Astrobiology Archives

May 18, 2024May 18, 2024 by Laurence Tognetti

Did Earth’s Multicellular Life Depend on Plate Tectonics?

Graphic depicting the last 1.6 billion years of Earth’s tectonic history. (Credit: Figure 2 from Stern & Gerya (2024))

How did complex life emerge and evolve on the Earth and what does this mean for finding life beyond Earth? This is what a recent study published in Nature hopes to address as a pair of researchers investigated how plate tectonics, oceans, and continents are responsible for the emergence and evolution of complex life across our planet and how this could address the Fermi Paradox while attempting to improve the Drake Equation regarding why we haven’t found life in the universe and the parameters for finding life, respectively. This study holds the potential to help researchers better understand the criterion for finding life beyond Earth, specifically pertaining to the geological processes exhibited on Earth.

May 9, 2024May 9, 2024 by Matt Williams

We Need to Consider Conservation Efforts on Mars

Curiosity at work firing a laser on Mars. This artist's concept depicts the rover Curiosity, of NASA's Mars Science Laboratory mission, as it uses its Chemistry and Camera (ChemCam) instrument to investigate the composition of a rock surface. ChemCam fires laser pulses at a target and views the resulting spark with a telescope and spectrometers to identify chemical elements. The laser is actually in an invisible infrared wavelength, but is shown here as visible red light for purposes of illustration. Credit: NASA

Astrobiology is the field of science that studies the origins, evolution, distribution, and future of life in the Universe. In practice, this means sending robotic missions beyond Earth to analyze the atmospheres, surfaces, and chemistry of extraterrestrial worlds. At present, all of our astrobiology missions are focused on Mars, as it is considered the most Earth-like environment beyond our planet. While several missions will be destined for the outer Solar System to investigate “Ocean Worlds” for evidence of life (Europa, Ganymede, Titan, and Enceladus), our efforts to find life beyond Earth will remain predominantly on Mars.

If and when these efforts succeed, it will have drastic implications for future missions to Mars. Not only will great care need to be taken to protect Martian life from contamination by Earth organisms, but precautions must be taken to prevent the same from happening to Earth (aka. Planetary Protection). In a recent study, a team from the University of New South Wales (UNSW) in Sydney, Australia, recommends that legal or normative frameworks be adopted now to ensure that future missions do not threaten sites where evidence of life (past or present) might be found.

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?

April 23, 2024April 23, 2024 by Nancy Atkinson

Purple Bacteria — Not Green Plants — Might Be the Strongest Indication of Life

Artist's impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity. Credit: Oleg Kuznetsov — Artist's impression of Earth in the early Archean with a purplish hydrosphere and coastal regions. Even in this early period, life flourished and was gaining complexity, and distant exoplanets might begin similarly. Credit: Oleg Kuznetsov

Astrobiologists continue to work towards determining which biosignatures might be best to look for when searching for life on other worlds. The most common idea has been to search for evidence of plants that use the green pigment chlorophyll, like we have on Earth. However, a new paper suggests that bacteria with purple pigments could flourish under a broader range of environments than their green cousins. That means current and next-generation telescopes should be looking for the emissions of purple lifeforms.

“Purple bacteria can thrive under a wide range of conditions, making it one of the primary contenders for life that could dominate a variety of worlds,” said Lígia Fonseca Coelho, a postdoctoral associate at the Carl Sagan Institute (CSI) and first author of “Purple is the New Green: Biopigments and Spectra of Earth-like Purple Worlds,” published in the Monthly Notices of the Royal Astronomical Society: Letters.

April 22, 2024April 22, 2024 by Matt Williams

Will We Know if TRAPPIST-1e has Life?

Artist's impression of the Archean Eon. Credit: Tim Bertelink/Wikimedia

The search for extrasolar planets is currently undergoing a seismic shift. With the deployment of the Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS), scientists discovered thousands of exoplanets, most of which were detected and confirmed using indirect methods. But in more recent years, and with the launch of the James Webb Space Telescope (JWST), the field has been transitioning toward one of characterization. In this process, scientists rely on emission spectra from exoplanet atmospheres to search for the chemical signatures we associate with life (biosignatures).

However, there’s some controversy regarding the kinds of signatures scientists should look for. Essentially, astrobiology uses life on Earth as a template when searching for indications of extraterrestrial life, much like how exoplanet hunters use Earth as a standard for measuring “habitability.” But as many scientists have pointed out, life on Earth and its natural environment have evolved considerably over time. In a recent paper, an international team demonstrated how astrobiologists could look for life on TRAPPIST-1e based on what existed on Earth billions of years ago.

April 17, 2024April 17, 2024 by Laurence Tognetti

Organic Chemistry: Why study it? What can it teach us about finding life beyond Earth?

In 2018, NASA's Curiosity rover discovered ancient organic materials on Mars. (Credit: NASA/GSFC)

Universe Today has recently had the privilege of investigating a myriad of scientific disciplines, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, and extremophiles, and how these multidisciplinary fields can help both scientists and space fans better understand how they relate to potentially finding life beyond Earth, along with other exciting facets. Here, we will examine the incredible field of organic chemistry with Dr. Andro Rios, who is an Assistant Professor in Organic Chemistry at San José State University, regarding why scientists study organic chemistry, the benefits and challenges, finding life beyond Earth, and potential paths for upcoming students. So, why is it so important to study organic chemistry?

March 31, 2024March 31, 2024 by Laurence Tognetti

Extremophiles: Why study them? What can they teach us about finding life beyond Earth?

Image of a tardigrade, which is a microscopic species and one of the most well-known extremophiles, having been observed to survive some of the most extreme environments, including outer space. (Credit: Katexic Publications, unaltered, CC2.0)

Universe Today has conducted some incredible examinations regarding a plethora of scientific fields, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, and radio astronomy, and how these disciplines can help scientists and the public gain greater insight into searching for life beyond Earth. Here, we will discuss the immersive field of extremophiles with Dr. Ivan Paulino-Lima, who is a Senior Research Investigator at Blue Marble Space Institute of Science and the Co-Founder and Chief Science Officer for Infinite Elements Inc., including why scientists study extremophiles, the benefits and challenges, finding life beyond Earth, and proposed routes for upcoming students. So, why is it so important to study extremophiles?

March 29, 2024March 30, 2024 by Laurence Tognetti

Search for Life on Mars Could Level-Up with MARSE Mission Concept

A breakdown of the Mars Astrobiology, Resource, and Science Explorers (MARSE) mission profile and its Simplified High Impact Energy Landing Device (SHIELD) system, which could revolutionize how we search for life on Mars by using four rovers at four different landing sites. (Credit: Longo (2024))

A recent study presented at the 55^th Lunar and Planetary Science Conference (LPSC) discusses the Mars Astrobiology, Resource, and Science Explorers (MARSE) mission concept and its Simplified High Impact Energy Landing Device (SHIELD), which offers a broader and cheaper method regarding the search for—past or present—life on the Red Planet, specifically by using four rovers at four different landing sites across Mars’ surface instead of just one-for-one. This concept comes as NASA’s Curiosity and Perseverance rovers continue to tirelessly explore the surface of Mars at Gale Crater and Jezero Crater, respectively.

March 21, 2024March 21, 2024 by Laurence Tognetti

Europa Might Not Be Able to Support Life in its Oceans

Natural color image of Europa obtained by NASA's Juno spacecraft. (Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)

Can Europa’s massive, interior ocean contain the building blocks of life, and even support life as we know it? This question is at the forefront of astrobiology discussions as scientists continue to debate the possibility for habitability on Jupiter’s icy moon. However, a recent study presented at the 55^th Lunar and Planetary Science Conference (LPSC) might put a damper in hopes for finding life as a team of researchers investigate how Europa’s seafloor could be lacking in geologic activity, decreasing the likelihood of necessary minerals and nutrients from being recycled that could serve as a catalyst for life.

March 19, 2024March 19, 2024 by Evan Gough

Earth’s Long-Term Habitability Relies on Chemical Cycles. How Can We Better Understand Them?

Biogeochemical cycles move matter around Earth between the atmosphere, the oceans, the lithosphere, and living things. Image Credit: By Alexander Davronov - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=106124364

We, and all other complex life, require stability to evolve. Planetary conditions needed to be benign and long-lived for creatures like us and our multicellular brethren to appear and to persist. On Earth, chemical cycling provides much of the needed stability.

Chemical cycling between the land, atmosphere, lifeforms, and oceans is enormously complex and difficult to study. Typically, researchers try to isolate one cycle and study it. However, new research is examining Earth’s chemical cycling more holistically to try to understand how the planet has stayed in the ‘sweet spot’ for so long.