What If Earth’s Axis Was Tilted by 90 Degrees?

WHAT IF

The Earth sits comfortably in its orbit tilted on its axis at 23 degrees. Knock the planet over - and it wouldn't be the Earth as you know it.

Transcript

00:00 The Earth sits comfortably in its orbit,

00:07 tilted on its axis at 23°.

00:10 Knock the planet over,

00:11 and it wouldn't be the Earth as you know it.

00:14 How can a slight change in its actual tilt

00:16 make the planet uninhabitable?

00:19 This is WHAT IF,

00:21 and here's what would happen

00:22 if the Earth's axis was tilted by 90°.

00:27 Only two planets in the Solar System lie on their sides,

00:30 Uranus and the dwarf planet Pluto.

00:33 Now, if something took the Earth off its stand,

00:36 the blue planet would have no chance

00:38 of developing any complex life on its surface.

00:41 But let's start at the beginning.

00:44 This actual tilt, or obliquity,

00:46 is what drives the seasons here on Earth.

00:49 Before the collision that created the Moon,

00:51 the Earth's axis was slowly wobbling around

00:54 somewhere between 0° and 85°.

00:57 Then, our newly formed Moon stabilized it.

01:01 But if that collision happened at a different time,

01:04 things would have turned out very different here on Earth.

01:08 It would be a strange new world.

01:10 As the Earth made its way through orbit,

01:12 its poles would be pointing straight towards the Sun.

01:15 One hemisphere would be shrouded in darkness

01:17 for six months straight,

01:19 while the other would be getting cooked

01:21 by the blazing sunlight.

01:23 One day on Earth would last a whole year.

01:27 At the North Pole,

01:28 the daytime temperatures would rise to a broiling 50°C (107°F).

01:33 A day at the South Pole would be even worse.

01:36 Because the South Pole would be located

01:38 away from climate-controlling ocean currents,

01:40 it would heat up to an almost boiling 80°C (107°F).

01:44 The poles would soak up so much heat from the Sun

01:47 that they wouldn't even freeze

01:48 during the six-month-long night.

01:51 You wouldn't recognize the steaming equatorial tropics.

01:54 With a 90° axial tilt,

01:56 part of the equator would stay encased in ice all year round.

02:01 At some point in this Earth's existence,

02:04 our continents would get clumped together

02:06 around one of the poles.

02:08 Inland temperatures in the daytime would get truly hellish,

02:11 reaching the boiling temperature of water.

02:14 Clouds could help the situation

02:16 and not let all the water vapor off the planet.

02:18 But you wouldn't know.

02:19 You wouldn't stick around that long.

02:21 In this scorching heat,

02:22 the best-case scenario

02:24 would see just a few kinds of bacteria survive.

02:27 Those bacteria might evolve into more complex life forms,

02:30 but they wouldn't be anywhere close

02:32 to how complex we turned out to be.

02:34 The reason would be a lack of oxygen.

02:37 Green plants would be having a hard time surviving

02:39 during the six months of complete darkness.

02:42 They'd drop their seeds at nightfall

02:43 to grow after sunrise.

02:45 But in these conditions,

02:46 would they even have evolved in the first place?

02:50 Interestingly enough,

02:51 if the Earth was 60 million km further away from the Sun,

02:55 a 90° axial tilt wouldn't be so bad.

02:58 The temperatures at the poles

03:00 would never raise above 46°C during the day.

03:03 The coldest it would get at night would be 3°C.

03:06 The only place covered with ice would be the highest mountains.

03:10 So you see,

03:11 simply orbiting a star in the habitable zone

03:14 doesn't mean that a planet is actually capable of sustaining life.

03:18 We're the lucky ones living here on Earth.

03:20 Maybe one day,

03:21 we'll discover another exoplanet just like our home.

03:24 But that's a story for another WHAT IF.

03:29 (dramatic music)

03:31 [MUSIC PLAYING]

03:35 you

Category

Transcript

Recommended