New Discoveries from Our Second Interstellar Visitor | SciShow News


[♪ INTRO] This year, scientists have had a chance to
study something pretty mind-boggling: a comet that came from outside of our solar system. The comet appeared this summer, and on December
8th, it made its closest approach to the Sun. It’s called 2I/Borisov, and it’s only
the second interstellar object we’ve ever detected. The second interstellar interloper,
if you will. It’s traveled billions of kilometers to
get here, and so long as it’s in our neighborhood, there’s a lot we can learn from it about regions
of space far beyond our own. In fact, there’s a lot we’re already learning. Last week, NASA released a shiny new image
of the comet, and over the last few weeks, scientists have published a handful of new
papers about it. And so far, all this research is demonstrating
that 2I/Borisov is full of surprises. The comet was discovered this August by a
Crimean telescope engineer named Gennady Borisov. Who, for the record, discovered this comet
using a telescope he built himself! I have a hard time building IKEA furniture. After Borisov saw the object, he submitted
his findings to the astronomy community so more researchers could take a look. And ultimately, everyone’s early data indicated
that something was super weird. For one, this comet had a very weird orbit. Most objects around here travel in a closed
loop around the Sun, but 2I/Borisov seemed to have a highly hyperbolic orbit. In other words, it wasn’t actually orbiting
the Sun. Instead, it was on a path that would swing
around our star and then zoom off into the distance, never to return. Now technically, it is possible that something
within our solar system could get bumped into an orbit like that. There’s even some evidence of this happening on a smaller scale way out in the Oort Cloud beyond Pluto. But 2I/Borisov was traveling on a path that
was dramatically tilted compared to the rest of our neighborhood. It also seemed to be moving especially fast,
at more than 30 kilometers per second. So, with that kind of speed and orbit, well, scientists eventually concluded that this thing wasn’t from around here. We mentioned this discovery on SciShow Space
in late September, but since then, scientists have been observing 2I/Borisov
as much as possible. And some of their results have been published
over the last few days or weeks. Using images from various ground and space
telescopes, these researchers have characterized every aspect of the comet they could. They’ve calculated its size and shape, the
rate it’s losing mass, and how it reflects light in different wavelengths, something that can tell us about its composition. So, now we know a few things. Like, the data show that the comet’s body,
called the nucleus, is less than 500 meters across. And they also show that its dust tail, or
coma, has a similar composition to some comets from the Oort Cloud. In fact, based on these results, if this comet
had come from inside our solar system, it would be pretty unremarkable. Which that’s actually kind of remarkable. Especially if you compare this comet to the
only other interstellar visitor we know of: ‘Oumuamua, which zoomed past us in 2017. With its probably cigar-like shape and shiny
surface, ‘Oumuamua was among the weirdest objects anyone had ever seen. So, how come 2I/Borisov looks so normal, even
though they’re both from interstellar space? Well, we don’t know, and it’s way too
early to make generalizations. The most we can say from these 2 data points is that the 2 objects seem to come from 2 different spots. By working back from their current trajectories, scientists think 2I/Borisov came from the general direction of the constellation Cassiopeia. Meanwhile, ‘Oumuamua likely came from somewhere
in the direction of the star Vega. So maybe that explains some of the differences. But also, let’s be honest: 2 data points
representing all interstellar objects… It’s just not a lot to go on. As telescopes get better and better at resolving
faint objects, we may have better luck at making more
discoveries like this. But until then, we’ll be left with more
questions than answers. The good news is, one way or another, we are
not done with 2I/Borisov yet! While we only saw ‘Oumuamua on its way out
of the solar system, we caught 2I/Borisov while it was sill coming in, so we have more time to observe it. It will be making its closest approach to
Earth around December 28th, so we’ll be able to study it with the best precision yet. And that means there will be plenty more to
learn about our second visitor from interstellar space. Thanks for watching this episode of SciShow
Space News! As December winds down, we wanted to remind
you about our Pin of the Month club. Every month, we release a new space-themed pin that you can use to celebrate your love of exploration. And this month, we’ve got one of an astronaut
riding around on the Apollo 17 lunar rover! It was designed by one of the amazing animators
on the SciShow team, and it’s really just so good. Also, it’s a great chance to tell people
about that one time we drove buggies on the Moon. If you want to get a pin for you or a friend,
they’re only available until the end of the month! You can find them at DFTBA.com, or in the
merch shelf below this video. [♪ OUTRO]