Print Email Font ResizeBoulder scientists key to discovering smallest planet outside our solar systemKepler-37b, smaller than Mercury, detected by Ball Aerospace-built Kepler craftBy Charlie Brennan Camera Staff WriterPosted:
NASA's Kepler mission scientists have discovered a new planetary system that is home to the smallest planet yet found around a star. (NASA PHOTO)
A planet-hunting mission with strong Boulder ties on Wednesday announced the discovery of the smallest planet ever identified outside our solar system, tagged with the less-than-celestial name Kepler-37b.
Kepler-37b is smaller than Mercury, likely has a rocky terrain and, with an estimated surface heat of 800 degrees Fahrenheit, no atmosphere or water, and would not be expected to be hospitable to life as we know it.
The planet is closest-in of three newly identified planets orbiting a host star about 210 light-years from Earth that has been designated Kepler-37, and is found in the constellation Lyra, which is seen in the summer sky in the Northern Hemisphere.
Detection of the planet, about 10 percent larger than our own Moon, is the latest achievement of the Kepler spacecraft, built by Ball Aerospace Technologies Corp., of Boulder.
Launched in March 2009, the Kepler photometer identifies planet candidates in the habitable zone -- the region where liquid water could exist on an orbiting planet. The probe continuously measures the tiny change in brightness of more than 150,000 stars to detect when a planet transits the face of the star. The size of the planet can be derived from these periodic dips in brightness.
"This project would not have been possible if not for the exquisite instrument built at Ball," said Thomas Barclay, a research scientist at NASA's Ames Research Center at Moffett Field, Calif. He is lead author on a paper announcing the discovery published Wednesday in the journal Nature.
"I, personally, found this discovery to be astounding," Barclay said. "I never expected to find anything like this, and neither did most of the people working on the project. To find a planet smaller than Mercury surprised everyone involved."
To put the size of Kepler-37b in context, Mercury is roughly 38 percent the size of Earth. Our moon is 28 percent the size of Earth. Kepler-37b is about 30 percent the size of Earth.
"The significance as far as I'm concerned is that when the mission first started it was hoped that we could find planets smaller than Mars, and we thought it might be able to find planets as small as Mercury," said Alan Gould, a co-investigator for education and public outreach for the Kepler mission. "So this is momentous in that here is a planet smaller than Mercury, and it is totally due to the incredibly precise light measuring capability of the Kepler instrument."
'Wheels grind slowly' The paper reporting the planet's discovery boasts 58 co-authors. One is Travis Metcalfe, a research scientist at the Space Science Institute of Boulder, and also director of the White Dwarf Research Corp., a nonprofit organization he founded, staffed by volunteers, to support space exploration.
Metcalfe was part of the seismology team that worked to determine the size of the new planet's host star, a critical step in the determining the size of its orbiting planets.
"It was about a year ago that we finished our contribution to this paper," Metcalfe said. "The wheels grind slowly over at NASA."
Metcalfe in January 2008 launched what he calls the Pale Blue Dot project, which has the goal of raising funds for the Kepler Asteroseismic Science Consortium, which supports the goals of the Kepler mission.
People making $10 donations through the Pale Blue Dot project can then adopt a star, with 100 percent of their donations helping to fund an international team of astronomers who determine the size of parent stars from seismology -- measuring natural oscillations in brightness caused by continuous star-quakes.
Since initiating the Pale Blue Dot effort five years ago, it has raised nearly $60,000. About $20,000 was raised in 2012 alone, making it the most successful year to date.
About $5,000 of that went directly to pay for the seismic analysis of the parent stars of Kepler planetary systems, while an additional $15,000 was used to help students and early-career scientists present their research at annual conferences focused on stellar seismology. The balance is supporting an endowment to sponsor future research and conferences.
'Huge effort' Metcalfe said that due to the small size of Kepler-37b, it took a "huge effort" to determine that the signal the Kepler craft was detecting was a true signal, and not a "false positive."
"Extraordinary claims require extraordinary evidence," Metcalfe said. "It's marvelous. I think it's a testament to how fruitful the collaboration has been, and will be in the future, between people who are interested in planets outside of our solar system and people who are interested in other stars -- because the two go hand in hand."
NASA announced in April 2012 that the Kepler mission was being extended through fiscal year 2016. Kepler's ties to Boulder go beyond the fact of its having been built by Ball Aerospace.
In addition, a team of about 20 students and 16 professionals from the Colorado's Laboratory for Atmospheric and Space Physics operate the Kepler craft from the LASP Space Technology Building in the CU Research Park.
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