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?

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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.

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Formation-Flying Spacecraft Could Probe the Solar System for New Physics

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

It’s an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge observatories, instruments, and new techniques, scientists are getting closer to experimentally verifying theories that remain largely untested. These theories address some of the most pressing questions scientists have about the Universe and the physical laws governing it – like the nature of gravity, Dark Matter, and Dark Energy. For decades, scientists have postulated that either there is additional physics at work or that our predominant cosmological model needs to be revised.

While the investigation into the existence and nature of Dark Matter and Dark Energy is ongoing, there are also attempts to resolve these mysteries with the possible existence of new physics. In a recent paper, a team of NASA researchers proposed how spacecraft could search for evidence of additional physical within our Solar Systems. This search, they argue, would be assisted by the spacecraft flying in a tetrahedral formation and using interferometers. Such a mission could help resolve a cosmological mystery that has eluded scientists for over half a century.

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Here's the Total Solar Eclipse, Seen From Space

Credit: NASA/Keegan Barber

On Monday, April 8th, people across North America witnessed a rare celestial event known as a total solar eclipse. This phenomenon occurs when the Moon passes between the Sun and Earth and blocks the face of the Sun for a short period. The eclipse plunged the sky into darkness for people living in the Canadian Maritimes, the American Eastern Seaboard, parts of the Midwest, and northern Mexico. Fortunately for all, geostationary satellites orbiting Earth captured images of the Moon’s shadow as it moved across North America.

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Gravity From Mars has an Effect on Earth’s Oceans

Earth and Mars

We are all too familiar of the Moon’s effect on our planet. It’s relentless tug causes our tides but even Mars, which is always at least 55 million kilometres away, can have a subtle effect too. A study has revealed a 2.4 million year cycle in the geological records that show the gentle warming and cooling of our oceans. The records match the interactions between the orbits of Earth and Mars over the longest timescales. These are known as the ‘astronomical grand cycles’ but to date, not much evidence has been found. 

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Satellite Measurements Show That Global Carbon Emissions are Still Rising

Tracking carbon emissions and sinks to determine Earth's annual Global Carbon Budget. Credit: NASA GEOS

According to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), human activities have significantly impacted the planet. As global greenhouse gas emissions (mainly carbon dioxide) have continued to increase, so too have global temperatures – with severe ecological consequences. Between 2011 and 2020, global surface temperatures rose by an estimated 1.07 °C (2.01 °F) above the average in 1850–1900. At this rate, temperatures could further increase by 1.5 to 2 °C (2.7 to 3.6 °F) in the coming decades, depending on whether we can achieve net zero by 2050.

Unfortunately, the data for the past year is not encouraging. According to the 2023 Global Carbon Budget (GCB), an annual assessment of Earth’s carbon cycle, emissions in 2023 continued to rise by 1.1 percent compared to the previous year. This placed the total fossil fuel emissions from anthropogenic sources at 36.8 billion metric tons (over 40 US tons) of carbon dioxide, with an additional 4.1 billion metric tons (4.5 US tons) added by deforestation, extreme wildfires, and other sources. This trend indicates we are moving away from our goals and that things will get worse before they get better!

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Can the Gaia Hypothesis Be Tested in the Lab?

A new paper proposes an experimental setup that could test the classic Daisyworld model — a hypothesis of a self-regulating planetary ecosystem — in the lab via two synthetic bacterial strains. Credit: Victor Maull/Image Designer

During the 1970s, inventor/environmentalist James Lovelock and evolutionary biologist Lynn Margulis proposed the Gaia Hypothesis. This theory posits that Earth is a single, self-regulating system where the atmosphere, hydrosphere, all life, and their inorganic surroundings work together to maintain the conditions for life on the planet. This theory was largely inspired by Lovelock’s work with NASA during the 1960s, where the skilled inventor designed instruments for modeling the climate of Mars and other planets in the Solar System.

According to this theory, planets like Earth would slowly grow warmer and their oceans more acidic without a biosphere that regulates temperature and ensures climate stability. While the theory was readily accepted among environmentalists and climatologists, many in the scientific community have remained skeptical since it was proposed. Until now, it has been impossible to test this theory because it involves forces that work on a planetary scale. But in a recent paper, a team of Spanish scientists proposed an experimental system incorporating synthetic biology that could test the theory on a small scale.

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NASA Launches a New Mission to Study the Effects of Climate Change

NASA's PACE mission launches from Cape Canaveral on Feb. 9th, 2024. Credit: NASA

NASA’s Plankton, Aerosol, Climate, ocean Ecosystem (PACE) satellite successfully launched and reached on Thursday, February 10th. The mission took off from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida, at 1:33 am EST 10:33 pm (PST) atop a SpaceX Falcon 9 rocket. About five minutes after launch, NASA confirmed that ground stations on Earth had acquired a signal from the satellite and were receiving data on its operational status and capabilities post-launch. For the next three years, the mission will monitor Earth’s ocean and atmosphere and study the effects of climate change.

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Since Interstellar Objects Crashed Into Earth in the Past, Could They Have Brought Life?

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

On October 19th, 2017, astronomers with the Pan-STARRS survey detected an interstellar object (ISO) passing through our Solar System for the first time. The object, known as 1I/2017 U1 Oumuamua, stimulated significant scientific debate and is still controversial today. One thing that all could agree on was that the detection of this object indicated that ISOs regularly enter our Solar System. What’s more, subsequent research has revealed that, on occasion, some of these objects come to Earth as meteorites and impact the surface.

This raises a very important question: if ISOs have been coming to Earth for billions of years, could it be that they brought the ingredients for life with them? In a recent paper, a team of researchers considered the implications of ISOs being responsible for panspermia – the theory that the seeds of life exist throughout the Universe and are distributed by asteroids, comets, and other celestial objects. According to their results, ISOs can potentially seed hundreds of thousands (or possibly billions) of Earth-like planets throughout the Milky Way.

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We Just had the Strongest Solar Flare in the Current Solar Cycle

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO
A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

On December 14th, at 12:02 PM Eastern (09:02 AM Pacific), the Sun unleashed a massive solar flare. According to the Space Weather Prediction Center, part of the National Oceanic Atmospheric Administration (NOAA), this was the strongest flare of Solar Cycle 25, which began in 2019 and will continue until 2030. What’s more, scientists at the SWPC estimate that this may be one of the most powerful solar flares recorded since 1755 when extensive recording of solar sunspot activity began.

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