Rosetta has both delighted and upset astro-boffins, sending back data that indicates the discovery of molecular oxygen on Comet 67P/Churyumov–Gerasimenko.

The scientists are excited because the O2, detected in the thin cloud of stuff surrounding the comet, is going to give them a pile of new science; and upset, because it’s not really supposed to be there. After billions of years, most of the molecular oxygen was expected to have reacted with hydrogen to form water.

The fact that the oxygen has survived suggests the comet – and probably other bodies in the solar system – must have formed so gently that it never got hot enough to spark oxygen reactions.

Oxygen is plentiful – it’s the third most abundant element in the universe – but it’s also highly reactive, and usually turns up bound to other atoms and molecules (or with itself, as O3, ozone).

Findings from the European Space Agency’s Rosetta probe solved the riddle of Comet 67P/Churyumov-Gerasimenko’s unusual shape. They have proof that the comet is in fact two planetary bodies joined at the hip.

ESA’s Rosetta probe took ten years to reach its target last July and, when it did, the science team had a bit of a shock. Normally comets are roughly circular, but this example looked more like a rubber duck, with a large body and smaller head supported by a thin neck. It’s approximately 4 kilometers across, measured the long way.

Between 6 August 2014 and 17 March 2015 Rosetta took a series of high-resolution pictures of the geology of 67P and the results are now in. The comet is definitely two objects joined together, and the proof is in how the surface of the comet is layered.

“It is clear from the images that both lobes have an outer envelope of material organized in distinct layers, and we think these extend for several hundred meters below the surface,” said Matteo Massironi, from the University of Padova, Italy.

“You can imagine the layering a bit like an onion, except in this case we are considering two separate onions of differing size that have grown independently before fusing together.”

The Rosetta probe’s Earth-bound shepherds have sternly stated that suggestions of alien life within comet 67P/Churyumov–Gerasimenko – around which the probe is in orbit – are “pure speculation”.

Talking at an astroboffinry conference in Llandudno on Monday, Dr Max Wallace and Professor Chandra Wickramasinghe suggested that the approaching 67P/Churyumov-Gerasimenko could contain alien “organisms”, perhaps of a sort similar to those found in slime, which might become “active” as the comet nears the Sun and warms up.

A statement from the Royal Astronomical Society questioned whether micro-organisms might be responsible for the curious sinkholes which are observable on the surface of 67P.

“No scientist active in any of the Rosetta instrument science teams assumes the presence of living micro-organisms beneath the cometary surface crust,” Uwe Meierhenrich of Université Nice Sophia Antipolis, France, told the Graun.

“I think it is highly unlikely,”

“It’s pure speculation,” he said: “I think it is unlikely.”

The European Space Agency (ESA) has whittled down the list of projects it is considering for deployment in the year 2025 and is now considering three missions for liftoff in that year.

The three projects are:

Ariel, aka Atmospheric Remote-Sensing Infrared Exoplanet Large-survey, which would analyse the atmospheres of around 500 planets orbiting close to nearby stars, to determine their chemical composition and physical conditions.” This one’s all about learning more about how planets form and work.
Thor, the Turbulence Heating ObserveR, would study “the interaction of the solar wind with Earth’s magnetic field” and “address a fundamental problem in space plasma physics concerned with the heating of plasma and the subsequent dissipation of energy.”
Xipe, the X-ray Imaging Polarimetry Explorer, could check out “X-ray emissions from high-energy sources such as supernovas, galaxy jets, black holes and neutron stars, to discover more about the behaviour of matter under extreme conditions.”

All three missions are “M-Class”, the agency’s designation for medium-sized missions. There’s also an “S” and “L” class and readers will not be surprised to learn they stand for “small” and “large” respectively.

The S-M-L classification was introduced long after the ESA’s decision to do things like the Rosetta comet-spotter

Rosetta’s scientific imaging system OSIRIS has witnessed a new jet of dust emerging from the surface of Comet 67P/Churyumov-Gerasimenko. The image was presented during the European Geosciences Union General Assembly, EGU, in Vienna last week.

On March 12, the Rosetta spacecraft was imaging Comet 67P/Churyumov-Gerasimenko from a distance of 75 kilometers (46 miles) and by pure chance it spotted an eruption of dusty material from the shaded nucleus.

Rosetta Watches Comet Erupt With a Dusty Surprise
http://news.discovery.com/space/rosetta-watches-comet-erupt-with-a-dusty-surprise-150420.htm

On March 12, the Rosetta spacecraft was imaging Comet 67P/Churyumov-Gerasimenko from a distance of 75 kilometers (46 miles) and by pure chance it spotted an eruption of dusty material from the shaded nucleus.

Long-duration spacecraft are essential if we are to fully understand the evolution of a comet as it gradually heats up during its approach to the sun. And it just so happens that Rosetta is always in orbit around 67P’s nucleus, ready to spot any transient event that could erupt at any time on the surface.

The Philae Lander should soon see enough sun to resume operations on Comet 67P/Churyumov-Gerasimenkoduring April or May, the European Space Agency’s (ESA’s) lander manager Stephan Ulamec told the European Geosciences Union General Assembly earlier this week.

Philae hitched a ride to 67P aboard the Rosetta probe and descended to the comet last year, but landed in a crack where its solar panels could not see the Sun. Once its batteries reached a certain level it therefore hibernated. The ESA tried to wake the lander last month, without success, but Ulamec feels 67P is now receiving enough sunlight that the craft’s innards should warm beyond -45C, the point at which it starts to do things other than self-preservation. With a little extra sunlight, it’s expected the lander may even gather enough energy to fire up its radios and start doing science.

If that happens, one of the things it won’t need to look for is a magnetic core, because the lander’s bounces across the comet’s surface have shown it doesn’t have one.

An anonymous reader sends word that the European Space Agency’s Rosetta spacecraft has detected traces of molecular nitrogen on the comet 67P/Churyumov–Gerasimenko.

Rosetta Spacecraft Makes Nitrogen Discovery on Comet
by Elizabeth Howell, Space.com Contributor | March 20, 2015 12:18pm ET
http://www.space.com/28884-rosetta-comet-nitrogen-discovery.html

A peculiar mix of molecular nitrogen on the comet target of Europe’s Rosetta spacecraft may offer clues to the conditions that gave birth to the entire solar system.

Boffins working for Caltech and NASA’s Jet Propulsion Laboratory have created comet-like stuff in a cryostat.

Along the way, they’ve decided that your average comet is kind of like fried ice-cream: squishy on the inside, crusty on the outside, with organic chemicals dusted on top.

Both the ESA’s Rosetta and NASA’s Deep Impact comet missions had found evidence of the soft, porous interiors of comets, and the Philae lander discovered the hard surface the hard way, with a triple-bounce that surprised mission scientists and degraded some of its activities

The fluffy interior, the researchers explain, are a form of ice not observed under normal Earth conditions. The “amorphous” porous ice forms when water vapour is flash-frozen at around 30 Kelvin, and never forms crystals.

The disorderly states of amorphous ice mean it’s somewhat like fairy floss (cotton candy) – light, fluffy, and with pockets of space throughout.

The European Space Agency (ESA) has released details of the first bushel of studies derived from the Rosetta spacecraft’s visit to Comet 67P/Churyumov–Gerasimenko.

The journal Science has devoted a special issue to seven studies of the comet