24/7 Space News
Researchers Develop Advanced Algorithm Pandora for Exomoon Hunt
Several influences can create a moon-like signal in a light curve - even without the presence of an actual moon.
Researchers Develop Advanced Algorithm Pandora for Exomoon Hunt
by Staff Writers
Gottingen, Germany (SPX) Dec 08, 2023

In the vast cosmos, where planets orbit distant stars, the existence of moons around exoplanets has been a topic of intrigue. Only two of the more than 5300 known exoplanets have so far provided evidence of moons in orbit around them, and these findings were associated with exoplanets Kepler-1625b and Kepler-1708b. However, a recent study conducted by scientists from the Max Planck Institute for Solar System Research (MPS) and the Sonnenberg Observatory in Germany has raised doubts about these previous claims.

In our own Solar System, it's a common occurrence for planets to be accompanied by one or more moons. With the exception of Mercury and Venus, all other planets have such companions. Saturn, a gas giant, boasts an astonishing 140 natural satellites. Given this, scientists have long speculated that distant star systems may also harbor moons. Yet, the discovery of exomoons has proven to be exceptionally challenging. These distant moons are significantly smaller than their host planets, making them elusive in astronomical observations. Additionally, sifting through the vast amount of observational data for thousands of exoplanets to find evidence of moons is a laborious process.

To overcome these challenges and expedite the search for exomoons, the researchers developed a specialized computer algorithm called Pandora. This algorithm, which was published as open-source code, streamlines and accelerates the hunt for exomoons. When applied to the data from Kepler-1625b and Kepler-1708b, the results were unexpected.

Dr. Rene Heller, the first author of the study, expressed their initial intentions, stating, "We would have liked to confirm the discovery of exomoons around Kepler-1625b and Kepler-1708b." However, their analysis led to a different conclusion.

One of the exoplanets under scrutiny, Kepler-1625b, had garnered attention five years ago when researchers at Columbia University in New York reported strong evidence of a massive moon in its orbit, surpassing all moons in our Solar System in size. The discovery was made using data from NASA's Kepler space telescope, which observed over 100,000 stars during its mission from 2009 to 2013 and identified more than 2000 exoplanets. Subsequently, the exomoon candidate seemed to vanish after systematic noise was removed from the Kepler data. However, it reappeared in further observations with the Hubble Space Telescope. Last year, researchers from New York claimed the existence of another giant moon, even larger than Earth, orbiting the planet Kepler-1708b.

The challenge in detecting exomoons lies in their remote location, making direct observation impossible even with the most advanced telescopes. Instead, astronomers rely on the fluctuations in the brightness of distant stars, known as light curves, to identify potential exomoons. If an exoplanet passes in front of its host star as viewed from Earth, it causes a slight dimming of the star's light. This event, called a transit, occurs periodically in sync with the exoplanet's orbit. A moon accompanying the planet would have a similar dimming effect, but it would be considerably weaker. Detecting these subtle signals is complicated by various factors, including planet-moon eclipses, natural variations in the star's brightness, and other sources of noise during measurements.

To identify exomoons, researchers generate millions of simulated light curves, each representing different sizes, distances, and orbital orientations of potential planets and moons. An algorithm then compares these simulations to the observed light curve, seeking the best match. The German scientists from Gottingen and Sonneberg used their specialized algorithm Pandora, significantly accelerating the exomoon search compared to previous methods.

However, the study cast doubt on the existence of moons around both Kepler-1625b and Kepler-1708b. For the latter, the researchers found that scenarios without a moon could explain the observational data just as accurately. According to Michael Hippke from the Sonneberg Observatory, co-author of the study, "The data do not suggest the existence of an exomoon around Kepler-1708b."

Regarding Kepler-1625b, the German researchers argued that the variation in brightness of the star caused by the limb darkening effect played a crucial role in the proposed exomoon signal. Depending on whether observations were made through the Kepler or Hubble telescopes, this effect appeared differently due to their sensitivity to different wavelengths of light. The scientists believe that their modeling of this effect provides a more conclusive explanation for the data than the presence of a giant exomoon.

Furthermore, the study highlighted the tendency of exomoon search algorithms to produce false-positive results. In cases like that of Kepler-1625b, the rate of these "false hits" was estimated to be around 11 percent. Dr. Rene Heller emphasized, "A false-positive finding is not at all surprising, but almost to be expected."

The researchers also used their algorithm to predict which exomoons could be detectable with current technology. Their analysis indicated that only exceptionally large moons, orbiting at a significant distance from their planets, could be identified using existing methods. These exomoons, compared to the familiar moons of our Solar System, would be extraordinary, being at least twice the size of Ganymede, the largest moon in our Solar System and nearly as large as Earth.

Dr. Rene Heller concluded by stating, "The first exomoons that will be discovered in future observations, such as from the PLATO mission, will certainly be very unusual and therefore exciting to explore."

Research Report:Large exomoons unlikely around Kepler-1625 b and Kepler-1708 b

Related Links
Max Planck Institute for Solar System Research
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Subscribe Free To Our Daily Newsletters

The following news reports may link to other Space Media Network websites.
Ariel moves from drawing board to construction phase
Paris (ESA) Dec 06, 2023
Today, the preliminary spacecraft design of ESA's future exoplanet mission Ariel got approval from the ESA review board and passed the Preliminary Design Review with flying colours. This concludes the important preliminary design phase B2 of the mission that lasted 19 months. During this phase, the design of the spacecraft has been refined, including the requirements for the interfaces, in particular with the payload elements. Ariel's development plans have also been finalised. Ariel's scien ... read more

NASA Stennis Achieves Major Milestone for In-Flight Software Mission

French 'Baguette One' rocket project gets funding

Blue Origin announces space launch next week, first since 2022 crash

Lost tomato found aboard International Space Station after eight months

France 2030 boosts HyPrSpace and Partners with 35M Euro for Micro-Launcher Development

NASA Teams Prepare Moon Rocket-to-Spacecraft Connector for Assembly

UK's Orbex secures funding for carbon-neutral spaceport development

Next-generation methane rocket to be more powerful

Mapping Mars: Deep Learning Could Help Identify Jezero Crater Landing Site

How Rocks Say Don't Touch: Sols 4032-4034

NASA's Perseverance Rover Deciphers Ancient History of Martian Lake

A Rinse and Repeat Kind of Plan: Sols 4035-4036

Long March rockets mark their 500th spaceflight

CAS Space expands into Guangdong with new rocket engine testing complex

China's Lunar Samples on Display in Macao to Inspire Future Explorers

China Manned Space Agency Delegation Highlights SARs' Role in Space Program

USAGM enlists SES Space and Defense for advanced global satellite Broadcasting

Investor Coalition demands leadership overhaul at Terran Orbital amid CEO controversy

Iridium's New GMDSS Academy to Bolster Safety Training for Maritime Professionals

Embry-Riddle's Innovative Mission Control Lab prepares students for booming space sector

Leidos completes successful Lonestar Tactical Space Support Vehicle demonstration

Momentus Partners with CalgaryToSpace for 2025 Satellite Launch

Transforming Waste into Strength: The Graphene Revolution in Concrete Recycling

Innovative 3D printing technology shapes future of Australian housing

Ariel moves from drawing board to construction phase

14-inch spacecraft delivers new details about 'hot Jupiters'

Seeing and Believing: 15 Years of Exoplanet Images

Researchers Develop Advanced Algorithm Pandora for Exomoon Hunt

Unwrapping Uranus and its icy moon secrets

Juice burns hard towards first-ever Earth-Moon flyby

Fall into an ice giant's atmosphere

Juno finds Jupiter's winds penetrate in cylindrical layers

Subscribe Free To Our Daily Newsletters


The content herein, unless otherwise known to be public domain, are Copyright 1995-2023 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.