Institute of Astronomy

Astronomy News

Gaia's first year of scientific observations

26 August 2015 - 8:04am

Last Friday, 21 August, ESA's billion-star surveyor, Gaia, completed its first year of science observations in its main survey mode.

Do comet fractures drive surface evolution?

21 August 2015 - 10:11am

Extreme thermal stresses experienced by a comet as it orbits around the Sun could explain the extensive fracturing thought to drive its long-term surface erosion, say Rosetta scientists analysing high-resolution images of Comet 67P/Churyumov-Gerasimenko's surface.

The tumultuous heart of our Galaxy

21 August 2015 - 10:04am

This new image of powerful remnants of dead stars and their mighty action on the surrounding gas from ESA's XMM-Newton X-ray observatory reveals some of the most intense processes taking place at the centre of our galaxy, the Milky Way.

Mars rover takes low-angle 'selfie'

21 August 2015 - 9:52am

The US space agency has issued another of the "selfie" portraits acquired by its Curiosity rover on Mars, but this one is taken from a much lower angle.

Sibling Stars

20 August 2015 - 9:36am
Open star clusters like the one seen here are not just perfect subjects for pretty pictures. Most stars form within clusters and these clusters can be used by astronomers as laboratories to study how stars evolve and die. The cluster captured here by the Wide Field Imager (WFI) at ESO’s La Silla Observatory is known as IC 4651, and the stars born within it now display a wide variety of characteristics.

Astrophysics: Mystery survivor of a supermassive black hole

20 August 2015 - 9:34am

Astrophysics: Mystery survivor of a supermassive black hole

Nature 524, 7565 (2015). doi:10.1038/524301a

Authors: John Bally

The G2 cloud in our Galaxy's core has survived an encounter with the central black hole and failed to trigger a major flare-up in the black hole's activity. A promising theory endeavours to explain the cloud's nature.

Growing the gas-giant planets by the gradual accumulation of pebbles

20 August 2015 - 9:34am

Growing the gas-giant planets by the gradual accumulation of pebbles

Nature 524, 7565 (2015). doi:10.1038/nature14675

Authors: Harold F. Levison, Katherine A. Kretke & Martin J. Duncan

It is widely held that the first step in forming gas-giant planets, such as Jupiter and Saturn, was the production of solid ‘cores’ each with a mass roughly ten times that of the Earth. Getting the cores to form before the solar nebula dissipates (in about one to ten million years; ref. 3) has been a major challenge for planet formation models. Recently models have emerged in which ‘pebbles’ (centimetre-to-metre-sized objects) are first concentrated by aerodynamic drag and then gravitationally collapse to form objects 100 to 1,000 kilometres in size. These ‘planetesimals’ can then efficiently accrete left-over pebbles and directly form the cores of giant planets. This model is known as ‘pebble accretion’; theoretically, it can produce cores of ten Earth masses in only a few thousand years. Unfortunately, full simulations of this process show that, rather than creating a few such cores, it produces a population of hundreds of Earth-mass objects that are inconsistent with the structure of the Solar System. Here we report that this difficulty can be overcome if pebbles form slowly enough to allow the planetesimals to gravitationally interact with one another. In this situation, the largest planetesimals have time to scatter their smaller siblings out of the disk of pebbles, thereby stifling their growth. Our models show that, for a large and physically reasonable region of parameter space, this typically leads to the formation of one to four gas giants between 5 and 15 astronomical units from the Sun, in agreement with the observed structure of the Solar System.

Astronomy: Direct look at a small exoplanet

20 August 2015 - 9:34am

Astronomy: Direct look at a small exoplanet

Nature 524, 7565 (2015). doi:10.1038/524268c

Astronomers have snapped a picture of a planet like those in the Solar System but orbiting another star — the lowest-mass exoplanet ever directly imaged.Bruce Macintosh of Stanford University in California and his team used the Gemini Planet Imager at the Gemini South Telescope

Rosetta sees sparks as comet 67P reaches closest approach to sun

20 August 2015 - 9:29am
The European Space Agency's comet team are celebrating perihelion, the day when comet 67P swings around the sun, taking Rosetta for a ride

Comet impacts cook up 'soup of life'

20 August 2015 - 9:27am

New lab results show how collisions between comets and planets can make the molecules that are the essential building blocks of life.

Send Your Name to Mars on NASA's Next Red Planet Mission

19 August 2015 - 9:05am
Mars enthusiasts around the world can participate in NASA’s journey to Mars by adding their names to a silicon microchip headed to the Red Planet aboard NASA's InSight Mars lander, scheduled to launch next year.

Moon’s gravity could govern plant movement like the tides

18 August 2015 - 9:28am

Historical data on how plants move over the course of the day seems to show that they line up with the position of the moon

Small stars may keep planets in line with magnetic harnesses

18 August 2015 - 9:27am

Some planets orbit their stars right around the star's equator, while others go at wonky angles – and it's all down to the star's size

Young 'alien Jupiter' discovered

17 August 2015 - 9:22am

A planet 100 light-years away resembles a young version of Jupiter, astronomers say.

VIDEO: Timelapse shows Northern Lights from space

17 August 2015 - 9:22am

Nasa astronaut Scott Kelly captures timelapse footage of Aurora Borealis, also known as the Northern Lights, from the International Space Station.

What makes a planet habitable?

17 August 2015 - 9:21am

Working out what is necessary for life