Space

Gamma ray bursts (GRBs), the brief flashes of light signalling distant, extremely energetic events, have been elusive targets for astronomical observation. (It's something like the fairground game of Whack-a-Mole:by the time you're aware of the GRB, it's vanished, and you have no way of knowing where the next one will appear.) An orbiting observatory that quickly alerts ground-based astronomers about GRBs has allowed a very quick response and an unprecedented look at the GRBs' aftermath.

From Mary, in response to my request for more information about the scientists who gave us the YORP effect:

An odd, six-sided, honeycomb-shaped feature circling the entire north pole of Saturn has captured the interest of scientists with the Cassini mission.

This atmospheric feature was already imaged by NASA’s Voyager 1 and 2 spacecraft over two decades ago. The fact that it has appeared in Cassini images indicates that it is a long-lived feature. A second hexagon, significantly darker than the brighter historical feature, is also visible in the Cassini pictures. The spacecraft's visual and infrared mapping spectrometer (VIMS) is the first instrument to capture the entire hexagon feature in one image.

Using ESO's Very Large Telescope, an international team of astronomers has shown how to use the chemical composition of stars in clusters to shed light on the formation of our Milky Way. This discovery is a fundamental test for the development of a new chemical tagging technique uncovering the birth and growth of our Galactic cradle.

The formation and evolution of galaxies, and in particular of the Milky Way - the 'island universe' in which we live, is one of the major puzzles of astrophysics: indeed, a detailed physical scenario is still missing and its understanding requires the joint effort of observations, theories and complex numerical simulations.

The Hubble Space Telescope (HST) has produced some of the most famous still images in astronomy (e.g., the pillars of creation in the Eagle Nebula). The latest images from HST are movies of Saturn and its moons. Astronomers wrote software that multiplies the relatively small number of images taken by Hubble for each event into the much larger number needed to make a movie. The original images covered several hours of observing time, and the videos range in length from 15 to 30 seconds, so time is compressed in the videos and the motions of Saturn and its moons are speeded up.

Two of the videos show Saturn with the rings edge-on either to Earth or to the sun.

Scientists have used the world's largest robotic telescope to make the earliest-ever measurement of the optical polarisation* of a Gamma Ray Burst (GRB) just 203 seconds after the start of the cosmic explosion. This finding, which provides new insight into GRB physics, is published in Science today (15th March 2007).

The scientists from Liverpool John Moores University and colleagues in the UK, Italy, France and Slovenia used the Liverpool Telescope on the island of La Palma and its novel new polarimeter, RINGO, to perform the measurement following detection of the burst by NASA's Swift satellite.


NASA's Swift spacecraft. Credit: Spectrum and NASA E/PO, Sonoma State University

This new estimate comes from mapping the thickness of the dusty ice by the Mars Express radar instrument that has made more than 300 virtual slices through layered deposits covering the pole. The radar sees through icy layers to the lower boundary, which in places is as deep as 3.7 kilometres below the surface.

"The south polar layered deposits of Mars cover an area as wide as a big portion of Europe. The amount of water they contain has been estimated before, but never with the level of confidence this radar makes possible," said Dr. Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena (California), co-Principal Investigator for the radar and lead author of the study.

Seas On Titan

Seas On Titan

Mar 14 2007 | comment(s)

Instruments on NASA's Cassini spacecraft, part of the joint NASA/ESA/ASI Cassini-Huygens mission to Saturn and its moons, have found evidence for seas, likely filled with liquid methane or ethane, in the high northern latitudes of Saturn's moon Titan.

One such feature is larger than any of the Great Lakes of North America and is about the same size as several seas on Earth.


This image of Saturn’s largest moon, Titan, obtained by Cassini's radar instrument during a near-polar flyby on 22 February 2007, features dunes and lakes, one of which is larger than any lake on Earth and could be legitimately called a sea. Titan’s lakes are thought to consist of liquid methane and ethane.

UNSW space scientists have outshone NASA by scoring a higher academic paper citation rate, according to the latest international ranking of universities and space science institutions.

The Thomson group recently reported on the output of refereed journal articles and citations in Space Sciences from 2001 to 2005.

UNSW did extremely well with a very high citation rate (15.69) that was better than NASA (15.42) and within 20 percent of Caltech and Harvard – the world’s three top-ranked space science institutions.

UNSW’s citation rate was the second highest amongst Australian universities, just behind ANU’s (16.09).

A new wide-field panorama reveals more than a thousand supermassive black holes in the centers of galaxies, some up to several billion times more massive than the sun. This survey, taken in a region of the Bootes constellation, involved 126 separate Chandra exposures of 5,000-seconds each, making it the largest contiguous field ever obtained by the observatory. At 9.3 square degrees, it is over 40 times larger than the full moon seen on the night sky, which is also shown in this graphic for scale.