Emma is one of my regular guest bloggers. I feel really thrilled about the possibility to post one educating post of this great blogger once a month over the next couple of months. Thank you so much, Emma, for sharing these great posts with us! If you would like to check out the previous guest posts, this amazing blogger wrote for me, head over here.
The Hubble Space Telescope is the sort of telescope that is never forgotten. Astronomers and astrophysicists move onto other projects. New Mars rovers are built, new space probes are launched, different light is analyzed, new ideas are formulated. But when you ask a non-astronomer what they know of astronomy, immediately they reply, “Like those images from—what’s it’s name—Hubble, right?”
Even I, a supporter of progress and change and an avid fan of the Chandra, Spitzer, and yet-to-be-launced James Webb telescopes, have to admit I’ve been caught in Hubble’s enchantment. While you have to specify Chandra in a google search, the search engine never questions that plenty of appealing images come from Hubble. Hubble is the unspoken command—enter “chandra x ray telescope images” and you get some Chandra, and some others. But just type in “awesome astronomy images” and you get all Hubble. Hubble is the public figurehead of astronomy, and it lives up to its name. It can even be called the little telescope that could.
Hubble isn’t only a figurehead, it’s a powerful leader in astronomy. After 25 years in space, Hubble has seen it all. It watched as fragments of a comet plummeted into Jupiter. It spied planet nurseries silhouetted by the light of new stars in the Orion Nebula. It confirmed that in the center of every large galaxy lies a supermassive black hole, an invisible giant capable of devouring its host galaxy from the inside out. Hubble has monitored pulsating stars as far as 70 million light-years away, and in doing so resolved a decades-long dispute about the expansion rate and age of the universe. Hubble has set the standard for how astronomers and the public view the universe.
Hubble didn’t start this way. It was sent out into space with a misshapen mirror. The mirror of a telescope is an essential pice for seeing cosmic objects, let alone photographing them. Hubble was a deformed youngster, the runt of the litter, the butt of jokes. But with a mission to add corrective optics to the mirror in 1993, completed by several astronauts, Hubble was transformed into a galactic superhero. Astronauts have returned five times to upgrade outdated instruments and to replenish the telescope with spare parts. The telescope is working better now than it ever has in the past. The images are sharper and reach farther than before. Hubble is expected to celebrate a 30th anniversary.
Among the instruments added was an infrared camera, added during the last servicing mission in 2009. Robert Kirshner, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, is trying to use it to figure out why the expansion of the universe is speeding up. And you thought Hubble only imaged things like the Butterfly and Crab Nebulas? Nope. It’s busy figuring out why the universe’s expansion is accelerating. And not only that, it’s using the physics of light to look back in time and study galaxies that look to us like they’re only the age they would be a few hundred million years after the Big Bang. Because light does not travel instantaneously, the farther away an object is, the longer ago the light we see right now left the object. So as we observe these distant objects, so far away that common telescopes designed for the public cannot hope to see, we are looking into a time machine to the beginning of the universe. The faraway galaxies Hubble observed appear to still be in their early stages because they’re so far away.
Hubble is an old telescope, in technology years. But it also may be the most important astronomical pioneer. It keeps chugging along, watching galaxies form and wondering why the universe’s expansion accelerates, despite our most certain predictions of its demise.