Hi, I'm Erin McCarthy, editor-in-chief of Mental Floss.com
Welcome to Mental Floss video and did you know that if you brought a block of
lead to Venus it would melt like a block of ice on earth? Of course *you* couldn't
bring a block of lead to Venus for many reasons, including the fact that the
surface temperature is around 900 degrees Fahrenheit. Even spacecraft that
get sent to Venus aren't able to withstand the environment for long. The
Soviet Union's Venera 13, for example, landed on Venus in 1982 and lasted about
two hours before its demise. Though the Venera was able to send back the first
color images of the planet and analyse its soil, so all in all, a pretty
productive visit. And that's just the first of many out-of-this-world facts
about the solar system that I'm going to share with you today.
An important question to begin with is, "What is the solar system?" Well, it's a
group of celestial bodies in the Milky Way galaxy. At its center is a 4.5
billion year old star, aka our Sun, that is orbited by eight planets, over 150
moons and millions of meteoroids, comets, and asteroids- plus a few dwarf planets.
That sounds impressive but it's just one of tens of billions of solar systems
that scientists estimate can be found within the Milky Way. We happen to know
the most about our own, though, so that's the one we're talking about today. Let's
start with our Sun, which is huge. If you combine the mass of everything in the
solar system, the Sun would account for more than 99% of that mass. Jupiter is
massive. It's large enough to fit all the rest of the planets inside of it, or put
another way, it would take 1300 earths to fill up the inside of Jupiter. And while
we're playing that game: even Jupiter's red spot is larger than Earth...sometimes.
The red spot is a storm containing winds up to 400 miles per hour that heats the
atmosphere above it to 2,400 degrees Fahrenheit, and its size isn't constant.
In fact it's currently getting taller but smaller in width. Another shrinking
part of our solar system is Mercury. Like Earth, Mercury experiences tectonic
activity. Pictures taken of the planet have indicated that the surface is
changing. The planet has a solid inner core that's surrounded by a liquid metal
outer core which is in the process of cooling. Every rocky planet is still
cooling from when they initially emerged, and as the liquid parts of Mercury's
core become solid there's contraction, leading to land shifting and a smaller
planet overall. The dwarf planet Eris, which was discovered in 2005, was
indirectly responsible for Pluto's demotion to a dwarf planet. Eris is
comparable in size to Pluto, which threw astronomers into a tizzy. They worried
about how many newly discovered bodies orbiting the Sun might have to be
considered planets. After Eris's discovery the International Astronomical
Union created new planet standards. "To be considered a planet now a celestial body
must be round, orbit the Sun and clear its orbit of smaller objects." Around the
time that Eris was discovered so was another dwarf planet: Haumea.
It's a weird looking place. It spins so fast that it's shaped like a football or
plump cigar, as NASA describes it. Haumea completes a rotation in under four
hours. I often tell people that I will never go to space and the reason why
boils down to two words: space junk. Between
meteoroids and debris created by humans, NASA knows of over 20,000 pieces of
space junk bigger than a softball orbiting the Earth. And that's out of
500,000 total pieces they track. Each one of those pieces is at least as large as
a marble. There are millions of pieces so small that it's not possible to track
them. According to the agency, manmade space junk includes quote "non-functional
spacecraft, abandoned launch vehicle stages mission related debris and
fragmentation debris." This stuff can be moving at more than 17,500 miles per
hour, so even something as small as a chip of paint can do damage to
operational spacecraft, and sometimes the International Space Station has to
maneuver to get out of the way of space junk. Beyond the danger to spacecraft
some scientists are worried about a thing called Kessler Syndrome, which is
when there's so much debris in low-earth orbit that it all starts bumping into
each other, creating more debris. Think of it like the domino effect, but in space-
so...terrifying. The European Space Agency has proposed cleaning up space junk via
nets. A team at Texas A&M University has suggested sending a mechanism to space
which would push objects into Earth's atmosphere where they would burn up, then
use the momentum from the pushes to travel from debris to debris. Okay: space
junk rant over. In 2008 an object was discovered that orbits the Sun at about
a 104 degree tilt.Technically, this means that the 30 mile wide object is orbiting
backwards. The team that discovered it gave it the name Drac based on the myth
that Dracula could walk up walls. Is it weird that that makes him less scary to
me? The object was found in the Kuiper belt which is an area of our solar
system past Neptune containing a lot of icy objects. The Kuiper belt is also
where Pluto lives. Interestingly, Neptune has a moon called Triton that's a lot
like Pluto, so Triton is probably one of those icy Kuiper belt objects that at
some point got trapped by Neptune's gravity and has been orbiting it ever
since. Triton has a couple other distinctive
features: it orbits Neptune in the opposite direction than the planet is
rotating, and it has geysers that erupt. (That's my geysers erupting.)
It's Ben Affleck on an asteroid.
So about Pluto: some claim that the
planet was named after the Walt Disney dog who appeared the same year that the
dwarf planet was discovered: 1930. But in 1930's The Picnic the dog was called
Rover. He wouldn't be known as Pluto until 1931, the year
after the discovery of the planet. Still, there's a fun coincidence that links
Pluto the dog and Pluto the dwarf planet. In 2015 NASA released new photos of
Pluto which revealed a light area that some said looked like an image of the
dog's head. Pluto's fellow dwarf planet Ceres takes up about 25% of the mass of
the main asteroid belt which is located between Mars and Jupiter. In the 19th
century Ceres was considered a planet, then it was demoted to an asteroid, and
finally, in 2006, it was upgraded to dwarf planet. You go, Ceres! There are millions
of asteroids in the same belt as Ceres. They can range from less than 33 feet to
329 miles long. NASA keeps an ongoing list of asteroids with the potential to
hit earth in the next century, along with the probabilities of that happening.
They're keeping a list because they (singing) don't want to miss a thing. ...And by a
thing I mean an asteroid. One of Saturn's moons Enceladus has water. It has an
entire ocean made up of salt water. In 2018 researchers found complex organic
molecules on Enceladus which is a sign that it could potentially contain life...
or not. That's why there are proposals to send a mission there to find out. Saturn
has a second moon with water, Titan, which also has carbon containing chemicals,
another promising sign for life. Any place that has both water and carbon-
containing chemicals is very exciting to researchers who are interested in
finding life in other places out in space. I've already mentioned the extreme
temperatures of Venus and Jupiter. Mars would give human visitors similar issues.
Compared to Earth's average temperature of 57 degrees Fahrenheit, Mars is at
negative 81. At the poles a temperature of negative 225 degrees is possible.
There's also been no rain on the planet for millions of years, which is hell on
Martian lawns. But if we could figure out that
temperature issue it would be totally worth it to go to Mars to see Olympus
Mons, the tallest volcano we know of. It's estimated to be 16 miles tall, meaning it's
basically three Mount Everests. It probably formed around 350 million years
ago, but it last erupted as recently as 2 million years ago. We have billions of
comets in our solar system, mostly in the Kuiper belt and the Oort Cloud. A comet
is made of ice and rock until it gets close enough to the Sun and then the
exterior turns into a cloud of gas and dust. That's when the distinctive tail
forms. In 2014 a probe landed on a comet for the
first time. Here's one interesting piece of information gathered from that
mission: due to the chemistry of its surface, a comet smells like cat pee,
rotten eggs, and bitter almonds. So maybe think twice before picking up any comet-
scented candles. Finally, so many of these facts would still be unknown if it
wasn't for the amazing space exploration that has taken place over the years. I
can't tell you about all of the missions so I'm just gonna tell you about the
Cassini spacecraft, which launched in 1997 and didn't stop collecting data
until 2017. In those twenty years it traveled four point nine billion miles
and completed 2.5 million commands. Most of that time was spent around Saturn,
doing everything from taking pictures to gathering data to analyzing samples.
Cassini was sent into Saturn's atmosphere to disintegrate on September
15th, 2017. At a press conference Cassini's program manager Earl Mays said,
quote, "To the very end the spacecraft did everything we asked." Aww.. Thanks for
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take a minute to stop and appreciate the stars tonight. We'll see you next time!