The Fastest Objects In The Universe Insane Curiosity
Did you know that some galaxies move relative to us faster than the speed of light?
Interesting huh?!
Actually, the universe is getting bigger all the time.
Some of the nearest galaxies to the Milky Way are receding at a rate surpassing 240,000
kilometers per hour.
And those are the slow pokes; the most distant galaxies actually zoom away from us faster
than the speed of light.
It’s important to bear in mind that this high-speed galactic exodus breaks no laws
of physics, however, from its viewpoint; the universe itself is expanding, that is the
very spacetime fabric upon which all of existence is stitched.
Curious to know more about our extreme Cosmos?
Keep watching!!
Astronauts and cosmologists orbiting the Earth on the international space station easily
exceed the land speed record which is over 1200 kilometers per hour, since they are hurtling
around the globe with velocity around 28,000 kilometers per hour.
And the fastest any human has ever travelled is 39,000 kilometers per hour which is equivalent
to 11 kilometers per second; it’s a speed hit by the american astronauts aboard Apollo
10 during their return from the Moon in May 1969.
These speeds sound to be very impressive until we realize that they are outpaced by even
the mundane astronomical objects.
In this video we are introducing the fastest objects in the universe!
Passage 1
1- Starting with our own planet Earth that orbits the Sun once each year, the Earth must
maintain an average speed of more than 107,000 kilometres per hour in order to stay in orbit.
Even though we are ferried along at this agitated speed at every moment of our daily lives,
we don’t feel its effects- luckily for us- and that’s because the Earth is approximately
moving in a straight line that’s the curve of its orbit is very slight and its course
is changing by only around 1 degree per day.
Therefore, despite the high velocity of our planet’s orbital motion, its orbit is so
big that the effects are virtually diminished.
It’s crucial to note that the Earth speed is far beyond the speeds we are used to experiencing
on a daily basis, however, the Earth in turn is dwarfed by the frantic speed that many
other celestial bodies routinely encounter.
2- The Earth orbits the Sun at 107,000 kilometers per hour but it’s easily outpaced by Mercury,
the innermost planet in our solar system.
Well suited by its name which means the fast-moving messenger to the gods, this hot and small
rock orbits the sun at more than 170,000 kilometers per hour.
Mercury was the fastest moving planet we knew of until the 1990s, however, various new discoveries
of planets outside our solar system revealed that Mercury no longer ranks even in the top
100 and it’s also quite pedestrian by our modern standards.
As of July 2020, there are 4,281 confirmed planets in 3,163 systems with 701 systems
having more than one planet.
Additionally, more planets are being added to the list on a weekly basis.
These other worlds known as extrasolar planets or exoplanets are a strange group, usually
bearing some resemblance to the familiar planets of our own solar system.
The most remarkable discovery among these exoplanets has been a category of planets
known as “Hot Jupiters” and yes, they are named so because they are gas giant planets
like our own Jupiter, the only difference is that their orbits are extraordinarily close
to their parent stars.
Consequently, a typical Hot Jupiter is separated from its parent star by only 5% of the Earth-Sun
distance and races around its entire orbit in a couple of days.
Comparing this to Mercury that sits about 40% of the Earth distance to the Sun and takes
88 days to complete one orbit, we can realize how Mercury is a real stroller!
The fastest moving Hot Jupiter is called WASP-12b which orbits an unremarkable star known as
“2 MASS J06303279+2940202” or “MASS J0630” ,for short, located 870 light years
from Earth in the constellation Auriga.
The term WASP refers to “ Wide Angle Search for Planets” and the number “12” is
because this was the 12th star for which the WASP project discovered an orbiting planet,
moreover, the “b” letter is placed to indicate that the planet is the second object
known in this star system.
For example, “WASP-12a” would be the parent star itself.
Meanwhile, if a second planet were discovered around this star it would be called “WASP-12c”.
It’s worth mentioning that WASP-12b is far too faint to be directly observed via any
telescope and that’s because its parent star outshines it by a factor of 3000.
Instead, it was discovered through a simple, but not easily applicable, technique called
the transit method.
3- The fastest Earth-sized planet, discovered by NASA’s Kepler Space Telescope, is called
Kepler-78b which is so close to its parent star that a year on that exoplanet lasts about
8.5 hours, making it the one of the fastest exoplanets ever seen.
The planet is far outside the habitable zone of its parent star, where liquid water and
maybe life could exist.
Due to these findings, scientists have described the Kepler-78b as a “lava planet”.
However, a good relieving discovery for scientists is that the parent star of this planet is
bright enough for other telescopes to closely spot and observe its surface along with the
other undiscovered planets that could exist in this star’s system.
Due to the fact that Kepler-78b is bearing a resemblance to the earth from a size perspective,
it’s more likely to be a hot Earth.
Actually, it’s about 100 times closer to its star than the Earth is to the Sun; in
addition to this, it’s orbiting a star system that’s about 750 million years old which
is about six times younger than the solar system.
The planet's surface temperature reaches from 2,026 to 2,826 degrees celsius.
4- Due to the homogeneity and isotropy of our universe, measuring any dynamical property
of a celestial body depends on a particular reference frame, such that, there’s no preferred
point in our universe.
For example; when we measure the speed of an object, the answer depends on our point
of view.
One physical concept to understand is the Doppler effect which is, by definition, an
increase or decrease in the frequency of sound, light or other waves as the source and observer
move “towards” or “ away from” each other.
The effect causes a sudden change in pitch noticeable in a passing siren, as well as
the Red Shift seen by astronomers.
Bearing this concept in mind, any claims of a cosmic speed record need to be qualified
by the point of view from which they were measured.
In particular, we have illustrated how the exoplanet WASP-12b orbits its parent star
at an extremely fast speed which is actually measured from the perspective of the parent
star itself.
You may ask yourself, if we are going to consider the relative velocity of the astronomical
objects at hand, such as exoplanets and their parent stars, then what if the star is also
moving across space at some high speed?
Actually, this is a very good question.
From an external point of view, our Sun is considered to be a racing star.
As is every star we can normally see with the naked eye, the Sun is in orbit around
the centre of the Milky Way galaxy.
Additionally, the Milky Way rotates at an extremely slow rate that our solar system
takes more than 200 million years to complete one cycle around the centre of the galaxy.
However, the length of the cycle is approximately 170,000 light years.
Therefore, even though the Sun might take 200 million years to cover one cycle, it has
no time to slow down as recent measurements have shown that the Sun’s orbital speed
around the Milky Way is around 914,000 kilometers per hour which sounds to be an extreme speed
from our point of view, however, most of the stars in our neighbourhood are following similar
orbits which appear to be gradual and circular orbits around the centre of the Milky Way.
Nevertheless, recently, astronomers have discovered a population of what is known to be “hypervelocity
stars” whose velocities exceed those of other regular stars like our Sun and follow
very different trajectories.
The existence of hypervelocity stars is strongly related to supermassive black holes at the
centre of most of the galaxies like the Milky Way.
More specifically, in 1951, australian astronomers “Jack Piddington” and “Harry Minnett”
built a radio telescope in the south-western suburbs of Sydney.
One of their important findings was an intense source radio emission coming from the Constellation
Sagittarius at the center of the Milky Way.
That source turned out to be a supermassive blacke hole and it’s called “Sagittarius
A*” pronounced A-star.
it also sits at the exact geometric center of our galaxy; everything in the Milky Way
circles around the centre in an orbit except for Sagittarius A* which stays still.
Furthermore, observations show that Sagittarius A* is millions of times heavier than the Sun,
however, it’s so small that it could actually fit inside the orbit of Mercury.
Before explaining the relation between hypervelocity stars and supermassive black holes such as
Sagittarius A*, be sure to like or dislike the video so that we can continue to improve
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Back to our question, what does a supermassive black hole at the centre of the Milky Way,
the one object in the entire galaxy that is perhaps not moving at all, have to do with
hypervelocity stars?
As an answer to this question, in 1998, astronomer Jack Hills considered a reasonable scenario
when two tightly bound stars that orbit each other in a binary system have a close encounter
with a supermassive black hole.
The straightforward guess is that the two stars will just fall into the black hole and
disappear forever.
However, Hills realised that, occasionally, the black hole’s gravity will be able to
break the binary system into two separate stars and one of them will be captured by
the black hole while the other one can be launched away at an extremely high speed of
one million kilometers per hour.
The first hypervelocity star in our galaxy was discovered by the astronomer Warren Brown
in 2005.
Using the MMT observatory in Tucson, Arizona, astronomers led by Dr. Brown at the Harvard-Smithsonian
Center for Astrophysics are the first to report the discovery of a star named SDSS J0907 leaving
our galaxy, speeding along at over 1.5 million miles per hour.
According to their report, this incredible speed is likely the result of a close encounter
with the Milky Way’s central black hole, which in turn flung the star outward like
a stone from a slingshot.
So strong was the event that the speedy star eventually will be lost altogether, travelling
alone in the blackness of intergalactic space.
Their findings are in agreement with Jack Hills’ proposed model of hypervelocity stars
back in 1998.
Brown and his colleagues spotted the first stellar exile in 2005, European groups identified
two more, one of which may have originated in a neighbouring galaxy known as the Large
Magellanic Cloud.
The latest discovery brings the total number of known exiles to five.
Astronomers suspect that about 1,000 exile stars exist within the galaxy.
By comparison, the Milky Way contains about 100 billion stars, making the search for hypervelocity
stars much more difficult.
5- In 1912, Austrain physicist Vector Hess, discovered the cosmic rays; it was a pioneering
discovery for which he won the 1936 Nobel prize.
Today we know alot about the cosmic rays, first of all they are not rays at all but
mostly they are protons and other subatomic particles.
The Milky Way is flooded with them and they travel extremely fast since they typically
travel at around 99% of the speed of light, which is faster than almost everything else
in the universe, but still 11 million kilometers per hour slower than the light itself.
However, the fastest speed ever measured in the universe, except for light itself, was
precisely set at 1:34 am and 16 seconds on Tuesday 15 October 1991, near Dugway town,
Utah in the United states.
At this particular moment, the “Fly’s Eye” telescope, which was designed for the
search of cosmic rays, detected a shower of sparks coming from a cosmic ray which was
probably a proton that slammed into the Earth’s atmosphere.
The scientists operating the telescope were able to measure the speed at which the proton
was travelling before being scattered into pisces, the proton was moving at 99.9999999999999999999996%
of the speed of light.
Cosmic-ray scientists refer to this particular proton as the “Oh-My-God particle”, they
have also suggested many models that describe the origin of such high speed cosmic rays.
6- The universal speed limit is the speed of light which is about 1 billion kilometers
per hour, so far exceeding this limit was discovered!
Thanks for Watching Everyone!
Do you know the names of the discovered hypervelocity stars other than the one mentioned in the
video?
Can you guess how the hypervelocity stars help with the search of dark matter in our
galaxy?
Did you learn anything new in this video?
Let me know in the comments below, be sure to subscribe, and I’ll see you next time
on the channel!