A pulsar is a rapidly rotating neutron star with an extremely strong magnetic field, vastly different from the conditions necessary for life. The magnetic field of a pulsar can reach up to 1 billion teslas, compared to Earth’s magnetic field, which is about 0.00005 teslas.
Imagine one day our Sun is no longer the bright shining star but transforms into a pulsar – a type of neutron star that emits intense radiation like a gigantic lighthouse spinning in the universe. This scenario raises the question: Could life on Earth survive, and what would happen if the Sun became a pulsar?
In contrast to the familiar image of the Sun, pulsars are among the densest objects in the universe, formed from the core of a massive star after it explodes as a supernova. They are very small, measuring about 10 km across, roughly the size of a small city, yet they have a mass over a million times that of Earth. With rotation speeds reaching hundreds of times per second, pulsars emit powerful beams of radiation from their poles, creating a phenomenon similar to the light from a rotating lighthouse.
If the Sun were a pulsar, darkness would almost permanently envelop Earth.
If the Sun were to transform into a pulsar, it would be one of about 200,000 pulsars existing in the Milky Way. Although it would be 70,000 times smaller than its current size, it would continue to spin rapidly and emit lethal radiation beams towards Earth every second or even every millisecond. At that point, the familiar light from the Sun would vanish, leaving behind a darkness almost permanently enveloping Earth.
The absence of sunlight would spell disaster for Earth’s biosphere. All photosynthesis would cease, preventing plants from producing oxygen and crops from growing. This would lead to a decline in food sources, pushing animals and humans into severe famine.
Nevertheless, there remains a glimmer of hope. Scientists have discovered that some exoplanets could exist in habitable zones around pulsars. This habitable zone is large enough for liquid water to exist on the surface, but the living conditions would be drastically different. Liquid water could be maintained by a warm atmosphere that retains energy from the pulsar’s radiation. However, the pressure from the powerful radiation beams would require the atmosphere to be several million times thicker than it currently is to protect life from the destructive X-ray and gamma radiation.
Some exoplanets may exist in habitable zones around pulsars.
Assuming Earth could thicken its atmosphere to the necessary level, humans would face extremely high atmospheric pressure, similar to being 10 km deep in the Mariana Trench – where the water pressure is so great it could crush a human in an instant. Living in this environment would cause eardrums to burst, lungs to fill with blood, and collapse before the body could adapt.
Even though this hypothesis sounds harsh, it remains unlikely because the radiation from a pulsar is strong enough to blow away this dense atmosphere from the planet. Once the atmosphere disappears, surface water on Earth would boil and evaporate, leading to the gradual extinction of life on our planet.
In reality, Earth would definitely not be able to sustain life when the Sun turns into a pulsar. The intense radiation and terrible atmospheric pressure would completely transform ecosystems and make it nearly impossible for any form of life to survive. This scenario is just one of the hypothetical outcomes of the Sun’s transformation and highlights the fragility of our blue planet in an unpredictable universe. Instead of the familiar warm light, we would only have beams of destructive radiation.
