Water Detected on Largest Object in the Asteroid Belt, Ceres

Scientists using the Herschel space observatory have made the first definitive detection of water vapor on the largest and roundest object in the asteroid belt, Ceres.

Plumes of water vapor are thought to shoot up periodically from Ceres when portions of its icy surface warm slightly. Ceres is classified as a dwarf planet, a solar system body bigger than an asteroid and smaller than a planet.

Herschel is a European Space Agency (ESA) mission with important NASA contributions.

“This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,” said Michael Küppers of ESA in Spain, lead author of a paper in the journal Nature.

The results come at the right time for NASA’s Dawn mission, which is on its way to Ceres now after spending more than a year orbiting the large asteroid Vesta. Dawn is scheduled to arrive at Ceres in the spring of 2015, where it will take the closest look ever at its surface.

“We’ve got a spacecraft on the way to Ceres, so we don’t have to wait long before getting more context on this intriguing result, right from the source itself,” said Carol Raymond, the deputy principal investigator for Dawn at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Dawn will map the geology and chemistry of the surface in high resolution, revealing the processes that drive the outgassing activity.”

For the last century, Ceres was known as the largest asteroid in our solar system. But in 2006, the International Astronomical Union, the governing organization responsible for naming planetary objects, reclassified Ceres as a dwarf planet because of its large size. It is roughly 590 miles (950 kilometers) in diameter. When it first was spotted in 1801, astronomers thought it was a planet orbiting between Mars and Jupiter. Later, other cosmic bodies with similar orbits were found, marking the discovery of our solar system’s main belt of asteroids.

Scientists believe Ceres contains rock in its interior with a thick mantle of ice that, if melted, would amount to more fresh water than is present on all of Earth. The materials making up Ceres likely date from the first few million years of our solar system’s existence and accumulated before the planets formed.

Until now, ice had been theorized to exist on Ceres but had not been detected conclusively. It took Herschel’s far-infrared vision to see, finally, a clear spectral signature of the water vapor. But Herschel did not see water vapor every time it looked. While the telescope spied water vapor four different times, on one occasion there was no signature.

Here is what scientists think is happening: when Ceres swings through the part of its orbit that is closer to the sun, a portion of its icy surface becomes warm enough to cause water vapor to escape in plumes at a rate of about 6 kilograms (13 pounds) per second. When Ceres is in the colder part of its orbit, no water escapes.

The strength of the signal also varied over hours, weeks and months, because of the water vapor plumes rotating in and out of Herschel’s views as the object spun on its axis. This enabled the scientists to localize the source of water to two darker spots on the surface of Ceres, previously seen by NASA’s Hubble Space Telescope and ground-based telescopes. The dark spots might be more likely to outgas because dark material warms faster than light material. When the Dawn spacecraft arrives at Ceres, it will be able to investigate these features.

The results are somewhat unexpected because comets, the icier cousins of asteroids, are known typically to sprout jets and plumes, while objects in the asteroid belt are not.

“The lines are becoming more and more blurred between comets and asteroids,” said Seungwon Lee of JPL, who helped with the water vapor models along with Paul von Allmen, also of JPL. “We knew before about main belt asteroids that show comet-like activity, but this is the first detection of water vapor in an asteroid-like object.”

The research is part of the Measurements of 11 Asteroids and Comets Using Herschel (MACH-11) program, which used Herschel to look at small bodies that have been or will be visited by spacecraft, including the targets of NASA’s previous Deep Impact mission and upcoming Origins Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-Rex). Laurence O’ Rourke of the European Space Agency is the principal investigator of the MACH-11 program.

Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. While the observatory stopped making science observations in April 2013, after running out of liquid coolant, as expected, scientists continue to analyze its data. NASA’s Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel’s three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the U.S. astronomical community.

Dawn’s mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. Caltech manages JPL for NASA.

More information about Herschel is online at: http://www.esa.int/SPECIALS/herschel. More information about NASA’s role in Herschel is available at: http://www.nasa.gov/herschel. For more information about NASA’s Dawn mission, visit: http://www.nasa.gov/dawn.

Opposition to HR 3625 Grows

On December 11 the United States House of Representatives Science, Space, and Technology Committee approved a bill, H.R. 3625, that would require an act of Congress to cancel four of NASA’s largest programs: The Space Launch System (SLS), the Orion crew vehicle, the International Space Station, and the James Webb Telescope.

On January 6, Space News published an editorial called “Kill This Bill” which they summarized “H.R. 3625 would turn NASA’s biggest programs into privileged juggernauts.” The editorial stated: “Legislation proposed in the U.S. House of Representatives that would effectively shield selected big-ticket NASA programs from termination without prior congressional approval is bad policy that should be rejected by the Senate, if it gets that far.” It went on to say the bill “would remove a powerful incentive for the relevant NASA center and its contractors to control costs,” that it would create “a new class of untouchable programs,” and it “should be killed before it comes anywhere near the president’s desk.”

Lori Garver, recent Deputy Director of NASA and former Executive Director of the National Space Society, was quoted in Space News stating “We should not be debating whether or not we should have the ability to terminate a program that is not working in a cost-plus environment.”

The Planetary Society Blog on December 10 stated that the bill sets a bad precedent and that these projects “like every other project at NASA, should be judged on their merits and their cost vs. benefits through the normal political process, not added to some protected list to the exclusion of all other NASA activities.”

The National Space Society drafted a position statement opposing HR 3625 in December and issued a press release on the subject on January 13.

National Space Society Opposes HR 3625

The Washington DC-based National Space Society (NSS) strongly opposes the passage of House of Representatives bill HR 3625. This bill would (a) require NASA to obtain legislative permission to cancel four of its most expensive human spaceflight and science programs, and (b) allow contractors for these programs to have immediate access to hundreds of millions of dollars in funds which currently are held in reserve to pay the government’s obligations in the event of such termination. The four covered programs are the Space Launch System, the Orion crew capsule, the James Webb Space Telescope (JWST), and the International Space Station.

Ordinarily, government agencies like NASA have the right to terminate a project if it no longer appears necessary or cost effective, provided it pays “termination liability costs” which are sometimes provided for in such contracts. It is unusual to require an act of Congress in order to stop a program. As a practical matter, getting Congress to pass such an act would be extremely difficult.

Consequently, if HR 3625 is enacted, even after the responsible agency determined that a project was no longer useful, contractors would continue to get millions of dollars for unnecessary and unwanted programs until such a time as Congress passed a bill specifically calling for the cancellation of the project and allocating the funds required for program termination.

“The ability to cancel a program for convenience is essential to allow the government to deal with changing circumstances,” said NSS Executive Vice President Paul Werbos. “Requiring explicit Congressional approval to terminate a program for convenience represents a significant shift in power between the Executive and Legislative branches of government that should not be taken lightly.”

National Space Society Position Statement on HR 3625
December 2013

The National Space Society (NSS) opposes passage of HR3625, which was approved December 11, 2013 by the House Science, Space and Technology Committee. This bill, if approved by the full House and Senate, would have the impact of requiring that funds currently reserved for termination costs in the case of program cancellation for convenience be immediately spent on a short list of named programs. HR3625 also states that NASA cannot cancel these programs without Congress first passing a law to that effect.

Although this may initially sound like a good idea, HR3625 violates standards of professional program management and creates a special class of NASA programs that may be more difficult to cancel in the future. As a result, potential termination actions could focus on other NASA programs that are not covered by this Act. Additionally, HR3625 sets a bad example for management across the entire US government, and may lead to further attempts to create a wide range of specially protected programs. All NASA, and all government programs, are normally evaluated regularly on their merits by both executive and legislative branches. Although it is probable that HR3625 would have minimal impact on termination-for-cause actions that derive from poor performance, it would add additional obstacles to termination-for-convenience actions and make such actions more difficult. Finally, this bill potentially could create a “moral hazard” — a precedent encouraging companies to take additional risks if they felt a covered program would be more difficult to terminate.