The TESS space telescope starts a new era of planet hunting, greatly increasing the odds of finding another truly Earth-like planet among the stars. But how will we know if there is a civilization like ours on an alien world?
The Transiting Exoplanet Survey Satellite is a follow-on to the highly successful Kepler space telescope. The Kepler mission discovered more than 2,600 planets orbiting other stars, with thousands more possible detections that have yet to be confirmed. But Kepler only looked at one portion of the sky, a small patch around the constellation Cygnus, about 500 or 600 light-years away. TESS will examine the entire sky over two years and look at stars that are closer to Earth, between 30 and 300 light-years away.
Finding a planet like Earth orbiting another star is not easy because Earth-like planets are small, as planets go. You could fit 1000 Earths inside the planet Jupiter. And to be really Earth-like, a planet must be not too close or too far from its parent star — in the “Goldilocks” or habitable zone where the temperature will allow liquid water to exist on the surface.
And finally, conditions have to be right for organic chemistry to somehow develop into living organisms. Then the possibility exists that those simple organisms could evolve into more complex life forms, and perhaps into intelligent beings who could build telescopes to look out into the cosmos and ask the same question that we are: “Is anyone else out there?”
A number of scientists reckon a more modest approach towards spreading life to other star systems might be possible. In the chill of deep space, bacteria somehow shielded from cosmic radiation might survive dormant for millions of years. Perhaps alien worlds could be seeded deliberately with terrestrial micro-organisms that might take hold there, jump-starting evolution on those planets.
There are many obstacles to directed panspermia, as this approach is known—and they are not just technical. Religiously minded critics claim “we’re playing God”, says Claudius Gros, a physicist at Goethe University in Frankfurt, who has floated the idea of scattering photosynthesising bacteria and algae on extrasolar planets. Critics argue in particular that “contaminating” other planets with terrestrial life in this way risks altering, or even destroying, any life that has arisen there independently. For support, they point to present-day concerns that bacteria carried by spacecraft might, if some form of life does exist there, do exactly that to Mars. This debate is hypothetical for now. But it will become more urgent if any of the projects currently being discussed to build probes to travel to nearby star systems gets off the drawing board and into space.
A NASA spacecraft has been launched on a two-year mission to find faraway planets and about half a million stars.
A SpaceX Falcon rocket blasted off from Cape Canaveral in Florida, carrying the Transiting Exoplanet Survey Satellite (TESS).
TESS is the next generation of exoplanet-hunting tools, with the ultimate goal of finding worlds out among the stars.
See: Hunting Tool
It has taken thousands of generations and countless migrations to explore our own small planet. Now, in less than one lifetime, our robot surrogates have ventured to nearly every significant object in the solar system. Vast new territories and landscapes have opened up before our eyes. The experience has transformed the way we understand our species and its place in the universe. It may yet uncover alien life. Join scientists in a discussion of what we are learning today from worlds beyond Earth and find out where this effort is likely to lead us next.
See: World Beyond Earth
Alien life may be more unlikely than commonly thought, according to a UK study that hints at a cosmic lack of phosphorus.
The element is vital to energy storage and transfer in cells, and is part of the chemical backbone of DNA.
Phosphorus is created in supernovae, exploding massive stars at the end of their lives.
Neither plants nor animals, fungi are the most underappreciated kingdom of the natural world. During a billion years of evolution, they’ve become masters of survival.
And yet, fungi have also been integral to the development of life on Earth. In fact, neither land plants nor terrestrial animals would exist them.