Scientists have made predictions about what the last days of our solar system will look like, and when they will happen.
Previously, astronomers believed that the Sun would turn into a planetary nebula - a luminous bubble of gas and cosmic dust.
Once again, an international team of astronomers turned the tide in 2018, finding that a planetary nebula is indeed the most likely solar remnant.
The age of the Sun is about 4.6 billion years, compared to the age of other bodies in the solar system that formed at approximately the same time. Based on observations of other stars, astronomers expect it to reach the end of its life in about another 10 billion years.
After about 5 billion years, the Sun is scheduled to turn into a red giant. The star's core will contract, but its outer layers will expand into Mars' orbit, swallowing our planet in the process.
By then, we will no longer exist. In fact, humanity only has about a billion years left unless we find a way to get off the planet. This is because the sun's brightness increases by 10% every billion years. This increase in brightness will end life on Earth, our oceans will evaporate, and their surface will become too hot to form water.
Several previous studies have found that for a bright planetary nebula to form, the protostar must be twice the mass of the Sun.
However, a 2018 study used computer modeling to determine that, like 90% of other stars, our Sun will likely shrink from a red giant to become a white dwarf and then end up as a planetary nebula.
Astrophysicist Albert Zijlstra, from the University of Manchester in the United Kingdom, explained: “When a star dies, it ejects a mass of gas and dust into space. This reveals the star’s core, which by this stage in the star’s life is running out of fuel, and then extinguishes before it can die.” "It eventually dies. Only then does the hot core make the ejecta shell shine brightly for about 10,000 years - a brief period in astronomy. This is what makes the planetary nebula visible."
The data model the team created actually predicts the life cycles of different types of stars, to see what planetary nebula brightness is associated with different star masses.
Nearly 30 years ago, astronomers noticed something strange: the brightest planetary nebulae in other galaxies have roughly the same level of brightness. This means that, at least in theory, by looking at planetary nebulae in other galaxies, astronomers can calculate how far away they are.
“Not only do we now have a way to measure the presence of stars a few billion years old in distant galaxies, a range that is remarkably difficult to measure, but we have also discovered what the Sun will do when it dies,” Zijlstra said.
The research was published in the journal Nature Astronomy.
A forgotten "victim" during wars
During armed conflict, it is natural for attention to be drawn to the human losses and material, physical and psychological damage of such catastrophic events.
However, most of us do not think that wars and armed conflicts also have bad effects on our natural environment, which includes land, air, water, plants, animals and all living things.
History has recorded many wars over the centuries, as this catastrophic effect has led to the deterioration of planet Earth and its natural environment.
Not only can war damage the social environment, but military activities produce large amounts of greenhouse gases, causing pollution that contributes to human-induced climate change and resource depletion.
Wars can include the destruction of agricultural infrastructure, such as canals, wells and pumps, leading to transboundary impacts of pollution of rivers, aquifers or the sea.
Weapons and military materials used during conflicts leave an environmental legacy, as landmines, cluster munitions and other explosive remnants of war can limit access to agricultural land, and contaminate soil and water sources with metals and toxic active substances.
Polluted water sources and chemical waste may cause cancer, birth defects, and other conditions linked to environmental pollution.
Militaries consume huge amounts of fossil fuels and release greenhouse gas emissions, which directly contribute to global warming.
Bombings and other modern warfare methods directly harm wildlife and biodiversity. Collateral damage from conflict can kill up to 90% of the large animals in an area.
Waste management in general tends to collapse during conflicts, threatening pollution of water bodies, soil and air.
All tanks and heavy vehicles deployed in conflict release abrasive particles, while abandoned munitions leak uranium into water systems.
In fact, the scale of wildlife losses, biodiversity destruction, deforestation, landscape degradation and the planet's depletion of its natural resources, caused by wars, has never been calculated.
Even in peacetime, militaries consume enormous amounts of energy, through training facilities and manufacturing plants.