What Sky Looks Like On Other Planets | Unveiled

What Sky Looks Like On Other Planets | Unveiled


What Sky Looks Like on Other Planets When we look up from the surface of Earth,
we’re met with roughly the same image every day: blue skies, clouds, and a bright, yellowish
sun. But all of those colors are determined by
the Earth’s atmosphere, and how light behaves when passing through it… And the solar system’s other planets have
very different atmospheres, with light reflecting across them in very different ways. This is Unveiled, and today we’re answering
the extraordinary question; What does the sky look like on other planets? Are you a fiend for facts? Are you constantly curious? Then why not subscribe to Unveiled for more
clips like this one? And ring the bell for more fascinating content! So, why is the sky blue on Earth? It’s a question that took scientists some
time to answer… and it wasn’t until 1911, when Einstein worked out his equations for
the scattering of light, that we finally began to understand. Fundamentally, it’s about the specific molecules
that make up the Earth’s atmosphere – which are mainly nitrogen and oxygen – and how they
react to light from the sun. Visible light travels in waves, and as those
waves hit the molecules of our atmosphere they’re diffracted and spread. While it appears a white-ish light to look
at, light from the sun is actually all colors of the rainbow – and blue light has a shorter
wavelength and higher frequency, which means it’s diffracted and scattered much more
than the other colors. And so, the sky appears blue. In contrast, red light is the opposite, with
a longer wavelength and shorter frequency, so it’s much less likely to diffract. That’s why we only tend to see a red sky
at sunset or sunrise, when the sun is furthest away and sunlight has passed through much
more of the atmosphere, effectively losing its blue-ness before it reaches your position. So, that’s Earth, but what about elsewhere? Mercury’s atmosphere contains hydrogen,
helium, and oxygen – however, Mercury is so small and close to the sun that it has very
little atmosphere left. Because of that, incoming sunlight is barely
diffracted by anything, so the sky (as seen from the surface, when not directly looking
at the sun) would look almost as though viewed from space: vast expanses of grey, black,
apparent darkness with thousands of bright stars scattered about. And that’s despite the sun itself appearing
more than twice as large as it does here on Earth, and more than six times as bright. Earth itself would be quite clearly visible
in the Mercurian sky as a bright and twinkling orb. And, as one day on Mercury also lasts 59 Earth
days, you’d have plenty of time to enjoy the view. Onto Venus, which is a strange planet by anyone’s
standards. The atmosphere is 96% carbon dioxide, making
it extremely lethal for humans. And because of the structure of that atmosphere,
with 90x as much atmospheric pressure as here on Earth, the sun isn’t actually visible
from the surface. Nevertheless, if you were able to see the
sun, you’d watch it rise in the west and set in the east. That’s because Venus rotates in a retrograde
motion, the opposite direction to that of most other solar system planets. It’s thought that the sky would appear orange
and cloudy, providing a foreboding backdrop for a pretty unforgiving place. Surface temperatures reach 480 degrees Celsius,
enough to destroy most of anything humans could send there, and the Venusian winds whip
violently across the plains, too, churning those orange clouds to form a famously hellish
landscape. On Earth’s other side sits Mars, which has
an atmosphere 100x thinner than our own. However, unlike with Mercury, scientists aren’t
exactly sure what happened to Mars’ atmosphere… but what little remains is 95% carbon dioxide. And, despite our sending various rovers to
its surface, finding out what the Martian sky looks like is still a challenge because
of the way our eyes respond to light. So far, scientists have loosely determined
that during the day it would appear a butterscotch color and a rosy red at sunset, while the
area immediately around the sun would at times look recognisably blue. During a typical and violent Martian dust
storm, though, all would appear a reddish haze – adding further fuel to Mars’ “Red
Planet” reputation. Other stand out features of the Martian sky
are its two moons – Phobos would appear around one third the size of the sun, while Deimos
would look much smaller. Jupiter is the first of the gas giants and
the largest planet in the solar system. It would be hard to actually stand on the
surface, because there isn’t really one, with large amounts of hydrogen and helium
accounting for most of its mass. But, regardless, the Jovian sky is believed
to be a very dim blue color, as the sun is 27 times fainter there than it is on Earth. The deeper into the planet you go, the darker
and more varied the clouds become; from blue, to brown, to red, and – once you’re close
to Jupiter’s centre – total darkness. While sky-gazing on Jupiter you could also
view some of the massive planet’s multiple moons, amidst otherwise probably violent and
stormy conditions. Io would appear larger than our own moon does;
Europa would be smaller but still noticeable; and Ganymede would also be smaller than Io,
but just as bright. All three moons would eclipse the sun fairly
frequently, though… so there’s that, too! And, if you’re really lucky, you might even
glimpse one of Jupiter’s most famous phenomena – diamond rain! Next, to Saturn – where hydrogen accounts
for the vast majority of the atmosphere, then helium. Again, the sky would appear blue, but there’s
also a noticeable smog around Saturn… so it’d be blue with a murky, yellowish tinge. Unlike Jupiter, Saturn’s moons wouldn’t
be much to look at, as even the largest of them, Titan, would seem only half the size
of Earth’s own from the Saturnian surface. But of course, the rings of Saturn would be
the main event on this particular skyline! The massive bands of glittering dust and ice
would stretch across the entire sky, though they would look different depending on where
upon the planet you were viewing them from… If you’re right below them, they’d look
quite thin; if you’re further away, they’d seem to expand. Uranus and Neptune are so far from the sun
that their skies are thought to be reasonably similar. Neptune is so far out, in fact, that it’s
only completed one full orbit around our central star since it was discovered in 1846! Uranus
has rings a little like Saturn, but they wouldn’t be as visible from the surface. Its sky would take on a very faint, light
blue tone (with so little sunlight actually reaching it), though its five largest moons
would be just about visible – in amongst the freezing ice storms that rampage across the
surface. Finally, Neptune also offers an exceptionally
dim, azure blue sky, while its relatively thin rings would also be invisible from the
planet’s surface. Perhaps surprisingly, the moons Triton and
Proteus would be fairly easy to pick out, and even Neptune’s smaller satellites would
be at least be identifiable, if you knew where to look! Though our solar system’s other skies offer
a mysterious point of interest, Earth’s is the only one that naturally allows for
our survival… so it could yet be quite a long time before we see any of the others
first hand. But that doesn’t mean that we shouldn’t
be curious. Fundamentally, the basic laws on the scattering
of light explain why most planets would host an in some way bluish sky regardless of their
position in the solar system, because that’s just how we’re programmed to view them. The notable exception is the notably dusty
Mars – which, in the future, could well prove the first alien sky we actually encounter. And that’s what sky looks like on other
planets. What do you think? Is there anything we missed? Let us know in the comments, check out these
other clips from Unveiled, and make sure you subscribe and ring the bell for our latest
content.

61 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *