Chemistry Archives

November 13, 2024November 13, 2024 by Evan Gough

Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable

Earth's ancient atmosphere was much different than now. How did it transition from hostile to hospitable? If scientists can figure that out, they'll be better able to understand exoplanets and their atmospheres. Image Credit: Tohoku University

Will we ever understand how life got started on Earth? We’ve learned much about Earth’s long, multi-billion-year history, but a detailed understanding of how the planet’s atmospheric chemistry evolved still eludes us. At one time, Earth was atmospherically hostile, and its transition from that state to a planet teeming with life followed a complex path.

September 26, 2024September 26, 2024 by Evan Gough

Another Building Block of Life Can Handle Venus’ Sulphuric Acid

Radar image of Venus created by the Solar System Visualization project and the Magellan science team at the JPL Multimission Image Processing Laboratory. Credit: NASA/JPL.

Venus is often described as a hellscape. The surface temperature breaches the melting point of lead, and though its atmosphere is dominated by carbon dioxide, it contains enough sulfuric acid to satisfy the comparison with Hades.

But conditions throughout Venus’ ample atmosphere aren’t uniform. There are locations where some of life’s building blocks could resist the planet’s inhospitable nature.

September 4, 2024September 4, 2024 by Evan Gough

Dark Oxygen Could Change Our Understanding of Habitability

This image shows a bed of manganese nodules offshore of the Cook Islands. Dark oxygen is produced by manganese nodules on the ocean floor. If the same thing happens on the Solar System's ocean moons, it changes our notion of what worlds could be habitable. Image Credit: By USGS, James Hein - https://www.usgs.gov/media/images/cook-islands-manganese-nodules, CC0, https://commons.wikimedia.org/w/index.php?curid=115692552

The discovery of dark oxygen at an abyssal plain on the ocean floor generated a lot of interest. Could this oxygen source support life in the ocean depths? And if it can, what does that mean for places like Enceladus and Europa?

What does it mean for our notion of habitability?

August 5, 2024August 5, 2024 by Evan Gough

Fast-Tracking the Search for Habitable Worlds

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

Modern astronomy would struggle without AI and machine learning (ML), which have become indispensable tools. They alone have the capability to manage and work with the vast amounts of data that modern telescopes generate. ML can sift through large datasets, seeking specified patterns that would take humans far longer to find.

The search for biosignatures on Earth-like exoplanets is a critical part of contemporary astronomy, and ML can play a big role in it.

June 28, 2024June 28, 2024 by Evan Gough

Could We Detect an Alien Civilization Trying to Warm Their Planet?

This artist's illustration shows a hypothetical Earth-like inhabited planet being terraformed with artificial greenhouse gases. We could detect these chemicals with infrared spectroscopy. Image Credit: Sohail Wasif, UC Riverside/Schwieterman et al. 2024

Humanity is facing an atmospheric threat of our own device, and our internecine squabbles are hampering our ability to neutralize that threat. But if we last long enough, the reverse situation will arise. Our climate will cool, and we’ll need to figure out how to warm it up. If that day ever arises, we should be organized enough to meet the challenge.

If there are other civilizations out there in the galaxy, one may already be facing a cooling climate or an ice age. Could we detect the greenhouse chemicals they would be purposefully emitting into their atmosphere in an attempt to warm their planet?

June 3, 2024June 3, 2024 by Evan Gough

Life Probably Played No Role in Mars’ Organic Matter

Color mosaic image of Mars, taken by the HRSC instrument aboard the ESA's Mars Express orbiter. Credit: ESA/DLR/FU Berlin (G. Michael)

The Martian surface shows ample evidence of its warm, watery past. Deltas, ancient lakebeds, and dry river channels are plentiful. When the Curiosity rover found organic matter in ancient sediments in the Jezero Crater paleolake, it was tempting to conclude that life created the matter.

However, new research suggests that non-living processes are responsible.

May 15, 2024May 15, 2024 by Evan Gough

Linking Organic Molecules to Hydrothermal Vents on Enceladus

Saturn's moon Enceladus isn't just bright and beautiful. It has an ocean under all that ice that could have hydrothermal vents that create organic chemicals. Image Credit: NASA, ESA, JPL, SSI, Cassini Imaging Team

Despite the vast distance between us and Saturn’s gleaming moon Enceladus, the icy ocean moon is a prime target in our search for life. It vents water vapour and large organic molecules into space through fissures in its icy shell, which is relatively thin compared to other icy ocean moons like Jupiter’s Europa. Though still out of reach, scientific access to its ocean is not as challenging as on Europa, which has a much thicker ice shell.

May 15, 2024May 15, 2024 by Evan Gough

New Answers for Mars’ Methane Mystery

There's methane on Mars, but only in Gale Crater, and only sporadically. Image Credit:

Planetary scientists perk up whenever methane is mentioned. Methane is produced by living things on Earth, so it’s considered to be a potential biosignature elsewhere. In recent years, MSL Curiosity detected methane coming from the surface of Gale Crater on Mars. So far, nobody’s successfully explained where it’s coming from.

NASA scientists have some new ideas.

May 7, 2024May 7, 2024 by Evan Gough

41,000 Years Ago Earth’s Shield Went Down

An illustration of Earth's magnetic field. Image Credit: ESA/ATG medialab

Earth is naked without its protective barrier. The planet’s magnetic shield surrounds Earth and shelters it from the natural onslaught of cosmic rays. But sometimes, the shield weakens and wavers, allowing cosmic rays to strike the atmosphere, creating a shower of particles that scientists think could wreak havoc on the biosphere.

This has happened many times in our planet’s history, including 41,000 years ago in an event called the Laschamps excursion.

April 30, 2024April 30, 2024 by Evan Gough

Binary Stars Form in the Same Nebula But Aren’t Identical. Now We Know Why.

This artist’s impression illustrates a binary pair of giant stars. Despite being born from the same molecular cloud, astronomers often detect differences in binary stars’ chemical compositions and planetary systems. Image Credit: NOIRLab/NSF/AURA/J. da Silva (Spaceengine)/M. Zamani

It stands to reason that stars formed from the same cloud of material will have the same metallicity. That fact underpins some avenues of astronomical research, like the search for the Sun’s siblings. But for some binary stars, it’s not always true. Their composition can be different despite forming from the same reservoir of material, and the difference extends to their planetary systems.

New research shows that the differences can be traced back to their earliest stages of formation.