atmosphere Archives

July 17, 2024July 17, 2024 by Evan Gough

Experimental Radar Technique Reveals the Composition of Titan’s Seas

This colorized mosaic from NASA's Cassini mission shows the most complete view yet of Titan's northern land of lakes and seas. Saturn's moon Titan is the only world in our solar system other than Earth that has stable liquid on its surface. The liquid in Titan's lakes and seas is mostly methane and ethane. New bistatic radar data from Cassini is revealing even more detail about Titan's hydrocarbon seas. Image Credit: NASA / JPL-Caltech / Agenzia Spaziale Italiana / USGS

The Cassini-Huygens mission to Saturn generated so much data that giving it a definitive value is impossible. It’s sufficient to say that the amount is vast and that multiple scientific instruments generated it. One of those instruments was a radar designed to see through Titan’s thick atmosphere and catch a scientific glimpse of the moon’s extraordinary surface.

Scientists are still making new discoveries with all this data.

May 8, 2024May 8, 2024 by Evan Gough

What Deadly Venus Can Tell Us About Life on Other Worlds

Earth and Venus. Why are they so different and what do the differences tell us about rocky exoplanet habitability? Image Credit: NASA

Even though Venus and Earth are so-called sister planets, they’re as different as heaven and hell. Earth is a natural paradise where life has persevered under its azure skies despite multiple mass extinctions. On the other hand, Venus is a blistering planet with clouds of sulphuric acid and atmospheric pressure strong enough to squash a human being.

But the sister thing won’t go away because both worlds are about the same mass and radius and are rocky planets next to one another in the inner Solar System. Why are they so different? What do the differences tell us about our search for life?

May 6, 2024May 6, 2024 by Evan Gough

What Can Early Earth Teach Us About the Search for Life?

This view of Earth from space is a fusion of science and art, drawing on data from multiple satellite missions and the talents of NASA scientists and graphic artists. This image originally appeared in the NASA Earth Observatory story Twin Blue Marbles. Image Credits: NASA images by Reto Stöckli, based on data from NASA and NOAA.

Earth is the only life-supporting planet we know of, so it’s tempting to use it as a standard in the search for life elsewhere. But the modern Earth can’t serve as a basis for evaluating exoplanets and their potential to support life. Earth’s atmosphere has changed radically over its 4.5 billion years.

A better way is to determine what biomarkers were present in Earth’s atmosphere at different stages in its evolution and judge other planets on that basis.

March 25, 2024March 25, 2024 by Evan Gough

Life Might Be Difficult to Find on a Single Planet But Obvious Across Many Worlds

This artist's illustration shows the exoplanet WASP-62B. Searching for chemical biosignatures on exoplanets is a painstaking process, weighed down by assumptions and prone to false positives. Is there a better way to find exoplanets with a chance to support life? Image Credit: CfA

If we could detect a clear, unambiguous biosignature on just one of the thousands of exoplanets we know of, it would be a huge, game-changing moment for humanity. But it’s extremely difficult. We simply aren’t in a place where we can be certain that what we’re detecting means what we think or even hope it does.

But what if we looked at many potential worlds at once?

March 5, 2024March 5, 2024 by Evan Gough

The LIFE Telescope Passed its First Test: It Detected Biosignatures on Earth.

LIFE will have five separate space telescopes that fly in formation and work together to detect biosignatures in exoplanet atmospheres. Image Credit: LIFE, ETH Zurich

We know that there are thousands of exoplanets out there, with many millions more waiting to be discovered. But the vast majority of exoplanets are simply uninhabitable. For the few that may be habitable, we can only determine if they are by examining their atmospheres. LIFE, the Large Interferometer for Exoplanets, can help.

December 23, 2023December 23, 2023 by Brian Koberlein

The Atmosphere of an Exoplanet Reveals Secrets About Its Surface

An artist’s concept of active volcanoes on Venus. Credit: NASA/JPL-Caltech/Peter Rubin

As astronomers have begun to gather data on the atmospheres of planets, we’re learning about their compositions and evolution. Thick atmospheres are the easiest to study, but these same thick atmospheres can hide the surface of a planet from view. A Venus-like world, for example, has such a thick atmosphere making it impossible to see the planet’s terrain. It seems the more likely we are to understand a planet’s atmosphere, the less likely we are to understand its surface. But that could change thanks to a new study in the Monthly Notices of the Royal Astrophysical Society.

September 27, 2023September 27, 2023 by Evan Gough

How Do Lava Worlds Become Earth-Like, Living Planets?

This is an artist's illustration of Kepler-10 b, a suspected magma ocean planet about 560 light years away. Image Credit: NASA/Kepler Mission/Dana Berry

Earth was once entirely molten. Planetary scientists call this phase in a planet’s evolution a magma ocean, and Earth may have had more than one magma ocean phase. Earth cooled and, over 4.5 billion years, became the vibrant, life-supporting world it is today.

Can the same thing happen to exo-lava worlds? Can studying them shed light on Earth’s transition?

September 15, 2023September 15, 2023 by Evan Gough

Engineers Want to Make Methanol by Pulling Carbon Right Out of the Air

Researchers at Western Virginia University are working on a method of extracting carbon out of exhausted air from office buildings and using it to make methanol. Image Credit: WVU Illustration/Savanna Leech

Methanol is one of our most extensively used raw materials. It’s used as a solvent, a pesticide, and in combination with other chemicals in the manufacture of plastic, clothing, plywood, and in pharmaceuticals and agrochemicals.

It’s also used as a fuel.

February 27, 2023February 27, 2023 by Evan Gough

Venus is Like an Exoplanet that’s Right Next Door

Venus' thick clouds mean that only radar imaging can reveal surface details. Image Credit: NASA/JPL-Caltech

We’re lucky to have a neighbour like Venus, even though it’s totally inhospitable, wildly different from the other rocky planets, and difficult to study. Its thick atmosphere obscures its surface, and only powerful radar can penetrate it. Its extreme atmospheric pressure and high temperatures are barriers to landers or rovers.

It’s like having a mysterious exoplanet next door.

February 2, 2023February 2, 2023 by Evan Gough

How Can We Know if We’re Looking at Habitable exo-Earths or Hellish exo-Venuses?

How can astronomers tell exo-Earths and exo-Venuses apart? Polarimetry might be the key. Image Credits: NASA

The differences between Earth and Venus are obvious to us. One is radiant with life and adorned with glittering seas, and the other is a scorching, glowering hellhole, its volcanic surface shrouded by thick clouds and visible only with radar. But the difference wasn’t always clear. In fact, we used to call Venus Earth’s sister planet.

Can astronomers tell exo-Earths and exo-Venuses apart from a great distance?