Galaxy Hunter

Yuko Kakazu studies massive star systems to learn more about the origins of our universe


THE SUBARU TELESCOPE, pictured here against our galaxy, the Milky Way. Scientists have used this telescope to photograph hundreds of thousands of galaxies.

The Subaru Telescope is located at the summit of Maunakea, a dormant volcano on the Big Island of Hawaii. At 4,140 meters (13,580 feet) above sea level, the volcano’s peak often juts above the clouds. The site is also far from any city lights that can brighten the night sky and make it hard to see the stars. This clear view makes Maunakea one of the best stargazing spots on Earth.

The telescope is part of the National Astronomical Observatory of Japan. It’s equipped with several powerful cameras that allow astronomers like Yuko Kakazu to study and capture images of distant objects in space. Kakazu uses the Subaru Telescope to search for newborn galaxies and learn how these huge collections of stars, planets, gas, and dust change over time.

When Kakazu isn’t scanning the skies, she serves as the Subaru Telescope’s outreach specialist. It’s her job to educate the public about the research happening at the observatory. Science World spoke with Kakazu about what it’s like to explore the mysteries of space—and share astronomical discoveries with others.

How can scientists learn about our universe by studying galaxies?

The universe is about 14 billion years old. Space itself and all matter started out as a single tiny, extremely dense point. Then it exploded outward— an event known as the big bang. Our universe has been expanding ever since.

After the big bang, the attractive force of gravity pulled matter together to form massive objects like stars and planets. Today, the Milky Way galaxy, where our solar system is located, is just one of hundreds of billions of galaxies in the universe.

Because it can take billions of years for light from distant galaxies to travel to a telescope lens, observing these objects is like looking back in time. We’re seeing what galaxies looked like long ago, which provides clues as to how the early universe developed.

What led you to become an astronomer?

I grew up in Okinawa, the southernmost island of Japan. When I was in middle school, I attended Space Camp at the U.S. Space and Rocket Center in Alabama. I was inspired by the space program and the launch of the Hubble Space Telescope. After camp, I visited the Smithsonian National Air and Space Museum in Washington, D.C. There, I was able to touch a moon rock from the Apollo 17 mission. That experience made me decide to become an astronomer.

What is a typical day at work like for you?

Even though I work at an observatory, I spend less time observing space than you might think. Many scientists want to use the Subaru Telescope, so people have to apply a year in advance. Most researchers are allowed access to the telescope for only a few nights each year.

When I’m not doing research, I’m doing outreach. I run the observatory’s YouTube channel, SubaruTelescopeNAOJe. I also give lectures and tours to visiting students. I really love this part of my job. Sharing my passion and scientific knowledge is extremely rewarding.

What do you wish more people knew about astronomy?


I think people would be surprised to find that some technology originally developed for astronomy is part of their everyday lives. The GPS in cell phones relies on satellites, which were first used to study outer space. A technology known as adaptive optics was created to improve images captured by a telescope lens and is now used in LASIK eye surgery to help correct people’s vision.

Something else people might not realize is that you don’t have to be an astronomer to work at an observatory. The telescope is a huge mechanical device run by computers. It needs a lot of people to take care of it. Only about 20 percent of our staff are astronomers. Many others are software engineers and technicians.

Why does astronomy fascinate people?

Since the earliest civilizations, humans have wondered about our place in the universe and have looked to the stars for answers. We’re still searching for those same answers today.

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