NASA's Asteroid Mission Is 'Statistically Flawed', Says New Paper

Ex-Microsoft billionaire Nathan Myhrvold suggests in a new paper, that NASA's Wide-field Infrared Survey Explorer (WISE) space telescope results are "fundamentally flawed" in judging the size of more than 157,000 asteroids. Yet, many in the community are firm that Myhrvold's techniques are flawed.

The WISE telescope as well as the follow-up mission, NEOWISE, have resulted in the finding of more asteroids than any other observatory. Still, Myhrvold says that papers using data from WISE and NEOWISE are full of mistakes.

"None of their results can be replicated," he said. "I found one irregularity after another."

In a 2011 paper, Myhrvold says they overlooked the margin of error while using a small sample size to "generalize to an entire population." They also neglected to factor Kirchhoff's law of thermal radiation when they built up thermal models of the asteroids.

"Asteroids are more variable than we thought they were," he said.

Yet, the WISE and NEOWISE teams still stand by their findings. They indicate that there are a number of flaws in Myhrvold's paper.

"For every mistake I found in his paper, if I got a bounty, I would be rich," said Ned Wright, the principal investigator for WISE at the University of California, Los Angeles.

Wright said WISE's data could match up with AKARI and IRAS, which were two other infrared telescopes. They were obtained in combination with radar observations as well as those made with spacecraft. They all made the data accurate.

"Our team has seen the paper in various versions for many months now, and we have tried to point out problems to the author," said Amy Mainzer, the principal investigator for NEOWISE at the Jet Propulsion Laboratory in Pasadena, Calif. "We have strongly encouraged that the paper be submitted to a journal and peer reviewed. Instead, he released it without peer review."

Myhrvold says that he is fixing the errors, but they are still "minor". He is firm about his main criticisms of WISE and NEOWISE. Moreover, he believes that their rigorous counterargument is mainly due to their suggestion for a future telescope called NEOCam that can hunt asteroids.

"They're up for this NEOCam thing, and they're afraid it looks bad," he said. "And it does look bad."

The findings were published May 23 on the pre-print server arXiv.