English edit: Katyanne M. Shoemaker
At the end of September of 2015, NASA scientists publically confirmed the existence of liquid water on Mars, the Red Planet (https://www.nasa.gov/press-release/nasa-confirms-evidence-that-liquid-water-flows-on-today-s-mars). I remember when this news was released and how it caused certain uproar over the possibility of finding life there.
Landscape of the mysterious Red Planet; from the movie The Martian.
We know that life depends on water: it is the largest constituent of every living being (e.g. the human body is composed, on average, of 60% water), it is necessary for photosynthesis, and it is indispensable for several other vital functions. However, the phrase just quoted neglects an important detail: life, AS WE KNOW IT, depends on water.
This made me remember the following cartoon, about two giant tubeworms talking to each other:
I had posted this cartoon on my personal Facebook page previously, but then I reflected: how many of my friends know what giant tubeworms are? Or what hydrothermal vents are?
Tubeworms are marine invertebrates in the phylum Annelida (yes, the same as the earthworms) and the class Polychaeta (aquatic worms), but they are sessile, i.e. they live fixed on an underwater surface. Their body is rounded by a tube, which extends the length of the whole body. The one illustrated in the cartoon are of the species Riftia pachyptila, popularly known as the giant tubeworms. These worms can live several kilometers down in the ocean, and they can reach a length of 2.4 m with a diameter of 4 cm. (more information on: https://en.wikipedia.org/wiki/Giant_tube_worm)
Giant tubeworms. Font
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated fluid emerges. The water that penetrates the crust at deep depths reacts with the minerals present, undergoing physical and chemical changes along the way. Usually there is an “oasis” of life along the hydrothermal vents. This is due to chemosynthesis, a process in which microorganisms use chemical energy to produce organic matter from carbon dioxide.
Hydrothermal vent. Font
Prior to the discovery of hydrothermal vents in the 1970s, the scientific community assumed that all life in the ocean depended on photosynthetic production, mainly produced by phytoplankton. Since photosynthesis depends on sunlight, it was like saying that all of the life in the oceans depended solely on the sun! The hydrothermal vents and the abundance of organisms that live around them proved the opposite.
And that's the point I wanted to get to in this post: WE KNOW AS LITTLE ABOUT THE OCEAN AS WE KNOW ABOUT SPACE!
We have explored around 1% of the oceans, and they cover 80% of our planet. Most of the ocean is only about 3 km deep, but Mars is about 60 million miles away from Earth! I am not saying that scientific exploration of space is not important, but I wish that the amount of money invested in space studies and the media attention space discoveries receive would also be given to the oceans. We know so little still, and yet they are so much more present in our lives.