Why Our Solar System Won't Be Pulled into the Milky Way's Black Hole — and What Scientists Are Learning

Why Our Solar System Is Safe from Sagittarius A*

At the center of the Milky Way lies a supermassive black hole called Sagittarius A* (Sgr A*). With a mass of roughly 4.3 million times that of the Sun, it is enormous by stellar standards — but in the context of the entire galaxy its gravitational influence at Earth's distance is negligible. Our solar system orbits the galactic center at a distance of about 27,000 light-years, and the Sun's gravity overwhelmingly dominates the motions of planets within our system.

Putting the numbers in perspective

Although Sgr A* is massive, it represents only a tiny fraction of the Milky Way's total mass (which includes stars, gas, and dark matter). The Sun alone accounts for more than 99% of the mass of the solar system, so the pull that governs Earth's orbit is local, not dominated by the galactic nucleus. In short: Sgr A* is far away enough and small enough relative to the galaxy that it won't "suck in" our solar system.

How we observed Sagittarius A*

A compact radio source at the galactic center was discovered in the 1970s, and Sgr A* was widely accepted as a supermassive black hole candidate. The first resolved image of Sgr A*'s shadow came in 2022 after a multi-year campaign by the Event Horizon Telescope collaboration — roughly 300 researchers from about 80 institutions working together. Imaging Sgr A* was more challenging than imaging the larger black hole in M87 because the gas near Sgr A* orbits much faster, blurring the picture without careful, rapid observations.

Signs it sometimes eats nearby material

Black holes are detected not only by gravity but by the light given off when matter falls toward them. Astronomers watch X-ray and infrared flares and echoes to track past feeding events; by studying X-ray reflections in the galactic center, researchers estimate that Sgr A* last experienced a significant accretion episode roughly two centuries ago. These flares are useful probes of how matter behaves in extreme gravity, but they do not indicate any present danger to the solar system.

The speculative idea: is our universe inside a black hole?

Beyond local astrophysics, some theoretical proposals—often grouped under the label Schwarzschild cosmology—suggest our observable universe might itself be the interior of a black hole embedded in a larger universe. One advocate, Nikodem Poplawski of Indiana University, has suggested that our universe could have formed inside a parent black hole and that this model avoids an initial singularity by giving the newborn universe the scale of the parent black hole.

"Our universe could have itself formed from inside a black hole existing inside another universe," said Nikodem Poplawski. "In my model, when the universe is born, there is no problem of having a singularity initially — instead of being infinitely small, it had the radius of its parent black hole."

While intriguing, such cosmological ideas are speculative and remain unproven. Meanwhile, astronomers continue to collect data on Sgr A* and other supermassive black holes to better understand their growth, behavior, and role in galaxy evolution.

Bottom line: Sgr A* is fascinating and powerful on local scales, but it poses no realistic threat to Earth or the solar system. It remains an active target of observation and theory, offering insight into gravity, high-energy astrophysics, and even bold ideas about the nature of the universe.