Tag: solar system

Surprising Finding: The Earth formed from local building blocks

Homogeneous accretion of the Earth in the inner Solar System refers to a recent scientific proposal that our planet formed entirely from material originating in the inner Solar System, with a relatively uniform (homogeneous) isotopic composition throughout the accretion process.

Homogeneous accretion of the Earth in the inner Solar System refers to a recent scientific proposal that our planet formed entirely from material originating in the inner Solar System, with a relatively uniform (homogeneous) isotopic composition throughout the accretion process.

This challenges earlier ideas that Earth incorporated a significant fraction of material from the outer Solar System (e.g., via pebble accretion or scattered carbonaceous chondrite- like bodies).

A paper published in Nature Astronomy (March 27, 2026) by Paolo A. Sossi and Dan J. Bower presents this model.

From Watts Up With That?

By Anthony Watts

From ETH Zurich.

Planetary scientists have long debated where the material that formed our Earth comes from. Despite its location in the inner Solar System, they consider it likely that 6–40 per cent of this material must have come from the outer Solar System, i.e., beyond Jupiter. 

For a long time, material from the outer Solar System was considered necessary to bring volatile components such as water to Earth. Accordingly, there must also have been an exchange of material between the outer and inner Solar Systems during the formation of the Earth. But is that really true? 

“We were truly astonished” 

Planetary scientists Paolo Sossi and Dan Bower, from ETH Zurich, compared existing data on the isotopic ratios of a wide range of meteorites, including those from Mars and the asteroid Vesta, with those of Earth. Isotopes are sibling atoms of the same element (same number of protons) that have a different mass (different number of neutrons).

The researchers analysed this data in a new way and arrived at a surprising conclusion: the material that makes up Earth originates entirely from the inner region of the Solar System. 

Material from the outer Solar System, by contrast, is likely to account for less than two per cent of Earth’s mass, or even nothing at all. The corresponding study has just been published in the journal Nature Astronomy. 

“Our calculations make it clear: the building material of the Earth originates from a single material reservoir,” says Sossi. His colleague Bower adds: “We were truly astonished to find that the Earth is composed entirely of material from the inner Solar System distinct from any combination of existing meteorites.” 

For their study, the ETH researchers used existing data on ten different isotopic systems from meteorites, and analysed them using a specialised statistical method. Previous studies have mostly considered only two isotopic systems. 

“Our studies are actually data science experiments,” says Sossi. ‘We carried out statistical calculations that are rarely used in geochemistry, even though they are a powerful tool.’ 

Isotope signature reveals origin 

Isotopes in meteorites have long been used by researchers to determine the origin of celestial bodies, i.e. which part of the Solar System they come from. Historically, however, only the various isotopes of the element oxygen could be used to determine their provenance. 

It was not until the early 2010s that an American researcher discovered that other isotopes, such as of chromium and titanium, could also be used for this purpose. This has enabled researchers to classify meteorites into two categories: non-carbonaceous ones, which form exclusively in the inner Solar System, and carbonaceous ones, which contain more water and carbon and originate in the outer Solar System. 

The new analysis reveals that the Earth is composed entirely of non-carbonaceous material. No evidence for the previously suspected exchange between the outer- and inner solar system reservoirs was found. 

Therefore, the Earth grew within a relatively static system, incorporating its smaller neighbouring planets as it grew. This also implies that most volatile elements, such as water, must have already been present in the inner Solar System. 

Jupiter acts as a material barrier 

But why are there two distinct material reservoirs in our Solar System? Researchers assume that our Solar System split into two reservoirs during its formation due to Jupiter’s rapid growth and size. The gravity of the gas giant tore a gap in the protoplanetary disc orbiting the young Sun. These discs are ring-shaped and consist of gas and dust; they are the birthplace of planets. Jupiter prevented material from the outer solar system from entering the inner region. However, the extent to which this barrier was permeable remained unclear until now. 

In their new analysis, the two ETH researchers demonstrate that almost no material from beyond Jupiter flowed towards Earth. “Our calculations are very robust and rely solely on the data itself, not on physical assumptions, as these are not yet fully understood,” Bower emphasises. The analysis also shows that Earth’s material composition is similar to that of Vesta and Mars.  

The researchers also suspect that Venus and Mercury lie on the same line. “Based on our analysis, we can theoretically predict the composition of these two planets,” says Paolo Sossi. However, he cannot verify this analytically, as no rock samples from Mercury and Venus, which are the two innermost planets in the Solar System, are currently available to the researchers. 

New light on the formation history 

“Our results shed new light on the formation history of our Earth and the other rocky planets,” says Sossi. 

Sossi and his team intend to follow up by investigating why there was sufficient water in the hot, inner Solar System to form the Earth’s oceans. Furthermore, they will examine whether these processes can be applied to exoplanetary systems.

“Until then, however, Dan and I will have to engage in many heated debates about the material composition of Earth and its neighbouring planets, because the scientific discourse over the building blocks of Earth is far from over, despite the new findings,” says Sossi.

Reference

Sossi PA, Bower DJ. Homogeneous accretion of the Earth in the inner Solar System, Nature Astronomy, 27 March 2026, DOI: 10.1038/s41550-026-02824-7

Mission to Jupiter’s icy moon, Europa, begins on October 10th…amazing work by Galileo 400+ years ago on the largest planet in our solar system and its moons

Galileo turned his primitive telescope towards Jupiter in the early 1600’s and saw tiny specks of light with no discernable features. What a difference 400+ years can make as today’s backyard telescopes can resolve Europa’s disk surprisingly well. Europa is now considered one of the most complex and fascinating worlds in the solar system. Cracks, ridges, and chaotic terrain on the moon’s icy crust may offer access to one of the largest oceans in the solar system–and a possible abode for aquatic life.

From Watts Up With That?

Overview

Galileo turned his primitive telescope towards Jupiter in the early 1600’s and saw tiny specks of light with no discernable features. What a difference 400+ years can make as today’s backyard telescopes can resolve Europa’s disk surprisingly well. Europa is now considered one of the most complex and fascinating worlds in the solar system. Cracks, ridges, and chaotic terrain on the moon’s icy crust may offer access to one of the largest oceans in the solar system–and a possible abode for aquatic life. NASA’s Europa Clipper spacecraft, due to launch one week from now on October 10th, will conduct a detailed reconnaissance of the moon’s surface to help plan future missions including a lander and perhaps even a submarine. Europa Clipper’s main science goal is to determine whether there are places below the surface of Europa that could support life.

Discussion on Europa and the mission

Europa is a world that shows strong evidence for an ocean of liquid water beneath its icy crust which could very well host conditions favorable for life. NASA will place a highly capable, radiation-tolerant spacecraft named “Clipper” into a long, looping orbit around Jupiter to perform repeated flybys of the icy moon. In fact, the plan is to have 49 flybys of Europa at closest approach altitudes as low as 16 miles, soaring over a different location during each to scan nearly the entire moon. With its massive solar arrays and radar antennas, Europa Clipper will be the largest spacecraft NASA has ever developed for a planetary mission. The spacecraft needs large solar arrays to collect enough light for its power needs as it operates in the Jupiter system, which is more than five times as far from the Sun as Earth. The spacecraft will be about 16 feet (5 meters) in height. With its arrays deployed, the spacecraft spans more than 100 feet and has a dry mass (no propellant in the tanks) of 7,145 pounds. The launch date for this spacecraft is currently set for Thursday, October 10th with arrival at Jupiter in April 2030.

Credit: NASA/JPL-Caltech

Because Europa is bathed in radiation trapped in Jupiter’s magnetic field, Europa Clipper’s payload and other electronics will be enclosed in a thick-walled vault. This strategy of armoring up to go to Jupiter with a radiation vault was developed and successfully used for the first time by NASA’s Juno spacecraft. The vault walls – made of titanium and aluminum – will act as a radiation shield against most of the high-energy atomic particles, dramatically slowing down degradation of the spacecraft’s electronics.

For Europa to be habitable, it needs the essential building blocks for life including carbon, hydrogen, oxygen, and sulfur. Liquid water is essential for the complex chemistry that makes life on Earth possible. Many scientists predict a salty ocean lies beneath the surface of Europa which has more water than all of Earth’s oceans combined. While the icy moon of Jupiter is far from the sun, Europa gets the energy to sustain life from Jupiter’s strong gravity which creates tides that stretch and tug the moon producing heat. One of the most important measurements by the Galileo mission which previously explored Europa showed how Jupiter’s magnetic field was disrupted in the space around Europa. The measurement strongly implied that a special type of magnetic field is created (induced) within Europa by a deep layer of some electrically conductive fluid (like saltwater) beneath the surface, which interacts with Jupiter’s strong magnetic field.

The amazing work of Galileo

Peering through his newly-improved 20-power homemade telescope at the planet Jupiter on Jan. 7, 1610, Italian astronomer Galileo Galilei noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with regard to the background stars and they remained in Jupiter’s proximity but changed their positions relative to one another. He later observed a fourth star near the planet with the same unusual behavior. By Jan. 15, Galileo correctly concluded that they were not stars at all but moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth. In March 1610, Galileo published his discoveries of Jupiter’s satellites and other celestial observations in a book titled Siderius Nuncius (The Starry Messenger).

Top: Two of Galileo’s telescopes. Bottom: Page from Galileo’s notebook about his observations of Jupiter’s satellites. Credits: National Geographic, gabrielevanin.it, University of Michigan Special Collections Library.

As their discoverer, Galileo had naming rights to Jupiter’s satellites. He proposed to name them after his patrons the Medicis and astronomers called them the Medicean Stars through much of the seventeenth century, although in his own notes Galileo referred to them by the Roman numerals I, II, III, and IV, in order of their distance from Jupiter. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer. The German astronomer Johannes Kepler suggested naming the satellites after mythological figures associated with Jupiter, namely Io, Europa, Ganymede, and Callisto, but his idea didn’t catch on for more than 200 years. Scientists didn’t discover any more satellites around Jupiter until American astronomer E.E. Barnard found Jupiter’s fifth moon Amalthea in 1892, much smaller than the Galilean moons and orbiting closer to the planet than Io. It was the last satellite in the solar system found by visual observation – all subsequent discoveries occurred via photography or digital imaging. As of today, astronomers have identified 79 satellites orbiting Jupiter.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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No One Talks About It: Solar System “Climate Change”… Happening Beyond Planet Earth

Mysteriously, warming is happening across the solar system. The one common factor is at the center of it all: the sun.

From NoTricksZone

By P Gosselin on 12. September 2023

Mysteriously, warming is happening across the solar system. The one common factor is at the center of it all: the sun. 

Artist's Concept of Solar Storm Hitting Mars
The solar system’s powerful sun. Artist’s image of a solar storm hitting Mars, stripping ions from the planet’s upper atmosphere. Image: NASA, public domain. 

Because man is burning fossil fuels, our planet is allegedly becoming increasingly covered by a blanket of “heat-trapping” greenhouse gases, scientists like to make people believe. The recent global warming simply couldn’t have anything to do with the sun, they insist.

They’re likely way off the mark.

Today German prof. Stefan Homburg tweeted a summary of warming that’s happening at other places within our solar system, suggesting the sun is behind it.

“Global warming isn’t only happening on earth,” he tweets.

Triton has warmed 3°K

For example, warming is happening on Triton, Neptune’s moon. According to Germany’s wissenschaft.de: “Neptune’s giant moon Triton is the first body in the solar system where global warming could be detected.”

According to measurements, the atmospheric pressure doubled and the temperature rose 3 degrees Kelvin. “The cause is probably higher solar irradiation of the nitrogen ice cap at Triton’s south pole.”

Mars warmed 0.65°K since 1970s

German online news weekly Stern also reported in 2007: “The average temperature on Mars has risen by about 0.65 degrees Celsius since the 1970s,” citing American astronomers. Blamed here, though, are Martian dust storms. Why would dust storms on Mars be getting stronger? It’s likely linked to increased solar activity.

The Moon 3°C warmer, due to man!

Newly analyzed temperature data show the surface temperature of the moon raised by about three degrees Celsius, reported Germany’s Business Insider here in 2018. But NASA blames the astronauts!  “By walking around and poking at the lunar surface.”

“Climate change” on Pluto

According to www.wissenschaft.de here, Pluto’s atmosphere has warmed to being 40°K warmer than the temperature at the surface (-220°C). The reason for this temperature gradient is the “absorption of sunlight [by methane] reflected from Pluto’s surface into the atmosphere.”

Methane makes up only half a percent of Pluto’s  atmosphere. This small fraction heats the atmosphere in sunlight.

But not only Triton, Pluto and Mars are warming in our solar system, as Prof. Homburg suggests, other planets are warming as well. And there’s only one common denominator: The Sun. Global warming scientists do all they can to ignore this rampaging elephant in the room.

Jupiter’s “planetary heat wave”

Scientists last year found “an unexpected ‘heat wave’ of 700 degrees Celsius, extending 130,000 kilometers in Jupiter’s atmosphere.”

What’s behind it? Jupiter experiences variable intensity auroras around its poles as an effect of the solar wind.

Saturn heating

The surface of Saturn has been “slowly heating up” as well, reports Popular Science here. But NASA blames Saturn’s rings for the recent phenomenon.

“According to the paper, the most feasible explanation is that icy ring particles raining down onto Saturn’s atmosphere cause this heating. writes Popular Science. “A few things could be driving this shower of particles, including the impact of micrometeorites, bombardments with particles from solar wind, solar ultraviolet radiation, or electromagnetic forces picking up electrically charged dust. Additionally, Saturn’s gravitational field is pulling particles into the planet while this is all occurring.

Note how it’s never the sun’s solar activity and variability. It’s always some mysterious explanation.

Yet, there’s a reason why it’s called the “solar” system. It’s because the sun is at its center, and so its solar storms and variability impact all the bodies in it.

Neptune’s Disappearing Clouds Linked to the Solar Cycle

Weather forecast for Neptune: After sunny weather for the past few Earth years, we’ll see increasingly more clouds over the next few years.

From NASA/Hubblesite

Summary

As Sunspots Come and Go, So Does the Cloudy Weather on the Blue Giant Planet

Weather forecast for Neptune: After sunny weather for the past few Earth years, we’ll see increasingly more clouds over the next few years.

In 1989, NASA’s Voyager 2 spacecraft provided the first close-up images of linear, bright clouds, reminiscent of cirrus clouds on Earth, seen high in Neptune’s atmosphere. They form above most of the methane in Neptune’s atmosphere and reflect all colors of sunlight, which makes them white.

On that frozen frontier the Sun is still influential regarding the Neptunian weather that produces cloud cover. At Neptune’s distance of nearly 3 billion miles, the Sun appears starlike at 1/30th the diameter of the full Moon. This feeble radiation is 1% the amount of starlight as received on Earth

Yet the Sun’s influence on Neptune became increasingly obvious when astronomers looked at 30 years of Neptune observations with the Hubble and Keck telescopes. Neptune’s abundance of clouds waxes and wanes over an 11-years cycle. The Sun also has an 11-year cycle where it becomes stormy as its magnetic fields become entangled, increasing sunspot number and rate of violent outbursts.

Neptune Cloud Cover Over Three Decades

Astronomers have uncovered a link between Neptune’s shifting cloud abundance and the 11-year solar cycle, in which the waxing and waning of the Sun’s entangled magnetic fields drives solar activity.

This discovery is based on three decades of Neptune observations captured by NASA’s Hubble Space Telescope and the W. M. Keck Observatory in Hawaii, as well as data from the Lick Observatory in California.

The link between Neptune and solar activity is surprising to planetary scientists because Neptune is our solar system’s farthest major planet and receives sunlight with about 0.1% of the intensity Earth receives. Yet Neptune’s global cloudy weather seems to be driven by solar activity, and not the planet’s four seasons, which each last approximately 40 years.

At present, the cloud coverage seen on Neptune is extremely low, with the exception of some clouds hovering over the giant planet’s south pole. A University of California (UC) Berkeley-led team of astronomers discovered that the abundance of clouds normally seen at the icy giant’s mid-latitudes started to fade in 2019.

“I was surprised by how quickly clouds disappeared on Neptune,” said Imke de Pater, emeritus professor of astronomy at UC Berkeley and senior author of the study. “We essentially saw cloud activity drop within a few months,” she said.

“Even now, four years later, the most recent images we took this past June still show the clouds haven’t returned to their former levels,” said Erandi Chavez, a graduate student at the Center for Astrophysics | Harvard-Smithsonian (CfA) in Cambridge, Massachusetts, who led the study when she was an undergraduate astronomy student at UC Berkeley. “This is extremely exciting and unexpected, especially since Neptune’s previous period of low cloud activity was not nearly as dramatic and prolonged.”

To monitor the evolution of Neptune’s appearance, Chavez and her team analyzed Keck Observatory images taken from 2002 to 2022, the Hubble Space Telescope archival observations beginning in 1994, and data from the Lick Observatory in California from 2018 to 2019.

In recent years, the Keck observations have been complemented by images taken as part of the Twilight Zone program and by Hubble’s Outer Planet Atmospheres Legacy (OPAL) program.

The images reveal an intriguing pattern between seasonal changes in Neptune’s cloud cover and the solar cycle – the period when the Sun’s magnetic field flips every 11 years as it becomes more tangled like a ball of yarn. This is evident in the increasing number of sunspots and increasing solar flare activity. As the cycle progresses, the Sun’s tempestuous behavior builds to a maximum, until the magnetic field beaks down and reverses polarity. Then the Sun settles back down to a minimum, only to start another cycle.

When it’s stormy weather on the Sun, more intense ultraviolet (UV) radiation floods the solar system. The team found that two years after the solar cycle’s peak, an increasing number of clouds appear on Neptune. The team further found a positive correlation between the number of clouds and the ice giant’s brightness from the sunlight reflecting off it.

“These remarkable data give us the strongest evidence yet that Neptune’s cloud cover correlates with the Sun’s cycle,” said de Pater. “Our findings support the theory that the Sun’s UV rays, when strong enough, may be triggering a photochemical reaction that produces Neptune’s clouds.”

Scientists discovered the connection between the solar cycle and Neptune’s cloudy weather pattern by looking at 2.5 cycles of cloud activity recorded over the 29-year span of Neptunian observations. During this time, the planet’s reflectivity increased in 2002 then dimmed in 2007. Neptune became bright again in 2015, then darkened in 2020 to the lowest level ever observed, which is when most of the clouds went away.

The changes in Neptune’s brightness caused by the Sun appear to go up and down relatively in sync with the coming and going of clouds on the planet. However there is a two-year time lag between the peak of the solar cycle and the abundance of clouds seen on Neptune. The chemical changes are caused by photochemistry, which happens high in Neptune’s upper atmosphere and takes time to form clouds.

“It’s fascinating to be able to use telescopes on Earth to study the climate of a world more than 2.5 billion miles away from us,” said Carlos Alvarez, staff astronomer at Keck Observatory and co-author of the study. “Advances in technology and observations have enabled us to constrain Neptune’s atmospheric models, which are key to understanding the correlation between the ice giant’s climate and the solar cycle.”

However, more work is necessary. For example, while an increase in UV sunlight could produce more clouds and haze, it could also darken them, thereby reducing Neptune’s overall brightness. Storms on Neptune rising up from the deep atmosphere affect the cloud cover, but are not related to photochemically produced clouds, and hence may complicate correlation studies with the solar cycle. Continued observations of Neptune are also needed to see how long the current near-absence of clouds will last.

The research team continues to track Neptune’s cloud activity. “We have seen more clouds in the most recent Keck images that were taken during the same time NASA’s James Webb Space Telescope observed the planet; these clouds were in particular seen at northern latitudes and at high altitudes, as expected from the observed increase in the solar UV flux over the past approximately 2 years,” said de Pater.

The combined data from Hubble, the Webb Space Telescope, Keck Observatory, and the Lick Observatory will enable further investigations into the physics and chemistry that lead to Neptune’s dynamic appearance, which in turn may help deepen astronomers’ understanding not only of Neptune, but also of exoplanets, since many of the planets beyond our solar system are thought to have Neptune-like qualities.

The findings are published in the journal Icarus.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.

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NASA, ESA, STScI, UC Berkeley, Keck Observatory