Do you know why stars twinkle but planets don't?

Why Stars Twinkle but Planets Don’t?

We have all stared up at the night sky and noticed it—stars seem to twinkle, but planets shine steadily. It is one of the first things we learn about space, but there is a lot more going on behind that twinkle than you might think!

Why Do Stars Twinkle?

Stars are incredibly far away. Because they are so distant, they appear as tiny pinpoints of light in the sky. As their light travels through Earth’s atmosphere, it gets bent and bounced around by moving air and temperature changes. This causes stars to appear as if they are flickering or “twinkling.”

Planets, on the other hand, are much closer to Earth and appear as small disks in the sky, not pinpoints. Their light still travels through the atmosphere, but because it is spread out over a slightly larger area, it does not flicker the same way. That is why planets usually shine with a steady glow.

But Twinkling Isn’t Just a Pretty Sight

Scientists have found that this flickering—or scintillation—is not just something nice to look at. It can actually help us study space! Recently, a team of Australian scientists used a twinkling star-like object called a pulsar to make new discoveries about the space between the stars.

What is a Pulsar?

A pulsar is a super dense, spinning star left behind after a giant star explodes. Pulsars send out regular beams of radio waves, and some of them “twinkle” just like stars. The scientists focused on one pulsar named J0437–4715, which is one of the closest to Earth.

By studying how its radio waves twinkled using a powerful telescope in South Africa, the scientists were able to look deep into the invisible space between stars. They discovered something surprising—our part of the galaxy is full of tiny blobs of hot gas (plasma) that we did not know were there!

The team also spotted something called a bow shock—a kind of shockwave formed as the pulsar moves incredibly fast through space, like the splash at the front of a speeding boat. For the first time ever, scientists were able to see inside this shockwave and measure how the plasma was moving.