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18: The Solar System - Geosciences

18: The Solar System - Geosciences


18: The Solar System - Geosciences

Special Issue Editors

The present Special Issue is dedicated to the study of the evolution of planets and satellites of our solar system. Since the solar system features astounding objects of various natures, this Special Issue will gather a large variety of scientific contributions.

The evolution of rocky bodies, satellites, and most icy satellites intrinsically cannot be observed at human time scales. Nonetheless, many surface features and various measurable quantities provide hints regarding a body&rsquos history that both theoretical and numerical models can attempt to reproduce. We therefore welcome contributions on either the observational or the modeling side.

The evolution of gas giants and some icy satellites is more closely related to observations of their current dynamics, occurring on much shorter time scales than on rocky bodies. The current issue therefore welcomes observations that can be related to the long-term evolution of gas giants or models/simulations of the evolution itself.

We also welcome contributions on the evolution of exoplanets.

Concluding, this Special Issue welcomes articles on the following topics:

  • Studies dedicated to the evolution of one or several selected planets, satellites or exoplanets
  • Observations of features related to the evolution of selected planets, satellites or exoplanets
  • The evolution of rocky planets, satellites, and gas giants in general, from a theoretical point of view
  • Review articles dedicated to any of the previous points.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Geosciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.


[ECS Interview] On the surface of Churyumov-Gerasimenko with Philae and Anthony

Rosetta recently made a breathtaking dive towards the surface, bringing a wealth of science close from the surface, but also bringing the mission to its end. The operations might be over, but the science is not as there is still a lot of data to analyse, especially for the next generation of cometary scientists.

To illustrate this new generation, we asked a few questions to an early career scientist: Anthony Lethuillier who recently defended is PhD thesis and is now a post-doc at the LATMOS laboratory near Paris in France.

What is your background?

I studied geology and geophysics during my bachelor and master courses and it was only during the last year of my masters that I specialized in planetary science. In October 2013 I started my thesis at the LATMOS lab. My thesis was dedicated to the data collected on the nucleus of the comet Churyumov-Gerasimenko by the SESAME-PP instrument on-board the Philae lander.

You were working on the Philae lander, could you tell us more about what you were doing?

My thesis was dedicated to the data acquired by the SESAME-PP instrument on-board the Philae lander. The objective of SESAME-PP was to measure the electrical properties of the close subsurface of the comet (down to 1m). To achieve this the instrument uses transmitting electrodes (located on one of the feet of the lander) to inject a signal into the subsurface, it then records this signal on two receiving electrodes (located on the two other feet of the lander). The difference in amplitude and phase of the transmitted and received signal allows us to derive the electrical properties of the subsurface. These properties are the dielectric constant and the electrical conductivity and they depend on the composition and temperature of the material located in between the electrode. Once these values are known we perform lab measurements on the electrical properties of potential analogues to try and determine the composition of the subsurface.

1:1 replica of Philae in tests in LATMOS, France (left) and in in-situ simulations in Dachstein ice caves in Austria.
Credit: A. Lethuillier/CNES/LATMOS

To derive the electrical properties I built 3D numerical model of the lander and its close environment. We also used a replica (scale 1:1) of the instrument and the lander we built to validate our method. This replica was used during field tests in the Dachstein ice caves in Austria (the closest we could get to a surface similar to a cometary surface).

Philae had a bit bouncy landing, wasn’t that a problem for you?

Yes it was for two reasons, the first is that the Lander entered a backup mode in which our instrument only performed part of the measurements it was supposed to do. The second, more important, problem was that the environment was far from flat and the position of the lander was unknown. To properly derive the electrical properties we need to know as precisely as possible the topography of the environment and the instruments attitude with regards to the surface.

Despite these limitations, using the available information on the lander’s position, we were able to constrain the porosity of the subsurface using accurate 3D numerical models.

3D modeling of the position of Philae after it landed in the Abydos region on the comet.
Credit: A. Lethuillier/CNES/LATMOS

What are your main conclusions then ?

We combined measurements of electrical properties performed on carbonaceous chondrites and on water ice with the measurements performed on the nucleus and found that the first meter of the nucleus has a maximum porosity of 55 %. We are only able to give a upper limit to the porosity due to the limitations explained above and we are not able to provide any information on the dust/ice ratio.

This value can then be compared to the porosity measured by the CONSERT radar which determined that the bulk porosity of the comet was between 70-80%. This lead us to the hypothesis of a consolidated shell covering a more porous interior. This is supported by the results from other instruments.

This shell could be, for example, the result of ice cementing processes where ice from the deep interior sublimates and refreezes when closer to the surface (our measurements were performed during the cometary night when the temperature is not high enough for the ice in the first meter to sublimate).

After a quite long search, Philae has been found. How does that influence your results?

We compared the picture taken by Osiris to our model in a similar orientation and found that our model was quite correct. By correcting our model we will find a more accurate value of the porosity but our conclusions will stay the same (a nucleus more compact on the surface).

Comparison of the numerical models of the attitude of the lander (left) and the actual position of Philae as seen from Rosetta.
Credit: A. Lethuillier and ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

In general what Rosetta result stands out according to you?

The ratio of Deuterium with regard to Hydrogen (D/H) in water is an important indicator its origin (theoretical simulations show that its value is dependent on the distance from the Sun at which the water formation took place). The origin of Earth’s ocean water can be investigated with this method: previous measurements on asteroids have shown a good agreement with Earth water. The D/H ratio measured on 67P/C-G is 3 times the ratio measured in the Earth’s oceans, suggesting that Jupiter family comets are not the source of Earth ocean–like water.

The interpretation made by multiple instruments of a consolidated shell covering a more porous interior will probably have a great influence on cometary formation models. The detection the amino acid glycine (found in proteins) and phosphorus (an essential part of DNA) by the ROSINA mass spectrometer is also quite stunning. The presence of geological features (identified by the OSIRIS camera) reminiscent of those found on earth was quite unexpected. The characterization of the comet’s water ice cycle (by the Rosetta spectrometer VIRTIS) is also very important for understanding the evolution of comets in general.

What are your plans for the future?

For the next three months I will be working on the PWA-HASI instrument of the Huygens lander (an instrument similar to SESAME-PP) to try and constrain the porosity of the surface of Titan. After that who knows ? I am looking for a post-doc that would allow me to keep on working on space instrumentation that helps understand the subsurface of planetary objects


Solar system project ideas

These easy solar system project suggestions are perfect for parents, teachers, or homeschooler to make the solar system interseting for kids and kick-start your solar system for kids lesson!

Tap Light Planets from Play at Home Mom 3. I love how this project will light up your childs room and serve as an educational night light.

Make practicing the names of the planets and the order of the planets from the sun with this easy to make Paint Stick Solar System Project. I love that there is an activity to this clever, unique science project for kids.


Planets Snowglobe from Red Ted Art. This science craft is such a creative way for kids to learn about the planets in our solar system and review day after day.


Solar System Brownies from Almost Unschoolers. This easy-to-make and yummy solar system project is sure to be a favorite of kids for years to come.


Paper Mache Planets from At Home with Ali. This inexpensive, DIY planet project uses baloons and paper mache to create a beautiful science project.


Playdough Solar System from Childhood Beckons. This project is simple to make as it uses a tactile material you probably already have on hand! This is a science project you can make and remake over and over again.

Solar System Button Craft from Relentlessly Fun, Deceptively Educational. If you have a stash of buttons you aren’t sure what to do with, this solar system planet project is just what you are looking for. Have your child repeat the planet names over and over again to help them retain the knowledge.


Felt Solar System from Counting Coconuts. For your crafty students, they will enjoy making their own solar system with just a little bit of sewing. This is a great activity to improve cordination and fine motor skills too.


Yarn Solar System from Art for Little Hands. This project combines yarn and paper mache to make really cool looking planets to display in your homeschool room.

Even preschoolers can help make these shaggy Yarn Planet balls There is no messy paper mache in this projects. Just wrapping and cutting to create planets you can hang or toss around.


Yarn Wrapped Planets from And Next Comes L. Yet another fun yarn project is an easy science craft for toddler, prek, and kindergarten age kids to complete. Plus it is great for using up random yarn pieces too.

This chalk planet project is an easy to make project to make today. Plus don’t miss the fun solar system game to help teach kids planet names, planet rotation, and time for the planets to get around the sun.


Plastic Lid Solar System from Still Playing School. I love how this project reuses plastic lids you probably have on hand from your weekly garbage.


Lego Solar System from Kitchen Counter Chronicles. Kids love making creations with Lego! This project allows kids to use their creativity and STEM to make their own brick solar system project. Have one child make the entire solar system or work together by having each child make a different planet.


Solar System Poster from Crafts n Coffee. Pop over to Joann Fabrics, Michaels, or Hobby Lobby and grab some different shaped foam balls to make this super cute solar system project perfect for a science fair board.


Solar System Mobile from Taming the Goblin. This solar system is not only fun to make, but great for hanging up in your homeschool room to remind your students about the planets.


Marble Solar System for Play from I Can Teach My Child. Do you have marbles laying around from a marble run or jacks? You can quickly whip up this creative solar system.


Hanger Solar System from Crafts and Coffee. Another creative idea for a hanging solar system for kids you can hang in your childs room.


18: The Solar System - Geosciences

Geosciences begin with the ground we walk on, delve inward to the center of the Earth and expand outward to other planetary bodies in our solar system. Time spans of interest to geoscientists range from the formation of the solar system through the evolution of the continents, atmosphere, biosphere, and natural resources to the present day.

Geoscientists study the composition, structure, and history of our surroundings and ultimately provide us with a better sense of ourselves, the universe around us, and our connection to everything.

Geoscientists employ remote sensing and geospatial information sciences technology while working on ships, climbing mountains, studying volcanoes, and digging for dinosaur bones in the desert. Geosciences careers appeal to those who enjoy working outdoors and traveling places both domestic as well as international. We've had students and alumni visit all seven continents and even travel in space.

The mission of the Department of Geosciences is to deliver a challenging, stimulating, and useful education in geosciences to undergraduates and graduates at all degree levels and to add to our understanding of the Earth through the research of students, faculty, and staff. And the department always appreciates keeping in contact with its former students.


Planetary geologists are really the Solar System’s forensic scientists

I have always been much more impressed by the natural world than by anything envisioned by the human mind. The beauty and complexity of nature seems to stand out, a deep and wondrous gallery not limited by our own thoughts or imaginations. Rocks and minerals especially interest me because, for the most part, they last all living organisms are magnificent in their time, but they fade quickly. It seems almost otherworldly that many geologic landscapes and individual minerals formed over tens of thousands to millions of years, when we live maybe a hundred years and the oldest trees, a few thousand. Geologic attractions such as the Grand Canyon, the hot springs at Yellowstone, and the volcanoes of Hawaii – three places I had the privilege of seeing when I was young – inspire awe among everyone who visits. But as much as I was fascinated by rocks and minerals and their longevity growing up, I could never really grasp how and why they form the way they do.

I got the chance to learn answers to those questions when I became an undergraduate research assistant early on at Rensselaer Polytechnic Institute working with experimental geochemist and mineral physicist Dr. Heather Watson. Together, we investigated the formation of metal cores in planetesimals, objects in our solar system around 100 kilometers in diameter. I was (and still am) fascinated that we can study fundamental planetary processes from samples smaller than a thumbtack, whether they be synthetic rocks I have produced in the lab or meteorites from space. This project expanded my curiosity from not only individual rocks and minerals, but to entire planets and planetary systems.

As a planetary scientist, I compare different objects in the solar system to figure out how they formed and why they are similar or different. For example, the Moon and Mercury are roughly the same size, but they are very different chemically and physically. On one hand, the Moon has a small metal core and large rocky shell, like an apple where the small seeds in the middle are the metal core. On the other hand, Mercury has a gigantic metal core compared to its thin, rocky shell, like an avocado with its large seed. Planetary cores are important because the magnetic fields they can produce protect life from harmful radiation, and among the inner solar system rocky bodies, only Earth and Mercury currently have substantial magnetic fields.

Why is this? What was the solar system like when planets formed? And if planets formed billions of years ago and millions of kilometers away, how can we study them to find out why?

Peeling back Mercury’s structural past through chemistry
To answer questions like these, we obviously can’t go back in time to watch Mercury form or see the inside of planets with X-ray vision. But we can study meteorites, which were the building blocks of the planets. And while we can infer that certain meteorites formed under similar conditions as Mercury due to chemical similarities, the other way to study these materials is to recreate natural processes in the lab to produce synthetic rocks, kind of like an alchemist, and compare them to our natural samples. In these ways, I also think of myself as a forensic scientist who looks at meteorites (the crime scene) to glean insights into solar system conditions during planetary formation (the crime). In the laboratory, I can create synthetic rocks under controlled conditions where I know both the crime (geological processes) and crime scene (planetary materials), though in a simplified system to disentangle more complicated natural samples like meteorites and Mercury.

Aluminum mount with meteorite chips embedded in indium (soft metal). Aubrites are in the top right third, EH chondrites in the top left third, and EL chondrites in the bottom third.

Let’s go back to our example of the Moon versus Mercury. Using both meteorites and synthetic rocks, we can try to understand why these planetary bodies have such different chemical and physical structures. As it turns out, there was at least one key difference when they were forming: the amount of oxygen.

Mercury had a lot less oxygen than the Moon (and Earth) when it formed. Without oxygen to oxidize things – like a car rusting – elements tend to be in a reduced state, meaning they have more electrons. When they’re reduced, some elements like iron prefer to be in metal rather than rock. This is consistent with Mercury’s large metal core more iron (Fe) moved into the core from the rocks, causing chemical (FeO or Fe2O3 in rock → Fe in metal) and physical (smaller, iron-poor rocky surface → larger, iron-rich core) changes. This lack of oxygen also opened the door for other elements, like sulfur, to replace oxygen in mineral and melt structures. Sulfur is a relatively abundant volatile element and is extremely reactive in part because it can exist under a range of charges from 2- to 6+, bonding to different elements (magnesium sulfide and calcium sulfide on Mercury compared with mostly iron sulfide on Earth and the Moon) under different redox (reduction and oxidation) conditions.

Chemical RGB images (Mg:Fe:S) of a) MAC 88136 (EL3) and b) LAR 12156 (EH3) showing fractured enstatite, metal, and sulfide textures in the meteorites.

Having two major anions (sulfur + oxygen) in the rocks changed the way Mercury evolved compared with the Moon and Earth that only have one (oxygen). These chemical differences affected Mercury’s physical structure by influencing the ability of certain minerals that incorporate iron, magnesium, and calcium to form. This led to Mercury’s rocky shell to have more of some minerals, like enstatite, and less of others, like plagioclase, compared with the Moon. While we have not yet visited Mercury, we do have certain meteorites —called enstatite chondrites and aubrites— that formed under similarly oxygen-poor and sulfur-rich conditions, which flew around space relatively unchanged for billions of years before crash-landing on Earth. We can use these specific meteorites to study Mercury’s chemical history.

How much oxygen did the early inner solar system have?
As a planetary “forensic” scientist, my work pieces together the chemical and physical evolution of Mercury, meteorites, and the asteroids the meteorites broke off of. My NSF/GSA-funded project aims to understand the redox environment and volatile elements of the early (4.48-4.57 billion years ago) inner solar system, where the rocky planets like Mercury and Earth formed. I explore these questions by looking at how volatile elements (elements like sulfur or chlorine that you would expect to be in a gas rather than a solid at Earth’s surface think of the rotten egg smell of hydrogen sulfide gas at hot springs or the distinctive smell of chlorine gas around a chlorinated pool), are stored in meteorites formed in very low-oxygen conditions. Without oxygen, many of these elements can get locked away in increasingly high amounts in rocks —the clue this forensic planetary geologist is looking for.

If a meteorite has minerals consistent with an oxygen-poor planet, such as magnesium sulfide and calcium sulfide, we can use the amount of sulfur in the mineral enstatite to quantify the early solar system’s oxygen environment. Pairing measurements on our tiny, precious meteorite samples with synthetic rocks created under known conditions, we found evidence for incomplete reduction of silicate minerals (including enstatite) in contrast with uniformly reduced metal during meteorite formation. This indicates a time in the early inner solar system with an oxygen- and hydrogen-poor, sulfur- and carbon- rich, and chlorine-bearing gas environment. We can also quantify the volatile budget of Mercury’s interior and to identify which volatile elements were responsible for the surprisingly high amount of explosive volcanism observed on a planet that formed so close to the Sun.

Author measuring volatile concentrations in meteorites using the Cameca IMS 1280 SIMS instrument at Woods Hole Oceanographic Institution.


Planetary system

A planetary system is a set of gravitationally bound non-stellar objects in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals [1] [2] and circumstellar disks. The Sun together with the planets revolving around it, including Earth, is known as the Solar System. [3] [4] The term exoplanetary system is sometimes used in reference to other planetary systems.

As of 1 July 2021, there are 4,777 confirmed exoplanets in 3,534 planetary systems, with 785 systems having more than one planet. [5] Debris disks are also known to be common, though other objects are more difficult to observe.

Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water, and thus the capacity to support Earth-like life.


Location of Stephenson 2-18

Stephenson 2-18 Star located in a cluster of stars “ Stephenson 2 ” that exist in the constellation of Scutum.

Scutum is a type of small constellation located in the southern celestial hemisphere (southern sky) in our Galaxy Milky Way. So Stephenson 2-18 also locates in the Milky Way Galaxy.

The estimated distance of Stephenson 2-18 star is around 19000 light-years away from the Earth . That is equal to almost 6,000 parsecs.


Answer your questions:

Can you find all the NASA and space-themed hidden objects?

Where there are signs of water, there might also be signs of life!

Learn about impact craters!

You probably know that a year is 365 days here on Earth. But did you know that on Mercury you’d have a birthday every 88 days? Read this article to find out how long it takes all the planets in our solar system to make a trip around the Sun.

Drive around the Red Planet and gather information in this fun coding game!

The biggest planet in our solar system

Each of the planets in our solar system experiences its own unique weather.

Yes, there is ice beyond Earth! In fact, ice can be found on several planets and moons in our solar system.

We can use a planet’s gravitational pull like a scale!

Learn more about what happens when the moon passes between Earth and the sun!

It all has to do with the distance between Earth and the sun and Earth and the moon.

Learn more about asteroids, meteors, meteoroids, meteorites, and comets!

And what can we learn from these space rocks in our solar system?

Make a mask and pretend to be your favorite planet in our solar system!

This future mission will try to find out if life ever existed on the Red Planet!

Mars had water long ago. But did it also have other conditions needed for life?

What did these twin rovers teach us about the history of water on Mars?

Learn more about the first rover to land on Mars!

How do rovers help us learn more about the Red Planet?

The coldest planet in our solar system

The planet that spins on its side

The planet with beautiful rings

The biggest planet in our solar system

The planet with living things

The hottest planet in our solar system

Learn more about the planets in our solar system

Learn to make a graph with the answer!

We have one, but some planets have dozens.

It's not because the Moon gets hit by meteors more often.

Dwarf planet Pluto is still fun to study.

The icy bits past Neptune’s orbit

The smallest planet in our solar system

Interstellar space begins where the sun’s magnetic field stops affecting its surroundings.

How far would we have to travel to get there?

Jupiter's core is very hot and is under tons of pressure!

The answer isn't so simple.

The story starts about 4.6 billion years ago, with a cloud of stellar dust.

Write your own zany adventure story!

For the New Moon, you must eat all the creme filling!

These are yummy and need no baking!

Make yummy potatoes look like asteroids.

And what are they made of?

Turn an old CD into Saturn's rings.

Astronomers may have found a planet without a sun!

Explore the many volcanoes in our solar system using the Space Volcano Explorer.

Could they have brought the water to our planet?

Glorious planets and moons to view or print.

These spacecraft traveled to the outer planets!

What do you get when you cross an earthquake with a tidal wave?

Put clues together to find the planets and moons.

What is out there that you cannot see with your bare eyes?

Paint pumpkins with space and Earth science designs

Share these with your friends and family!

And how does it help us find new planets?

Marshmallow? Chewy caramel? Nuts?

Help the big antennas gather data from the spacecraft.

Help Juno reveal Jupiter's true nature.

Paper models of your favorite solar system explorers. This link takes you away from NASA Space Place.


As all the planets have different orientation and tilt of their orbits, so it becomes quite rare for the eight major planets of the Solar System to come into perfect alignment. The last time they appeared even in the same part of the sky was over 1,000 years ago, in the year AD 949, and they won’t manage it again until 6 May 2492.

The solar system have 205 natural satellites with different planets .
Jupiter – 79
Saturn – 82
Uranus – 27
Neptune – 14
Mars -2
Earth – 1


Solstices and Equinoxes

The Zodiac display is centred on the Earth and oriented with the tilt of the earth. This display shows in which sign of the zodiac the Sun lies at any time. The sign of the Sun at a persons birth is called that person's Star Sign.

The Zodiac is locked to the tilt of the earth in this way: Because the earth is tilted the Sun lies in the northern hemisphere for six months and then in the southern hemisphere for six months. When the Sun crosses from the northern to the southern hemisphere this is called the Vernal Equinox and this event defines the direction between Aries and Pisces and hence the orientation of the whole Zodiac for the following year.

Currently, the winter and summer solstices occur as the Sun crosses the vertical zodiac line and the spring and autumn equinoxes when the Sun crosses the horizontal zodiac line. So, to use our anti-clockwise clock analogy (e.g. with the app in northern hemisphere mode) the winter (December) solstice is when the Earth is exactly at 12 o'clock from the Sun, the spring (March or Vernal) equinox is when the Earth is at 9 o'clock from the Sun, Summer (June) Solstice - it's at 6 o'clock and autumn (September or Autumnal) Equinox - it's at 3 o'clock from the Sun.

The longest and shortest days occur at the Solstices. At the Equinoxes, the day is almost exactly the same (12 hours long) all over the world.

Solstice and Equinox Data Courtesy of Fred Espenak, www.Astropixels.com


Watch the video: Gravity Visualized