Replacing the sun with a black hole would quickly collapse life on Earth

The sun will become a red giant after it exhausts the hydrogen fuel in its core, causing gravity to collapse the core and heat it enough for the surrounding hydrogen shell to ignite, releasing enough energy to cause the star to swell.

Black holes do not 'suck' matter and energy in like a vacuum cleaner

Despite its immense magnitude, the force of gravity exerted by black holes acts in the same way as provided by stars and planets, allowing objects to maintain stable orbits around them. Even in cases where tidal forces and friction cause objects to change their orbit and fall towards a black hole, they are more likely to glance by, be whipped around, and get ejected rather than absorbed.

If the sun disappeared, we would not know about it for 8 minutes and 20 seconds, at which point the Earth would suddenly move in a straight line on its way out of the solar system.

Why Earth will be made uninhabitable by the sun far sooner than when the sun dies

The star has enough fuel to continue fusing hydrogen into helium for another 5 billion years, but the gradual increase in core temperature from these reactions will brighten the sun by 10% every billion years. Some models predict that the increased radiation will be enough to vaporize all of Earth's surface water about 1 billion years from now, long before the sun becomes a red giant and disintegrates the planet.

Explaining 'impossible' black holes

When stars collapse, the black holes they form can have the mass of either 50 suns or over 120—but current models claim strongly that no black hole should have a mass that falls in between that range. But in 2019, gravitational wave observatories detected two within it: one at 66 solar masses, the other at 85. The discovery disrupted established science and left researchers questioning the Standard Model of physics.

Stars hold off gravitational collapse with the energy produced in nuclear reactions in their core, but when massive stars run out of fuel for these reactions, runaway collapse can produce a black hole.

A black hole with the mass of the observable universe would be larger than the observable universe, leading some theorists to suggest that we may live inside a black hole.

Watch a simulation of a collapsing star becoming a black hole

When a massive star can no longer release enough energy through fusion in its core to fight off gravitational collapse, the dense core collapses first, producing an event horizon that traps light within it, including some light produced within the star at the time of collapse. As more material falls into the growing event horizon, the star will appear to eclipse itself from the inside.

Excluding using another planet's gravity to redirect the object, it takes less energy for a spacecraft to leave the solar system than to hit the sun.

Falling into a black hole would stretch and shred your body beyond recognition

As you approach a black hole, you initially feel weightless. Eventually, the difference in gravity between your feet and head would create a powerful stretching force that overcomes the molecular bonds in your body and pulls you apart.

TON 618, the largest black hole ever detected, has the mass of 66 billion suns

The supermassive black hole is 18 billion light-years away and emits radiation with the brightness of 100 trillion stars. It is so massive that light would take an entire week to travel from its edge to its center.

More than 40 quintillion black holes are estimated to exist in the universe, including about 100 million in the Milky Way, each with masses up to hundreds of times that of the sun.

How black holes form

Don’t let the name fool you: A black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City.

Black holes are formed from massive stars collapsing under their own gravity

This creates a region where spacetime curves infinitely, known as a singularity. Black holes' intense mass and energy allow them to trap light, distort time and space, and present challenges with reconciling Einstein's theory with quantum mechanics.

How Robert Oppenheimer determined when neutron stars become black holes

Building on the work of Richard Tolman and George Volkoff, Oppenheimer reasoned that, once massive enough, a hypothetical, star-sized atomic nucleus would be unable to stave off gravitational collapse with neutron degeneracy—quantum pressure—alone. The mathematical model estimated the maximum mass of a non-rotating neutron star, known as the Tolman-Oppenheimer-Volkoff limit.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

An overview of the sun, from its formation to its role in fueling and protecting life on Earth

With a surface gravity almost 28 times Earth's, the sun's mass exerts enough pressure to raise temperatures in its core above 15 million degrees Celsius (27 million degrees Fahrenheit) and enable nuclear fusion. These reactions produce the energy that sustains Earth's photosynthesis-dependent food chains, while the sun's magnetic field protects the solar system from cosmic ionizing radiation.

How big is a supernova explosion?

Supernovas are the biggest explosions in the universe, often obliterating the area surrounding them. So what would happen if one exploded near Earth? If the sun went supernova it'd be like getting hit by a nuclear explosion every second for weeks. Of course, that's not happening anytime soon. This animated video shows how distance is the key factor, and how you shouldn't be worried.

There may be as many as four types of black holes, categorized by their mass

Three types are known to exist: stellar mass black holes, supermassive black holes, and intermediate black holes. A fourth type—micro black holes—is theoretical and would have the same mass as Mount Everest in a space the size of an atom.

How the sun heats the Earth

We all know it: Without the sun's heat, the Earth would be uninhabitable. So how does it work? The sun fuses roughly 600 million tons of hydrogen every second, the energy from which bursts out into space—including toward our planet. Our atmosphere...

Black holes can disrupt the formation of galaxies

A team of astronomers in Munich detected a gas cloud being stretched and torn apart by the supermassive black hole at the center of the Milky Way, preventing matter from coalescing into new stars. Energy released from siphoned gas produced warm winds that may also prevent surrounding gas from coalescing.

The event horizon is an inescapable sphere around a black hole singularity

The horizon is often surrounded by an accretion disc of superheated material that orbits the black hole while emitting radiation. Light emitted behind a black hole can be bent around it to create the appearance of a ring of material known as a photon sphere.

Mars' orbit may provide evidence that dark matter is made of primordial black holes

Physicists at MIT have found that, statistically, one such microscopic black hole should pass through the solar system every decade, which they predict would introduce a detectable wobble in Mars' orbit. Such black holes would have formed in the early universe from collapsing gas clouds and scattered as the universe expanded.

What lies inside a black hole remains one of the universe's greatest mysteries

At the center of black holes is a theoretical point of infinite density called a singularity. Alternatively, one theory suggests a black hole's core could form a Planck star—a mind-bogglingly tiny object just a trillionth trillionth trillionth of a meter in size.

Why Earth would become a more deadly environment without the ozone layer

The ozone layer blocks almost all of the sun's harmful, including dangerous UVC rays that can damage cells by breaking chemical bonds. Without it, rates of skin cancer, crop failures, oceanic die-offs, and widespread ecosystem collapse would increase significantly, making Earth largely uninhabitable.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Despite fears of creating black holes, the Large Hadron Collider produces collisions with energies of 13.6 trillion electronvolts, about one million times smaller than the energy needed to create the lightest possible black holes.

Nothing can enter white holes—the opposites of black holes

Although a mathematical possibility according to general relativity, there is no observational evidence for these objects, which would endlessly eject material into the universe via anti-gravity. It is also unclear how they would form or avoid collapsing due to the gravity of the ejected material.

When they merge, black holes release multiple solar masses of energy

The energy emanates outward in the form of gravitational waves, which can be detected at observatories like LIGO. After merging, it is impossible to determine the characteristics of the two black holes that merged to create it.

Solar eclipses are a cosmic coincidence because the moon is 400 times smaller than the sun but about 400 times closer to Earth, allowing it to block sunlight for those on Earth within its shadow.

Invisible to direct observation, scientists determined the object at the center of the Milky Way—Sagittarius A*—was a supermassive black hole based on the orbits of fast-moving stars in the area.

Violent storms and crushing pressure await those inside Jupiter’s Great Red Spot

As seen from space, Jupiter’s most striking feature is an anticyclone 30% larger than Earth, with winds twice the speed of Category 5 hurricanes. The descent into the storm brings enough pressure to strip atoms of their electrons.

From the stellar core to the surface, the sun's density decreases from more than 10 times that of lead to 0.00001% that of air.

From the stellar core to the surface, the sun's density decreases from more than 10 times that of lead to 0.00001% that of air, while temperatures drop from millions to thousands.

If the Earth stopped spinning, 85% of the world's population would experience supersonic winds

The planet's equator moves about 470 meters per second—over 1,000 miles per hour—and air there would continue moving at this speed for several minutes if the ground stopped rotating. These conditions would cause tsunamis, global storms, and fling debris fast enough to destroy nearly all human-made structures.

Due to dark energy, the universe is expected to end as a dark, sparse place

While the sun is expected to continue shining for another five billion years, the expansion of the universe will cause nearby stars and galaxies to become ever more distant, until they are too far to observe. Once the last old, red, dim stars cool into darkness after trillions of years, the universe will settle into a state of eternal, dark emptiness.

The sun is not as exceptional as once believed, but it remains rarer than most stars

Once believed to be the center of the universe, the sun is a G-class star, the same category to which about 6% of the Milky Way's stars belong. However, the sun is younger than 85%, more massive than 95%, and more metal-rich than about 93% of all stars. Unlike the sun, half of all stars also exist in multi-star systems.

If particle accelerators did create black holes by packing tremendous energy into a small volume, then trillions would be created in Earth's atmosphere daily by cosmic rays.

Attempts to 'fix' black hole physics have led scientists to theorize new types

Along with their spin and charge, mass is used to categorize black holes as supermassive, intermediate, or stellar-mass. However, ongoing research suggests various additional types may exist, including primordials that formed one second into the universe's birth, fuzzballs—tangles of vibrating strings—and gravastars, which have a shell of dense matter around repulsive vacuum energy.

Our solar system is currently traveling through a 'dark matter hurricane'

The phenomenon refers to a stream of cosmic debris, including stars and dark matter, leftover from a small galaxy that passed too close to the Milky Way and was torn apart. There are over 30 such streams known in our galaxy, and the stream intersecting the solar system is predicted to continue to do so for millions of years.

Research suggests that about 1% of all matter in the universe is locked inside black holes, millions of which are likely to lurk undetected near us in space.

The mysterious origins of the universe’s biggest black holes

Think you know everything about black holes? You might be surprised. Thought of as massive vacuum cleaners sucking up everything in their cosmic path, black holes actually accrete matter at an incredibly slow pace. Yet, some black holes existed when the universe was only a few billion years young. Learn more in this BBC report.

Time seems to stop for objects at the event horizon of black holes

At that location, the warping of space-time is so severe that the entirety of an object's space-time motion is solely through space, leaving it immobile in the time dimension. Faraway observers looking at the object would see it appear frozen before slowly dimming and reddening.

If the moon were less than one-twelfth its current distance from Earth, the planet's tidal forces would overcome the moon's internal gravity, tearing it apart and forming a ring of debris.

Because it loses more atmospheric gas to outer space than the cosmic dust it collects as it moves through space, the Earth loses about 50,000 metric tons of mass every year.

What would happen if a massive asteroid struck Earth?

While NASA states that no known asteroid currently threatens Earth, past impacts demonstrate that the risk is real. The agency has tested deflection technology to alter an asteroid's path, as this visualization imagines a worst-case collision scenario.

One of the hottest known exoplanets seems to snow an active ingredient of sunscreen, titanium dioxide—but only on the dark side of the planet.

Planets' high orbital speeds prevent them from falling into their host star

Although the gravitational force attracts a planet and the star it orbits around, the large speed the planet orbits with, which is acquired during its formation process, causes it to continuously miss the star as it orbits around it. This is analogous to theoretically throwing a baseball horizontally faster and faster until it's fast enough to orbit the Earth while attempting to fall to its surface.

LIGO confirmed Stephen Hawking's theorem about black hole surface areas

Black holes are known to grow with increased mass but lose energy during mergers through the emission of gravitational waves. Amid these competing factors, the black hole area theorem—confirmed in 2021 using LIGO data—states that a merged black hole's size cannot be smaller than the combined surface area of its progenitors.

The majority of exoplanets—planets outside the solar system—have been discovered through mini-eclipses created when they pass in front of their host star and block some of its light from reaching Earth.

Nearly 50 years before the first observational evidence, a soldier fighting on the Eastern Front in World War I found a mathematical solution to Einstein's equations that suggested the existence of black holes.