- Borisov is the first identified comet to visit our solar system (from another star).
- It is the second known interstellar object to pass through the solar system.
- The comet’s nucleus (a cluster of dust and ices) is approximately 975 meters across.
Comets are icy celestial body (made of rock, dust, and gases) that orbit the Sun. So far, more than 6,600 comets have been identified and the number is steadily increasing. However, there are about one trillion comet-like bodies in the outer Solar System.
Recently, a research team at the University of California, Los Angeles, identified a comet streaking through our solar system. They captured images of this comet, named 2I/Borisov, using Hubble Space Telescope.
This the first identified comet to visit our solar system (from another star) and the second known interstellar object to pass through the solar system. The first known object was Oumuamua, 1I/2017 U1. It was discovered via the Pan-STARRS telescope in 2017.
What Do We Know About This Comet?
Hubble telescope has been following the comet since October 2019. The sharpest views revealed that a loose cluster of dust and ice particles (the heart of 2I/Borisov) is approximately 975 meters across.
Since its chemical composition is similar to the other comets found inside the solar system, it might have formed around other stars. Researchers do not know when and where the Borisov started heading toward the Sun, but it will soon leave our solar system.
The Sun’s gravitational force is deflecting the comet’s trajectory to some extent, but cannot capture it because of its high velocity (160,000 km/h) and orbit’s shape.
At the moment (late December), Borisov is making its closest approach to Earth at a distance of 290,000,000 kilometers. By the mid-2020, it will be 800,000,000 kilometers from Earth on its way back to its interstellar roots.
Image captured on 16th November
NASA has released two magnificent images captured by the Hubble Telescope. The image obtained in November shows Borisov in the front of a distant spiral galaxy.
In this exposure, the comet is nearly 327,000,000 kilometers from Earth. The blue color reveals fine detail in the halo of dust surrounding the comet’s nucleus (a cluster of dust and ices).
Source: NASA | Hubble Space Telescope
Image captured on 9th December
Borisov received significant heating after its closest approach to the Sun. In this photo, the comet is near the asteroid belt’s inner edge, about 297,000,000 kilometers from Earth.
Hubble data show that the comet’s nucleus is 15 times smaller than what previous studies proposed. This is important information: the size of the comet could help scientists calculate the number of similar objects in our solar system and galaxy.
There are billions of similar comets out there, and most of those are faint and unspectacular. Researchers will continue their search for the next mysterious visitor from the frozen abyss of space.