Hunting the aliens

NASA's ailing Kepler spacecraft could hunt alien planets once more 

NASA's hobbled Kepler space telescope may be able to detect alien planets again, thanks to some creative troubleshooting.

Kepler's original planet hunt ended in May when the second of its four orientation-maintaining reaction wheels failed, robbing the spacecraft of its ultraprecise pointing ability. But mission team members may have found a way to restore much of this lost capacity, suggesting that a proposed new mission called K2 could be doable for Kepler.

Engineers with the Kepler mission and Ball Aerospace, which built the telescope, have oriented the spacecraft such that it's nearly parallel to its path around the sun. In this position, the pressure exerted by sunlight is spread evenly across Kepler's surfaces, minimizing drift. 

This strategy is returning some promising results, mission officials say. During a 30-minute pointing test in late October, for example, Kepler captured an image of a distant star field that was within 5 percent of the image quality achieved during Kepler's original mission.

"This 'second light' image provides a successful first step in a process that may yet result in new observations and continued discoveries from the Kepler space telescope," Charlie Sobeck, Kepler deputy project manager at NASA's Ames Research Center in Moffett Field, Calif., said in a statement.

The Kepler team is currently conducting tests to see if the spacecraft can maintain such pointing stability over periods of days and weeks — a necessity for discovering exoplanets.

Kepler launched in March 2009 on a mission to determine how frequently Earth-like planets occur around the Milky Way galaxy. The spacecraft finds exoplanets via the "transit method," noting the telltale brightness dips caused when an alien world crosses the face of, or transits, its host star from the instrument's perspective.

Kepler has been remarkably successful, spotting more than 3,500 planet candidates to date. Just 167 of them have been confirmed so far by follow-up observations, but mission scientists think 90 percent or so will end up being the real deal.

Researchers are still sifting through the mountains of data Kepler returned during its four years of science operations. Kepler team members have expressed confidence that they'll find Earth analogs in these databases, allowing the mission's primary goal to be achieved.

The proposed K2 mission would continue Kepler's exoplanet hunt, albeit in a modified fashion. K2 would also gather data about supernova explosions, star formation and solar-system bodies such as asteroids and comets, among other things, team members have said.

The Kepler team has officially presented the K2 mission concept to NASA Headquarters, which is expected to decide by the end of the year if the idea progresses to a vetting stage called "senior review." The ultimate fate of K2, and the Kepler spacecraft, will likely be known by the middle of next year, Kepler officials have said.

New Mystery In Space

Weird Black hole

An extremely bright black hole that is powering an energetic X-ray source in a neighboring galaxy has left astronomers baffled with its surprising capacity to consume matter, despite being unexpectedly lightweight, a new study reveals.

The black hole, which resides in the Pinwheel Galaxy about 22 million light years away from Earth, swallows the dust and gas around it in a “surprisingly orderly fashion.” And, with its incredible luminosity, this celestial phenomenon is expected to force a rethink of how some black holes radiate energy.

“It has elegant manners,” Stephen Justham of the National Astronomical Observatories of China said, in astatement. “We thought that when small black holes were pushed to these limits, they would not be able to maintain such refined ways of consuming matter. We expected them to display more complicated behavior when eating so quickly. Apparently we were wrong."

According to astronomers, larger black holes tend to produce softer X-rays while smaller black holes tend to produce relatively harder X-rays. The black hole system in question, called M101 ULX-1, is dominated by soft X-rays, so researchers had expected to find a large black hole as its energy source.

In addition, the black hole’s brightness is so incredible that astronomers had suspected that ULX-1 contained an intermediate-mass black hole weighing in between 100 and 1,000 times the sun's mass. However, new observations made at the Gemini Observatory in Hawaii, published in the Nov. 28 issue of Nature, indicate that M101 ULX-1’s black hole is on the smaller side, confusing astronomers.

Theories have been suggested which allow such low-mass black holes to eat this quickly and shine this brightly in X-rays. But those mechanisms leave signatures in the emitted X-ray spectrum, which this system does not display,” Jifeng Liu, of the National Astronomical Observatories of China, and the lead author of the study, said in the statement. “Somehow this black hole, with a mass only 20-30 times the mass of our Sun, is able to eat at a rate near to its theoretical maximum while remaining relatively placid. It’s amazing. Theory now needs to somehow explain what’s going on.”

The discovery also delivers a blow to astronomers hoping to find conclusive evidence for an “intermediate-mass” black hole in M101 ULX-1 as such black holes would have masses roughly between 100 and 1,000 times the mass of the Sun.

“Studying objects like M101 ULX-1 in distant galaxies gives us a vastly larger sampling of the diversity of objects in our universe,” Joel Bregman of the University of Michigan, a member of the research team, said. “It’s absolutely amazing that we have the technology to observe a star orbiting a black hole in another galaxy this far away.”