Humanity owes NASA's Hubble Space Telescope a debt of gratitude. Launched on April 24, 1990, the workhorse has taken 1.2 million observations, giving scientists the data to publish more than 12,800 scientific articles. In short, the Hubble has allowed us to get to know our universe better, revealing new stars, moons and planets and bringing the cosmos within reach.

Now, 15 years later, a team of scientists is looking toward the future, proposing a new telescope that would succeed not only the Hubble, but also the soon-to-be released James Webb Space Telescope, and the Wide-Field infrared Survey Telescope set to launch in about a decade.

"If we think about what we want in the sky after the James Webb Space Telescope, we need to start thinking about it now," said University of Washington astronomy professor Julianne Dalcanton, a co-chair on the committee from the Association of Universities for Research in Astronomy (AURA). "These are decades-long projects. No mission happens accidentally. AURA thought that it was time to start looking ahead to find a path forward that is scientifically transformative but also technologically possible."

The proposed instrument called the High Definition Space Telescope, or HDST, would be stationed at an observatory roughly 1 million miles from Earth, and utilize its almost 40-foot-wide mirror to search for light from far away planets. Using cameras, spectrographs and a coronagraph, the HDST could capture data that would help scientists figure out more information about each planet such as the composition and the planet’s atmosphere, and specifically information about planets that could potentially contain life. It would have 25 times the resolution of the Hubble.

AURA knows how far we’ve come, but the group says that some of our biggest questions are still unanswered. Are we alone in the universe? Is Earth unique, or are there other similar inhabited planets out there? Where and how did life begin?

Based on discoveries from Kepler's space observatory — with its more than 1,000 confirmed planets that orbit a star, similarly to Earth — statistically AURA notes it is likely that worlds like our own planet do exist out in the galaxy. With the HDST's improved technology, they could be observed.

"When we imagine the landscape of astronomy in the decade of 2030, we realize it is at last within our grasp to make a monumental discovery that will change mankind forever. We hope to learn whether or not we are alone in the universe," said AURA President Matt Mountain in a press release.

The University of Washington reports that AURA wants the HDST to look at several dozen planets that could contain signs of life. Because of the telescope's advancements, it would be able to view light rays that are 10 billion times fainter than the nearby stars. In addition, the HDST would provide images about five times sharper than the Hubble and would be 100 times more sensitive to ultraviolet radiation.

Dalcanton believes that this next telescope could help blossoming astronomers make remarkable strides in the field. She said, “Hubble launched 25 years ago when I started grad school, and at lot of us in my generation realize that we have to pay this success forward. I would like to see the High-Definition Space Telescope in the sky because there will be another astronomy graduate student who’s going to have a fantastic career of discovery using it.”

AURA notes that like Hubble, this equipment would be modular so that robots or astronauts could replace parts as needed, helping to ensure that the HDST stays in working order for decades.

After Hubble: Scientists dream of next big scope
With 25 times the resolution, the powerful new telescope would search other planets for signs of life.