Comet Bernardinelli-Bernstein, about 150 kilometers across, may be the largest comet ever detected. The comet will pass through the inner solar system in 2031. With a bit of luck it should then be visible with an amateur telescope.
Bernardinelli-Bernstein, named after are discoverers Pedro Bernardinelli and Gary Bernstein, is about a thousand times more massive than a typical comet. The object is so large that scientists initially thought that it was a dwarf planet. However, further observations revealed that the object was beginning to form a tail, indicating that it is a comet. A comet’s tail forms as it approaches the sun, because gas and dust from the comet is heated up and blown away.
The comet is currently 29 astronomical units (AU) from the sun. An AU is the distance between the Earth and the Sun, or about 150 million kilometers. That means that Bernardinelli-Bernstein is about 4.5 billion kilometers from the sun. According to its discoverers it takes the comet a staggering 3.5 million years to complete one orbit around the sun. In addition, Bernardinelli-Bernstein is at its furthest point an almost unimaginable 40,000 AU from the sun.
A happy accident
Bernardinelli-Bernstein offers scientists a great opportunity to study a comet in the early stages of its approach to the sun. Yet his discovery was not planned at all. Bernardinelli found the comet entirely by accident, barely a week before he had to defend his thesis. By the way, his thesis was about a completely different subject, namely the so-called transneptunian objects (TNOs). Bernstein wasn’t looking for comets at all either. He was looking for dark matter, a form of matter that does not interact with ordinary matter, but does exert gravity.
The scientists were therefore surprised when they discovered the colossal comet. They did this by using data from the 570-megapixel Dark Energy Camera (DECam) in Chile by digging. DECam was used to dark energy to (try to) detect. That is a force that makes the universe expand, but scientists still have no idea what dark energy is.
Back in time
Until the dark energy case kicks in, scientists will use the images captured with DECam for other purposes. They use the images, among other things, to discover new objects in the solar system. DECam is now no longer operational, but on the basis of the data obtained with the camera, researchers could 817 objects identify.
According to Bernardinelli these observations are extremely valuable because they can give us a better view of the early years of our solar system. Objects beyond Neptune formed during the early years of the solar system and, due to their distance, have not been affected by the rest of the solar system. According to Bernardinelli, this ensures that they can contain valuable information about the formation of our solar system. Who knows, maybe we’ll get one step closer to an answer the big questions of life.
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