The asteroid that wiped out the dinosaurs may have catapulted life from Earth to Mars and Jupiter's moon Europa, researchers say.

Nasa's Iris mission has observed the region between the Sun's surface and its outer layers, where temperatures reach 2,000,000C.

Astrophysics: Trio of distant quasars found

Nature 504, 7479 (2013). doi:10.1038/504190d

Astronomers have discovered three distant quasars that will allow them to probe the conditions of the early Universe.A team led by Bram Venemans at the Max Planck Institute for Astronomy in Heidelberg, Germany, discovered the active galactic nuclei using the European Southern Observatory's Visible

Extrasolar planets: Inner edge of the habitable zone

Nature 504, 7479 (2013). doi:10.1038/504221a

Authors: James F. Kasting & Chester E. Harman

A three-dimensional climate model indicates that the fraction of Sun-like stars that might harbour a rocky planet within their habitable zone could be smaller than previously estimated. See Letter p.268

Astrophysics: Tracking our neighbours' past

Nature 504, 7479 (2013). doi:10.1038/504226a

Authors: Alan McConnachie

The collective motions of dwarf galaxies in planes around the Andromeda galaxy and the Milky Way have presented a challenge to theory. Interactions between galaxy groups in the distant past may have left their imprint on these dwarfs.

Increased insolation threshold for runaway greenhouse processes on Earth-like planets

Nature 504, 7479 (2013). doi:10.1038/nature12827

Authors: Jérémy Leconte, Francois Forget, Benjamin Charnay, Robin Wordsworth & Alizée Pottier

The increase in solar luminosity over geological timescales should warm the Earth’s climate, increasing water evaporation, which will in turn enhance the atmospheric greenhouse effect. Above a certain critical insolation, this destabilizing greenhouse feedback can ‘run away’ until the oceans have completely evaporated. Through increases in stratospheric humidity, warming may also cause evaporative loss of the oceans to space before the runaway greenhouse state occurs. The critical insolation thresholds for these processes, however, remain uncertain because they have so far been evaluated using one-dimensional models that cannot account for the dynamical and cloud feedback effects that are key stabilizing features of the Earth’s climate. Here we use a three-dimensional global climate model to show that the insolation threshold for the runaway greenhouse state to occur is about 375 W m−2, which is significantly higher than previously thought. Our model is specifically developed to quantify the climate response of Earth-like planets to increased insolation in hot and extremely moist atmospheres. In contrast with previous studies, we find that clouds have a destabilizing feedback effect on the long-term warming. However, subsident, unsaturated regions created by the Hadley circulation have a stabilizing effect that is strong enough to shift the runaway greenhouse limit to higher values of insolation than are inferred from one-dimensional models. Furthermore, because of wavelength-dependent radiative effects, the stratosphere remains sufficiently cold and dry to hamper the escape of atmospheric water, even at large fluxes. This has strong implications for the possibility of liquid water existing on Venus early in its history, and extends the size of the habitable zone around other stars.

The US space agency releases an extraordinary new movie of Earth and the Moon moving through space together.

Nicknamed Peggy, an unusual object stirring things up in Saturn's rings might mark the first time we have seen the genesis of a moon
    

NASA's Mars Reconnaissance Orbiter (MRO) has revealed to scientists slender dark markings -- possibly due to salty water – that advance seasonally down slopes surprisingly close to the Martian equator.

Think it's tough getting up in the morning when the alarm clock sounds? Imagine what it must be like waking up 673 million kilometres from the warmth of the Sun and with no coffee. You might need some help...

Life possible in the early Universe

Nature 504, 7479 (2013). http://www.nature.com/doifinder/10.1038/504201a

Author: Zeeya Merali

Planets orbiting the first stars could have been habitable, challenging arguments for a multiverse.

The cosmic radiation that existed about 15 million years after the big bang could have made the whole universe warm enough to support life
    

NASA's Curiosity rover has dated rocks on the surface of Mars – their relative youth suggests that if there ever was life on Mars, Curiosity has a chance of finding it
    

NASA's Curiosity rover is providing vital insight about Mars' past and current environments that will aid plans for future robotic and human missions.

The Today programme's Tom Feilden looks at cosmologists' future exploration of "the dark universe".

Comet Siding Spring will arrive at Mars next year, bringing with it an epic and beautiful meteor shower that could pose a danger to orbiting spacecraft
    

Strange ribbons of matter spiralling out of a bright galaxy suggest that it hosts a pair of black holes that are about to collide
    

Do you know anyone who took a career break from research but wants to come back?

The RAS Daphne Jackson Fellowship enables a talented astronomer or geophysicist to return to research after a career break for family, caring or health reasons. Applications are due by 27 January 2014.

https://www.ras.org.uk/news-and-press/%20224-news-2013/2365-ras-daphne-jackson-fellowship


RAS Daphne Jackson Fellowship
www.ras.org.uk
Applications are now open for an RAS Daphne Jackson Fellowship. This fellowship, run by the Daphne Jackson Trust (DJT) and sponsored by the RAS, enables a talented astronomer or geophysicist to return to research after a career break.

A classic equation to estimate the number of detectable alien civilisations has been rebooted as a tool for finding asteroids worth mining for resources
    

Data from NASA's Chandra X-ray Observatory has revealed faint remnants of a supernova explosion and helped researchers determine Circinus X-1 -- an X-ray binary -- is the youngest of this class of astronomical objects found to date.