The Nearest Black Hole to Earth: How Far Is the Abyss and Could It Threaten Us?

Black holes are one of the most mysterious riddles of the cosmos. These giant monsters, possessing unimaginable gravitational force, capture the imagination of scientists and dreamers, becoming a symbol of infinite possibilities and unrecognised boundaries of reality. We have already looked into this tantalising yet frightening abyss in our article What’s Inside A Black Hole? And today we will tell you how close is the nearest black hole to Earth and if such a neighbourhood threatens us. 

What is the closest black hole to Earth?

The closest black hole to us that was discovered is Gaia BH1. It is located at a distance of 1560 light-years from Earth. Gaia BH1 was discovered in 2022 using ESA’s Gaia space telescope and telescopes from the ground-based Gemini Observatory. The object is part of a binary system in the constellation Ophiuchus. Its companion star is a yellow dwarf with a mass of about 0.93 times the mass of our Sun. The mass of the hole itself is estimated at almost ten solar masses. But that’s not all. Scientists suggest that Gaia BH1 was formed from a several-million-year-old star that was at least 20 times the mass of the Sun!

How long would it take to get to the nearest black hole?

To understand how far 1560 light years is, let’s calculate how long it would take for a spacecraft to fly to the closest black hole. Today, the fastest spacecraft invented by man is the Parker Solar Probe, launched to the Sun by NASA in 2018 to study the influence of our star on the Earth’s weather. Parker Solar Probe managed to achieve a record speed, making it the fastest man-made object that travels at 430 thousand miles per hour or 120 miles per second! At this speed, for example, you could get from Glasgow to London in 3.5 seconds and from Edinburgh to Sydney in one and a half minutes! On an Earthly scale, this is very fast, but on the scale of the Universe, it is no faster than a snail.

Now, let’s recall what a light year is. A light year is the distance light travels in one Earth year (365 days). The speed of light is 186,400 miles per second. Thus, one light year equals approximately 5.9 trillion miles. Parker Solar Probe could theoretically travel about 3.77 billion miles in one Earth year, assuming it keeps moving at its top speed the entire time. So, to cover a distance of one light year, it will need 1565 Earth years, and to cover the distance to the nearest black hole… 2.44 million years.

In other words, humanity will unlikely have the time to reach the dark abyss that can swallow it before it goes extinct as a species. Unless we master the fourth and fifth dimensions to make hyperjumps in space and time, but so far, this technology has been mastered only by science fiction writers and screenwriters of sci-fi movies. And yet…

Is Gaia BH1 a threat to Earth?

If Mohammed won’t come to the mountain, will the mountain come to Mohammed? More specifically, could the dark abyss expand or move and get so close to the Earth that its gravity would swallow us? Scientists do not exclude this possibility but consider it extremely unlikely.

Even though scientists have found evidence that black holes can wander around their galaxies and even leave them, the distance to these objects is too great to talk about the threat of potential contact.

Besides, these space abysses pose a real danger only close to their event horizon, the radius of which (also known as the Schwarzschild radius) is only 3 km for holes with the mass of the Sun. The mass of the closest black hole to us, Gaia BH1, is 10 solar masses; accordingly, the radius of its event horizon does not exceed 30 km, which is 212 times less than the radius of the Earth. As it moves away from the event horizon, the hole behaves like an ordinary celestial body, exerting a gravitational effect on surrounding bodies according to the principles of Newtonian mechanics. Thus, given the distance and radius of Gaia BH1’s event horizon, it is safe to say that it does not pose a threat to Earth.

The situation is somewhat different with supermassive black holes. Their mass can be several hundred billion times greater than the mass of the Sun, and their event horizon radius allows them to swallow the Earth without a blink. But the fact is, the closest supermassive black hole Sagittarius is located at the centre of our own Milky Way galaxy, approximately 26,000 light-years from Earth, which makes it absolutely safe for us.

Even if we imagine that tomorrow, scientists discover a new black hole somewhere at the edge of the solar system, its gravity will unlikely cause significant changes in the trajectories of planets and asteroids to do harm. What we do have to fear is the evolution of our Sun, which, sooner or later, will die, but not before its radiation burns us like a giant magnifying glass burns a piece of paper. If you find that hard to believe, read our article How Old Is The Sun?

And yet what would happen if the Earth was pulled into a black hole?

The consequences of the Earth’s absorption by a space chasm will be catastrophic and absolute. A phenomenon called spaghettification will happen to our planet. The gravitational forces of the hole will begin to stretch the Earth’s sphere into a long and thin shape. This will lead to devastating earthquakes, tsunamis and volcanic eruptions beyond anything we have ever experienced. The Earth’s magnetic field, created by the movement of molten iron in its core, would also be disrupted by the tidal forces of the event horizon, leading to further destruction before the final absorption. This process will be so extreme that from the outside, it will seem as if the Earth has simply disappeared beyond the event horizon.

However, scientists do not exclude a positive scenario. We are talking about the Fuzzballs hypothesis, proposed by physicist Samir Mathur from Ohio University.

In this hypothesis, black holes do not have an event horizon but consist of quantum strings and other quantum objects distributed throughout their volume rather than concentrated at a sole singularity point. This means that information falling into a black hole does not disappear without a trace but is encoded in these quantum structures.

The main goal of this hypothesis is to solve the so-called black hole information paradox, which arises due to the apparent contradiction between the general theory of relativity and quantum mechanics. According to the general theory of relativity, all information caught in this space chasm is destroyed, but quantum mechanics states that information cannot be completely destroyed.

Fuzzballs remain an unproven theory, but it does suggest a mechanism by which information can be stored, leaving us with a small sliver of hope that if we ever encounter a dark stellar abyss, we won’t be swallowed up into eternal darkness and oblivion.

What other closest black hole to Earth did scientists discover in 2024?

For now, the first on the list of closest black holes are still held by the small Gaia BH1, from which we are separated by 1560 light years. But the scientific community does not stand still and continues to explore space, parsec by parsec, as far as modern telescopes allow us.

On April 16, 2024, it was made public that astronomers discovered another one of the closest black holes to Earth — Gaia BH3. The object is located 1,926 light-years away in the constellation Aquila and weighs 32.7 solar masses, which makes it the heaviest known stellar hole in the Milky Way galaxy and the second closest black hole to Earth. In the third place, we have Gaia BH2 in the constellation Centaurus, discovered in 2023 and located 3800 light years away from us.

So, we’ll wait for the list to be replenished, hoping that the new nearest black hole inquisitive astronomers will definitely discover should turn out a harmless fuzzball, not a voracious dark abyss.

References and Additional Information:

• Gaia BH1 Black Hole: Size, Mass, Diameter, Radius, Temperature, Distance From Earth https://astrophotographylens.com/blogs/astro/gaia-bh1-black-hole
• A wobble reveals the most massive stellar black hole in our galaxy. https://www.ctvnews.ca/sci-tech/a-wobble-reveals-the-most-massive-stellar-black-hole-in-our-galaxy-1.6850009
• Will the Earth be swallowed by a Black Hole? https://www.vietnam.vn/en/lieu-trai-dat-co-bi-ho-den-nuot-chung/
• Astronomers Discover a ‘Sleeping Giant’ Black Hole in Our Galaxy—the Second-Closest Known to Earth  https://www.smithsonianmag.com/smart-news/astronomers-discover-a-sleeping-giant-black-hole-in-our-galaxy-the-second-closest-known-to-earth-180984174/
• NASA spacecraft keeps on going faster and faster and faster https://mashable.com/article/nasa-parker-solar-probe-speed
• Black holes may not exist, but fuzzballs might, wild theory suggests.  https://www.livescience.com/string-theory-fuzzballs-are-black-holes.html