The real reason why stars twinkle in the night sky and planets don't is nothing that you expected

From the spectacular Northern Lights to the mysterious blackholes, space is filled with intriguing phenomena that continue to capture human imagination. Stars are a relatively common feature of the night sky, but these sparkling globes of gas also have their own set of mysteries since the twinkle and planets don't. According to a publication by Ian Todd on BBC's Sky At Night Magazine, it's all an optical illusion since the stars just appear to twinkle from our perspective but they don't.

Since Earth's atmosphere is 10,000 kilometers above the surface of the planet, the atmospheric air gets blown around where hot air rises, mixing with cooler air. As a result, the stars appear to twinkle because the light passing through the atmosphere gets bent and distorted by the change in temperature and density of air. There is also a scientific term atmospheric scintillation used to describe the twinkling phenomenon and it causes the stars to flicker red and blue and even some other colors at times.

Experts have managed to capture this atmospheric distortion of the starlight through astrophotography where the colors are visible to the naked eye. Now the question is why planets don't appear to flicker and twinkle at night. Here, the distance between these celestial bodies plays a major part. Stars appear to twinkle because they are further away from Earth and hence look like small dots of light from our planet. On the other hand, the planets don't appear to twinkle because they are much closer to Earth compared to stars. The sunlight is reflected off these planets returns to Earth in thicker beams and is not affected by the atmospheric distortion.

According to Space, researchers have found that the twinkling of the stars can reveal the strength of gravitational pull on its surface. By studying the gravitational pull of the stars, experts can find more insights into the evolutionary state of the planets that could be orbiting those stars. "Fluctuations in the light of sun-like stars are driven by many factors, such as the presence of darker, cooler areas on its surface," the study published on the site mentions. "This spottiness or granulation results from the way the material that makes up the stars rises and falls. The strength of the gravitational pull on the surface of that star can in turn influence how great this churning gets."

"Once you know a star's surface gravity, then you only need one other measurement, its temperature, which is pretty easy to obtain, to determine its mass, size and other important physical properties," study author Keivan Stassun, an astrophysicist at Vanderbilt University in Nashville, said in a statement, per the outlet. "Measuring stellar surface gravities well has always been a difficult business," said Gibor Basri, another author who worked on the study at the University of California, Berkeley. He further explained, "So it is a very pleasant surprise to find that the subtle flickering of a star's light provides a relatively easy way to do it."