The most powerful space telescope in the world is also an alert system that will help us prevent potentially lethal phenomena for life on Earth.
The James Webb Space Telescope is completing the commissioning of its scientific instruments and will soon be ready to begin operations. This telescope is the most powerful we have launched into space to date, and once operational it will help scientists better understand what is happening in our cosmic neighborhood, and how galaxies form or search for other planets that may harbor life. But it will also help them, peer, into space for potentially lethal threats to our planet that cannot be seen with telescopes here on the ground.
In fact, despite still testing the performance of its instruments, the James Webb has already proven that it is capable of detecting and tracking Tenzing 6841, a main-belt asteroid between the orbits of Mars and Jupiter. When fully operational, the James Webb will help create the most reliable warning system against the phenomena in space that lie in wait for us.
The question is when
In the history of our planet, there have been and will continue to be space objects that impact the Earth and cause the death and extinction of the life forms that inhabit it. The largest impact happened shortly after it formed. An object the size of Mars hit our planet making it uninhabitable and creating a constellation of rocks and debris that ended up forming what is now our Moon. Many years later, about 66 million years ago, the impact of a large asteroid caused billions of tons of sulfur to rise into the atmosphere. This caused the sky to darken and some frosts to occur that lasted about a decade that killed the dinosaurs and other living beings on the planet.
Recently we have also suffered from asteroid impacts, although, fortunately, much less lethal. In 1908, the Tunguska event took place, a huge explosion near the Podkamennaya Tunguska River in Russia, flattening some 80 million trees in a sparsely populated forest area of some 2,150 km 2 . And recently, in 2013, there was a huge explosion over Chelyabinsk in Russia, caused by a meteorite the size of a six-story building, damaging the city and injuring about 1,200 people.
So far our systems have detected 1,000 meteorites that have dangerously pᴀssed close to our planet, almost 19 a year on average. So it’s a matter of time, hopefully, thousands or millions of years, before another big meteor hits us. As seen in the movie ‘Don’t Look Up’, this impact would cause a huge shock wave that would wipe out all life on the Earth’s surface. It will then spew out huge numbers of particles that would rise into the atmosphere and block the pᴀssage of sunlight and make our planet uninhabitable for a long time.
Dangers beyond the asteroids
2.6 million years ago a mᴀss extinction occurred that is thought to have been caused by a supernova. Researchers believe that after the explosion, particles called cosmic rays bathed the planet destroying the ozone layer and causing changes in the climate that could cause a great extinction between the Pliocene and Pleistocene. It is believed that another of these supernovae, which was 65 light years from Earth, exploded 350 million years ago and was the cause of the Devonian mᴀss extinction that wiped out most of the planet’s species.
Africa dried up and much of the forest became savannah. Around this time and after, we started having glaciations – ice ages – over and over again, and it’s not clear why it started to happen,” he said in his moment Adrian Melott researcher at the University of Kansas and co-author of the study on the Devonian extinction. “It’s controversial, but maybe cosmic rays had something to do with it.” Although this type of extinction event is unlikely to affect us, as Big Think points out, the closest star at risk of becoming a supernova is called Betelgeuse and it is 640 light years away. Although there are other phenomena that can affect us from further away. If two stars collide or a large one explodes, they would generate gamma rays that produce a huge amount of energy capable of reaching Earth. Scientists think that such an event caused the Ordovician-Silurian mᴀss extinction about 450 million years ago wiped out half of the planet’s animals.
James Webb can’t warn us of everything
There are dangerous space phenomena that are undetectable even by our most powerful space telescope. Wolf-Rayet stars, 20 times the size of the Sun, are capable of unleashing gamma-ray bursts that researchers think are “the most powerful cosmic explosions since the Big Bang.” There is one of these stars in the Gamma Velorum system, 800 light-years away. It is far from Earth, but its axis of rotation points in our direction and if it were to explode, gamma rays could reach our planet at the speed of light without leaving us time to manoeuvre.
There are also wandering planets. Planets that do not orbit around a star and that wander through space at high speed. The effect of the impact of one of these wandering planets against the Earth would be catastrophic —as Lars Von Trier’s film Melancholy shows— and against them there is no time for warning or possible defense.
The same happens with neutron stars or wandering black holes, which, even if they do not hit us, would end up destabilizing or destroying the entire solar system. The only solution to preserve our species in the face of these phenomena would be, as Elon Musk insistently maintains, to become an interplanetary species that does not have all its eggs in the same basket. Although in order to avoid the impact of gamma rays or that of a wandering black omen, technology would have to be developed that takes us out of the solar system and converts us into an interstellar species.
Meanwhile, we have no choice but to trust in the warning capacity of James Webb and convince our leaders to join together to invest in preventive measures that protect us against some of these phenomena. Although seeing what happens in ‘Don’t look up’, a film that more than telling fiction seems to put a realistic mirror in front of our faces, it won’t be easy at all.
