I’ve never been much of a cook though I do make a pretty tasty chili. Now it turns out I’ve been bested by little more than sunlight and dust. A research team, led by John Bradley of the University of Hawaii in Honolulu, used a transmission electron microscope to discover tiny pockets of water on the surface of cosmic dust particles. This specialized instrument focuses a beam of electrons instead of light to to resolve details right down to the atomic level.
Dribs and drabs of debris blown into space by both aging stars and supernovae salt and pepper the universe with cosmic dust. They’re extremely teeny with sizes ranging from just a few molecules to millionths of an inch and mostly made of silicates, which are minerals made of silicon and oxygen. Quartz is one of the most familiar silicates on Earth.
When the Apollo astronauts returned samples of lunar rocks, scientists noticed that bombardment by hydrogen and helium ions in the gusty solar wind had chipped away and damaged the rocks’ outer surfaces. That has fascinating consequences when it comes to dust from vaporized comets, asteroid collisions and debris left from the birth of the solar system.
When hydrogen in the million mile an hour solar wind smacks interplanetary dust it loosens up the oxygen atoms in the silicates. Now free to move and react with its surrounding elements, oxygen combines with hydrogen to potentially make water.
Those molecular bits of water were too difficult to detect until Bradley used the state-of-the-art microscope to spot them inside tiny bubbles on the surface of the particles. Their findings, published this month in the journal Proceedings of the National Academy of Sciences, make my cooking skills seem primitive by comparison.
Previous work has shown that the element carbon, so critical to life as we know it, is also found in space dust. It’s not hard to imagine a rain of water and carbon-saturated dust wafting its way down through Earth’s atmosphere during the early days of the solar system seeding the planet with essential ingredients for the formation of life.
Picture yourself standing there – appropriately dressed in a spacesuit as Earth was uninhabitable at that time – on the first solid rock as fireballs and their tiny, dusty cousins prepped the planet for the greatest unintentional experiment ever conducted in the universe. Life.