Water Geysers on Europa Moon

SAN FRANCISCO — The apparent discovery of water geysers on Jupiter's moon Europa makes the icy body an even more attractive target for a life-hunting mission, researchers say.

Scientists announced Thursday (Dec. 12) that they had detected transient plumes of water vaporerupting from Europa's south poleand extending about 125 miles (200 kilometers) into space. The ice-covered moon is thought to contain a subsurface ocean of liquid water, and the geysers represent a way to sample this potentially life-supporting environment, NASA officials said.

"Indeed, the plumes are incredibly exciting, if they are there," Jim Green, head of NASA's planetary science division, said here Thursday at the at the annual meeting of the American Geophysical Union. "They're bringing up material from within the ocean; perhaps there's organic material that will be laying on the surface of the south pole." 

An artist's illustration of Jupiter's icy moon Europa, with a water geyser erupting in the foreground while Jupiter appears as a backdrop. Images from the Hubble Space Telescope suggest Europa may have water plumes like Saturn's moon Enceladus.

The new find, made using observations by NASA's Hubble Space Telescope, could build some momentum for a mission concept the space agency is developing called the Europa Clipper.

The Europa Clipper probewould orbit Jupiter but make multiple flybys of the 1,900-mile-wide (3,000 kilometers) moon, using a number of different science instruments to study Europa's ice shell and subsurface ocean. The strategy would be similar to that employed by NASA's Cassini mission, which has made flybys of many Saturn moons since entering into orbit around the ringed planet in 2004.

"What we have been doing is studying several approaches to really understand Europa from a spacecraft in that environment, and it looks like the Clipper concept is our best one," Green said.

"Based on these [new] observations, we're going to redouble our efforts to take a good look at Clipper — its orbital trajectories, the plans for the mission architecture — to ensure that we have the right instrumentation and that we can cover this area very well and really, really understand it," he added.

Artist's concept of the Europa Clipper mission investigating Jupiter's icy moon Europa.

The Clipper could conceivably fly directly through Europa's plumes, taking samples as it goes, researchers said.

The Europa Clipper is not formally on NASA's books; it remains a concept at the moment, and some rethinking may be required to make the mission a reality. For example, its price tag — estimated last year to be $2 billion — is too high to be approved in these tough fiscal times, Green said.

The Clipper mission "is what we would call a flagship, and right now the budget horizon is such that we're deferring that kind of mission until later in the decade," he said.

The European Space Agency, meanwhile, has its own plans to study Europa. ESA plans to launch a mission called the Jupiter Icy Moon Explorer, or JUICE, in 2022, with arrival in the Jovian system slated for 2030.

JUICE will focus on three of Jupiter's moons: Ganymede, Callisto and Europa. However, the spacecraft will likely make just two flybys of Europa over the course of its mission, researchers said.

Crab Nebula

Humans who keep pretending there is no other life out there in the Universe, should consider the vast space this occupies all on it's own.

Across the Universe, every ending is a new beginning. When a massive star dies, exploding as a spectacular supernova, huge amounts of matter and energy are ejected into surrounding space, and the remnant of the explosion itself remains a hub of fierce activity for thousands of years.

One of the most iconic supernova remnants is the Crab Nebula. A wispy and filamentary cloud of gas and dust, it originated with a supernova explosion that was seen by Chinese astronomers in the year 1054. A spinning neutron star – or pulsar – remains at its centre, releasing streams of highly energetic particles into the nebula.

This composite image combines a new infrared view of the Crab Nebula, obtained with ESA’s Herschel Space Observatory, with an optical image from the archives of the NASA/ESA Hubble Space Telescope.

Herschel’s observations are shown in red and reveal the glow from cosmic dust present in the nebula. Hubble’s view, in blue, traces oxygen and sulphur gas in the nebula.

A team of astronomers studying the nebula with Herschel has revealed that this supernova remnant contains much more dust than they had expected – about a quarter of the mass of the Sun.

The new observations also revealed the presence of molecules containing argon, the first time a noble gas-based molecule has been found in space.

Argon is produced in the nuclear reactions that take place during supernova explosions, and astronomers had already detected this element in the Crab Nebula. However, it is surprising that argon bonded with other elements, forming molecules that survived in the hostile environment of a supernova remnant, with hot gas still expanding at high speeds after the explosion.