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Astronomers have searched for years for rocky planets beyond our solar system with an atmosphere, a trait considered essential for any possibility of harbouring life.
they finally located one, But this hellish planet, apparently with a surface of molten rock, offers no hope for habitability.
Researchers said on Wednesday the planet is a "super-earth", a rocky world significantly larger than our planet but smaller than Neptune, and it orbits perilously close to a star dimmer and slightly less massive than our sun, rapidly completing an orbit every 18 hours or so.
Infrared observations using two instruments aboard the James Webb Space Telescope indicated the presence of a substantial, if inhospitable, atmosphere, perhaps continuously replenished by gases released from a vast ocean of magma.
The planet, called 55 Cancri e or Janssen, is about 8.8-times more massive than the earth, with a diameter about twice that of our planet.
It orbits its star at one-25th the distance between our solar system's innermost planet Mercury and the sun.
As a result, its surface temperature is about 1,725 degrees C.
The planet is probably tidally locked, meaning it perpetually has the same side facing its star, much like the moon does toward the earth.
The planet is located in our Milky Way galaxy about 41 light-years from the earth, in the constellation Cancer.
A light year is the distance light travels in a year, 9.5 trillion km.
Four other planets, all gas giants, are known to orbit its host star.
The James Webb Space Telescope (JWST) is a revolutionary observatory launched in December 2021.
Here are its key features that make it crucial for exoplanet research:
1. Infrared Vision: Unlike Hubble Space Telescope which primarily observes visible and ultraviolet light, JWST focuses on infrared wavelengths.
This allows it to see cooler objects like exoplanets that are often hidden by the glare of their host stars in visible light.
2. High Resolution and Sensitivity: JWST boasts a massive mirror and advanced detectors, enabling it to see faint objects in exquisite detail.
This is essential for distinguishing exoplanets from the background and studying their atmospheres.
3. Coronagraphy: JWST is equipped with special instruments called coronagraphs that can block out the light of a star, allowing scientists to directly image the faint light reflected by orbiting exoplanets.
4. Spectroscopy: JWST can analyze the spectrum of light passing through an exoplanet's atmosphere, revealing the presence of various molecules like water vapor, methane, and carbon dioxide.
This information provides clues about the planet's potential habitability.
JWST's Role in Exoplanet Research:
Discovery of new exoplanets: JWST's ability to detect faint, distant objects makes it ideal for finding new exoplanets, especially smaller, rocky planets in the habitable zones of their stars.
Characterization of exoplanet atmospheres: By analyzing the atmospheres of exoplanets, JWST can help determine their composition, temperature, and potential for harboring life.
Understanding planetary formation: Studying exoplanets at various stages of development can provide insights into how planetary systems form and evolve.
Overall, JWST is a game-changer in exoplanet research.
It allows us to see farther, with greater detail, and uncover the secrets of these distant worlds, bringing us closer to finding another Earth-like planet.
Key differences between gas giants and rocky planets
Composition:
Gas Giants: Primarily composed of lighter elements like hydrogen and helium, with a small rocky core.
Rocky Planets: Made mostly of heavier elements like oxygen, silicon, iron, and magnesium.
Size and Mass:
Gas Giants: Much larger and more massive than rocky planets.
Jupiter, the largest gas giant in our solar system, is 318 times more massive than Earth.
Rocky Planets: Smaller and less massive than gas giants.
Earth is the largest rocky planet in our solar system.
Atmosphere:
Gas Giants: Thick and extensive atmospheres composed mainly of hydrogen and helium, with some methane, ammonia, and water vapor.
Rocky Planets: Can have a wide variety of atmospheres, ranging from very thin (like Mercury) to thick and dense (like Venus) or even absent (like Mars).
The composition of the atmosphere depends on the planet's size, temperature, and geological history.
Formation:
Gas Giants: Formed further out from the star where it's cooler, allowing lighter elements to condense.
They may have accreted large amounts of hydrogen gas from the protoplanetary disk.
Rocky Planets: Formed closer to the star where it's hotter, causing lighter elements to vaporize.
They accreted heavier elements leftover from star formation.
Surface:
Gas Giants: No well-defined surface because the gas giants are fluid down to great depths.
As pressure increases towards the core, the hydrogen gas might eventually turn metallic.
Rocky Planets: Have a solid, rocky surface with features like mountains, valleys, and craters.
Habitability:
Gas Giants: Not considered habitable due to their extreme pressure, composition, and often violent weather patterns.
Rocky Planets: Have the potential to be habitable if they are in the star's habitable zone (the region where liquid water can exist on the surface) and have a suitable atmosphere.
Earth is the only known habitable planet so far.
Examples:
Gas Giants: Jupiter, Saturn, Uranus, Neptune
Rocky Planets: Mercury, Venus, Earth, Mars
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