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.

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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?

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Watch What Happens to Astronauts When the International Space Station Gets an Orbital Reboost

Astronauts on the International Space Station experience an orbital reboost. Credit: NASA/ESA

This is reminiscent of going down slide on the playground – and then immediately getting back in line to go down again. Except in space.

Here’s what it looks like on board the International Space Station when thrusters fire for an orbital reboost. While it seems like the astronauts are moving inside the station, in in reality it is the Space Station that is moving around them. And in actuality, the acceleration doesn’t happen this fast – the video is sped up eight times. But it still looks like fun!

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How did Earth go From Molten Hellscape to Habitable Planet?

An artist's impression of the Hadean eon. Image Credit: By Tim Bertelink - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48916334

Earth formed from the Sun’s protoplanetary disk about 4.6 billion years ago. In the beginning, it was a molten spheroid with scorching temperatures. Over time, it cooled, and a solid crust formed. Eventually, the atmosphere cooled, and life became a possibility.

But how did all of that happen? The atmosphere was rich in carbon, and that carbon had to be removed before the temperature could drop and Earth could become habitable.

Where did all the carbon go?

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With no Solid Surface, the Atmosphere of Jupiter Behaves Quite Differently Than Earth

Jupiter’s atmosphere has plenty of distinct features, including lightning and the Great Red Spot.  But the underlying processes that drive these features are less well understood, as the physics of the gases that make up Jupiter’s atmosphere is complicated.  A team of scientists from all over the globe has found a familiar process in all the chaos, though.  They think a process that happens here on Earth might be happening on a grander scale at Jupiter.

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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.

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Astronomers Have Found the Perfect Exoplanet to Study Another World’s Atmosphere

An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth. Credit: NASA/JPL-Caltech

TESS (Transiting Exoplanet Survey Satellite) has found a new planet, and the discovery of this sub-Neptune exoplanet has scientists excited about atmospheres. The combination of the planet’s size, its thick atmosphere, and its orbit around a small M-class star close to Earth provides researchers with an opportunity to learn more about exoplanet atmospheres. We’re getting better and better at finding exoplanets, and studying their atmospheres is the next step in understanding them as a whole.

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Earth’s Atmosphere Can Generate a “Space Hurricane”

Illustration of a space hurricane, created using the observational data. Credit: Qing-He Zhang / Shandong University

There are hurricanes in space.

Researchers looking through archival data found evidence of a previously unobserved phenomenon — a giant swirling mass of plasma above Earth’s northern polar region. The “space hurricane,” as the science team calls it, churned for hours, raining down electrons instead of water.

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We Could Find Extraterrestrial Civilizations by Their Air Pollution

Exoplanet Kepler 62f would need an atmosphere rich in carbon dioxide for water to be in liquid form. Artist's Illustration: NASA Ames/JPL-Caltech/T. Pyle

Upcoming telescopes will give us more power to search for biosignatures on all the exoplanets we’ve found. Much of the biosignature conversation is centred on biogenic chemistry, such as atmospheric gases produced by simple, single-celled creatures. But what if we want to search for technological civilizations that might be out there? Could we find them by searching for their air pollution?

If a distant civilization was giving our planet a cursory glance in its own survey of alien worlds and technosignatures, they couldn’t help but notice our air pollution.

Could we turn the tables on them?

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Astronomers Challenge Recent Findings About Venus. “No Statistically Significant Detection of Phosphine”

This artistic impression depicts Venus. Astronomers at MIT, Cardiff University, and elsewhere may have observed signs of life in the atmosphere of Venus. Credits:Image: ESO (European Space Organization)/M. Kornmesser & NASA/JPL/Caltech

In September, a team of scientists reported finding phosphine in the upper atmosphere of Venus. Phosphine can be a biomarker and is here on Earth. But it’s also present on Jupiter, where it’s produced abiotically. The discovery led to conjecture about what kind of life might survive in Venus’ atmosphere, continually producing the easily-degraded phosphine.

The authors of that study were circumspect about their own results, saying that they hope someone can determine a source for the phosphine, other than life.

Now a new study says that the original phosphine detection is not statistically significant.

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