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Astronomers Find Planet in Unusual Polar Orbit Around Twin Suns

Astronomers have discovered an exoplanet, 2M1510 (AB) b, orbiting at a 90° angle around a pair of brown dwarfs—an arrangement never before confirmed in any binary system, opening new questions about how planets form and survive in extreme gravitational environments.

Summary

Astronomers using the European Southern Observatory’s Very Large Telescope detected unexpected wobbling in the brown dwarf pair 2M1510, indicating a third body in the system.
The newly confirmed planet, 2M1510 (AB) b, travels on a polar orbit, meaning its orbital plane is perpendicular to that of its two host brown dwarfs.
The host objects are brown dwarfs—“failed stars” roughly 35 times the mass of Jupiter—that eclipse one another as viewed from Earth, making this only the second known eclipsing brown dwarf binary.
2M1510 (AB) b lies about 120 light-years from Earth, and is likely a gas giant several times Earth’s mass, though exact mass remains uncertain.
This is the first confirmed instance of a circumbinary polar planet, expanding the diversity of known planetary architectures and challenging models of planet formation.
The discovery was serendipitous: observations aimed at characterizing the brown dwarfs revealed orbital perturbations best explained by a third body on a polar trajectory.
The finding appears in Science Advances, led by Thomas Baycroft and Amaury Triaud at the University of Birmingham.
Simulations suggest such polar orbits can remain stable for billions of years, despite the complex gravitational pulls from two central objects.
The discovery hints that other polar circumbinary planets may lurk undetected in existing data sets.
Future observations, including with the James Webb Space Telescope, could probe the planet’s atmosphere and refine its mass and composition.

Astronomers Find Planet in Unusual Polar Orbit Around Twin Suns — Astronomers saw a planet going around two unusual stars. The planet’s path is sideways, not aligned with the stars, at a right angle.

Introduction

Planetary systems around two suns capture the imagination, from science fiction’s Tatooine to real circumbinary worlds discovered by Kepler. Yet all previously confirmed circumbinary planets have orbits roughly aligned with their stars’ orbital plane. The recent detection of 2M1510 (AB) b on a perpendicular path shatters that pattern and reveals new complexity in how planets can orbit multiple hosts.

The Host Brown Dwarfs

Brown dwarfs bridge the gap between stars and giant planets. They pack up to a few tens of Jupiter masses but lack the heft to sustain hydrogen fusion in their cores. The 2M1510 system consists of two such objects, each about thirty-five times Jupiter’s mass, that eclipse each other every few days. From Earth, their mutual eclipses make them stand out as an “eclipsing binary,” an uncommon configuration among brown dwarfs.

Property	2M1510 A	2M1510 B
Mass (Jupiter masses)	~35	~35
Type	Brown dwarf	Brown dwarf
Orbital period	~— days	~— days
Discovery method	SPECULOOS survey	SPECULOOS survey

The Unusual Planet

The planet 2M1510 (AB) b was not found by the usual transit dips but by tiny, rhythmic wobbles in the brown dwarfs’ motion. These perturbations could only be explained by a third body tugging at the binary, and the best fit places that body in a polar, or perpendicular, orbit relative to the brown dwarfs’ plane. This marks the first time a circumbinary planet has been seen on such an orbit.

Characteristic	Value
Orbit inclination	~90° (polar)
Estimated mass	4–5 Earth masses (min.)
Distance from Earth	~120 light-years
Host type	Eclipsing brown dwarf pair
Discovery instrument	ESO VLT

How It Was Discovered

Astronomers led by Thomas Baycroft at the University of Birmingham were analyzing high-precision data from ESO’s Very Large Telescope in Chile when they noticed odd shifts in the timing of the brown dwarfs’ eclipses. After ruling out stellar activity or additional faint stars, the team found that only a planet on a polar orbit could reproduce the observed signals. As Baycroft noted, “I am particularly excited to be involved in detecting credible evidence that this configuration exists”.

Why Polar Orbits Matter

Planets form in discs of gas and dust that usually align with their star’s equator. A polar circumbinary planet suggests dramatic early dynamics—perhaps interactions with other planets or disc warping by the binary—that flipped the orbit by 90°. Such extreme tilts can test and refine models of planet formation under complex gravity.

Implications for Planet Formation Theories

Traditional models struggle to explain how a planet remains stable on a perpendicular path around two massive objects. Computer simulations now must account for strong, time-varying gravitational forces that can pump up orbital eccentricities or eject bodies entirely. The longevity of 2M1510 (AB) b’s orbit implies that polar circumbinary niches can be safe harbors for planets over billions of years.

Future Observations

Follow-up studies will aim to measure the planet’s mass more precisely and search for an atmosphere. Instruments like the James Webb Space Telescope could detect atmospheric signatures, while long-term monitoring will reveal whether the orbit drifts or remains locked in its polar orientation. Surveys may also re-examine other eclipsing binaries for similar wobbles, potentially uncovering more polar worlds.

Facts

Humans once imagined Tatooine worlds in fiction. Now we know nature can produce even stranger setups than movies.
Brown dwarfs glow faintly in infrared, so the sky from 2M1510 (AB) b would show two dim red suns instead of bright yellow ones.
Polar orbits around a binary mean seasons could be extreme: months of darkness followed by months of light as the planet passes above and below the binary plane.

Conclusion

The discovery of 2M1510 (AB) b on a perpendicular orbit shatters our expectations of planetary layouts. It highlights the surprising outcomes possible when planets form in turbulent, multi-body systems. As telescopes grow more powerful, we may find that polar circumbinary planets are not one-off oddities but a hidden population awaiting detection.

References

“Big surprise”: astronomers find planet in perpendicular orbit around pair of stars. ESO. April 16, 2025. ESO — The European Southern Observatory
Luke Skywalker’s planet orbited two stars… brown dwarfs instead? Reuters. April 18, 2025. Reuters
Evidence for a polar circumbinary exoplanet orbiting a pair … Science Advances. Last week. Science
Astronomers detect exoplanet on rare perpendicular path around … SpaceDaily. April 22, 2025. SpaceDaily
Polar planet 2M1510 (AB) b around binary brown dwarfs. Sky at Night Magazine. April 20, 2025. Sky at Night Magazine
A tilted “Tatooine planet” whose two suns aren’t stars at all. Science. Last week. Science
Rare exoplanet orbits twin stars in ‘Star Wars’-like twist. Phys.org. Last week. Phys.org
New Planet In Strange Perpendicular Orbit Around Binary Stars Is … IFLScience. IFLScience
Planet Found Orbiting Two Stars at a Perfect 90-Degree Angle. SciTechDaily. SciTech Daily
Descubren un “planeta Tatooine” en órbita perpendicular… Cadena SER. cadenaser.com

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The Science Behind Liquid Water on Mars: Missions to Mars.

Key Takeaway

Understanding the presence and accessibility of liquid water on Mars is crucial for the success of future crewed missions. Despite some recent findings, the existence of liquid water on Mars remains a subject of debate.

Summary

NASA and China are planning crewed missions to Mars in the coming decades.
In-situ resource utilization (ISRU) is essential for sustaining astronauts on Mars.
Historical missions have revealed surface features suggesting past water flow on Mars.
ESA’s Mars Express detected bright radar reflections beneath the southern polar ice cap.
The MARSIS instrument found bright patches that could indicate liquid water.
Recent research suggests these reflections might be due to ice composition and layer thickness.
Liquid water on Mars would need to be very briny or heated by magma.
Future missions might need to rely on ice deposits or chemical reactions for water.
Findings about Mars’s geological activity suggest it may still be geologically active.
The possibility of microbial life existing on Mars remains a tantalizing prospect.

The Science Behind Liquid Water on Mars: Missions to Mars

In the coming decades, NASA and China intend to send the first crewed missions to Mars. Given the distance involved and the time it takes to make a single transit (six to nine months), opportunities for resupply missions will be few and far between. As a result, astronauts and taikonauts will be forced to rely on local resources to meet their basic needs – a process known as in-situ resource utilization (ISRU). For this reason, NASA and other space agencies have spent decades scouting for accessible sources of liquid water.

Finding this water is essential for future missions and scientific efforts to learn more about Mars’s past, when the planet was covered by oceans, rivers, and lakes that may have supported life. In 2018, using ground-penetrating radar, the ESA’s Mars Express orbiter detected bright radar reflections beneath the southern polar ice cap that were interpreted as a lake. However, a team of Cornell researchers recently conducted a series of simulations that suggest there may be another reason for these bright patches that do not include the presence of water.

Historical Evidence of Water on Mars

When the first robotic probes began making flybys of Mars in the 1960s, the images they acquired revealed surface features common on Earth. These included flow channels, river valleys, lakebeds, and sedimentary rock, all of which form in the presence of flowing water. For decades, orbiters, landers, and rovers have explored Mars’ surface, atmosphere, and climate to learn more about how and when much of this surface water was lost. In recent years, this has led to compelling evidence that what remains could be found beneath the polar ice caps today.

The most compelling evidence was obtained by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument aboard the Mars Express orbiter. This instrument was designed by NASA and the Italian Space Agency (ASI) to search for water on the Martian surface and down to depths of about 5 km (3 mi). The radar returns indicated that the bright patches could be caused by layered deposits composed of water, dry ice, and dust. These South Polar Layered Deposits (SPLD) are thought to have formed over millions of years as Mars’ axial tilt changed.

Subsequent research by scientists at NASA’s Jet Propulsion Laboratory (JPL) revealed dozens of other highly reflective sites beneath the surface. The implications of these findings were tremendous, not just for crewed missions but also for astrobiology efforts. In addition to being a potential source of water for future missions, it was also theorized that microbial life that once existed on the surface might be found there today. However, the findings were subject to debate as other viable explanations were offered.

The Debate on Liquid Water

While the same bright radar reflections have detected subglacial lakes on Earth (such as Lake Vostok under the East Antarctic Ice Sheet), Mars’s temperature and pressure conditions are very different. To remain in a liquid state, the water would need to be very briny, loaded with exotic minerals, or above an active magma chamber – none of which have been detected. As Lalich said in a recent interview with the Cornell Chronicle:

Research and Simulations

In a previous study, Lalich and his colleagues used simpler models to demonstrate that these bright radar signals could result from tiny variations in the thickness of the layers. These variations would be indiscernible to ground-penetrating radar and could lead to constructive interference between radar waves, producing reflections that vary in intensity and variability – like those observed across the SPLD. For their latest study, the team simulated 10,000 layering scenarios with 1,000 variations in the ice thickness and dust content of the layered deposits.

Their simulations also excluded any of the unusual conditions or exotic materials that would be necessary for liquid water. These simulations produced bright subsurface signals consistent with observations made by the MARSIS instrument. According to Lalich, these findings strongly suggest that he and his colleagues were correct in suspecting radar interference. In essence, radar waves bouncing off of layers too close together for the instrument to resolve may have combined, amplifying their peaks and troughs and appearing much brighter.

Implications for Future Missions

The team is not prepared to rule out the possibility that future missions with more sophisticated instruments could find definitive evidence of water. However, Lalich suspects that the case for liquid water (and potential life) on Mars may have ended decades ago.

If so, future missions may be forced to melt polar ice deposits and permafrost to get drinking water or possibly chemical reactions involving hydrazine (a la Mark Watney). In addition, astrobiology efforts may once again be placed on the back burner as they were when the Viking Landers failed to find conclusive evidence of biosignatures in 1976. But as we’ve learned, Mars is full of surprises. While the results of the Viking biological experiments were disappointing, these same missions provided some of the most compelling evidence that water once flowed on Mars’ surface.

Mars’ Geological Activity

Moreover, scientists once suspected that the Red Planet was geologically dead, but data obtained by NASA’s InSight Lander showed that it is actually “slightly alive.” This included evidence that hot magma still flows deep in the planet’s interior and that a massive magma plume still exists beneath the Elysium Planitia region, which may have caused a small eruption just 53,000 years ago (the most recent in Martian history). Perhaps the same will hold true for briny patches of liquid water around the poles and the equatorial region.

Potential for Microbial Life

With any luck, some of these patches may even house countless microorganisms that could be related to life on Earth. The possibility of finding life on Mars, even if it is microbial, would have profound implications for our understanding of biology and the potential for life elsewhere in the universe. How cool would that be?

Tables and Data

Table 1: Key Mars Missions and Discoveries

Mission	Year Launched	Key Discovery
Mariner 4	1964	First images of Mars, surface features
Viking 1 & 2	1975	Search for biosignatures, evidence of water flow
Mars Global Surveyor	1996	Detailed maps of Mars surface, climate
Mars Odyssey	2001	Detection of water ice beneath the surface
Mars Express	2003	Evidence of water beneath polar ice caps
Curiosity Rover	2011	Study of Mars’ habitability, organic molecules
InSight Lander	2018	Mars’ seismic activity, interior structure

Table 2: Comparison of Earth and Mars Conditions

Condition	Earth	Mars
Atmospheric Pressure	101.3 kPa (at sea level)	~0.6 kPa
Surface Temperature	-88°C to 58°C	-125°C to 20°C
Presence of Water	Abundant in liquid form	Mostly in ice, traces of vapor
Geologic Activity	Active	Slightly active, recent magma

Conclusion

The quest to find liquid water on Mars is ongoing and fraught with challenges. While recent findings cast doubt on the presence of liquid water, the pursuit has led to a deeper understanding of the planet’s geology and climate. Future missions will continue to explore this enigmatic planet, with the hope of uncovering the secrets that lie beneath its surface. Whether or not we find liquid water, the journey itself will expand our knowledge and pave the way for human exploration.

References

Cornell Chronicle: Interview with Daniel Lalich
NASA’s Jet Propulsion Laboratory research
Science Advances journal article: “Small Variations in Ice Composition and Layer Thickness Explain Bright Reflections Below Martian Polar Cap without Liquid Water”

Hashtags

#Mars, #NASA, #MarsMissions, #LiquidWater, #SpaceExploration, #Astrobiology #Geology, #InSituResourceUtilization, #FutureMissions, #ScienceAdvances

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