Atmosphere Archives

January 3, 2023January 3, 2023 by Evan Gough

Minerals Could Form on Mars Without an Oxygen-Rich Atmosphere

This scene shows NASA's Curiosity Mars rover at a location called "Windjana," where the rover found rocks containing manganese-oxide minerals, which require abundant water and strongly oxidizing conditions to form. Credits: NASA/JPL-Caltech/MSSS

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.

But a new study puts the brakes on that idea.

December 5, 2022February 8, 2023 by Nancy Atkinson

SOFIA Fails to Find Phosphine in the Atmosphere of Venus, But the Debate Continues

The spectral data from SOFIA overlain atop this image of Venus from NASA’s Mariner 10 spacecraft is what the researchers observed in their study, showing the intensity of light from Venus at different wavelengths. If a significant amount of phosphine were present in Venus’s atmosphere, there would be dips in the graph at the four locations labeled “PH3,” similar to but less pronounced than those seen on the two ends. Credit: Venus: NASA/JPL-Caltech; Spectra: Cordiner et al.

The on-again, off-again detection of phosphine in the atmosphere of Venus appears to be off-again – for now. The latest study, based on data from the SOFIA telescope, reveals that the flying observatory didn’t see any signs of phosphine. According to the results, if there is any phosphine present in Venus’s atmosphere at all, it’s a maximum of about 0.8 parts per billion, much smaller than the initial estimate.

However, the team that made the initial detection of phosphine, which was announced in 2020, disagrees with the researchers’ interpretation of the SOFIA data.

October 27, 2022October 27, 2022 by Carolyn Collins Petersen

NASA is Mapping Giant Clouds of Methane Released by “Super-Emitters” Across the World

Methane super-emitters — This image shows a methane plume 2 miles (3 kilometers) long that NASA’s Earth Surface Mineral Dust Source Investigation mission detected southeast of Carlsbad, New Mexico. Methane is a potent greenhouse gas that is much more effective at trapping hea... Credit: NASA/JPL-Caltech

Everybody’s heard of methane. It’s a major part of the atmosphere in places like Uranus and Neptune. On Earth, it’s also part of our atmosphere, where it works to warm things up. Some of it gets there from natural causes. But, a lot of it comes from industrial super-emitters and other human-caused processes. That’s not good because too much methane works, along with other greenhouse gases (like carbon dioxide, or CO₂) to “over warm” our atmosphere.

October 19, 2022October 19, 2022 by Evan Gough

The Heaviest Element Ever Seen in an Exoplanet’s Atmosphere: Barium

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

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.

October 18, 2022October 18, 2022 by Evan Gough

Scientists Discover a New Way Exoplanets Could Make Oxygen; Unfortunately, it Doesn’t Require Life

Oxygen is a valuable biosignature because Earth is oxygen-rich, and because life made all that oxygen. But if we find oxygen in an exoplanet atmosphere does that mean life made it? Or is there an abiotic source of oxygen? Image Credit: NASA

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.

But scientists can’t rule them out.

July 15, 2022July 15, 2022 by Evan Gough

These Ancient Microbes Give a Glimpse of What Extraterrestrial Life Might Look Like

Rhodopsins are ancient proteins evolved by some of Earth's first life forms. They turned sunlight into energy without photosynthesis. Image Credit: Sohail Wasif/University of California, Riverside.

Will we discover simple life somewhere? Maybe on Enceladus or Europa in our Solar System, or further away on an exoplanet? As we get more proficient at exploring our Solar System and studying exoplanets, the prospect of finding some simple life is moving out of the creative realm of science fiction and into concrete mission planning.

As the hopeful day of discovery draws nearer, it’s a good time to ask: what might this potential life look like?

July 14, 2022July 14, 2022 by Carolyn Collins Petersen

A New Instrument is Going to the ISS to Study the Climate Impact of Dust in Earth’s Upper Atmosphere

People often seem surprised when they learn that NASA doesn’t just look out to the other planets, stars, and galaxies. It’s also an agency that studies our own home planet—from space! And why not? Earth is part of the solar system, too. So, to that end, there’s a new Earth studies mission called EMIT on its way to the International Space Station. It’s designed to track dust as it moves from one place to another on our planet through through our atmosphere.

The official name of the mission is the Earth Surface Mineral Dust Source Investigation (EMIT, for short). It will use a high-tech imaging spectrometer to study dust around the globe over the next year.

A dust plume stretches over the eastern Mediterranean, shrouding parts of Greece, Turkey, and Cyprus. The June 2020 image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. NASA’s EMIT mission will help scientists better understand how airborne dust affects climate. Credits: NASA — A dust plume stretches over the eastern Mediterranean, shrouding parts of Greece, Turkey, and Cyprus. The June 2020 image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. NASA’s EMIT mission will help scientists better understand how airborne dust affects climate. Credit: NASA

March 15, 2022March 15, 2022 by Evan Gough

Smaller, Ground-Based Telescopes can Study Exoplanet Atmospheres too

An artist's illustration of exoplanet Kelt-9b. Image Credit: NASA/JPL-Caltech

The next step to understanding exoplanets is to understand their atmospheres better. Astronomers can determine a planet’s mass, density, and other physical characteristics fairly routinely. But characterizing their atmospheres is more complicated.

Astronomers have had some success studying exoplanet atmospheres, and spacecraft like the James Webb Space Telescope and the ESA’s ARIEL mission will help a lot. But there are thousands of confirmed exoplanets with many more to come, and the Webb has many demands on its time.

Can smaller, ground-based telescopes play a role in understanding exoplanet atmospheres?

February 11, 2022February 11, 2022 by Evan Gough

We Might Know Why Mars Lost its Magnetic Field

This figure shows a cross-section of the planet Mars revealing an inner, high density core buried deep within the interior. Dipole magnetic field lines are drawn in blue, showing the global scale magnetic field that one associates with dynamo generation in the core. Mars must have one day had such a field, but today it is not evident. Perhaps the energy source that powered the early dynamo has shut down. The differentiation of the planet interior - heavy elements like iron sinking towards the center of the planet - can provide energy as can the formation of a solid core from the liquid. Credit: NASA/JPL/GSFC

Mars is a parched planet ruled by global dust storms. It’s also a frigid world, where night-time winter temperatures fall to -140 C (-220 F) at the poles. But it wasn’t always a dry, barren, freezing, inhospitable wasteland. It used to be a warm, wet, almost inviting place, where liquid water flowed across the surface, filling up lakes, carving channels, and leaving sediment deltas.

But then it lost its magnetic field, and without the protection it provided, the Sun stripped away the planet’s atmosphere. Without its atmosphere, the water went next. Now Mars is the Mars we’ve always known: A place that only robotic rovers find hospitable.

How exactly did it lose its magnetic shield? Scientists have puzzled over that for a long time.

October 7, 2021October 7, 2021 by Evan Gough

An Exoplanet Reaches 2400 C in One Hemisphere. Does it Really Rain Iron?

This artist's illustration shows the fiery exoplanet WASP-76b. Previous study shows the planet rains iron it's so hot. Now astronomers have detected barium in its atmosphere. Image Credit: ESO/M. Kornmesser

WASP-76b is an ultra-hot Jupiter about 640 light-years away from Earth in the constellation Pisces. A few years ago it gained notoriety for being so hot that iron falls as rain. It’s tidally locked to its star, and the planet’s star-facing hemisphere can reach temperatures as high as 2400 Celsius, well above iron’s 1538 C melting point.

Scientists have been studying the planet since its discovery in 2013, and new evidence suggests that it’s even hotter than thought. But, almost disappointingly, there might be no iron rain after all.