Water, a key ingredient and indicator for the presence of life, is fairly common in the universe. Most of the time we see ice on asteroids and planets which is unlikely to show us any signs of life. However liquid water , as we see in oceans and lakes here on Earth, acts a great facilitator for the complex chemistry needed for life to occur.
Evidence from deep space exploration missions shows that a few of the moons in the outer solar system such as Europa and Enceladus could have liquid oceans under their icy surfaces. Often times we can water erupting from geysers into outer space. This suggests that not only are their bodies of liquid water, but there’s heat present to push that water out to the surface. The hydrothermal vents on our own ocean floor are teeming with diverse biological activity. Maybe something similar exists within the other ocean worlds in our solar system.
NASA’s recent announcement about the presence of hydrogen gas in the plumes of Saturn’s moon Enceladus has many scientists and space nerds enthused. Hydrogen, for those who don’t know, is a great energy source and can be used by microbes to fuel their metabolisms. It is one of several key ingredients for life as we know it. This recent data makes a strong case for the possibility that we may not need to look too far to see if life exists beyond Earth.
Currently most of our resources (and funding!) for space exploration are going towards ideas and projects for a manned mission to Mars. However, it may be better if we invested more in robotic missions to the ocean worlds of the outer solar system. While safely landing humans on Mars would be quite an accomplishment, finding any form of life outside of Earth would be a bigger scientific discovery. In fact it would be the biggest discovery in the history of mankind. It would redefine humanity’s perspective of the universe leading to countless questions and new forms of science and technology to help find the answers.
Robotic missions to the ocean worlds of the outer solar system have practical advantages over a manned mission to Mars. Robots don’t have demanding needs for food or shelter from space radiation like humans do. They are able to go faster and further with less materials making them ultimately cheaper than a manned spacecraft. From an engineering perspective the greatest challenges of these ocean missions would be actually getting through the ice to explore the subsurface oceans and finding an effective ways to analyze the water samples. Those are relatively easy obstacles to overcome compared to providing a small group of humans the necessary technology and training to survive on another planet.
Perhaps the greatest advantage of searching for life in the outer solar system before heading to Mars would be what would happen if we actually found it. Currently NASA receives one half of one cent of every tax dollar, which makes it challenging to develop the technology we need for a Mars mission. However, discovering extraterrestrial life would renew the public’s interest in space exploration and jump start a second space race. That will certainly learn to more funding for NASA and more opportunities to develop technology for future missions both unmanned and manned. The road to Mars and beyond could be paved by oceans on Enceladus, Europa, Titan, and other moons in our solar system