HONG KONG: As NASA continues to release highly detailed, unprecedented images of the dwarf planet Pluto captured by the New Horizons probe, it raises the question: Why couldn’t it have just used the powerful Hubble telescope to capture the same scenes, instead of sending a spacecraft across the solar system on a $700-million (US) mission? Why is Hubble able to get extremely detailed images of galaxies and nebulae millions of light years away, but when it comes to taking pictures of Pluto, it shows up as a blurry ball?
The answer is straightforward but perhaps not intuitive. Pluto may be close, but it is very small. Galaxies millions of light years away appear larger (as seen from Earth), and that is why the Hubble is able to photograph them in more detail, and why NASA had to send a spacecraft to get good photos of Pluto.
The best images of Pluto taken by the Hubble Space Telescope are a series of blurred shots just a few pixels across. Compare these with the stunning images of galaxies millions of light years away.
“There’s a good reason Hubble can take brilliant sharp images of distant galaxies millions of light years away, but ends up with blurry pictures of Pluto which is just a few light hours away,” Chris Lidman of the Australian Astronomical Observatory said.
