Forget rats and cockroaches: Scientists reveal the species most likely to survive Earth’s last catastrophe

Forget that cockroaches took over the Earth after a nuclear war. When scientists at Oxford and Harvard Universities set out to determine which creatures would be the last survivors after an apocalyptic catastrophe, they focused on microscopic eight-legged animals that avoid urban pests altogether and reach just half a millimeter in length. of TardigradeThis animal, also known as the Kumam, has emerged as the definitive standard for animal survival against the most violent forces unleashed by the universe.

A research team led by Dr. David Sloan and Dr. Rafael Alves-Batista from the University of Oxford published their analysis in the journal. scientific report. Their research calculated the precise astrophysical threshold needed to wipe out all tardigrades on Earth, as well as human civilization and surface ecosystems. The conclusion was clear: the event that can achieve complete fulfillment is Sterilization It remains so rare that the chance of it existing on Earth is less than 1 in 10 million every billion years.

Why ocean boiling has become the only indicator that matters

The study’s methodology abandoned the traditional focus on extinction events on land. An asteroid strike that darkens the sky and disrupts the food chain would certainly end human life, but it would not affect tardigrade populations that live in deep-sea sediments. The researchers argued that to truly sterilize the most resilient animals from Earth-like planets, we need to eliminate their last refuge: the global ocean.

Tardigrades have near-legendary invasive abilities Cryptobiosisa dormant state in which metabolism slows to near zero. In this state, the organism can withstand temperatures as high as 150 degrees Celsius for several minutes, and frozen conditions as low as -20 degrees Celsius for decades. Humans remain unharmed even at radiation doses exceeding 5,000 Gy, which would instantly kill humans.

The ocean’s vast volume provides both thermal buffering and radiation shielding. That is, the energy required to kill a tardigrade at depth exceeds the energy required to boil the water above it. According to the original study published in Scientific Reports, the sterile bar amounted to the total heat energy needed to bring all of Earth’s oceans to boiling point.

Asteroid threat requires magnitude that exceeds any reasonable risk

Applying this ocean boiling threshold, we get asteroid impact A number has been created that trivializes the object that caused the demise of the dinosaurs. The researchers calculated that an asteroid would need a mass of about 1.7 quintillion kilograms to provide the thermal energy needed to boil the oceans. This represents a very different type of object than the typical near-Earth threats tracked by planetary defense systems.

To put this number in perspective, the study noted that only about a dozen known objects in the entire solar system have enough mass to theoretically meet this requirement. These include the asteroid Vesta and dwarf planet Pluto and Eris. As the Daily Galaxy reported in its summary of the 2026 findings, the study adds details that greatly constrain this scenario. In other words, none of these giant objects are in orbits that intersect Earth’s.

Based on extrapolated impact models, the incidence of immortal asteroid impacts remains less than once every billion years. A smaller, but still devastating, impact would leave deep-sea refugia intact and surface life reset.

Supernovae and gamma-ray bursts face distance problems

The same energy calculations apply to exploding stars. The University of Oxford team supernova For the ocean to boil, it would have to occur within about 0.13 light-years of Earth. This distance is astronomically small. Proxima Centauri, the closest star system to Earth, is located about 4 light years away. There are no stars in the Alpha Centauri system massive enough to cause a supernova, and the closest potential candidate, the IK Pegasi system, is 45 parsecs away, far outside the danger zone.

The researchers modeled the probability of a sterile supernova explosion across different regions of the Milky Way. Even near dense areas center of the galaxyIn areas where stellar traffic is most active, the chance that a planet will experience an ocean boiling explosion within 1 billion years is about 1%. for gamma ray burstconcentrating the energy into a narrow jet reduces that probability to about 3 in 10 billion per billion years.

Alves-Batista summarized the broader implications of this study: “Humans are a very sensitive species unless technology protects us. Subtle changes in our environment can have dramatic effects on us. There are many more resilient species on Earth. Life on this planet could continue long after humans are gone.”

A detailed explanation of what survival actually means

The Scientific Reports paper includes important caveats that should limit your conclusions. The analysis only considered direct effects, such as immediate boiling of seawater due to stored energy. This does not fully model secondary climate feedback loops. Runaway greenhouse effecta low initial energy input can cause the ocean to evaporate. More importantly, the study’s definition of life is intentionally narrow. It uses tardigrades as surrogates for complex animal life rather than life itself.

As pointed out in public comments on this paper, prokaryotes Bacteria, archaea, etc. are far more resilient than tardigrades. Chemolithotrophic microorganisms that live several kilometers deep in the Earth’s crust are likely to survive events that would kill all animals on Earth.

Additionally, tardigrades need food. Complete collapse occurs even if individuals survive the initial catastrophe in a dormant state. Nutrition related And disruption of photosynthetic or chemosynthetic food webs can ultimately lead to extinction. The authors of this study acknowledged this by focusing on the physical energy of sterilization rather than ecological continuity.

of rogue planet This scenario represents another special case. If a passing star were to eject Earth from our solar system, life around deep-sea volcanic vents could theoretically persist for billions of years due to internal heat even after the surface has frozen solid. Researchers have calculated the rate of such stellar collapses to be around 3 in 1 billion every billion years in our star’s neighborhood, an event so rare that it can be ignored.