold for instability. Here we report observations showing that this precipitation threshold extends over a large range in cluster radius, cluster mass and cosmic time. We incorporate the precipitation threshold into a framework of theoretical models for the thermodynamic state of hot gas in galaxy clusters. According to that framework, precipitation regulates star formation in some giant galaxies, while thermal conduction prevents star formation in others if it can compensate for radiative cooling and shut off precipitation.