No, a single supernova cannot wipe out a galaxy; galaxies contain billions of stars and are vast, so a supernova's effects are localized, though a nearby one can sterilize planets by damaging atmospheres, and massive galactic events (like an AGN outburst) have more galactic impact, but even those don't "destroy" galaxies, just alter them. A galaxy is simply too big, with supernovas only affecting their immediate vicinity, creating heavier elements and triggering new star formation, not galactic destruction.
Supernovas are some of the brightest events in the universe, occasionally outshining entire galaxies at their peak. Many supernovas can be seen from billions of light-years away, and nearby supernovas in past centuries have been visible during the daytime.
Before you get too complacent, though, you should know about gamma-rays bursts, which result from neutron star mergers and hypernovas. They are much more dangerous because they are incredibly powerful and their explosive energies are focused into narrow beams that can punch over 10,000 light-years through a galaxy.
If a supernova explosion were to occur within about 25 light-years of Earth, our planet would probably lose its atmosphere, and all life would perish. However, astronomers haven't found any dangerous supernova candidates in our cosmic backyard, so there's no reason to worry.
Hypernovae are thought to be supernovae with ejecta having a kinetic energy larger than about 1045 joule, an order of magnitude higher than a typical core collapse supernova. The ejected nickel masses are large and the ejection velocity up to 99% of the speed of light.
Where Does Gold Come From. Gold's origin story is as fascinating as it is scientifically significant. The process known as supernova nucleosynthesis. This occurs during the implosion of a star, is responsible for creating many elements, including gold.
In 1 sextillion years (10²¹ years), the universe will be a vastly different, dark place: the era of star formation will have ended, all stars will have burned out into white dwarfs, neutron stars, or black holes, planets will be cold and lifeless, and even protons might begin to decay, leading towards the "Big Freeze" or heat death, with only black holes slowly evaporating via Hawking radiation over unimaginable timescales. All familiar structures, including galaxies, will have long dissolved as the universe expands, leaving behind a cold, dark, and nearly empty expanse.
About 95% of the universe is "invisible" because it's composed of dark matter (around 27%) and dark energy (around 68%), which don't emit, absorb, or reflect light, unlike the normal matter (stars, planets, us) that makes up the visible 5%. Dark matter's presence is inferred through its gravitational pull on visible galaxies, while dark energy is a mysterious force causing the universe's accelerated expansion.
Gamma-ray bursts are the most violent events since the birth of the universe. They are about ten times more energetic than the most powerful supernovae. At their peak, gamma-ray bursts are the brightest objects in space, about 100,000 times brighter than an entire galaxy.
About 4 to 7 billion years from now, when hydrogen fusion in the Sun's core diminishes to the point where the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature which will cause its outer layers to expand, eventually transforming the Sun into a red giant.
A nova is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", Latin for "new") that slowly fades over weeks or months.
If the mass is less than about 3 times the mass of the Sun, what is left is a very small, extremely dense object known as a neutron star. When the collapsing core is more massive than this limit, it continues collapsing and becomes one of the strangest objects in our universe: a black hole.
The Vela supernova remnant is one of the closest known to Earth, being around 800 light years away. The Geminga pulsar is closer (and also resulted from a supernova), and in 1998 another near-Earth supernova remnant was discovered, RX J0852.
Our Sun will become a white dwarf in about 7 billion years. At that point, it will no longer produce energy through nuclear fusion, having exhausted its fuel (hydrogen and helium).
Fresh milk is yet another commodity prohibited in space due to its perishable nature. Milk would spoil within a few hours in the zero-gravity environment, which would be harmful for health if not refrigerated. Astronauts use powdered or ultra-pasteurized milk instead, which has a much longer shelf life.
The environment of space is lethal without appropriate protection: the greatest threat in the vacuum of space derives from the lack of oxygen and pressure, although temperature and radiation also pose risks. The effects of space exposure can result in ebullism, hypoxia, hypocapnia, and decompression sickness.
A 300m-wide asteroid will not hit the Earth in 2036, US astronomers say. It was thought there was a one-in-200,000 chance that it could strike on 13 April 2036, but revised calculations have now ruled this out. Instead, Nasa scientists said it would not get closer than 31,000km as it flies past on this date.
Humans Could Live For 1,000 Years by 2050—Ushering in the Dawn of 'Practical Immortality,' Futurists Say. Some experts warn that this radical change may remain out of reach for many, due to societal and economic challenges. Technology futurists foresee advances that will enable humans to live up to 1,000 years.
The Bible does not directly address the age of the Earth or the universe. The number of 6000 years came from Archbishop Ussher in the 17th century.
Based on known risks, the really cataclysmic ones, those that might exterminate us as a species, are fairly rare. Based on what we know today, it would be very unlikely that we wouldn't be around in the year 3000. There certainly would be bad times, but some of us would get through it.
While no planet in our solar system is entirely made of gold, the asteroid 16 Psyche is believed to contain an astonishing amount of gold and other precious metals. Located between Mars and Jupiter, this metallic giant could be worth trillions—yes, trillions! —of dollars.
“It's totally 100% true – nearly all the elements in the human body were made in a star and many have come through several supernovas.”
An adult human body contains approximately 5 liters of blood, which contains different metals such as iron, chromium, and zinc, as well as about 0.2 milligrams of gold [1]!