Artist's view of plumes on Europa (right) // NASA
Artist's view of plumes on Europa (right) // NASA

Plumes on Europa May Enable the Hunt for Alien Life

Artist's view of plumes on Europa (right) // NASA
Artist's view of plumes on Europa (right) // NASA

Jupiter’s moon Europa likely has water plumes—great geysers of saline ocean blasting from its icy shell. That's what scientists announced earlier today, reaffirming previous observations of plume activity on the Galilean moon. The findings raise the stakes for the agency's next flagship planetary mission, slated to launch for Europa around 2022.

The plumes, which are estimated to rise 125 miles above Europa's surface, were captured using the Hubble Space Telescope, NASA's 26-year-old space-based orbiting observatory. "We are working at the limits of Hubble's unique capabilities," said William Sparks, an astronomer with the Space Telescope Science Institute, during a press teleconference. To find the plumes, scientists used what’s known as transit imaging operations, observing the silhouette of Europa against the bright surface of Jupiter. It took 50 million observation events to generate the plume images, which were carefully processed through specially designed software.

NASA teased the results last week, promising "surprising activity" on the moon. Plumes fit the bill, and have implications beyond celestial wonder and geologic thrill-seeking. Europa is an ocean world, and is thought to have all of the ingredients necessary for life. Though it is only about the size of our own moon, it hosts a saltwater ocean with twice the water of Earth's oceans. That water is sandwiched between an ice shell and a rocky mantle. When water touches rock, interesting chemical processes result—especially if there are hydrothermal vents from the planet's interior blasting hot water into the ocean. The conditions for life on Europa are at least as hospitable as what can be found in the deepest parts of Earth's ocean. The plumes help kick open the door for alien, Europan creatures, though what we might find there remains a mystery.

The problem has always been getting to Europa’s ocean to take a sample. The ice shell is likely many miles thick—beyond the drilling capacity even here on Earth. Plumes solve that problem. We don't need to go to the ocean; we can have the ocean come to us. The Europa Multiple Flyby Mission in development by NASA will see a spacecraft enter orbit around Jupiter, circling the gas giant hundreds of times. Each time it comes around to Europa, it will scan and image the icy world. This technique, rather than a direct Europa orbiter, allows the spacecraft to avoid the worst of the punishing radiation belt in the Jovian environment. Scientists can now plan trajectories that allow the spacecraft to fly through the plumes in order to analyze their composition.

However, nobody is promising life detection yet. The multiple flyby mission is designed to study habitability. Follow-up missions—likely Europa landers—would actually determine the life question. (The plumes help a lander as much as they do a flyby, since water that blasts from Europa's shell would rain back down to the surface. A lander could make extraordinary observations by drilling only a few inches down.) Lander concepts are currently under development at Jet Propulsion Laboratory in southern California. The multiple flyby spacecraft is being developed jointly by JPL and the Johns Hopkins University Applied Physics Laboratory in Maryland.

"For a long time, humanity's been wondering whether there is life beyond Earth," said Paul Hertz, director of the astrophysics division at NASA headquarters. "We're lucky to live in an era when we can address such evidence scientifically."

For now, the discovery could only have been made with the sensitivity of the Hubble. "Hubble is the only telescope that we have right now capable of observing Jupiter and Europa at this detail in ultraviolet light," said Jennifer Wiseman, senior Hubble project scientist at NASA's Goddard Space Flight Center. The space telescope's science mission was recently extended by five years, until 2021, at which time NASA will have to decide whether to keep the space telescope operational. The powerful James Webb Space Telescope, Hubble's successor, is slated to launch in 2018. "We're particularly excited about using the James Webb Space Telescope ... to look for additional evidence of Europa water,” Wiseman says.

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ESO, A. Müller et al.
Here's the First Confirmed Image of a Planet Being Born
ESO, A. Müller et al.
ESO, A. Müller et al.

One of the newest landmarks in the observable universe has finally been captured, according to the European Southern Observatory. The image, snapped at its Very Large Telescope (VLT) in Chile, marks the first time a newborn planet has been seen as it forms. 

The image was documented by SPHERE, an instrument at the VLT that's built to identify exoplanets. It shows a planet, dubbed PDS 70b, taking shape in the disc of gas and star dust surrounding the young dwarf star PDS 70. In the past, astronomers have caught glimpses of what may have been new planets forming, but until now it had been impossible to tell whether such images just showed shapes in the dust or the beginnings of true planet formation. The results of the research will be shared in the journal Astronomy & Astrophysics [PDF].

This latest cornograph (an image that blocks the light of a star to make its surroundings visible) depicts the new planet clearly as a bright blob beside the black star. The two bodies may look close in the photo, but PDS 70b is roughly 1.8 billion miles from PDS 70, or the distance of Uranus to the Sun. SPHERE also recorded the planet's brightness at different wavelengths. Based on information gathered from the instrument, a team of scientists led by Miriam Keppler of the Max Planck Institute for Astronomy says that PDS 70b is a gas giant a few times the mass of Jupiter with a surface temperature around 1830°F and a cloudy atmosphere.

Astronomers known that planets form from solar clouds which stars leave behind when they come into a being, but until now, the details surrounding the phenomena have been mysterious. “Keppler’s results give us a new window onto the complex and poorly understood early stages of planetary evolution,” astronomer André Müller said in a press release. “We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.”

This is just the latest history-making image captured by the ESO's Very Large Telescope. In the last 20 years, it has documented nebulae, light from gravitational waves, and interacting galaxies.

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iStock
Saturn and a Strawberry Moon Will Brighten Night Skies This Week
iStock
iStock

Summer has officially arrived. That means the weather is finally warm enough in parts of the country to lay down a blanket in your backyard and spend the night staring at the sky. This week is especially exciting for stargazers. According to Mashable, Saturn will be visible in the sky beside a "strawberry moon."

One of the first major celestial events of the season takes place Wednesday, June 27. The Earth will fall directly between Saturn and the Sun on Wednesday and a brightly shining Saturn will be visible in the eastern sky after the Sun goes down. The best time to spot the ringed planet is around midnight, and it will appear in the sky for the next several months.

On Wednesday, when Saturn is at its brightest, the sky will present another treat. A full strawberry moon will rise not far from Saturn's spot around 12:53 a.m. EDT that night and accompany the planet as it moves across the sky. The name isn't a reference to the Moon's hue, but to the time of year when it appears: A strawberry moon is the first full moon of summer, and it was once used by farmers to mark the beginning of strawberry picking season.

These two events are just the start of a promising time of year for astronomy fans. Sync your digital planner to this space calendar so you don't miss out on any other big dates, like the partial solar eclipse on August 11.

[h/t Mashable]

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