WASHINGTON — Scientists are stepping up the search for “tenacious” forms of primitive life on planets orbiting distant stars, with promising technologies that could begin assessing 3,500 candidate planets within five to ten years, three astrobiology experts told Congress Wednesday.
Rep. Lamar Smith, R-San Antonio, chairman of the House Committee on Science, Space and Technology, called the prospect “inspiring,” adding that confirmation of distant life would transform mankind’s understanding of life on earth and human beings’ place in the universe.
The scientists and lawmakers from both parties readily agreed that despite the budget squeeze, NASA needs more money to pursue the pioneering research, and national leaders need to build stronger public support for the spending.
The James Webb space telescope scheduled for launch in 2018 potentially could evaluate some planets for the telltale buildup of atmospheric gases that could signal single cell life, Sara Seager, an astrophysicist and planetary scientist at MIT, told the panel.
But the best chance of spying signs of life would be a direct imaging mission that relies on a next generation, space-based telescope and a so-called “star shade” that would screen out stars’ light to enable the telescope to get a better shot of orbiting planets, said Seager.
Seager heads the NASA advisory team testing the concept.
“If that one (approach) could be implemented, when it was launched it would take a few years,” Seager said. “And in that case we also have to be lucky. We would be able to find signs of life.”
NASA astrobiology senior scientist Mary Voytek called the coming exploration “a golden age,” adding that astrobiology “aims to achieve a better understanding of our own world and the life it hosts and also of potential habitable worlds and life beyond Earth.”
Voytek, Seager and Steven Dick, an astronomer and former chief historian at NASA now with the Library of Congress, voiced support for continued NASA spending on the quest for extra-terrestrial life in an era when manned exploration has stalled.
“We need to invest in the technology now so this (quest) can actually happen at some point,” said Seager, recipient of a MacArthur Fellowship in 2013 for work detecting chemical signatures in exoplanet atmospheres. “I don’t want to leave you with just being optimistic — we really do need to invest in the future.”
Both Republicans and Democrats on the panel voiced support for NASA to continue ambitious missions to Mars and other planets in the search for extra-terrestrial life. But the reality is the space agency faces a looming budget crunch.
The White House asked for $17.7 billion for the fiscal year that began Oct. 1. But the Senate and House remain roughly 10 percent apart, with senators supporting $18.1 billion for fiscal 2014 and House Republicans weighing rival proposals to provide NASA between $16.1 billion and $16.9 billion.
“The practicalities and budget realities may not permit the detection of biosignature gases in the near future,” Seager conceded. “However, the first step towards the robust identification of potentially habitable worlds” will be made with the Transiting Exoplanet Survey Satellite scheduled for launch in 2017 working with the James Webb space telescope.
“There’s no denying the fascination with, `Does life exist elsewhere,’” said Rep. Eddie Bernice Johnson, D-Dallas, the ranking Democrat on the House panel. “I hope Congress understands the value of future NASA space science missions. This is an opportunity to shine a light on those contributions.”
Congress can bolster the effort not only with money but by sending a “very strong message” that astrobiology is “a legitimate science now,” Seager said.
“We’re not like searching for aliens or looking for UFOs,” Seager said. “It really is a legitimate field of research – one that’s critical.”