We have walked on the moon; discovered a planet that’s roughly 13,000 light-years from Earth; sent probes to the edge of our solar system; and rovers have searched Mars for signs of life – yet the ocean’s depths elude us.

More than 80 percent of the deep blue is unmapped and unexplored, according to the National Oceanic and Atmospheric Administration. Despite all the technology we have built to explore outer space, we have yet to figure out how to conduct research down, down, down in the darkness of the big drink.

We applaud local researchers from SeaDoc and the Friday Harbor Marine Laboratories for taking on deepwater exploration via submarine in the waters of the Salish Sea. It may be just a drop in the bucket, but it’s one more step forward in the quest to understand our environment.

Researchers hope to learn more about sea urchins and their possible deepwater nursery grounds. They will also be able to better understand the practice of trawling and how it damages the sea floor. The submarine will also help educate scientists about how sand lances behave in the depths of the ocean. Sand lances are an important food source for salmon, which are necessary food for local orcas, which are in peril of extinction.

The more we know about our waters, the better we can protect the fragile ecosystems within its realm.

The deepest reaches of the ocean are still not in our grasp, but the submarine in the Salish Sea is a symbol of the importance of ocean exploration. The ocean makes up more than 70 percent of the surface of our planet. We cannot hope to keep our planet healthy without understanding one of its greatest treasures.

Here are some facts from NOAA that may put the ocean vastness mystery into perspective:

• Scientists estimate that 91 percent of ocean species have yet to be classified. The total number of sea creatures is unknown.

• Studies show that some coral can live for up to 5,000 years, making them the longest living animals on Earth.

• The average depth of the ocean is about 12,100 feet. The deepest part of the ocean is called the Challenger Deep and is located beneath the western Pacific Ocean in the southern end of the Mariana Trench, which runs several hundred kilometers southwest of the U.S. territorial island of Guam. Challenger Deep is approximately 36,200 feet deep.

• Life in some parts of the ocean may be similar to conditions on other planets and moons. For example, Jupiter’s moon Europa is completely covered by ice, but the tidal energy generated by giant Jupiter is so strong that a global ocean likely exists under the ice and it could be 10 times as deep as what we find on Earth. Many scientists think that hydrothermal vents may exist at the bottom of this vast ocean and that some kind of life may dwell there.