On the left is a snapshot of the Earth from a DSCOVR-EPIC camera. On the right - the same frame, but degraded to a resolution of 3 x 3 pixels. This is what researchers will see when reviewing exoplanets
Mankind believed that Clyde Tombo would be the last to discover the planet (Pluto). But in 1992, two scientists were able to find a planet near an alien star, and since then their number has been constantly growing. Today, more than 3,500 exoplanets in 2,700 star systems have already confirmed their existence.
Of course, while life is found only on our planet. But when analyzing foreign worlds, it will be necessary to involve various scientists and create the necessary tools to study all sorts of forms.
When looking for life it is important to understand where to look and what exactly. That is, one should understand which planets in general are capable of having the necessary conditions for creating and maintaining living organisms. The same climate models are now being used to explain the climate change on Earth in the 21st century.
Moreover, scientists agree that life can exist in the most amazing places and bizarre forms, which is not at all like the creatures we are used to. When searching for one of the main criteria is the presence of liquid water.
Life in the Ocean
Researchers examine the worlds and filter out those that are not capable of holding water in a liquid state. For example, among the candidates are some of the icy satellites of Saturn and Jupiter, capable of hiding the oceans under the ice crust. They were formed by tidal heating - the melting of ice due to friction of the surface ice and the core. For example, only the Cassini mission was able to see the water world in the boring Enceladus. The device recorded water jets ejected from geysers. The presence of fluid in Europe is indicated by the observations of Galileo and Voyager.
The land is often used as a test field. So the deserts became an ideal place to run rovers before launching to Mars, while the Arctic and Antarctic are used to test the functioning of vehicles on ice worlds.
Water in space
For any star, you can determine the range of remoteness, where the orbital planets are able to have liquid water on the surface. This area is called habitability zone. Researchers already have a list of such objects and are now creating ways to conduct more in-depth studies.
But this is not enough. Extraterrestrial intelligence would find 3 planets in the habitable zone of our system, but we know that only one of them has life. Therefore it is necessary to add details. For example, it turns out that larger rocky planets more often have the necessary temperature regime.
When any traces are found, you first have to exclude all the options, and “life” is in the last position. For example, terrestrial oxygen in the atmosphere is filled with living beings, but it can also be created by inorganic chemical reactions. A biosignal can be the detection of two or more molecules in the atmosphere that should not be present at the same time. Oxygen absorbs methane, and therefore there must also be a permanent source of its replenishment.
Earth as an exoplanet
When scientists begin to review, even the worlds close to us on the detector are displayed in the form of several pixels (like the blue point of the Earth from the position of Saturn). How to see life?
Researchers are trying to deal with this, working out the technique of the review on Earth. To do this, use the camera apparatus DSCOVR with a resolution of 2000 x 2000. He takes a picture with a break of half an hour in orbit for two years. Now the archive has accumulated more than 30,000 frames.
When will we find life?
In this matter, opinions are divided. Someone thinks that a breakthrough will happen in the next 20 years. Others increase the mark to 50 years. But many agree that you should rely not only on observations and resources, but also on luck.