NASA images reveal the structure of two cosmic nebulae
The Snail nebula resembles a glowing eye with a bright shell around the center. The horse's Head looks different: its recognizable silhouette forms a dark cloud of gas and dust against the background of a brighter nebula. Both objects have been repeatedly photographed by space telescopes, but there are different processes behind the external similarity to terrestrial images. The snail shows what happens to the star at the end of its life, and the Horsehead is located in the area of new star formation. About what the images of space telescopes have shown and why the nebulae look exactly like this, see the "Izvestia" material.
Snail shell of a dying star
The Snail nebula, also known as NGC 7293, is located in the constellation Aquarius about 650 light-years from Earth. It's a planetary nebula.: This is the name of the luminous gas that the star ejected at a late stage of its existence. The name has nothing to do with planets — it was fixed due to the fact that some such objects seemed similar to planetary disks when observed with small telescopes.
"""" Hubble's images show numerous comet-like formations along the inner edge of the gas shell: each has a dense "head" and an elongated "tail." These are not celestial bodies flying through the nebula, but patches of its own matter. They occur where faster gas flows interact with previously ejected material.
In January 2026, NASA presented an image of a small section of the Snail, obtained by the "James Webb" telescope in the near infrared range. On it, these structures are visible in much more detail. "Webb" took a close-up of part of the shell, so the familiar contour of the "eye" in the new frame is not fully visible. The white dwarf in the center of the nebula also remained outside of this image.
Details are also important for understanding chemical processes. The radiation from the white dwarf illuminates the surrounding gas, closer to it the substance is more heated and ionized, and further there are colder regions with molecular hydrogen. More complex molecules can persist and form in areas protected by dust. Thus, the image shows not only the beautiful structure, but also how the matter of the dying star returns to the interstellar medium.
A horse's head is a dark cloud on a light background
The Horsehead Nebula, or Barnard 33, is located in the constellation of Orion about 1300 light-years from Earth. Its characteristic shape is the result of the accidental resemblance of a dense protrusion of an interstellar cloud to the head of a horse. In visible light images, the cloud appears dark because the dust obscures the light of the bright IC 434 nebula located behind it. Therefore, the "head" stands out primarily as a silhouette.
The shape of the cloud is gradually changing under the influence of radiation from nearby massive stars. The less dense gas around it dissipates faster, while the dense protrusion lasts longer. This allows us to study how stellar radiation heats and destroys interstellar matter. Changes are taking place on astronomical timescales: according to NASA estimates, millions more years may pass before the recognizable structure is destroyed.
Images from different telescopes show a Horse's Head in different ways. Her dark silhouette is clearly visible in the visible light. Infrared observations allow you to explore areas that dust usually hides from view. In April 2024, NASA released images of the upper part of the cloud obtained by "James Webb". The telescope's cameras examined the boundary between dense cold matter and gas, which is affected by the ultraviolet radiation of young stars. This frame is a close-up of the edge of the nebula, not a new image of the entire silhouette.
Why do the pictures look so different?
Images of space objects depend on the range of light in which they are observed and how the data is processed. "Hubble" showed recognizable general outlines of a Snail and a Horse's Head, and "James Webb" allowed us to study in more detail individual areas of their gas and dust in the infrared range. The colors in scientific images help distinguish between the observed structures and ranges of radiation; they do not always correspond to how an object would be seen by the human eye.
The origin of the nebulae themselves also differs. The snail is the shell left after the star has shed its outer layers. The Horsehead is a dense part of a much larger cloud associated with the birth of stars. Their spectacular shapes attract attention, and observations in several ranges allow us to explore what happens to matter at opposite stages of stellar life.
Переведено сервисом «Яндекс Переводчик»
