In an encouraging sign of life beyond earth, NASA scientists have found faint signatures of water in the atmospheres of five distant planets.
Though the presence of atmospheric water was reported previously on a few exoplanets orbiting stars beyond the solar system, but this is the first study to conclusively measure and compare the profiles and intensities of these signatures on multiple worlds, NASA said.
The five planets -- WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b -- orbit nearby stars, a NASA report said adding that this was based on the research done through the Hubble telescope.
The strengths of their water signatures varied, it said. WASP-17b, a planet with an especially puffed-up atmosphere, and HD209458b had the strongest signals. The signatures for the other three planets, WASP-12b, WASP-19b and XO-1b, also are consistent with water, NASA said.
"We're very confident that we see a water signature for multiple planets," said Avi Mandell, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland., and lead author of an Astrophysical Journal paper, published yesterday, describing the findings for WASP-12b, WASP-17b and WASP-19b.
"This work really opens the door for comparing how much water is present in atmospheres on different kinds of exoplanets, for example hotter versus cooler ones," Mandell said.
NASA said the five planets are hot Jupiters, massive worlds that orbit close to their host stars. The researchers were initially surprised that all five appeared to be hazy.
"These studies, combined with other Hubble observations, are showing us that there are a surprisingly large number of systems for which the signal of water is either attenuated or completely absent," said Heather Knutson of the California Institute of Technology, a co-author.
"This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters," he added.
Meanwhile, NASA said it is committed to explore not only the Mars, but also asteroids, the Moon and other parts of the Solar system as the American space announced plans restructure its planetary research.
"NASA is committed to a vibrant and coordinated strategy, not only of Mars exploration, but missions that currently include ground-breaking science missions to asteroids, the moon, and other locations in our solar system," the space agency said.
These missions include Pluto New Horizons that has yet to reach their destinations; Dawn's mission to the dwarf planet, Ceres, and multiple missions still in operation, such as the Cassini mission to Saturn and Messenger mission to Mercury.
In addition to launching last month a mission to the study the upper atmosphere of Mars, NASA currently operates two rovers on the Martian surface.
The agency also is planning to launch a lander and another rover in the coming years, it said.
"NASA's commitment to planetary exploration research and analysis activities will remain strong with no lessening of our resolve to continue to lead the world in this area while reflecting fiscal realities," NASA's Planetary Director Jim Green said.
"This restructuring better aligns the program with the planetary goals and objectives in direct response to National Academy report recommendations.
"The restructuring of the research and analysis program has been occurring over the last several years and has been based on significant community input," he said.
During the virtual town hall meeting, he outlined and answered questions about the proposed agency restructuring plans to consolidate some of the supporting research and technology activities to ensure a balanced planetary science portfolio for the next decade.