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  • Back in 2019, a mysterious comet from a far away star system whizzed by Earth.

  • At first glance, the visitor, named 2I/Borisov, seemed to be rather ordinary,

  • but studies since have revealed signs that it is far from an average comet.

  • Now, two research studies released in March 2021 have shed new light on our visitor, and helped unveil information

  • about our own solar system. When Borisov was first sighted by an amateur astronomer, initial data suggested it was a typical comet.

  • Meaning it was made of things like ice, dust, and gassy materials that researchers had all seen before in our solar system.

  • Soon after its finding, NASA's Scout system at JPL automatically identified the comet as a potential interstellar object.

  • This software alerted astronomers across the world, and they quickly pointed their instruments toward Borisov to learn more.

  • And what exactly were those astronomers looking for in this alien comet?

  • In order to study a comet, astronomers take a look at the particles being expelled from the comet's surface.

  • In fact, you're probably most familiar with images showing a comet shedding their outermost layer, in what's known as a coma.

  • The coma forms when comets pass close to their host star and are bombarded by heat and radiation.

  • Dust and debris break off from the comet's main body, and ice sublimates into gas.

  • And by studying the released particles, observers are able to make educated guesses about the composition

  • and the history of the comet. Previous studies found that Borisov likely contains between nine and twenty-six times

  • more carbon monoxide than other comets we've seen before, meaning that Borisov probably formed

  • in extremely cold temperatures around negative 250 degrees Celsius. And these latest studies have built upon

  • this conclusion to provide additional evidence of the comet's alien nature.

  • Using different methodologies, two recent studies took a closer look at Borisov's coma.

  • The first from the Armagh Observatory and Planetarium measured the reflected light of the coma.

  • As the light from the sun scatters through the particles, astronomers are able to determine

  • size, composition, and shape based on the electromagnetic waves.

  • The team concluded that the observed light was being reflected through extremely small particles,

  • suggesting that the comet is close to its original form.

  • This ultimately helps us to better understand the comet's origin.

  • And almost simultaneously, astronomers at the European Southern Observatory conducted a separate study

  • that measured heat signatures from Borisov's coma.

  • With a combination of data from VLT and the Atacama Large Millimeter/submillimeter Array, or ALMA, for short,

  • the team discovered millimeter-sized grains rich in carbon monoxide and water being expelled from the comet.

  • These findings suggest two things: number one, that Borisov comes from an extremely cold environment,

  • and number two, that it was more of a traveler than a stationary rock,

  • beginning in the inner area of a star system before being pushed outward and collecting ice along its journey.

  • Borisov likely moved further and further away until finally resting in an area deep within its star system

  • and undisturbed by either heat or radiation. Astronomers believe the process of Borisov exchanging materials

  • was influenced by giant planets in the early universe through a process calledgravitational stirring”.

  • And this same process is thought to have contributed to the formation of our solar system.

  • Unfortunately for researchers, Borisov has made its exit out of our Solar System, and they won't be able to make

  • any new observations of the comet.

  • These studies have left the astronomy community with many questions:

  • Is the star system Borisov hails from really so different from our own?

  • And how much has the comet actually changed since its creation?

  • And we'll hopefully get closer to answering some of these questions as teams across the world

  • are looking to study comets more closely, and learn about the star systems they originally come from.

  • The Vera C. Rubin Observatory is set to open in late 2022 and will hopefully detect interstellar objects while surveying the sky.

  • And the European Space Agency aims to launch its Comet Interceptor mission in 2029

  • to pursue traveling objects as they move through our Solar System, hoping to give us an even closer look

  • at visitors from distant galaxies.

  • Including Borisov, did you know that humans have only seen two objects from outside our solar system?

  • The first discovered in 2017, Oumuamua, which is the flat rock thought by many to be an alien spacecraft.

  • To learn more about the first interstellar comet, check out this episode on Oumuamua here.

  • Make sure to subscribe and thanks for watching.

Back in 2019, a mysterious comet from a far away star system whizzed by Earth.

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Meet the Interstellar Comet Helping Map the Solar System’s Evolution

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    Summer posted on 2021/07/12
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