Why Can’t We Capture Planets When Photographing Galaxies?

Space, which humanity has been wondering about for hundreds or even thousands of years, has finally begun to be discovered, albeit slowly, with space telescopes. Thanks to space telescopes like Hubble and James Webb, we can photograph planets thousands or even hundreds of thousands of light years away.

But somehow these space telescopes cannot view the surfaces of planets. How is it that these technological devices that take pictures of galaxies cannot perform such a ‘simple’ task? Let’s take a closer look at how telescopes work and why this is not possible.

Let’s first understand the working logic of telescopes

In fact, in order to understand the answer to this question, we first need to know how telescopes work. As many people know, telescopes present us images by focusing the light in the direction in which it is directed, with the help of the lenses inside. However, in space telescopes, the situation is slightly different. Space telescopes, on the other hand, gather light at the maximum level by using a few huge lenses and dozens of mirrors.

Space telescopes have parts called mirrors. These parts collect the rays from the celestial bodies and send them to the lenses inside the telescope that detect different types of light. These lenses, which distinguish between infrared and ultraviolet lights, collect the rays from dozens of mirrors and send them to experts on our planet. Then the experts combine the incoming images to create the amazing space pictures we see.

Why can’t we photograph the surfaces of planets when we photograph galaxies?

Space telescopes, equipped with lenses and mirrors at the peak of technology, can deliver images of galaxies thousands of light years away from our planet. This is because galaxies are really, really big. To give an example, the Milky Way Galaxy, which we are also in, is actually so large that it is 890 billion times larger than the Sun, whose radius is 696,340 km.

When this is the case, it is much easier for telescopes to catch the light emitted by gigantic galaxies. Space telescopes tuned to collect a certain amount of light have trouble capturing the ‘pale’ light of planets, which look like dust grains compared to galaxies. Of course, we should not forget the dust and gas clouds that cover the atmospheres of some planets. When this is the case, these telescopes, which photograph huge galaxies, cannot help us observe planets.

So how do they photograph galaxies thousands of light years away?

Because galaxies are huge, they can emit a lot of light. The rays they send are so powerful that space telescopes can detect them even from thousands of light-years away. But of course, just because we’re photographing that galaxy right now doesn’t mean it exists right now. If you are taking a photo of a celestial body 1 million light years away, it means that you are taking a photo of that celestial body 1 million years ago. So in fact, none of the galaxies photographed by the James Webb Space Telescope may exist right now.

Scientists are constantly working to produce more advanced telescope lenses and mirrors. Who knows, maybe we can photograph the planets of those distant galaxies in the future.