A world of advice is issued for scientists looking for alien life

It’s one of the biggest questions there is: Are we alone in the universe?

NASA scientists in the field of astrobiology are looking for answers. A new report from the National Academies of Sciences, Engineering and Medicine has some advice to help them along.

Here are some of recommendations. its

If you were to look at Earth from space with an extremely powerful telescope, the signs of life would be obvious: Trees clustered in rainforests, herds of elephants roaming across the savanna, the distinctive colors of algae blooms on the water.

But there’s also plenty of life beneath the surface. Consider the soil microbes that produce natural antibiotics, or the giant tube worms (they’re actually mollusks) that thrive on the freezing ocean floor, fueled by hydrothermal vents instead of light from the sun.

Other worlds that may look dormant on the surface could harbor life in their interiors.

Enceladus, Saturn’s sixlargest moon, is a prime example. Its frozen exterior may give the impression that it’s nothing more than a giant ice cube.

But you can’t judge a world by its outer shell. NASA’s Cassini spacecraft revealed that Enceladus has a briny subsurface ocean with complex organic molecules. That, along with heat generated by tidal forces, makes scientists think that the moon could be hospitable to life.

If astrobiologists detect evidence of life, how would they know? Are there certain essential features that any form of life must have? Are some of them unique to living things?

In science-speak, the thing astrobiologists are looking for is a “biosignature,” a detectable sign that life is (or was) present. It may be a particular shape that only a living being could produce. It may be a pattern of chemical compounds that must have had a biological origin.

There is still much debate about what would qualify as a biosignature. The report recommends that astrobiologists buckle down and figure this out.

One possibility for detecting life is to focus on biosignatures in exoplanet atmospheres. In the last decade, new technologies have greatly improved scientists’ ability to analyze the contents of these distant atmospheres, and NASA should do what it can to accelerate this work, the report said.

It’s also important to look closer to home. Potential biosignatures from some of Earth’s oldest sedimentary rocks can provide scientists something to practice on.

When NASA sends robotic explorers into space, they should be capable of analyzing DNA and RNA with great precision.

Another important consideration: Any technologies used on other worlds should tread as lightly as possible. And no matter what, they should not contaminate any other part of the universe with life from Earth.

And they shouldn’t wait to be consulted until after key decisions are made — astrobiological factors should be baked in from the very beginning, when a mission is still in the conceptual stage.

People with expertise in astrobiology should remain involved at every step of the way. That includes the operational phase, when a space probe is actually carrying out its assigned work.