Oxygen find on comet ‘big surprise’

Spacecraft to sample water plumes from Saturn moon

PARIS, Oct 29, (Agencies): Stunned scientists announced Wednesday the unexpected discovery of large quantities of oxygen on a comet which streaked past the Sun in August with a European spacecraft in tow.

The find came as a “big surprise”, and challenges mainstream theories on the formation of our Solar System, said scientist Andre Bieler of the University of Michigan.

Measurements made by the Rosetta probe suggested that oxygen molecules in the 67P comet’s gassy halo must have existed “before or at” its formation, he told journalists.

This may have implications for mankind’s understanding of the chemistry involved in the formation of the Solar System some 4.6 billion years ago.

“We believe this oxygen is primordial, which means it is older than our Solar System,” said Bieler.

Scientists had previously ruled out the presence of oxygen (O2) on comets such as 67P/ChuryumovGerasimenko, the subject of intensive prodding and probing by a European robot lab.

Survive As O2 mixes easily with other elements, “we never thought that oxygen could ‘survive’ for billions of years” in a pristine state, said Kathrin Altwegg of the University of Bern, who co-authored a study in the journal Nature.

“This evidence of oxygen as an ancient substance will likely discredit some theoretical models of the formation of our Solar System,” she said.

Fish cry for help:

Distressed fish caught by predators emit a cry for help to attract other carnivores so they can escape during the ensuing chaos, Australian scientists said Thursday.

While researchers had discovered that fish emit a chemical substance found in their skin when injured to alert others nearby of the dangers, they did not know whether the distress call also benefited the captured prey.

“Within a minute (of the chemical alarm being emitted), you get this aggregation of little predators coming in,” the study’s coauthor Mark McCormick of James Cook University told AFP, adding that most fish

The comet is being tracked on its deep space journey around the Sun by the European Space Agency’s Rosetta spacecraft.

The historic mission seeks to unlock the mystery of the origins of life on Earth.

Scientists believe that comets “seeded” early Earth with some of the ingredients for life.

The team monitored the ratio of oxygen to water on the comet for several months to see if the gas molecules would dissipate as solar winds ripped away layers of surface.

They did not — proving the oxygen was embedded in the comet, not just hanging around its surface.

Prevailing theories of the Solar System’s birth posit a chaotic, collision-strewn mixing of matter flowing toward and away from the newly-formed Sun.

Pristine, icy grains containing oxygen would not have made it through such violence intact, the scientists said, leading them to speculate that the process was, in fact, “gentler”.

The oxygen molecules must have “survived from the dark molecular clouds from which they were probably formed into comets as we have them today,” said Altwegg.

Icy Only twice before — on the icy moons of Jupiter and Saturn — have oxygen molecules been found in the Solar System beyond Earth’s atmosphere, and never before on a comet.

Oxygen is difficult to detect with Earth-bound telescopes.

Rosetta offered a rare opportunity to study 67P’s “coma” — the envelope of dust, gas and ice that forms as it nears the Sun on an elliptical orbit.

The new data suggests that water on comets is probably the rule rather than the exception, the scientists said.

Scientists not involved in this study underlined its importance, but said more time was needed to assess the implications.

The discovery “imposes a severe constraint on the mechanism for the formation of the Solar System,” said French astrophysicist Francis Rocard.

“But we shouldn’t jump to conclusions,” he cautioned.

A US spacecraft was poised to make a deep dive into plumes of water, ice and organic matter blasting from Saturn’s small, ocean-bearing moon Enceladus, in an effort to learn if it could support life, NASA said on Wednesday.

Only a drop of water will be collected during the 19,000 mph (30,600 kph) flyby, which is scheduled to take place about 1:00 pm EDT/1700 GMT.

Scientists say that will be enough to answer some key questions about Enceladus, which has a global ocean sealed beneath its icy surface.

“This is a very big step in a new era of exploring ocean worlds in our solar system bodies with great potential to provide oases for life,” said program scientist for NASA’s Cassini mission at Saturn.

The spacecraft does not have instruments to directly detect life, but scientists hope to ferret out details about the underground ocean that is believed to be the source of Enceladus’ geyser-like plumes. Scientists suspect tidal forces are keeping the ocean liquid.

Cassini discovered the plumes, which stretch hundreds of miles into space, in 2005, a year after reaching Saturn.

Also: MIAMI: NASA astronaut

was to Thursday set a new record for the longest single stretch of time spent in space by an American, with 216 consecutive days at the International Space Station.

Kelly is more than midway through an entire year at the ISS, as part of an experiment to study the effects of long-term spaceflight on the body and mind. Russian cosmonaut

is also spending a year at the orbiting outpost for the study.

Kelly’s twin brother, Mark, is taking part on Earth to help scientists compare any genetic changes they see in Scott while in space.

Astronauts typically spend no longer than five to six months at a time in space.

“Breaking such a record for time in space is important because every additional day helps us better understand how long-duration spaceflight affects bodies and minds, which is critical to advancing NASA’s journey to Mars,” the space agency said in a statement. ty’s Centre of Excellence for Coral Reef Studies.

“It means that the fundamental way that predators interact with prey, and vice versa, will change.” (AFP)