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Big picture, 2020 hasn’t been a great year.
But in the world of space exploration,
at least, it’s been pretty good!
I mean, humanity has sent missions to explore the Moon, Mars, and the Sun this year.
We snatched a piece of one asteroid and will be returning samples of another.
But of course, there are always discoveries that are more —
bigger, faster, or just plain cooler.
Including, in 2020, these three.
First, we have to go waaay back to January.
And also, to the beginning of the universe.
For the 700 million years or so after the Big Bang,
the universe was basically nothing but a fog of hydrogen gas.
And all that gas meant even light couldn’t freely travel around.
But!
We also know the first stars and galaxies were gradually
beginning to form during this time.
And back in January,
researchers announced the discovery of another key step in this saga:
the oldest known galaxy cluster.
Called EGS77, its light has taken so long to reach us that we’re seeing it as it appeared
just 680 million years after the Big Bang.
It consists of three galaxies, each separated by around two million light-years.
That makes them even closer than the Milky Way and our neighboring galaxy, Andromeda.
The cluster’s existence gives us a better sense of how the universe grew in complexity
in those early days.
But what’s more,
EGS77 seems to have played an active role
in the end of the cosmic dark ages.
At the time, it looks like its stars were shining brightly
with light in the far-ultraviolet part of the spectrum.
And far-ultraviolet light was responsible
for breaking up the fog of hydrogen covering the universe, in a process called ionization.
With hydrogen broken up, light could travel freely in the cosmos,
ushering in the universe we see today.
And eventually, more than 13 billion years later,
some of that light reached Earth and revealed all this to us.
Next, in other over-the-top discoveries, there’s a star called S4714.
Astronomers described it in a paper published in August.
It lives at the center of the Milky Way, and was spotted going ludicrously fast.
Like, more than 85 million kilometers per hour at its fastest.
That is 8% the speed of light.
An object traveling that fast could leave Earth on Monday
and arrive at Pluto by Wednesday night.
This star gets all its speed
by traveling within spitting distance of the Milky Way’s supermassive black hole,
called Sagittarius A*.
At its closest, it gets within 1.9 billion kilometers of the black hole —
which sounds like a lot to us, but is still extremely close.
Sagittarius A* has a mass around four million times greater than the Sun,
and all that mass means it creates a whole lot of gravity.
And all that gravity accelerates S7414 to its incredible speed.
It’s more than just a curiosity, though.
That close to our supermassive black hole,
the star directly experiences the mind-bending effects described
by Einstein’s general theory of relativity —
like, frame dragging.
As the black hole spins,
its intense gravity doesn’t just warp space: it actually twists it like a whirlpool.
And as the star travels through this shifting fabric, its orbit is constantly being affected.
So by studying its orbit,
astronomers should be able to better understand the subtle ways those effects can manifest.
That is, if they can catch a glimpse of this speedster blazing through the sky.
Finally, let’s talk size.
Astronomers are always looking to take better pictures and,
in September, a team of researchers announced a groundbreaking new result.
They had captured the highest-ever resolution in a single image:
3200 megapixels.
That’s around 30 to 60 times higher
than what you’ll find in even amazing consumer cameras.
And their target?
A leafy hunk of broccoli.
You heard me right:
2020 saw a major breakthrough in astronomy’s long-sought broccoli-based imaging system.
But, seriously, this vegetable pic was proof that we are on the doorstep
of the next major advance in astronomy.
See, the camera that took this gigapixel image won’t be shooting salads forever.
That picture was just for a test to see
how the camera would do with broccoli’s super-detailed surface.
Soon, the camera will be installed in the brand-new Vera C. Rubin Observatory in Chile,
which is scheduled to go live in 2021.
Once operational, each photograph it takes
will cover an area equal to 40 full Moons on the night sky.
At that size, it will be able to image the entire night sky every three days —
and all the images will have that super-high resolution.
You can think of the Rubin Observatory as basically instant replay for the universe.
Pick any patch of sky the telescope can see,
and scientists will be able to look up a picture of it from within the last three days.
That will allow us to study all kinds of events, including things like recent supernovas.
To make these outrageous pictures happen, everything about the camera is supersized.
The detector—the part that actually collects the photons of light—
is 64 centimeters in diameter.
And with its lens attached,
the whole thing will be around the size of an SUV.
That enormous size, coupled to the observatory’s 8.4-meter telescope,
will result in astonishing detail —
a system so sensitive that it could pick up the light from a single candle from thousands
of kilometers away.
And at the same time, 3.2 gigapixels of resolution means
that it will capture enough detail to spot somethin
g the size of a golf ball from more than 24 kilometers away.
Astronomers hope that all that photography prowess will help the Rubin Observatory
reveal the dynamic nature of a universe that so often can seem like it’s frozen in time.
That’s what astronomy is all about, really.
So here’s to another year of incredible discoveries that help
us understand our place in this vast, awe-inspiring universe just a little bit better.
Thanks for watching this episode of SciShow Space!
We’re excited to keep bringing you more stories like these in 2021, and if you want
to keep up with our latest episodes, you can hit subscribe — either below, or at youtube.com/scishowspace.
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