Astrobiology: Prescient words on comets and life

Nature 516, 7531 (2014). doi:10.1038/516329a

Author: Milton Wainwright

The landing of the Philae probe on comet 67P/Churyumov–Gerasimenko last month has led to speculation that comets might have delivered the building-block elements of life to Earth — an idea anticipated by the French astronomer Camille Flammarion more than a century ago in his 1880

The exclusion of a significant range of ages in a massive star cluster

Nature 516, 7531 (2014). doi:10.1038/nature13969

Authors: Chengyuan Li, Richard de Grijs & Licai Deng

Stars spend most of their lifetimes on the main sequence in the Hertzsprung–Russell diagram. The extended main-sequence turn-off regions—containing stars leaving the main sequence after having spent all of the hydrogen in their cores—found in massive (more than a few tens of thousands of solar masses), intermediate-age (about one to three billion years old) star clusters are usually interpreted as evidence of internal age spreads of more than 300 million years, although young clusters are thought to quickly lose any remaining star-forming fuel following a period of rapid gas expulsion on timescales of order 107 years. Here we report, on the basis of a combination of high-resolution imaging observations and theoretical modelling, that the stars beyond the main sequence in the two-billion-year-old cluster NGC 1651, characterized by a mass of about 1.7 × 105 solar masses, can be explained only by a single-age stellar population, even though the cluster has a clearly extended main-sequence turn-off region. The most plausible explanation for the existence of such extended regions invokes a population of rapidly rotating stars, although the secondary effects of the prolonged stellar lifetimes associated with such a stellar population mixture are as yet poorly understood. From preliminary analysis of previously obtained data, we find that similar morphologies are apparent in the Hertzsprung–Russell diagrams of at least five additional intermediate-age star clusters, suggesting that an extended main-sequence turn-off region does not necessarily imply the presence of a significant internal age dispersion.

The Philae lander is getting enough sunlight to keep warm, team members say, and the Rosetta spacecraft may have already taken pictures of its landing spot

An image has been released that shows the hairy moment that the Philae comet lander bounced back into space.

It might not happen for a quarter of a million years, but a nearby star coming closer to the sun could send planetary remnants hurtling to Earth

NASA will host a media teleconference at 4 p.m. EST today during which agency officials will discuss and answer questions on the selection of an Asteroid Redirect Mission concept.

This spectacular image of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars.

NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill.

NASA has selected SpaceX to provide launch services for the Transiting Exoplanet Survey Satellite (TESS) mission. TESS will launch aboard a Falcon 9 v1.1 launch vehicle, with liftoff targeted for August 2017 from Cape Canaveral Air Force Station in Florida.

We can now grow plants in microgravity – and crops grown in asteroid soil could sustain vast human populations off-planet

Nasa's Curiosity rover has detected "belches" of methane gas on Mars - a gas that could hint at past or even present life on the planet.

ESA's Venus Express has ended its eight-year mission after far exceeding its planned life. The spacecraft exhausted its propellant during a series of thruster burns to raise its orbit following the low-altitude aerobraking earlier this year.

Since 2012, NASA's Voyager 1 spacecraft has experienced three 'tsunami waves' in interstellar space. The most recent, which reached the spacecraft earlier this year, is still propagating outward according to new data.

NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill.

A popular theory holds that ocean water was brought to Earth by the ancient impacts of comets and asteroids. However, new data from the European Space Agency’s Rosetta spacecraft indicate that terrestrial water did not come from comets like 67P/Churyumov-Gerasimenko.

Observations by NASA’s Curiosity Rover indicate Mars' Mount Sharp was built by sediments deposited in a large lake bed over tens of millions of years. This suggests ancient Mars maintained a climate that could have produced long-lasting lakes at many locations on the Red Planet.

Earth is passing through a stream of debris from "rock comet" 3200 Phaethon, source of the annual Geminid meteor shower. Forecasters expect as many as 120 meteors per hour when the shower peaks on Dec. 13-14.

The first colour image from the Rosetta spacecraft shows that Comet 67P is even more dark and monochrome than expected.

As a pair of colliding galaxies merges, a flurry of forming stars produce ultra-bright x-ray bursts

As a pair of colliding galaxies merges, a flurry of forming stars produce ultra-bright x-ray bursts