Although their name suggests that they are comets, the shape of “dark comets” is closer to that of an asteroid as they do not have a “tail.” However, they sometimes show great accelerations due to the gas expelled from their surface and show a movement similar to that of a comet. In these characteristics, the dark comet is very similar to 1I/’Oumuamua, which was identified in 2017 as the first interstellar object from outside the Solar System.
On December 9, NASA confirmed the discovery of seven new dark comets, extremely interesting and mysterious objects. The list of these celestial objects amounts to a total of 14, and it is clear that dark comets can be classified into at least two types: interior and exterior of the Solar System.
An ‘asteroid’ provided the first clue
In 2016 the orbit of the celestial object 2003 RM was discovered; At first it was believed to be an asteroid, as it was slightly different from the orbit expected in the calculations. This change was caused by the acceleration of the object; However, this increase was so large that it could not be applied due to the Yarkovsky effect, which is the most common cause of asteroid acceleration. The Yarkovsky effect is what occurs when a celestial body is heated by radiation from the sun, and this in turn radiates heat in the form of electromagnetic waves. The waves have pressure and, although they are influenced by several factors, they accelerate the celestial body by a very small amount and affect its orbit.
However, the acceleration caused by the Yarkovsky effect is negligible. Specialists theorize that the large acceleration that caused RM 2003’s orbital change was probably due to gas eruptions on the surface. “When such a change in the orbit of a celestial object is observed, the change is due to acceleration due to surface outgassing, and the object is generally considered a comet,” explains the co-author of the paper.
However, no matter how hard you look, you cannot find the comet-like tail of RM 2003. For a long time, astronomers had no choice but to treat this body as a “foreign object” that they could not understand. in its entirety. In 2017, ‘Oumuamua was confirmed to be the first interstellar object said to have come from outside the Solar System.also had a tail and its orbit changed as it accelerated due to the gas gushing from the surface.
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