MISTRY OF EARTH IN MILKY WAY|| SANDS OF MARS||
The new Paramount film “Interstellar” imagines a future where astronauts must find a new planet suitable for human life after climate change destroys the Earth’s ability to sustain us. Multiple NASA missions are helping avoid this dystopian future by providing critical data necessary to protect Earth. Yet the cosmos beckons us to explore farther from home, expanding human presence deeper into the solar system and beyond. For thousands of years we’ve wondered if we could find another home among the stars. We’re right on the cusp of answering that question.
If you step outside on a very dark night you may be lucky enough to see many of the 2,000 stars visible to the human eye. They’re but a fraction of the billions of stars in our galaxy and the innumerable galaxies surrounding us. Multiple NASA missions are helping us extend humanity’s senses and capture starlight to help us better understand our place in the universe.
Largely visible light telescopes like Hubble show us the ancient light permeating the cosmos, leading to groundbreaking discoveries like the accelerating expansion of the universe. Through infrared missions like Spitzer, SOFIAand WISE, we’ve peered deeply through cosmic dust, into stellar nurseries where gases form new stars. With missions like Chandra, Fermiand NuSTAR, we’ve detected the death throes of massive stars, which can release enormous energy through supernovas and form the exotic phenomenon of black holes.
Yet it was only in the last few years that we could fully grasp how many other planets there might be beyond our solar system. Some 64 million miles (104 kilometers) from Earth, the Kepler Space Telescope stared at a small window of the sky for four years. As planets passed in front of a star in Kepler’s line of view, the spacecraft measured the change in brightness. Kepler was designed to determine the likelihood that other planets orbit stars. Because of the mission, we now know it’s possible every star has at least one planet. Solar systems surround us in our galaxy and are strewn throughout the myriad galaxies we see. Though we have not yet found a planet exactly like Earth, the implications of the Kepler findings are staggering—there may very well be many worlds much like our own for future generations to explore.
NASA also is developing its next exoplanet mission, the Transiting Exoplanet Survey Satellite (TESS), which will search 200,000 nearby stars for the presence of Earth-size planets.
As of now, the distance between stars is too great for spacecraft to traverse using existing propulsion. Only one spacecraft is poised to leave the solar system in the near future. Voyager 1, launched in 1977, made the historic entry into interstellar space in August of 2012, reaching the region between stars, filled with material ejected by the death of nearby stars millions of years ago. It won’t encounter another star for at least 40,000 years.
The near-term future of exploration should be cause for much excitement, though, as humans and robotic spacecraft pioneer the path Voyager traveled, deeper into our solar system, where extra-terrestrial life may exist, and where humans could one day thrive.
Life as we know it requires water and heat. On our watery planet, we find life teeming at even the most extreme temperatures. Scientists are eager to know if evidence of microbial life exists on other planets and moons within our reach. On Jupiter’s moon Europa, for example, there is a temperate ocean caught between a volcanic core and icy surface. Just as life exists in the dark, hot reaches of Earth’s ocean, so too could it exist on Europa, waiting to be discovered. NASA is studying a future missionto the watery moon next decade