Earth’s oxygen-rich atmosphere does more than provide the foundation for complex life. The oxygen in the atmosphere is so reactive that it readily combines with other chemical elements. Together, they form important ores like iron oxides and manganese oxides found in the Earth’s crust. So, when rovers spotted manganese oxides on Mars, scientists interpreted them as clues to Mars’ earlier atmosphere: it must have contained oxygen.
Jupiter is the most-visited planet in the Solar System, thanks largely to NASA. It all started with Pioneer 10 and 11, followed by Voyager 1 and 2. Those were all flyby missions, and it wasn’t until 1996 that the Galileo spacecraft became the first to orbit the gas giant and even send a probe into its atmosphere. Then in 2016, the Juno spacecraft entered orbit around Jupiter and is still there today.
All of these missions were focused on Jupiter, but along the way, they gave us tantalizing hints of the icy moon Europa. The most impactful thing we’ve learned is that Europa, though frozen on the surface, holds an ocean under all that ice. And that warm, salty ocean might contain more water than all of Earth’s oceans combined.
Our modern telescopes are more powerful than their predecessors, and our research is more focused than ever. We keep discovering new things about the Solar System and finding answers to long-standing questions. But one of the big questions we still don’t have an answer for is: ‘How did life on Earth begin?’
Trees are like sentinels that preserve a record of shifting climates. Their growth rings hold that history and dendrochronology studies those rings. Scientists can determine the exact ages of trees and correlate their growth with climatic and environmental changes.
But they also record the effects of more distant changes, including the Sun’s activity.
Astronomers have spotted barium in the atmosphere of a distant exoplanet. With its 56 protons, you have to run your finger further down the periodic table than astronomers usually do to find barium. What does finding such a heavy element in an exoplanet atmosphere mean?
It means we’re still learning how strange exoplanets can be.
Finding oxygen in an exoplanet’s atmosphere is a clue that life may be at work. On Earth, photosynthetic organisms absorb carbon dioxide, sunlight, and water and produce sugars and starches for energy. Oxygen is the byproduct of that process, so if we can detect oxygen elsewhere, it’ll generate excitement. But researchers have also put pressure on the idea that oxygen in an exoplanet’s atmosphere indicates life. It’s only evidence of life if we can rule out other pathways that created the oxygen.
Earth’s oceans are one huge, uniform electrolyte solution. They contain salt (sodium chloride) and other nutrients like magnesium, sulphate, and calcium. We can’t survive without electrolytes, and life on Earth might look very different without the oceans’ electrolyte content. It might even be non-existent.
On Earth, electrolytes are released into the oceans from rock by different processes like volcanism and hydrothermal activity.
Are these life-enabling nutrients available on water worlds?
Each of us is, as it says in Max Ehrmann’s famous poem “Desiderata”, a child of the universe. It speaks metaphorically about our place in the cosmos, but it turns out to be a very literal truth. Our bodies contain the stuff of stars and galaxies, and that makes us children of the cosmos. To be more precise, we are carbon-based life forms. All life on Earth is based on the element carbon-12. It turns out this stuff is a critical gateway to life. So, how did the universe come up with enough of it to make you and me and all the life on our planet? Astrophysicists and nuclear physicists think they have an answer by using a supercomputer simulation of what happens to create carbon. As it turns out, it’s not very easy.
Have you ever held a chunk of gold in your hand? Not a little piece of jewelry, but an ounce or more? If you have, you can almost immediately understand what drives humans to want to possess it and know where it comes from.
We know that gold comes from stars. All stars are comprised primarily of hydrogen and helium. But they contain other elements, which astrophysicists refer to as a star’s metallicity. Our Sun has a high metallicity and contains 67 different elements, including about 2.5 trillion tons of gold.
Now astronomers have found a distant star that contains 65 elements, the most ever detected in another star. Gold is among them.