Comets, the frozen leftovers from the formation of the Solar System, have always been a matter of curiosity for
scientists across the world, as they could hold clues about the formation of the universe. Astronomers have now
discovered an object, bigger than a comet, on the outskirts of the Solar System, and it is hurtling towards us.
Dubbed as 2014 UN271, the object is likely to make a close pass by the Sun, bringing it into Saturn’s orbit in 2031. The
object was observed in data from the Dark Energy Survey conducted between 2014 and 2018.
Estimated to be between 100 to 370 kilometres in width, the object is bigger than the normal specification of a
comet and is likely to be a dwarf planet.
A 6,00,000 year orbit
When first observed in 2014, the mega comet was about 29 Astronomical Units away from Sun — 1 AU is the distance
between Earth and Sun. Since then, the 2014 UN271 has travelled nearly 7 AU and is now nearly 22 AU away from Sun.
This distance brings it closer to us than Neptune. At its closest approach to planets in our Solar System, it is expected
to pass by just 10.9 AU of the Sun, almost reaching the orbit of Saturn.
One of the most unique aspects of the observation is the massive orbit of this mega comet that extends between the
inner solar system and the Oort cloud on the boundary of interstellar space spanning around 6,12,190 years.
Interstellar space is the region beyond the heliosphere where Sun’s influence wanes and solar winds slow down.
Astronomers expect that before it reaches Saturn and as it gets closer and closer to the Sun, the object will develop the
typical characteristics of a comet that includes a tail, and the coma formed as the material on the surface vaporises
from the heat and radiation of the Sun.
Not the first visitor from the edge of Solar System
As 2014 UN271 visits the outer solar system from the edge of the interstellar space, it is not the first to journey its way
into our system. A cigar-shaped object travelling at 92,000 kilometres per hour entered our Solar System travelling
around the Sun before it was sent back to interstellar space in 2017. Named ‘Oumuamua’, which means “visitor from
afar arriving first” in Hawaiian, it was the first visitor from interstellar space to be detected by Earth.
Scientists had trained almost all observatories and telescope to study this visitor, which was observed to be 1,300 feet
in length and 2,600 feet in width. While scientists believe it originated from the Lyra constellation, it did not have a tail
like other comets which made scientists speculate that it could be an asteroid or a new class of interstellar object.
By Cynthia N.