After the emergence of the prospect of the presence of seasonal water on the surface of Mars, discussions about the fact that this planet is most similar to Earth and life can be on it have returned. But this is not the only place intriguing scientists. At the congressional hearings held this week, scientists put forward four main candidates from the solar system. Other researchers searched for radio and optical emissions from distant stars to find advanced civilizations. Soon, scientists plan to look for chemical signs of life in the atmospheres of planets orbiting nearby stars. Consider the most likely applicants.
Ellen Stofan, NASA Chief Researcher, nominated her main candidate - Mars. “We know for sure that Mars was a water world, like the Earth, with clouds and a water cycle. For hundreds of billions of years, about half the northern hemisphere has been an ocean, reaching miles in depth in some places. As we know, life requires water, which in the liquid state has been on the surface of Mars for a long time. That is why the red planet is the main point in our search for extraterrestrial life. ” Next rover plan to launch in 2020. His tools must find microbial life. Although Stofan, a geologist by training, believes that in the near future, astronauts themselves will land on the planet in order to obtain the necessary rocks and conduct experiments with them.
The satellite of Jupiter Europe, the size of our Moon, still stores a salty ocean with a volume of water twice that of Earth’s oceans. The ocean is in contact with a rocky core, which represents suitable conditions for the emergence of life. Also in the moon there are abundant sources of energy. But the question remains: does it have organic matter? The mission of 2020 will try to find organic matter that has broken out of the sea through cracks on the icy surface of the moon. They will also search for a mysterious plume (water vapor over the southern polar region of Europe), discovered by the Hubble Space Telescope in 2012. Scientists also want to find out how deep the ocean is buried under the icy crust of the moon.
One of the biggest surprises of the NASA Cassini mission on Saturn was the discovery of loops taken in space from the moon Enceladus. Now they are known as subsurface oceans. “There is a list of requirements for defining life. You can not do without liquid water, minerals, organic matter, energy and chemical gradients. And the mission managed to find them all in this train, ”said Jonathan Lunin of Cornell University.
Scientists see prospects for life on the largest satellite of Saturn Titan. Although, most likely, the finds will be different from everything that we see on Earth. Cassini’s mission and the Huygens apparatus opened up a whole world with methane clouds, rain, river valleys and seas consisting of methane and ethane. “We cannot but ask ourselves whether there is a likelihood of the emergence of a new biochemical form of life in this cold environment,” said Jonathan Lunin. “Titan is a real test for universal life and a test for cosmic evolution.” To search for life, it is planned to introduce a capsule into the sea of Titan, so that it will float on the surface and take measurements.
As long as we know that life exists only on planet Earth. But scientists do not know how it started and how many false starts it was before a successful trial. “Since the Earth is the only instance of habitable life, the discovery of other forms on extraterrestrial objects will allow us to better explore our planet,” said Ellen Stofan. “We know that after conditions stabilized here, life began to develop very quickly. And it gives hope that this could happen again in another place in the solar system. Some evidence of how life appeared on the planet was etched on the moon. “Therefore, it must be carefully examined,” Lunin said. “This is the perfect place to experiment. And since we have already identified 4 good places for finding life, then it’s time to start a search. ”