The Hubble Space Telescope Is Still Awesome

Hubble is going strong despite its decades in space and next-generation successors

- PHIL PLAIT

ON APRIL 24, 1990, HUMANITY LAUNCHED a scientific revolution.

I mean “launched” literally: on that date the space shuttle Discovery roared into the sky with the Hubble Space Telescope nestled in its cargo bay. The telescope was on a mission destined to forever change our view of the universe. Hubble wasn’t the largest telescope ever—its 2.4-meter mirror is actually considered small these days—but being above the atmosphere gave it superpowers. Our air boils and roils, blurring the views from ground-based instruments. It glows, too—dimly but enough to limit how faint an object astronomers can see. And our air absorbs most ultraviolet and infrared light—interesting wavelengths, cosmically speaking. Getting up, up and away from all that atmosphere made Hubble one of the most important telescopes ever built.

It revolutionized astronomy. Hubble saw objects fainter than had ever been observed before. The telescope homed in on the speed of universe expansion, watched weather changes on the outer planets and proved that every big galaxy has a supermassive black hole at its heart, just to name three amazing feats off the top of my head. The major breakthroughs and discoveries that came out of this magnificent satellite are so numerous, really, that even listing them here would be excessive (and a bit tedious, if incredible astronomical exploration could ever be tedious).

Yet despite these successes, I see a lot of chatter online (and even in the news) somewhat cavalierly dismissing Hubble, saying NASA’s James Webb Space Telescope (JWST) is Hubble’s “replacement.” That’s not just unfair; it’s wrong. JWST was never intended to supplant the Hubble telescope, and in fact it can't, given that it was designed for very different observations.