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Space Exploration

Big Red Spot on Jupiter: A Historical Overview from the 1800s

By Jonathan Bala June 19, 2024

Big Red Spot on Jupiter: A Historical Overview from the 1800s

Key Takeaways

Jupiter’s Great Red Spot (GRS) is a massive, long-lived storm larger than Earth. First observed in the 1600s, the GRS has a complex and debated history. The storm is an anti-cyclonic vortex with wind speeds exceeding 400 km/h. Historical records and modern simulations suggest the GRS we see today likely formed in the mid-1800s. New research combines historical data with computer simulations to explore the GRS’s formation mechanisms.

Summary

Jupiter’s GRS: A massive, iconic storm larger than Earth, observed since the 1600s.
First Observations: Early sightings by astronomers like Giovanni Cassini and others in the 1600s and 1700s.
Lost Track: The GRS wasn’t observed for 118 years until its reappearance in the mid-1800s.
Historical Records: Early drawings and observations provide valuable data on the GRS’s appearance and movement.
Modern Observations: Spacecraft like Voyager, Galileo, and Juno have provided detailed images and data.
Wind Shear: Jupiter’s atmosphere contains winds running in opposite directions, creating conditions for the GRS.
Simulations: Supercomputer simulations explore possible formation mechanisms of the GRS.
Conclusion: The GRS likely formed from a South Tropical Disturbance (STrD) around the mid-1800s, acquiring its current form over time.

The Great Red Spot on Jupiter: How It Probably Formed in the Early 1800s

Jupiter’s Great Red Spot (GRS) is one of the most fascinating and enduring features of our Solar System. This massive storm, larger than Earth, has been observed by astronomers for centuries, with its formation and longevity still a topic of debate. The GRS is an enormous anti-cyclonic storm, rotating counter-clockwise with wind speeds exceeding 400 km/h (250 mph). It’s a striking feature that has captivated humans since at least the 1800s, and possibly earlier. Understanding its history and formation requires a look at both historical observations and modern scientific research.

Early Observations of the Great Red Spot

The earliest observations of the GRS may date back to 1632 when a German Abbott used his telescope to observe Jupiter. Thirty-two years later, another astronomer reported seeing a large spot moving from east to west across the planet. By 1665, the renowned astronomer Giovanni Cassini examined Jupiter and noted the presence of a storm at the same latitude as the current GRS. Cassini and his contemporaries observed this storm continuously until 1713, referring to it as the Permanent Spot.

Despite these early records, the GRS disappeared from astronomical observations for 118 years, only to be rediscovered in 1831 by astronomer S. Schwabe. He observed a clear, oval structure at the same latitude, which many believe marks the first sighting of the current GRS. This gap in observations has led to questions about the continuity of the storm and its relation to the earlier Permanent Spot.

These images from the research show how the GRS formed. a is a drawing by T. E. R. Phillips in 1931–1932 of the STrD. The red arrows indicate the flow direction. The longitude scale is indicated. b and c are maps drawn from images taken by the New Horizons spacecraft. The yellow arrows mark position-velocity changes in the STrD. The STrD trapped winds. It created a long cell that generated the Great Red Spot. Image Credit: Sánchez-Lavega et al. 2024.

The Role of Historical Records

Historical records play a crucial role in understanding the GRS. Early drawings and descriptions by astronomers like Cassini provide valuable insights into the size, structure, and movement of the storm. However, interpreting these records is challenging due to the variable appearance of the GRS over time. Changes in size, albedo, and contrast with surrounding clouds have made it difficult to definitively link the Permanent Spot observed by Cassini with the current GRS.

A recent study in Geophysical Research Letters, led by Professor Agustín Sánchez-Lavega of the University of the Basque Country in Bilbao, Spain, attempts to bridge this gap. The research combines historical records with computer simulations to better understand the formation and evolution of the GRS.

Modern Observations and Technology

Modern technology has revolutionized our understanding of the GRS. Space telescopes and spacecraft have provided detailed images and data that were unimaginable in Cassini’s time. NASA’s Voyager 1 spacecraft captured the first detailed image of the GRS in 1979, revealing intricate wave patterns within the storm. Subsequent missions, including Galileo and Juno, have provided even more detailed observations.

Juno, in particular, has made significant contributions to our understanding of the GRS. Its close flybys of Jupiter have allowed scientists to capture high-resolution images and measure the depth of the storm. Juno’s instruments have shown that the GRS is relatively shallow, with a vertical extent of about 500 km, compared to its vast horizontal dimensions.

A new view of Jupiter and its GRS. Credit: NASA/SwRI/MSSS/Navaneeth Krishnan S © CC BY

The Mechanisms Behind the Great Red Spot

Jupiter’s atmosphere is characterized by powerful winds blowing in opposite directions at different latitudes. North of the GRS, winds blow westward at speeds of 180 km/h, while south of the storm, winds flow eastward at 150 km/h. This wind shear creates the conditions necessary for the formation and maintenance of the GRS.

Researchers have used supercomputer simulations to explore various mechanisms that could produce the GRS under these conditions. One hypothesis involves the eruption of a gigantic superstorm, similar to those observed on Saturn, while another suggests that smaller vortices created by wind shear merged to form the GRS. However, these simulations did not fully match the characteristics of the current GRS.

A New Hypothesis: The South Tropical Disturbance

A more promising explanation emerged from simulations involving the South Tropical Disturbance (STrD), an instability in Jupiter’s winds. The researchers found that the STrD could trap winds and create an elongated cell that eventually evolved into the GRS. This process likely began in the mid-1800s, when the GRS was much larger than it is today.

The simulations show that over time, the GRS would rotate more rapidly and become more compact as it shrank, eventually resembling the current storm. This hypothesis aligns with historical observations and modern data, suggesting that the GRS we see today is about 150 years old.

This research figure compares the Permanent Spot (PS) and today's GRS. a, b, and c are Cassini's drawings from 1677, 1690, and 1691. d is a 2023 GRS image. Image Credit: Sánchez-Lavega et al. 2024. — This research figure compares the Permanent Spot (PS) and today’s GRS. a, b, and c are Cassini’s drawings from 1677, 1690, and 1691. d is a 2023 GRS image. Image Credit: Sánchez-Lavega et al. 2024.

Detailed Analysis of Historical Observations

To support their hypothesis, the researchers analyzed historical records in detail. They compared drawings and descriptions of the Permanent Spot from the 1600s and 1700s with observations of the GRS from the 1800s onwards. They also examined photographs and telescopic images from the late 19th and early 20th centuries.

Table 1: Comparison of Historical Observations

Year	Observer	Description	Notes
1665	Giovanni Cassini	Large spot at GRS latitude	Named it the Permanent Spot
1831	S. Schwabe	Oval structure at GRS latitude	First modern observation of the GRS
1879	A. A. Common	Clear photograph of GRS	Confirms presence of a large storm
1890	Observatory Lick	Yellow filter photograph	Detailed image showing GRS structure

These historical records provide a timeline of the GRS’s appearance and changes over the centuries. By comparing these records with modern observations, researchers can better understand the storm’s evolution.

Modern Spacecraft Observations

Spacecraft missions have been instrumental in studying the GRS. NASA’s Voyager 1 provided the first detailed image in 1979, revealing the storm’s complex structure. The Galileo spacecraft, which orbited Jupiter from 1995 to 2003, captured additional images and data. More recently, the Juno spacecraft has provided the most detailed observations yet, including measurements of the storm’s depth and high-resolution images.

Table 2: Key Spacecraft Observations

Spacecraft	Year	Key Observations
Voyager 1	1979	First detailed image of GRS
Galileo	1995-2003	Extensive imaging and data collection
Juno	2016-Present	High-resolution images and depth measurements

These observations have provided critical data on the GRS’s structure, composition, and dynamics. They have also revealed changes in the storm over time, such as its shrinking size and increasing rotation speed.

The Future of GRS Research

As technology continues to advance, our understanding of the GRS will deepen. Future spacecraft missions and advanced telescopes will provide even more detailed observations, allowing scientists to study the storm in unprecedented detail. Additionally, improved computer simulations will help researchers test new hypotheses and refine existing models.

Conclusion

Jupiter’s Great Red Spot is a remarkable and enduring feature of our Solar System. Its formation and longevity have intrigued astronomers for centuries. By combining historical records with modern observations and simulations, researchers have developed a plausible explanation for the GRS’s formation in the mid-1800s. This iconic storm, with its swirling red clouds and powerful winds, continues to captivate scientists and the public alike.

Hashtags

#Jupiter, #GreatRedSpot, #Astronomy, #Space, #NASA, #Voyager, #Galileo, #Juno, #SpaceScience, #PlanetaryScience, #SolarSystem

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Earth Observation Satellites

Water Frost on Mars Discovered: ‘We Thought It Was Impossible’ Near Red Planet’s Equator

By Jonathan Bala June 11, 2024

Water Frost on Mars Discovered: ‘We Thought It Was Impossible’ Near Red Planet’s Equator

Key Takeaway:

Water frost has been discovered for the first time near Mars’s equator, challenging previous beliefs that frost couldn’t exist in this region due to its warm temperatures and thin atmosphere. This finding, made by ESA’s ExoMars Trace Gas Orbiter and Mars Express, suggests exceptional processes at play and has significant implications for understanding water distribution and climate on Mars.

Summary:

Discovery: Water frost found near Mars’s equator, a region previously believed too warm for frost.
Instruments: ESA’s ExoMars Trace Gas Orbiter (TGO) and Mars Express.
Location: Tharsis region, home to the largest volcanic mountains, including Olympus Mons.
Significance:
- Challenges previous understanding of Mars’s climate.
- Highlights unique microclimates on Martian volcanoes.
- Important for future human exploration of Mars.
Details:
- Frost is thin and ephemeral, forming only for a few hours at sunrise.
- Covers a vast area despite its thinness, containing water equivalent to 60 Olympic swimming pools.
Scientific Implications:
- Shows water exchanges between Mars’s atmosphere and surface.
- Reveals Earth-like meteorological processes on Mars.
Research Team: Led by Adomas Valantinas, a PhD student at the University of Bern, Switzerland.
Publication: Study published in Nature Geoscience.

Water Frost on Mars: Challenging the Impossible

Water frost has been discovered for the first time near Mars’s equator, a region where scientists previously believed frost formation was impossible. This unexpected finding could reshape our understanding of Martian climate and water distribution, with significant implications for future Mars exploration.

The Discovery

Adomas Valantinas, a PhD student at the University of Bern, Switzerland, made this groundbreaking discovery using data from two European Space Agency (ESA) missions: the ExoMars Trace Gas Orbiter (TGO) and the Mars Express. Valantinas, now a postdoctoral researcher at Brown University, expressed his astonishment:

“We thought it was impossible for frost to form around Mars’ equator, as the mix of sunshine and thin atmosphere keeps temperatures relatively high at both surface and mountaintop – unlike what we see on Earth, where you might expect to see frosty peaks. Its existence here is exciting and hints that there are exceptional processes at play that are allowing frost to form.”

The TGO, which arrived at Mars in 2016, and Mars Express, which has been orbiting the planet since 2003, played crucial roles in this discovery. Both spacecraft have orbits that allow them to observe the Martian surface at various times of the day, including early morning when the frost forms. This capability was vital, as frost on Mars’s equator appears briefly around sunrise before evaporating under the sun’s rays.

A view of Olympus Mons from the side shows a wide patch of thin ice. (Image credit: ESA/DLR/FU Berlin)

Location: Tharsis Region

The frost was detected in the Tharsis region, the largest volcanic area on Mars. This region includes 12 large volcanoes, such as:

Olympus Mons: The tallest peak in the solar system, towering 18.6 miles (29.9 kilometers), approximately 2.5 times the height of Mount Everest.
Ascraeus Mons
Arsia Mons
Pavonis Mons
Ceraunius Tholus

These volcanoes have deep hollows at their summits called “calderas,” created by magma chambers during eruptions. The team believes that unique microclimates within these calderas, driven by air circulation patterns, allow frost to form.

Microclimates and Frost Formation

According to Nicolas Thomas, Principal Investigator of TGO’s Colour and Stereo Surface Imaging System (CaSSIS):

“Winds travel up the slopes of the mountains, bringing relatively moist air from near the surface up to higher altitudes, where it condenses and settles as frost. We actually see this happening on Earth and other parts of Mars, with the same phenomenon causing the seasonal Martian Arsia Mons Elongated Cloud.”

The frost patches are incredibly thin, with a thickness equivalent to that of a human hair (about one-hundredth of a millimeter). Despite their thinness, they cover extensive areas of the volcanoes, with their water content potentially filling 60 Olympic swimming pools, or about 29.4 million gallons (111 million liters) of water.

Scientific Implications

This discovery has several important scientific implications:

Water Exchange: It highlights the dynamic exchange of water between Mars’s atmosphere and surface. This exchange is critical for understanding the planet’s climate and water cycle.
Microclimate Formation: The presence of frost suggests unique microclimates on Mars, driven by specific air circulation patterns.
Comparative Planetology: The finding provides insights into Earth-like meteorological processes on Mars, enhancing our understanding of both planets’ climates.

Research Challenges and Future Exploration

Detecting frost at Mars’s equator was challenging due to several factors. Most Mars orbiters are synchronized to observe the planet in the afternoon, making it difficult to catch the frost, which forms only in the early morning. Additionally, frost deposition is linked to colder Martian seasons, further narrowing the window for observation.

Adomas Valantinas explained:

“Firstly, we need an orbit that lets us observe a location in the early morning. While ESA’s two Mars orbiters – Mars Express and TGO – have such orbits and can observe at all times of day, many from other agencies are instead synchronized to the sun and can only observe in the afternoon. Secondly, frost deposition is linked to colder Martian seasons, making the window for spotting it even narrower.”

Future Research Directions

The discovery of water frost near Mars’s equator opens new avenues for research:

Detailed Climate Modeling: Improved models of Mars’s climate are needed to understand the conditions that allow frost to form in equatorial regions.
Microclimate Studies: Further investigation into the unique microclimates of the Tharsis region could reveal more about atmospheric and surface interactions on Mars.
Human Exploration: Understanding water distribution on Mars is crucial for future human missions, as water is essential for life support and fuel production.

“Finding water on the surface of Mars is always exciting, both for scientific interest and for its implications for human and robotic exploration. Even so, this discovery is particularly fascinating.”

Frost on the caldera floor of the Ceraunius Tholus volcano. The frames show (A) a view of Ceraunius Tholus from NASA's Mars Reconnaissance Orbiter's Context Camera. Early morning observations made by CaSSIS are overlaid within the blue-toned rectangle. This rectangle is shown close-up in frame (B). The white rectangle marking an even more zoomed-in image is shown in frame (C). Frost is on the caldera floor, but there is none on the caldera rim. (D) shows a CaSSIS image of the same region acquired at a different time of day, with the frost gone. (Image credit: ESA/DLR/FU Berlin) — Frost on the caldera floor of the Ceraunius Tholus volcano. The frames show (A) a view of Ceraunius Tholus from NASA’s Mars Reconnaissance Orbiter’s Context Camera. Early morning observations made by CaSSIS are overlaid within the blue-toned rectangle. This rectangle is shown close-up in frame (B). The white rectangle marking an even more zoomed-in image is shown in frame (C). Frost is on the caldera floor, but there is none on the caldera rim. (D) shows a CaSSIS image of the same region acquired at a different time of day, with the frost gone. (Image credit: ESA/DLR/FU Berlin)

Comparative Analysis: Earth vs. Mars

Despite the thin atmosphere and low temperatures on Mars, the discovery of frost highlights similarities between Martian and Earth climates. On Earth, frost forms in high-altitude regions where moist air cools and condenses. A similar process appears to be at work on Mars, albeit under different atmospheric conditions.

Conclusion

The discovery of water frost near Mars’s equator is a remarkable achievement that challenges our understanding of the Red Planet’s climate. It stresses the importance of continued exploration and observation, using advanced instruments and innovative approaches. This finding not only enhances our knowledge of Mars but also provides valuable insights into planetary climates and the potential for water on other celestial bodies.

Tables

Table 1: Key Features of Mars’s Tharsis Volcanoes

Volcano Name	Height (miles)	Height (kilometers)	Notable Features
Olympus Mons	18.6	29.9	Tallest peak in the solar system
Ascraeus Mons	9.3	15.0	Large caldera, significant lava flows
Arsia Mons	11.8	19.0	Known for its elongated cloud
Pavonis Mons	8.7	14.0	Central location among Tharsis volcanoes
Ceraunius Tholus	3.1	5.0	Smaller but significant volcanic activity

Table 2: Frost Formation on Mars vs. Earth

Parameter	Mars	Earth
Atmospheric Pressure	0.6% of Earth’s	101.3 kPa
Temperature Range	-195°F to 70°F (-125°C to 20°C)	-128°F to 134°F (-89°C to 57°C)
Frost Formation	Occurs in early morning on slopes	High altitudes, cold regions
Water Content in Frost	Extremely thin, covers large area	Variable, dependent on humidity

References

European Space Agency (ESA): Information about the ExoMars Trace Gas Orbiter and Mars Express missions.
Nature Geoscience: Research publication detailing the discovery of water frost near Mars’s equator.
NASA: Contextual information on Mars’s atmosphere and climate.

Hashtags

#Mars, #WaterFrost, #SpaceExploration, #TharsisRegion, #OlympusMons, #ESA, #ExoMars, #MarsExpress, #PlanetaryScience, #FutureExploration

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Technology

Phoenix Planet: A New Discovery That Defies Atmospheric Loss Theories

By Jonathan Bala June 9, 2024

Phoenix Planet: A New Discovery That Defies Atmospheric Loss Theories

Key Takeaway

Phoenix, a newly discovered exoplanet, retains a thick atmosphere despite being close to a red giant star, challenging existing theories on planetary evolution and atmospheric retention. This discovery, led by researchers from Johns Hopkins University, provides fresh insights into how planets can defy expectations in extreme environments.

Summary

Discovery: Phoenix is a rare exoplanet that retains a thick atmosphere close to its red giant star.
Significance: Challenges existing theories about planetary evolution and atmospheric retention in harsh stellar environments.
Characteristics: Smaller, older, and hotter than expected; 6.2 times the size of Earth and 60 times less dense than the densest “hot Neptune.”
Research Techniques: Utilized NASA’s Transiting Exoplanet Survey Satellite and the W.M. Keck Observatory to filter and combine data for precise measurements.
Implications: Provides new insights into planetary system evolution, particularly for Earth’s future atmospheric changes.
Future Discoveries: The research team has identified a dozen potential candidates for similar studies.
Publication: Findings published in The Astronomical Journal on June 5, 2024.

An artist's concept shows TIC365102760 b, nicknamed Phoenix. This planet can survive intense radiation from a nearby red giant star. Credit: Roberto Molar Candanosa/Johns Hopkins University. — An artist’s concept shows TIC365102760 b, nicknamed Phoenix. This planet can survive intense radiation from a nearby red giant star. Credit: Roberto Molar Candanosa/Johns Hopkins University.

Introduction

In a groundbreaking discovery, astronomers have identified an exoplanet, named Phoenix, that defies conventional expectations of planetary evolution and atmospheric retention. This planet, orbiting a red giant star, should have been stripped of its atmosphere due to intense radiation, yet it maintains a thick, puffy atmosphere. This finding, published by Johns Hopkins University researchers, challenges existing theories and opens new avenues for understanding planetary behavior in extreme environments.

Characteristics of Phoenix

Phoenix, officially designated TIC365102760 b, belongs to the rare category of “hot Neptunes.” Despite being situated close to its host star, Phoenix has retained a substantial atmosphere. This discovery is particularly surprising given the planet’s characteristics:

Size and Mass: Phoenix is 6.2 times larger than Earth and exhibits significantly lower density, being 60 times less dense than the densest known hot Neptune.
Orbit and Proximity: The planet completes an orbit around its red giant star every 4.2 days, at a distance six times closer than Mercury is to the Sun.
Age and Temperature: Phoenix is notably older and hotter than anticipated for planets in such proximity to a red giant star.

Unusual Atmospheric Retention

“This planet isn’t evolving the way we thought it would,” said Sam Grunblatt, the lead researcher from Johns Hopkins University. “It appears to have a much bigger, less dense atmosphere than we expected for these systems.” This phenomenon challenges our understanding of how atmospheres can persist in harsh stellar environments where intense radiation is expected to strip them away.

Table 1: Characteristics of Phoenix

Characteristic	Detail
Size	6.2 times the size of Earth
Density	60 times less dense than the densest hot Neptune
Orbital Period	4.2 days
Proximity to Star	6 times closer than Mercury to the Sun
Age and Temperature	Older and hotter than expected

Research Techniques

The discovery of Phoenix was made possible through innovative research techniques. Grunblatt and his team utilized NASA’s Transiting Exoplanet Survey Satellite (TESS) and the W.M. Keck Observatory to obtain precise measurements. TESS detects low-density planets by observing the dimming of their host stars’ brightness as they pass in front. The team enhanced this data by filtering out unwanted light and combining it with measurements of the stars’ wobbles caused by orbiting planets, observed by the Keck Observatory.

Implications for Planetary Evolution

The persistence of Phoenix’s atmosphere, despite its proximity to a red giant star, has significant implications for our understanding of planetary evolution. The slow atmospheric stripping observed in Phoenix suggests that other factors may influence atmospheric retention. This insight is crucial for predicting the future of Earth’s atmosphere as our Sun evolves into a red giant.

“We don’t understand the late-stage evolution of planetary systems very well,” Grunblatt noted. “This is telling us that maybe Earth’s atmosphere won’t evolve exactly how we thought it would.”

Potential for Future Discoveries

Phoenix’s discovery highlights the potential for finding other unusual exoplanets. Puffy planets like Phoenix are rare, with scientists estimating that only about 1% of stars host such planets. Their smaller size makes them challenging to detect, but Grunblatt’s team has already identified a dozen potential candidates for further study using their refined techniques.

Conclusion

Phoenix’s discovery marks a significant milestone in astrophysics, challenging existing theories and providing new insights into planetary evolution. The planet’s ability to retain a thick atmosphere despite intense stellar radiation prompts a re-evaluation of our understanding of atmospheric loss and planetary decay in extreme environments. As researchers continue to uncover more about these rare puffy planets, we can expect to learn even more about the diverse and complex nature of solar systems.

Table 2: Future Research Directions

Research Area	Description
Atmospheric Retention	Investigate factors influencing atmospheric persistence in extreme environments.
Late-Stage Planetary Evolution	Study how planetary systems evolve as their host stars enter late stages of life.
Detection Techniques	Refine methods for detecting small, low-density exoplanets.
Comparative Planetology	Compare atmospheric characteristics across different types of exoplanets.

Reference

“TESS Giants Transiting Giants. IV. A Low-density Hot Neptune Orbiting a Red Giant Star” by Samuel K. Grunblatt et al., The Astronomical Journal, June 5, 2024. DOI: 10.3847/1538-3881/ad4149
Johns Hopkins University Press Release, June 8, 2024.

Hashtags

#Astronomy, #Astrophysics, #Exoplanets, #PhoenixPlanet, #JohnsHopkinsUniversity, #NASA, #TESS, #KeckObservatory, #PlanetaryScience, #RedGiantStar

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Earth Observation Satellites

How the Juno Spacecraft Found New Evidence of Europa’s Shifting Icy Shell

By Jonathan Bala May 21, 2024

How the Juno Spacecraft Found New Evidence of Europa’s Shifting Icy Shell

Key Takeaways

NASA’s Juno spacecraft has provided high-definition images of Europa, one of Jupiter’s largest moons. Europa’s surface is covered by a thick layer of ice, beneath which lies a vast ocean of liquid water. Geological features such as ridges, bands, chaos terrain, and impact craters indicate powerful surface activity. “True polar wander” suggests Europa’s icy shell shifts over its liquid ocean. The “Platypus” region and plume deposits hint at recent surface activity and potential subsurface water. Future missions, like NASA’s Europa Clipper and ESA’s Juice, aim to further explore Europa’s habitability.

Summary

Europa’s icy shell is 10-15 miles thick, covering a massive ocean.
The ocean might contain twice the water volume of Earth’s oceans.
Geological features include:
- Ridges and bands
- Chaos terrain
- Few impact craters, indicating a young surface
True polar wander shows the icy shell moving over the liquid ocean.
The “Platypus” region and plume deposits suggest recent activity and subsurface water.
Juno’s brief flyby offers valuable data for future missions.
Future missions will map the surface, search for water plumes, and sample the subsurface ocean.
Europa’s exploration may reveal whether life exists beyond Earth.

Europa, one of Jupiter's moons, has shifting ice. NASA's Juno mission captured this phenomenon from 1 million miles away.the Juno Spacecraft — Europa, one of Jupiter’s moons, has shifting ice. NASA’s Juno mission captured this phenomenon from 1 million miles away.

Europa’s Deep Ocean and Icy Shell

Europa, one of Jupiter’s largest moons, has long fascinated scientists and astronomers alike. Its surface, covered by a thick layer of ice, hides a vast ocean beneath. This intriguing moon, orbiting in the shadow of the gas giant Jupiter, has become a prime target for exploration due to its potential for harboring life.

Ice Thickness and Ocean Depth

Europa’s icy shell is estimated to be about 10-15 miles (15-25 kilometers) thick. Beneath this ice, scientists believe there is a vast ocean of liquid water. This ocean might contain twice as much water as all of Earth’s oceans combined, making it one of the most significant bodies of water in the solar system.

Geological Activity and Surface Features

Europa’s surface is not just a static sheet of ice. It displays a variety of geological features that suggest a dynamic and active world beneath its frozen exterior. The primary surface features include:

Ridges and Bands: These long, linear cracks and ridges crisscross Europa’s surface, some stretching for thousands of miles. They are believed to be caused by the tidal forces exerted by Jupiter’s immense gravity.
Chaos Terrain: Regions where the surface ice appears to be broken and refrozen in a chaotic jumble. This suggests periods of significant surface disruption and movement.
Impact Craters: Europa has relatively few impact craters, indicating a young and frequently resurfaced exterior. This lack of craters implies that geological processes are continually renewing the surface.

True Polar Wander

Europa is not a static, frozen ball. Recent images from Juno support the theory of “true polar wander,” a phenomenon where the moon’s icy shell shifts and slides over the liquid ocean below. This is akin to a giant jigsaw puzzle slowly rearranging itself, with new cracks and ridges forming over time.

“True polar wander occurs if Europa’s icy shell is decoupled from its rocky interior, resulting in high stress levels on the shell, which lead to predictable fracture patterns,” explains Candy Hansen, a Juno co-investigator who leads planning for the JunoCam.

These shifting plates could have significant implications for the potential habitability of Europa. The movement of the ice could bring nutrients and energy from the ocean to the surface, creating conditions that might support life.

The “Platypus” Region

One of the most intriguing features captured by Juno is a chaotic region nicknamed “the Platypus.” This area has a jumbled landscape with ridges, hummocks, and dark stains. These characteristics hint at recent surface activity and the potential presence of subsurface water.

The Platypus isn’t the only sign of activity on Europa. Juno also captured images that appear to show plume deposits. These deposits might indicate that water vapor is erupting from the ocean below the ice. These plumes could provide a direct way to sample the moon’s subsurface and search for signs of life.

Future of Juno’s Research on Europa

Juno’s flyby of Europa was brief, but it provided a wealth of information to ponder. It’s also a fascinating preview of what’s to come.

“These features hint at present-day surface activity and the presence of subsurface liquid water on Europa,” said Heidi Becker, lead co-investigator for the Stellar Reference Unit on Juno.

“The SRU’s image is a high-quality baseline for specific places NASA’s Europa Clipper mission and European Space Agency’s (ESA’s) Juice missions can target to search for signs of change and brine,” Becker concluded.

Upcoming Missions: Europa Clipper and Juice

NASA’s Europa Clipper mission and ESA’s Juice mission are set to carry a suite of instruments designed to study Europa’s composition, surface features, and potential for life. These missions will map the moon’s surface in unprecedented detail, search for plumes of water vapor, and even attempt to sample the subsurface ocean.

The primary objectives of these missions include:

Mapping Surface Features: Using high-resolution cameras and spectrometers to capture detailed images and compositions of Europa’s surface.
Detecting Water Plumes: Searching for evidence of water vapor plumes erupting from the subsurface ocean.
Sampling the Subsurface Ocean: Employing instruments to detect and analyze the chemical composition of the ocean below the ice.

Expected Outcomes

These missions aim to provide answers to some of the most pressing questions about Europa:

Habitability: Determining whether the conditions beneath Europa’s icy shell are suitable for life.
Geological Activity: Understanding the processes that drive the moon’s geological activity and surface renewal.
Ocean Composition: Analyzing the composition of the subsurface ocean to understand its potential to support life.

The Eternal Fascination of Europa

Europa has always been a source of wonder and speculation. It’s a world that challenges our understanding of where life can exist. The images from Juno have only deepened this fascination, revealing a dynamic and active moon with a hidden ocean that could hold the keys to some of the biggest questions in science.

Europa’s Impact on Astrobiology

Europa’s exploration has significant implications for the field of astrobiology. The presence of a subsurface ocean, combined with geological activity, makes it one of the most promising places to search for life beyond Earth. The potential discovery of microbial life on Europa would revolutionize our understanding of the universe and our place within it.

As we continue to explore this distant world, we may find that we’re not alone in the universe, that life can thrive in the most unexpected places. Europa, once a mysterious moon, is now a beacon of hope in our quest to understand the cosmos and our place within it.

The journey to Europa is just beginning, and it promises to be a thrilling one. With each new mission and discovery, we move closer to unlocking the secrets of this enigmatic moon. Europa’s hidden ocean and dynamic surface present an exciting opportunity for scientific exploration and the potential for groundbreaking discoveries.

Tables

Table 1: Key Geological Features of Europa

Feature	Description
Ridges and Bands	Long, linear cracks crisscrossing the surface.
Chaos Terrain	Broken and refrozen ice in a chaotic jumble.
Impact Craters	Few in number, indicating a young and dynamic surface.

Table 2: Upcoming Missions to Europa

Mission	Agency	Objectives
Europa Clipper	NASA	Mapping surface, detecting plumes, sampling subsurface.
Juice (JUpiter ICy Moons Explorer)	ESA	Studying composition, surface features, and habitability.

Hashtags

#Europa, #JupiterMoons, #NASA, #SpaceExploration, #Astrobiology, #SubsurfaceOcean, #TruePolarWander, #EuropaClipper, #JUICEMission, #PlanetaryScience #the juno spacecraft

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Satellite Technology

Bepicolombo Mission to Mercury

By Jonathan Bala May 20, 2024

Bepicolombo Mission to Mercury

Key Takeaways

BepiColombo is a joint mission by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to study Mercury. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). BepiColombo aims to map Mercury’s surface, analyze its magnetic field, and study its exosphere and core. Launched on October 20, 2018, BepiColombo is expected to arrive at Mercury in 2025. The mission will provide insights into the planet’s formation, geology, and its extreme environment.

Summary

Joint Mission: Collaboration between ESA and JAXA.
Spacecraft: Two orbiters – MPO and MMO.
Launch Date: October 20, 2018.
Arrival at Mercury: Expected in 2025.
Mission Goals:
- Map Mercury’s surface.
- Study Mercury’s magnetic field.
- Investigate the planet’s exosphere and core.
Significance:
- Understand planetary formation.
- Study Mercury’s geology and extreme conditions.
Scientific Instruments: Includes cameras, spectrometers, magnetometers, and particle analyzers.
Challenges: High temperatures, intense solar radiation, and gravitational influences.

The BepiColombo Mission to Mercury

The BepiColombo mission is a collaborative effort between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), aiming to explore Mercury, the least explored terrestrial planet in our solar system. Named after Giuseppe “Bepi” Colombo, an Italian scientist who significantly contributed to the study of Mercury, the mission marks a significant milestone in planetary science.

Mission Objectives

The primary objectives of the BepiColombo mission are to:

Map Mercury’s Surface: High-resolution imaging and spectral mapping to study the planet’s surface composition and geological history.
Analyze the Magnetic Field: Understanding Mercury’s internal magnetic field and its interaction with the solar wind.
Study the Exosphere: Investigating the thin, tenuous atmosphere of Mercury.
Investigate the Core: Gaining insights into the structure and composition of Mercury’s core.

Spacecraft Components

The BepiColombo mission consists of two main spacecraft:

Mercury Planetary Orbiter (MPO): Built by ESA, the MPO is designed to study Mercury’s surface and internal composition. It carries a suite of instruments including cameras, spectrometers, and a laser altimeter.
Mercury Magnetospheric Orbiter (MMO): Developed by JAXA, the MMO focuses on studying Mercury’s magnetic environment. It is equipped with magnetometers, particle analyzers, and plasma detectors.

This simple schematic shows the three separate spacecraft that combine to create the BepiColombo mission. — This simple schematic shows three separate spacecraft that make up the BepiColombo mission. Image Credit: ESA

Scientific Instruments

The BepiColombo mission boasts a variety of scientific instruments:

Cameras: For high-resolution imaging of Mercury’s surface.
Spectrometers: To analyze the chemical composition of the surface and exosphere.
Magnetometers: To measure Mercury’s magnetic field.
Particle Analyzers: To study the composition and dynamics of the exosphere.
Laser Altimeter: For precise topographic mapping.

Launch and Journey

BepiColombo was launched on October 20, 2018, from the European Spaceport in Kourou, French Guiana, aboard an Ariane 5 rocket. The mission is expected to arrive at Mercury in 2025, after a seven-year journey that includes multiple gravity-assist flybys of Earth, Venus, and Mercury. These flybys are critical for adjusting the spacecraft’s trajectory and reducing its speed for orbital insertion around Mercury.

Challenges of the Mission

Exploring Mercury poses several unique challenges:

Extreme Temperatures: Mercury’s proximity to the Sun results in surface temperatures ranging from -290°F (-180°C) to 800°F (430°C). The spacecraft must endure these extremes and maintain the functionality of its instruments.
Intense Solar Radiation: The spacecraft must be protected from the Sun’s intense radiation, which is about ten times stronger than what Earth experiences.
Gravitational Influences: Navigating the spacecraft to Mercury requires precise calculations to account for the gravitational pull of the Sun and other celestial bodies.

Mission Goals and Scientific Return

The BepiColombo mission is expected to revolutionize our understanding of Mercury. Some key scientific goals include:

Mapping Mercury’s Surface: The MPO’s high-resolution cameras and spectrometers will create detailed maps of Mercury’s surface, revealing its geological history and surface composition.
Understanding the Magnetic Field: The MMO will provide valuable data on Mercury’s magnetic field, helping scientists understand its origin and structure.
Studying the Exosphere: The mission will investigate the composition and dynamics of Mercury’s thin exosphere, offering clues about its interaction with the solar wind.
Investigating the Core: By studying Mercury’s gravitational field and rotational dynamics, scientists hope to gain insights into the planet’s internal structure and core composition.

Significance of the Mission

The BepiColombo mission holds great significance for planetary science. By studying Mercury, scientists can gain a better understanding of:

Planetary Formation: Insights into how terrestrial planets, including Earth, formed and evolved.
Geological Processes: Understanding the geological history and surface processes on Mercury.
Extreme Environments: Studying how planetary environments close to the Sun are shaped and maintained.

Key Milestones

2018: Launch of BepiColombo.
2020: First flyby of Earth.
2021-2022: Flybys of Venus.
2023-2024: Multiple flybys of Mercury.
2025: Orbital insertion around Mercury.

Collaborative Efforts

The BepiColombo mission is a testament to international collaboration. ESA and JAXA have pooled their expertise and resources to tackle the formidable challenges of exploring Mercury. This partnership extends to numerous scientific institutions and universities worldwide, which contribute to the mission’s scientific payload and data analysis.

This schematic shows the components of BepiColombo’s solar-electric propulsion system without the solar arrays. There are four T6 gridded ion thrusters mounted on gimbals. The system has three tanks holding 1,400 kg of xenon gas, a high-pressure regulator, four flow control units, and two power processing units. It also includes several metres of high-voltage harness and piping needed to connect everything. Image Credit: ESA

Scientific Instruments Overview

Here is a detailed look at some of the key instruments onboard the BepiColombo spacecraft:

Table 1: Scientific Instruments on MPO

Instrument	Function
Mercury Radiometer and Thermal Imaging Spectrometer (MERTIS)	Maps surface temperature and composition.
Mercury Gamma-ray and Neutron Spectrometer (MGNS)	Analyzes elemental composition of the surface.
Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO-SYS)	High-resolution imaging and spectral mapping.
Mercury Laser Altimeter (BELA)	Measures surface topography.
Italian Spring Accelerometer (ISA)	Measures non-gravitational forces acting on the spacecraft.

Table 2: Scientific Instruments on MMO

Instrument	Function
Mercury Magnetometer (MMO-MAG)	Studies Mercury’s magnetic field.
Plasma Wave Investigation (PWI)	Analyzes plasma waves and their interaction with the magnetic field.
Mercury Sodium Atmospheric Spectral Imager (MSASI)	Studies sodium in Mercury’s exosphere.
Mercury Dust Monitor (MDM)	Measures dust particles in Mercury’s vicinity.
Solar Intensity X-ray and Particle Spectrometer (SIXS)	Monitors solar X-rays and energetic particles.

Data and Discoveries

The data collected by BepiColombo will be crucial in addressing several unanswered questions about Mercury. For instance, the mission will investigate:

Surface Features: Detailed mapping to identify geological formations such as craters, cliffs, and volcanic plains.
Volcanism and Tectonics: Studying evidence of past volcanic and tectonic activity.
Polar Regions: Investigating the presence of water ice in permanently shadowed craters at Mercury’s poles.
Magnetosphere Dynamics: Understanding how Mercury’s magnetosphere interacts with the solar wind.

The success of the BepiColombo mission will pave the way for future missions to Mercury and other inner planets. It will also enhance our understanding of exoplanets in close orbits around their parent stars, as these environments can be analogs to Mercury’s extreme conditions.

The BepiColombo mission represents a monumental effort in space exploration and scientific discovery. By delving into the mysteries of Mercury, the mission promises to unlock secrets about the formation and evolution of terrestrial planets. The data gathered will not only expand our knowledge of Mercury but also provide broader insights into planetary science and the conditions that shape our solar system.

Hashtags

#BepiColombo, #MercuryMission, #SpaceExploration, #ESA, #JAXA, #PlanetaryScience, #Mercury, #Astronomy, #SpaceScience, #InterplanetaryMission

References

European Space Agency: BepiColombo
http://sci.esa.int/bepicolombo/
Japan Aerospace Exploration Agency: BepiColombo
https://www.isas.jaxa.jp/en/missions/spacecraft/current/mmo.html
National Space Science Data Center Master Catalog: BepiColombo
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2018-080A
European Space Agency (ESA). (2023). “BepiColombo Mission Overview”. Retrieved from ESA Website.
Japan Aerospace Exploration Agency (JAXA). “BepiColombo: Mission to Mercury”. Retrieved from JAXA Website.

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Satellite Imagery

Juno Discovers Massive Lava Lake on Io

By Jonathan Bala April 21, 2024

Juno Discovers Massive Lava Lake on Io

Key Takeaway

Juno spacecraft’s close flybys of Jupiter’s moon Io revealed a giant lava lake called Loki Patera, providing detailed insights into the moon’s volcanic activity and surface features. Scientists also concluded that Io has been erupting volcanically since the early Solar System due to tidal heating.

Summary

Juno spacecraft made close flybys of Jupiter’s moon Io, revealing new details about its surface.
A giant lava lake named Loki Patera was observed, showcasing volcanic activity.
Juno captured images of Io’s northern latitudes, revealing its pizza-like appearance, caused by volcanic activity.
Io exhibits various surface features like volcanic plumes, lava flows, and calderas.
Scientists recreated features like “The Steeple,” a spired mountain on Io, using JunoCam data.
Recent papers concluded that Io has been erupting volcanically since the early Solar System due to tidal heating.
Observations with ALMA in Chile revealed isotopic evidence of long-lived volcanism on Io, indicating billions of years of tidal heating.
Juno will continue to explore Jupiter’s system, with its latest flyby of Io on April 9 and upcoming flyby on May 12.
JunoCam allows public participation in selecting imaging targets and processing data.

Exploring the Fiery Depths of Io

Jupiter’s moon Io has long fascinated astronomers and space followers alike with its otherworldly landscapes and intense volcanic activity. Recent revelations from NASA’s Juno spacecraft have further deepened our understanding of this mysterious moon, Revealing breathtaking details of its fiery surface and shedding light on its geological history.

One of the most striking discoveries made by Juno is the observation of a massive lava lake known as Loki Patera. Stretching over 200 kilometers, this colossal lava lake is surrounded by islands within a depression filled with molten magma. Juno’s close flybys provided unprecedented views of this geological wonder, revealing a landscape reminiscent of Earth’s volcanic regions but on a grander scale.

Io’s surface shows its violent volcanic past. It is covered with vents, calderas, and lava flows. Juno’s sharp images reveal Io’s changing geology. They show bright plumes and complex designs formed by thousands of years of volcanic activity. Io has high mountains and wide lava plains. These features show the strong forces active below its surface.

Io has a unique mountain called “The Steeple.” It is very tall, standing between 5 and 7 kilometers high. This mountain shows how intense volcanic activity has formed Io’s surface for billions of years. Thanks to Juno’s observations, scientists can understand Io’s geological history. They learn how its volcanoes work.

Io’s volcanic activity comes from its special orbit around Jupiter. Its eruptions are caused by tidal heating. This heating happens because of gravity from Jupiter and its moons, Europa and Ganymede. Studies with data from ALMA show Io’s volcanoes have been active for billions of years. This activity has changed Io’s surface and atmosphere.

Juno’s mission continues to solve the mysteries of Io and the wider Jupiter system. With each close flyby, Juno gathers invaluable data that enhances our understanding of Io’s geology and its significance in planetary science. Furthermore, JunoCam invites the public to participate in this journey of exploration, allowing followers to engage with the mission and contribute to the study of Io’s volcanic landscapes.

Hashtags:

#Juno #Io #Volcanoes #SpaceExploration #PlanetaryScience #Astronomy #NASA #Jupiter #LavaLake #Geology #Astrophysics #Massive Lava Lake On Io

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