STEPHEN
Welcome to Idaho Skies for
the weekend of December 6th. We’re your hosts, Stephen…
DAN
…and Dan.
STEPHEN
On the 8th, Comet
Borisov reaches perihelion. So let’s talk about perihelion and Comet Borisov.
The word perihelion comes from the Greek “peri” and that’s the prefix meaning “about”
or “around”. Think of the word perimeter as an example. And the word Helion comes
from the word Helios, which is the Greek name for the sun.
DAN
Perihelion can only occur for
objects that travel in non-circular orbits. That means at perihelion, objects
like Comet Borisov pass their closest to the sun. However, Comet Borisov has an
orbit that’s a bit odd - it’s hyperbolic and not elliptical in shape. That
means the orbit of Borisov doesn’t begin nor end in our solar system.
STEPHEN
Comet Borisov is traveling so fast
that it will escape our solar system. It didn’t pick up this speed from a close
pass to another planet in our solar system. Instead, it’s traveling so fast because
it escaped from another star system and fell into ours. The gravity of another
object in its original solar system must have kicked it into interstellar
space.
DAN
Astronomers predict that there’s
at least one interstellar visitor in our solar system at any given time. They
approach the sun in a hyperbolic orbit and then fly away to never be seen
again. Currently, visits by interstellar objects are the best way we can study
the materials and formation of other solar systems.
STEPHEN
That’s Idaho Skies
for the weekend of December 6th.
DAN
Be sure to read our blog for additional information.
It’s at idahoskies.blogspot.com
For Idaho Skies this is Dan…
STEPHEN
…and Stephen.
DAN
Dark skies and bright stars.
No comments:
Post a Comment