The iconic Hubble Space Telescope was launched into orbit 25 years ago this week. Since 1990, it鈥檚 been capturing crystal clear images of stellar nurseries, planetary rings and much more. It has been responsible for some major astronomical breakthroughs and has helped shape our knowledge of the universe.
St. Michael鈥檚 College professor John O鈥橫eara has used Hubble three separate times for observation and research and will be celebrating its anniversary this week.
O鈥橫eara says Hubble鈥檚 breakthroughs in the world of astronomy are too many to list, but that he has several personal favorites. 鈥淗ubble has been able to revolutionize our understanding of the entire universe by constraining this dark energy, which takes up about 70 percent of the energy density of the universe,鈥� he says. 鈥淎nd this was something we didn鈥檛 know about at all when Hubble launched. And since [then] we鈥檝e really changed our view of the universe with it.鈥�
The professor says he used Hubble mainly to look at distant objects called quasars. 鈥淭hey are very bright and they serve as background light bulbs. I try to figure out how the universe looks by doing science in silhouette. When the gas from a galaxy or a group of galaxies gets in the way of the quasar, the light is changed, and from that we can figure out what large swaths of the universe is made of,鈥� says O鈥橫eara. 鈥淚t鈥檚 a really good day when you can wake up and say, 鈥楾his morning I told Hubble where to point.鈥欌��
"It's a really good day when you can wake up and say, 'This morning I told Hubble where to point.'" - John O'Meara, professor at St. Michael's College
The only way to service the telescope is to send astronauts up to Hubble, which first happened in 1993 to fix a major mistake. 鈥淚t has this mirror that is about 8 feet across 鈥� and that mirror has to be exceedingly well-figured. You have to know all parts of the mirror extremely well to get a crisp image,鈥� explains O鈥橫eara. 鈥淲ell, the device they use to test the figuring of that mirror was actually assembled slightly incorrectly, and as a result said the mirror was fine, when it wasn鈥檛.鈥� Since the initial service trip in 1993, there have been four other trips to Hubble, the last in 2009.
"Unless we can find a different way to get astronauts up there, or unless we can come up with a robotics servicing mission, there will be no more missions to service Hubble."
Now that the space shuttle program is retired, O鈥橫eara says there is no way to service Hubble moving forward. 鈥淯nless we can find a different way to get astronauts up there, or unless we can come up with a robotics servicing mission, there will be no more missions to service Hubble,鈥� says the professor. 鈥淭he good news is, all of the instruments in there are working well. Hubble is churning out the best science it ever has in terms of productivity and impact. It is going strong and we plan on using it at least for the next five years, hopefully more.鈥�
When Hubble is no longer operational, NASA will de-orbit the space telescope. 鈥淭hat basically means have it burn up in the atmosphere,鈥� says O鈥橫eara.
No need to worry, though. A new telescope, called the James Webb Space Telescope, will take over Hubble鈥檚 job at a much bigger capacity. 鈥淗ubble is 2.4 meters in diameter. James Webb is going to be 6.5 meters in diameter, so it鈥檚 much, much larger. It will be able to see objects that are much, much fainter, and usually in astronomy fainter means farther away,鈥� explains O鈥橫eara. He says that James Webb will also be optimized for infrared light, which will allow it to capture light from the most distant galaxies. 鈥淗ubble has really opened our eyes on to the scope of the universe and Webb is just going to take that and run with it, gangbusters,鈥� says O鈥橫eara.
"Hubble has really opened our eyes on to the scope of the universe and Webb is just going to take that and run with it, gangbusters."
Like Hubble, the James Webb Telescope won鈥檛 be able to be serviced by human astronauts. 鈥淲ebb will be flying way out, where the gravitational forces from the earth and the sun balance out and it won鈥檛 be serviced. It鈥檚 going to be too far away, unless we can cook up something interesting to do with astronauts,鈥� explains O鈥橫eara.
As for Hubble, O鈥橫eara admits he never gets tired of talking about the telescope. 鈥淚 get jazzed up every day when I get to talk about Hubble,鈥� he says.
To celebrate Hubble鈥檚 25th anniversary, there is on Wednesday, April 22 at 4 p.m. at the Echo Lake Aquarium in Burlington. On Friday, April 24 at 6 p.m. at St. Michael鈥檚 College, O鈥橫eara will also followed by stargazing with a NASA ambassador.
