HomeScienceHubble spots a rogue planet in the Milky Way using Einstein's theory

Hubble spots a rogue planet in the Milky Way using Einstein's theory

Einstein's theory posits that mass distorts space. This distortion can bend light from distant objects. Astronomers use this effect to find dark objects in space.

July 31, 2025 / 11:00 IST
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Rogue planets are free-floating planets that do not orbit a star and instead travel through space. (Image: NASA)
Rogue planets are free-floating planets that do not orbit a star and instead travel through space. (Image: NASA)

Stargazing occasionally provides serendipitous findings in the dark of night. That’s what happened when astronomers spotted a hidden planet using old Hubble data. It is the sole planet orbiting its lonely universe, which is billions of light-years away from any star. It was found with help from Albert Einstein’s theory of general relativity.

What Is a Rogue Planet and How Was It Discovered?
The lonely world, called a rogue planet, was not orbiting a star. It was found through a brief event recorded in 2023. The Optical Gravitational Lensing Experiment and Korea Microlensing Telescope Network first spotted it. Hubble then helped confirm the find.

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The planet caused a microlensing effect, predicted by Einstein in 1915. When the object passed in front of a far-off star, its gravity warped and magnified the starlight. The whole process took a mere eight hours, making it one of the briefest ever recorded.

Einstein's Theory Uncovered the Rogue Planet
Einstein's theory posits that mass distorts space. This distortion can bend light from distant objects. Astronomers use this effect to find dark objects in space. Because rogue planets give off no light, they’re usually invisible. But microlensing makes them briefly visible by brightening background stars.