Astronomers were eagerly awaiting the arrival of comet MAPS, hoping for an unforgettable spectacle in this spring's sky. However, it has vanished, leaving behind only a simple cloud of dust.
Its discovery last January had raised high hopes due to its early detection. Usually, objects of this type are only spotted a few days before their approach to the Sun. This advanced detection is made possible by modern instruments that can now capture very weak signals from great distances. However, the most recent observations had shown that comet MAPS was much smaller than expected, with a nucleus only about 400 meters (1,300 feet) in diameter.
The most massive comets survive: here the nucleus of Halley's Comet as observed by Giotto
During its approach to the Sun, scientists tracked its trajectory using tools like the SOHO observatory. The object was moving at an impressive speed, exceeding 500 kilometers per second (1.1 million mph). Shortly before its closest pass to the Sun, a sudden increase in brightness was observed, likely signaling the beginning of its breakup. Subsequently, images showed an elongated trail with no distinct nucleus, confirming the fragmentation.
After it passed behind the occulting disk of the coronagraph, only a diffuse mass of material reappeared. The nucleus had completely shattered under the combined effect of the Sun's intense heat and gravitational forces. This rapid disintegration prevented the formation of a visible tail, thus depriving astronomy enthusiasts of the expected spectacle in the evening sky.
Comet MAPS on its way to the Sun.
Credit: NOAA This phenomenon is explained by the nature of these comets, belonging to the "Kreutz Group." Originating from the fragmentation of a larger body several centuries ago, they orbit very close to the Sun. Their survival depends largely on the size of their nucleus, with the smallest ones often being destroyed. Historical examples, like the Great Comet of 1882, were able to withstand thanks to a larger size.
For comet MAPS, the thermal shock proved fatal. After traveling in the deep cold of space, its nucleus warmed up abruptly, creating internal stresses. This temperature difference, added to tidal forces, caused it to burst apart.
The remains of the comet after its close approach to the Sun.
Credit: LASCO C3/ESA/NASA Kreutz comets: extreme solar visitors
These comets belong to a particular family named after the astronomer Heinrich Kreutz. They share similar orbits that bring them very close to the Sun, sometimes within 100,000 kilometers (62,000 miles) of its surface. The main hypothesis indicates that they all come from the breakup of a large comet about a millennium ago, giving rise to many fragments of different sizes.
Over time, these fragments continue to break apart during their solar passages. Only the largest ones, with a diameter of several kilometers, manage to survive and offer remarkable spectacles. Examples include the great comets of the 19th century, which impressed observers with their exceptional brightness.
The early detection of comet MAPS was unusual, as most of these objects remain invisible until their approach to the Sun. Modern instruments, such as telescopes equipped with CCD cameras, now allow them to be spotted earlier. This helps scientists better understand their behavior and evolution.
These comets represent an important subject of study for astronomy, as they highlight the extreme conditions near the Sun. Their fates, between survival and destruction, offer clues about the composition and resilience of cometary nuclei in our Solar System.