May 14 2018

From The Space Library

---

Current revision

RELEASE 18-034 Old Data Reveal New Evidence of Europa Plumes

Scientists re-examining data from an old mission bring new insights to the tantalizing question of whether Jupiter’s moon Europa has the ingredients to support life. The data provide independent evidence that the moon’s subsurface liquid water reservoir may be venting plumes of water vapor above its icy shell.

Data collected by NASA’s Galileo spacecraft in 1997 were put through new and advanced computer models to untangle a mystery -- a brief, localized bend in the magnetic field -- that had gone unexplained until now. Previous ultraviolet images from NASA’s Hubble Space Telescope in 2012 suggested the presence of plumes, but this new analysis used data collected much closer to the source and is considered strong, corroborating support for plumes. The findings appear in Monday’s issue of the journal Nature Astronomy.

The research was led by Xianzhe Jia, a space physicist at the University of Michigan in Ann Arbor and lead author of the journal article. Jia also is co-investigator for two instruments that will travel aboard Europa Clipper, NASA’s upcoming mission to explore the moon’s potential habitability.

“The data were there, but we needed sophisticated modeling to make sense of the observation,” Jia said.

Jia’s team was inspired to dive back into the Galileo data by Melissa McGrath of the SETI Institute in Mountain View, California. A member of the Europa Clipper science team, McGrath delivered a presentation to fellow team scientists, highlighting other Hubble observations of Europa.

“One of the locations she mentioned rang a bell. Galileo actually did a flyby of that location, and it was the closest one we ever had. We realized we had to go back,” Jia said. “We needed to see whether there was anything in the data that could tell us whether or not there was a plume.”

At the time of the 1997 flyby, about 124 miles (200 kilometers) above Europa’s surface, the Galileo team didn't suspect the spacecraft might be grazing a plume erupting from the icy moon. Now, Jia and his team believe, its path was fortuitous.

When they examined the information gathered during that flyby 21 years ago, sure enough, high-resolution magnetometer data showed something strange. Drawing on what scientists learned from exploring plumes on Saturn’s moon Enceladus -- that material in plumes becomes ionized and leaves a characteristic blip in the magnetic field -- they knew what to look for. And there it was on Europa –- a brief, localized bend in the magnetic field that had never been explained.

Galileo carried a powerful Plasma Wave Spectrometer (PWS) to measure plasma waves caused by charged particles in gases around Europa’s atmosphere. Jia’s team pulled that data as well, and it also appeared to back the theory of a plume.

But numbers alone couldn’t paint the whole picture. Jia layered the magnetometry and plasma wave signatures into new 3D modeling developed by his team at the University of Michigan, which simulated the interactions of plasma with solar system bodies. The final ingredient was the data from Hubble that suggested dimensions of potential plumes.

The result that emerged, with a simulated plume, was a match to the magnetic field and plasma signatures the team pulled from the Galileo data.

“There now seem to be too many lines of evidence to dismiss plumes at Europa," said Robert Pappalardo, Europa Clipper project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “This result makes the plumes seem to be much more real and, for me, is a tipping point. These are no longer uncertain blips on a faraway image."

The findings are good news for the Europa Clipper mission, which may launch as early as June 2022. From its orbit of Jupiter, Europa Clipper will sail close by the moon in rapid, low-altitude flybys. If plumes are indeed spewing vapor from Europa’s ocean or subsurface lakes, Europa Clipper could sample the frozen liquid and dust particles. The mission team is gearing up now to look at potential orbital paths, and the new research will play into those discussions.

“If plumes exist, and we can directly sample what’s coming from the interior of Europa, then we can more easily get at whether Europa has the ingredients for life,” Pappalardo said. “That’s what the mission is after. That’s the big picture.”

JPL manages the Europa Clipper mission for the agency's Science Mission Directorate.

RELEASE 18-036 NASA Announces New Director of Johnson Space Center

NASA Administrator Jim Bridenstine announced Monday the selection of Mark Geyer as the next director of the agency’s Johnson Space Center in Houston. He’ll assume the director’s position on May 25, when current Center Director and former astronaut Ellen Ochoa retires after 30 years at the agency.

As Johnson’s center director, he’ll lead one of NASA’s largest installations, which has about 10,000 civil service and contractor employees - including those at White Sands Test Facility in Las Cruces, New Mexico - and oversee a broad range of human spaceflight activities.

“Mark brings with him almost three decades of distinguished NASA leadership experience at the program, center and headquarters levels – he’s managed and he’s worked his way through the ranks and knows what it’s going to take to get our astronauts back to the Moon and on to Mars. Johnson has been NASA’s home base for astronauts and mission control throughout our history, and Mark is eminently qualified to carry on this historic legacy,” said Bridenstine. “I also want to thank Ellen for her years of service to America and this agency. Her legacy and contributions to this center and to NASA are timeless. She will be missed.”

Geyer currently is serving as the acting deputy associate administrator for Technical for the Human Explorations and Operations Mission Directorate at NASA Headquarters in Washington. In this position, which he assumed Oct. 1, 2017, he’s responsible for assisting the associate administrator in providing strategic direction for all aspects of NASA’s human spaceflight exploration mission. Before that, Geyer served as deputy center director at Johnson until September 2017.

“It’s an honor to be appointed to lead the men and women of this proud center,” Geyer said. “The Johnson Space Center has unique capabilities that are critical to NASA’s ability to execute our mission to take humans farther into the solar system, and I look forward to working with each and every one of you on the ambitious tasks ahead.”

Born in Indianapolis, Geyer earned his Bachelor of Science degree in Aeronautics Engineering as well as his Master of Science degree in Aeronautics from Purdue University in Indiana. Geyer is the recipient of the NASA Distinguished Service Medal, Meritorious Executive Rank Award and the Distinguished Executive Rank Award.

MEDIA ADVISORY M18-080 NASA TV Coverage Set for Next Resupply Mission to Space Station NASA commercial cargo provider Orbital ATK is scheduled to launch its ninth contracted mission to the International Space Station at 5:04 a.m. EDT Sunday, May 20 from NASA’s Wallops Flight Facility in Virginia. Live launch coverage will begin at 4:30 a.m. on NASA Television and the agency’s website.

NASA TV also will air two prelaunch briefings beginning at 11 a.m. Saturday, May 19. Mission managers will provide an overview and status of launch operations, and at 1 p.m. scientists and researchers will discuss some of the investigations to be delivered to the station. The briefings also will be streamed live on the agency’s website.

Orbital ATK’s Cygnus cargo spacecraft will launch on the company’s Antares rocket from Pad 0A of Virginia Space’s Mid-Atlantic Regional Spaceport, located at Wallops. Coverage of the spacecraft’s solar array deployment will begin at 6:15 a.m. and a post-launch briefing from the launch site will follow at 7:30 a.m.

Under the agency’s Commercial Resupply Services contract, Cygnus will carry about 7,400 pounds of science and research to the space station in support of dozens of research investigations, as well as crew supplies and hardware.

Cygnus will carry a physics laboratory to observe atoms in extreme cold and a facility that will be the first commercial European opportunity to conduct research in space. Other experiments will advance genetic sequencing of micro-organisms aboard the station and validate a system to extract one liquid from another. The spacecraft will also transport several CubeSats to conduct a variety of missions, from Earth science missions and a technology demonstration for laser communications, to mapping a gas surrounding our Milky Way galaxy.

With a May 20 launch, the spacecraft will arrive at the station on Thursday, May 24. NASA TV coverage of Cygnus’ rendezvous and capture will begin at 3:45 a.m. Capture is scheduled for 5:20 a.m. as Expedition 55 Flight Engineer Scott Tingle of NASA will grapple the spacecraft, backed up by Ricky Arnold of NASA. NASA astronaut Drew Feustel will monitor Cygnus systems during its approach for capture. They will use the space station’s robotic Canadarm2 to take hold of the spacecraft and after Cygnus’ capture, ground controllers will command the station’s arm to rotate and install it on the bottom of the station’s Unity module. NASA TV coverage resumes for installation operations at 7:30 a.m.

Cygnus will remain at the space station until July 15, when the spacecraft will depart the station, deploy NanoRacks’ customer CubeSats, and then dispose of several tons of trash during its fiery reentry into Earth’s atmosphere.

This Cygnus spacecraft is dubbed the S.S. J.R. Thompson, a distinguished leader in the aerospace industry as former NASA deputy administrator and a member of Orbital ATK for more than 20 years. Throughout his life, Thompson held prominent positions at Orbital and NASA, including at the agency’s Marshall Space Flight Center.