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Cosmic disappearance: NASA solves the mystery of shrinking planets

Researchers have found that certain planets outside the solar system are shrinking due to the loss of their atmosphere

This artist rendering shows what the sub-Neptunian exoplanet TOI-421 b might look like. In a new study, scientists have found new evidence of how planets of this type can lose their atmosphere. Credit: NASA, ESA, CSA, and D. Player (STScI)
This artist rendering shows what the sub-Neptunian exoplanet TOI-421 b might look like. In a new study, scientists have found new evidence of how planets of this type can lose their atmosphere. Credit: NASA, ESA, CSA, and D. Player (STScI)

Certain planets outside the solar system appear to be losing their atmospheres and shrinking. In a new study using the Kepler space telescope, astronomers find evidence for a possible reason: the cores of these planets are pushing their atmospheres from the inside out.

Extrasolar planets range in size from small rocky planets to huge gas giants. In between are rocky super-Earth planets and larger sub-Neptunian planets with bloated atmospheres. But there is a suspicious absence - a "size gap" - of planets that are 1.5-2 times the size of Earth (or between Super-Earth and Sub-Neptune) that scientists are trying to understand better.

"Scientists have so far confirmed the discovery of more than 5,000 exoplanets, but there are fewer planets than expected that are 1.5-2 times the diameter of Earth," said Caltech/IPAC research scientist Jessie Christiansen, scientific director of the NASA Planetary Archive. A and lead author of the new study in The Astronomical Journal. "Exoplanet scientists now have enough information to say that this gap is no accident. Something happens that prevents planets from reaching this size or staying at it."

The scientists think that a possible explanation for this discrepancy is that some sub-Neptunian planets lose their atmosphere over time. This loss will happen if the planet does not have enough mass, and therefore gravity, to maintain its atmosphere. Sub-Neptunians that are not massive enough will therefore shrink to roughly the size of a super-Earth, leaving a gap between the two planet sizes.

But how exactly these planets lose their atmosphere is still a mystery. The scientists converged on two possible mechanisms: one called core-driven mass loss and the other photoevaporation. The study revealed new evidence supporting the first mechanism.

This video explains the differences between the main types of exoplanets. Credit: NASA/JPL-Caltech

Core-driven mass loss occurs when radiation emitted from a planet's hot core pushes the atmosphere away from it over time, "and that radiation pushes the atmosphere from below," Christiansen said.

The second leading explanation for the planetary gap, photoevaporation, occurs when a planet's atmosphere is actually blown out by the hot radiation of its host star. In this scenario, "the high-energy radiation from the star acts like a hair dryer on an ice cube."

It is believed that photoevaporation occurs in the first hundred million years of a planet, while core-driven mass loss occurs much later - closer to a billion years after its formation. But in both mechanisms, "if there isn't enough mass, you can't hold on and you lose the atmosphere and shrink," Christiansen added.

This artist rendering shows what the sub-Neptunian exoplanet TOI-421 b might look like. In a new study, scientists have found new evidence of how planets of this type can lose their atmosphere. Credit: NASA, ESA, CSA, and D. Player (STScI)
This artist rendering shows what the sub-Neptunian exoplanet TOI-421 b might look like. In a new study, scientists have found new evidence of how planets of this type can lose their atmosphere. Credit: NASA, ESA, CSA, and D. Player (STScI)

In this study, Christiansen and her colleagues used data from NASA's K2, an extended Kepler space telescope mission, to observe the Beehive and Evaporation star clusters, which are 600 to 800 million years old. Planets are generally thought to be the same age as their host star, so the sub-neptunities in this system would be beyond the age where photoevaporation could occur but below the age of core-driven mass loss.

So if they see that there are a lot of sub-neptunities in the clusters (compared to older stars in other clusters), they can conclude that photoevaporation did not occur. In this case, core-driven mass loss would be the most likely explanation for what happened to less massive sub-neptunities over time. Observations found that nearly 100% of the stars in these clusters still have sub-Neptunian planets orbiting them. Based on their size, researchers think they have retained their atmosphere.

More of the topic in Hayadan:

5 תגובות

  1. Parashat Beresheit of physics and geometry

    In the beginning, God created
    the infinite geometric emptiness.

    Geometric emptiness had an infinite amount of length.
    Geometric emptiness had an infinite amount of space.
    Geometric emptiness had an infinite amount of volume.

    The imagination filled the geometric emptiness with geometric shapes such as a circle, triangle, square, etc.

    The shape of the circle is created from a certain amount of closed length, containing a certain amount of area.

    The shape of the triangle was created from a certain amount of closed length, containing a certain amount of area.

    The square shape is created from a certain amount of closed length, containing a certain amount of area.

    And so on, many geometric shapes were created.
    And God will see that the infinite geometric emptiness contains only geometric shapes, and will fill the emptiness with a passive time that does not move from its place, and is completely at rest.
    Absolute resting passive time already presents a physical creation, which joins the geometric creation.
    The passive time, occupied an infinite geometric volume.

    And God will turn passive time into absolute cold, and this is how the limit of cold in the world is determined.

    And the passive time was absolute rest and absolute cold, and it occupied an infinite geometric volume.
    And God said - the deed we have done is good.

    And God saw the lonely and sad state of the passive time that is on the border of the cold, and added to it the joyful, multi-faceted quantitative energy.

    And God will drown in the cheerful quantum energy a physical law that says:
    Many appearances will the cheerful quantum energy have, but the ever-changing quantity will be preserved.

    And God saw that the joyful quantitative energy does change its appearances, while being careful to preserve the changing quantity - and said that this is good until very much..

    After these things, God commanded the passive time and energy to create together the substance that appears in many physical forms, such as gold, iron, carbon, hydrogen, and more.
    And the passive time and energy did as God commanded.
    A quantity of passive time was combined with a quantity of joyful energy, and from this particular combination of quantities, a physical form of gold was created.

    And once again, a quantity of passive time was combined with a quantity of joyful energy, and from this new combination of quantities, a physical form of iron was created.

    And once again, a quantity of passive time was combined with a quantity of joyful energy, and from this new combination of quantities, a physical form of carbon was created.

    And so the passive time and the joyful energy created many and varied physical forms, and many types of matter filled the geometric space.
    From these types of materials, the stars were formed.

    This is how the geometric space, full of passive time and energy, became the place of creation of stars that stand still and do not move.

    Then God commanded the stars to move, only in a screw-shaped orbit, which has 3 data.
    speed
    The diameter of the screw track,
    Advancement angle of the track.
    And the stars began to move as expected.
    They did not move in an open straight line path, nor in a closed circular path.

    Each planet moves in a Borgi orbit that has three data unique only to it - a unique diameter, a unique advancement angle, and a unique speed in a Borgi orbit...

    This form of orbit connected all the stars in the world
    For a wonderful movement unit in the shape of a discus.

    And God commanded this wonderful unit of movement, in which all the stars of the world are located - to move in a straight line.
    This wondrous movement unit was named a universe.

    The universe moves forever in a straight line, in an infinite space full of passive time and energy, when the stars in it move in spiral orbits -

    The speed of the universe in a straight line is absolute, and only an observer at absolute rest can notice it. (C12 estimated value)

    Man is always moving, because he lives on the surface of a planet.
    All the stars of the universe are always moving, and Noah's star does not exist.

    Therefore, man will never be in a state of absolute rest, and is unable to discern the absolute speed of the universe,
    which takes place in an infinite geometric space, full of passive time and energy.
    This infinite space is the place where stars are formed, and it is also the place where they disintegrate.
    When a star disintegrates, it gives up its passive time and its energy to the infinite space.

    The number of stars in the universe is finite but not fixed.
    Stars are always being formed, and they are always being destroyed.

    And man has not yet been created.
    The active time has not yet been created either,
    Only the passive time and the joyful energy were created, and they create the material of the stars..

    Light was also created, as waves of passive time,
    Waves of passive time move in the absolute rest and absolute cold of passive time, filling infinite space.

    Sunlight is waves of passive time, moving in an infinite space full of passive time, which is completely still and completely cold.

    There is no void in the world, and it is full of passive time and energy.

    And man had not yet been created, and had not yet spoken,
    When man was created, he received natural knowledge from the Creator.
    With this natural knowledge man invented language.
    When an ancient man approached a campfire, a natural knowledge miraculously reached him, and he gave it a name.
    The name chosen by the ancient man was completely arbitrary and consists of the combination of the letters חמ

    This is the secret of human language - which is the language of names.
    After an act that brings a person natural knowledge, a combination of letters is chosen to be the name of the natural knowledge.

    The ancient man knew this secret when he did an act and approached a fire, and then a knowledge of nature came to him, which received the name ... Ham.

    And since humans did not know the secret of words, they were caught in the trap of words, which turns every word into noise.
    The noise of words does not convey to a person any natural knowledge,
    And so he remains in a state of ignorance.

    Man is caught in the trap of words, and has never been able to free himself from it. The word trap is clearly shown with the help of the combination of the letters time.

    It is impossible to answer the question, what is the combination of the letters time, with the help of other combinations of letters.
    It is possible to answer this question, with the help of an act that brings natural knowledge to the doer.
    Time is the name of a natural knowledge that comes to man when he listens to his heartbeat.
    The person listening to his heartbeat detects the amount of "something" between every two beats, and for this something an arbitrary name is chosen consisting of the letters Z
    This time... is active time.

    There are two types of time, the passive time that actually exists in physical reality, and there is the active time that man invented, and it only exists in his imagination.
    Active time disappears as soon as you think about it.

    The man who was created on a planet is the one who invented the active time. Has the words past, present, future.
    Past and future are in man's imagination, when
    In physical reality there is only the present.

    Man, who was created on a planet in eternal motion, was caught in the trap of words, and was never able to free himself from it. Man loves the trap of words because it contains love and hope, anger and jealousy, and the escape hatches to the lie, to the truth, and to free imagination. With the trap of words man entered heaven, and the trap of words expelled him from there.
    The trap of words always works, and since then man has been looking for a new good language, and he has not yet found it.
    And since a new language has not yet been found, there is doubt whether everything written in this article will be understood.
    A. Asbar

  2. Engravings, all without the possibility of proof.
    The world is flat, water creates a uniform level.

  3. Pseudo-scientists, who insist on "finding out"...
    All space science is a waste of time and money, a lot of money. And nobody on earth is interested, except the pseudo-scientists who want more and more articles and huge research budgets…..

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