Taking a closer look at the planets of nearby galaxies is challenging due to several factors:
Enormous distances: Nearby galaxies are typically located millions or even billions of light-years away from us. The vast distances make it extremely difficult to observe the individual planets within those galaxies. Light from these planets takes a significant amount of time to reach us, and by the time it does, it may have weakened or become indistinguishable from the background noise.
Planetary detection methods: Most of the exoplanets (planets outside our solar system) discovered so far have been detected through indirect methods such as the transit method and the radial velocity method. These techniques rely on observing changes in the brightness or motion of a star caused by the presence of a planet. However, these methods are not as effective for observing planets in other galaxies, as the required precision and sensitivity are challenging to achieve across such vast distances.
Resolution limitations: Even with advanced telescopes, the resolution and clarity of images obtained from distant galaxies are often limited. Resolving the small details, such as individual planets, becomes exceedingly challenging due to the angular size limitations and the effects of atmospheric distortion.
Brightness and contrast: Planets are much smaller and less luminous than the stars they orbit. When observing planets in nearby galaxies, the brightness of the host stars can overwhelm the feeble light reflected by the planets, making them incredibly difficult to detect and study.
Time-consuming observations: Conducting detailed observations of planets in other galaxies requires long-term monitoring and data collection. Gathering sufficient data to study the characteristics and properties of these distant planets can be time-consuming and often impractical.
Overall, the combination of vast distances, observational limitations, and technical challenges makes it extremely difficult to take a closer look at the planets of nearby galaxies. Most of our current knowledge about exoplanets comes from studying planets within our own Milky Way galaxy, where we have better access and observational capabilities.