Our galaxy may be full of planets identical to Earth at formation that turned into uninhabitable hellscapes — and the one sitting next door to us has been so thoroughly ignored that a leading researcher called it criminally underexplored while we spent decades looking at Mars

Preliminary results from a study presented at the European Geosciences Union General Assembly in Vienna earlier this month suggest that Venus-like planets, with dense carbon dioxide atmospheres and surface conditions lethal to any life we know, may be roughly twice as common in the galaxy as planets that form with liquid water oceans.

The finding is preliminary, the work not yet peer-reviewed, and the researchers are careful about what can and cannot be concluded. But the framing it invites is worth sitting with: the galaxy may be considerably better at making hellscapes than Earths, and the best reference point we have for understanding that pattern sits 41 million kilometres away and has been largely ignored.

What the research actually says

The conference abstract, titled “The Diversity of Venus-like Atmospheres on Exoplanets” and presented by Sean Jordan, a postdoctoral fellow in exoplanet studies at ETH Zurich, was co-authored by Gian Rungger, Daniel Bower, and Paolo Sossi, also at ETH Zurich. The abstract was submitted to the EGU General Assembly 2026, session PS1.2, and is available via the conference proceedings. 

The argument runs as follows:

Geochemical models of atmospheric formation predict that Venus-like atmospheres, dominated by CO₂ and thicker than a few bars of pressure, are among the most common types of atmosphere that can develop on rocky exoplanets during and after the magma ocean phase of their early evolution.

In plain terms: as a rocky planet cools from its molten early state, the chemistry appears to favour building a thick CO₂ atmosphere, not an oxygen-nitrogen one with liquid oceans. The Earth, on this view, is the harder outcome to produce.

Jordan told Universe Today at the EGU conference that forming a CO₂-dominated atmosphere from a magma ocean phase is, in his words, quite plausible, and that such atmospheres should therefore be quite common. The easier construction, he added, is a model that ends up with Venus as it is. Building a model where a planet condenses oceans and then avoids a runaway greenhouse effect is considerably harder.

That is a significant claim, and it should be read with the appropriate weight: this is preliminary work presented at a conference, based on modelling, not on confirmed observations of exoplanet atmospheres. The researchers themselves acknowledge that there is going to be lots of variability between extrasolar Venus-type planets, and that factors including the type of host star and the surrounding interstellar environment will all shape outcomes. The broad picture, that Venus-like atmospheres may be more common than Earth-like ones, is what the modelling supports. The specifics will take considerably longer to establish observationally.

The detection problem

There is a structural reason the question is hard to answer. Exoplanet hunters have found a growing number of rocky bodies in short-period orbits around red dwarf stars. What we do not yet know, in most cases, is whether those planets have atmospheres at all, and if so, whether those atmospheres are stable. High-energy radiation and particle flux from the host star continually strips away atmospheric mass, and whether a given planet can hold onto its atmosphere over long periods is not yet established for most candidates.

Jordan’s framing of the open question is useful here. The relevant issue is not simply whether a planet forms in the right orbital zone, but whether it can hold onto an atmosphere in the face of its parent star’s radiation. That is why, as Jordan noted in his EGU presentation, which Universe Today also reported on, no Venus-like atmosphere on an exoplanet has yet been confirmed. 

The detection problem is compounded by where these planets tend to be found. Astronomical biases towards short-period orbits mean that rocky exoplanets are commonly found inside what the abstract calls the Venus Zone, bounded at its inner edge by the so-called cosmic shoreline and at its outer edge by the CO₂-condensation line. Whether those planets are genuinely Venus-like in their atmospheric composition is another question entirely, one that current telescope capabilities can only partially address.

The problem with Venus itself

This is where the study’s second argument connects to its first. If Venus-type atmospheres are common, and if confirming them on exoplanets depends on understanding the photochemical and geochemical processes that produce them, then Venus is the obvious reference point. We can study it directly. We can send a spacecraft there. We have not done so in any sustained way.

Jordan told Universe Today at the conference that Venus has been criminally underexplored. That phrase is worth taking seriously, not as polemic but as a genuine description of the data situation. The Soviet Venera programme put landers on the surface in the 1970s and 1980s; the most recent images of the Venusian surface date from that era. ESA’s Venus Express orbited from 2006 to 2014. JAXA’s Akatsuki has been in orbit since 2015 and continues to return data. But a dedicated atmospheric probe or lander with modern instrumentation has not reached Venus since the Soviet programme ended.

Jordan noted that Venus science does have one advantage despite the data deficit. We still have a level of detail about the composition and chemistry of the deep atmosphere down to trace abundance gases, he said. That is a legacy of the Venera missions, which returned ground-level atmospheric data no subsequent mission has replicated. It is also the outer limit of what is currently available.

The irony is hard to miss. Venus is our nearest planetary neighbour. At its closest approach it is roughly a million times closer than the nearest confirmed exoplanet. And yet in the conversation about which rocky planets elsewhere in the galaxy might look like which solar system bodies, Venus is the template for what may be the galaxy’s most common planetary type, and it is the least studied of the inner planets by a considerable margin.

What this suggests for the next decade

Jordan’s read on the timeline is not optimistic about speed. Truly answering the question of how common exo-Venuses are will, in his estimation, take a couple of decades, contingent on at least some of the proposed missions to Venus proceeding and on future space telescope capability. The observational confirmation of a Venus-like atmosphere on an exoplanet is not, on the available evidence, imminent.

The proposed NASA missions DAVINCI and VERITAS, both selected in 2021 and representing the entirety of NASA’s Venus portfolio, were proposed for termination in the White House’s FY 2027 budget request, as we reported earlier this month. ESA’s EnVision mission, in which NASA has a contribution, was also on the cancellation list. Whether those missions survive the appropriations process remains to be seen, but the timing places Jordan’s argument in an uncomfortable context: the research community is building a case that Venus is among the most scientifically pressing targets in the solar system precisely as the political process in the United States is moving toward eliminating the missions that would address it.

Jordan’s framing of whether Venus ever went wrong is also worth noting. It is not necessarily true, he said, that Venus went wrong at all. It may simply have been born as it is, its dense CO₂ atmosphere an entirely ordinary outcome of its formation chemistry rather than a cautionary tale about what happens to a potentially habitable world.

That distinction matters for how we think about rocky planets elsewhere. The Earth may not be the default. It may be the exception.