Saving Our World–Chapter Eight–The Universe and our Planet

8 terrifying ways the world could actually end

The outcome of a presidential election might inspire unbridled hope — or make you feel like the world is ending. Yet both feelings ignore the humbling truth about our fragile existence. Life exists on Earth only because it teeters in a delicate and truly improbable balance. Our atmosphere, proximity to the sun, and countless other beautiful coincidences not only permit living things to survive and evolve but also thrive. And yet, here we are, sitting at desks and in coffee shops and walking down the street like it isn’t some kind of extraordinary miracle. But all good things must come to an end.

There are things out there in the vast universe that are potentially life threatening. The life on this planet likely won’t cease until billions of years from now. But, depending on the vicissitudes of astrophysics, it could also happen tomorrow or anytime in between. The malignant universe is full of objects that could destroy not only civilization but the entire solar system.

Earth is a small little world when compared to the entire universe and wiping it off the face of space isn’t as difficult as you think. Here are the many ways scientists believe the Earth could die.

With objects like black holes and neutron stars wandering close by, and by close we mean in cosmic terms – light years, it isn’t not hard to believe that our home planet could be under potential danger.

Let’s take a look at some of the scary cosmic monsters that are lurking around us:

1) The Earth’s molten core might cool.

Earth is surrounded by a protective magnetic shield, called the magnetosphere.

The field is generated by Earth’s rotation, which swirls a thick shell of liquid iron and nickel (the outer core) around a solid ball of metal (the inner core), creating a giant electric dynamo.

The magnetosphere deflects energetic particles that emanate from the sun, changing its size and shape as it’s hit.

The resulting flood of high-energy particles that slam into Earth’s air can trigger beautiful auroras, or sometimes disruptive geomagnetic storms.

But if the core cools, we’d lose our magnetosphere — and also our protection from solar winds, which would slowly blast our atmosphere into space.

Mars — once rich with water and a thick atmosphere — suffered this same fate billions of years ago, leading to the nearly airless, seemingly lifeless world we know today.

2) The sun could start to die and expand.

The sun, and our position relative to it, is perhaps the most important piece of our tenuous existence.

But the sun is still a star. And all stars die.

Right now, the sun is midway through life, steadily converting hydrogen into helium through fusion.

That won’t last forever, though. Billions of years from now the sun will run low on hydrogen and start fusing helium.

It’s a more energetic reaction and will push the sun’s layers outward, and possibly start pulling the Earth toward the sun.

We’d be incinerated and then vaporized.

That or the sun’s expansion would push the Earth out of orbit. It’d die frozen as a rogue planet, untethered to any star and drifting through the void.

3) Earth could get shoved into a deadly orbit.

Speaking of rogue planets, worlds often get kicked out of their solar systems during formation.

According to recent simulations, in fact, rogue planets may outnumber stars in the Milky Way by 100,000 to one.

One of those rogue planets could drift into the solar system and destabilize Earth into an extreme and inhospitable orbit.

A world that’s large enough and drifts close enough could even kick us out of the solar system entirely. (Or cause us to collide with a nearby planet, like Venus or Mercury.)

As its own rogue planet, Earth would become an ice ball. Meanwhile, a significant gravitational shove could also make extreme and deadly seasons that alternate between blisteringly cold and searingly hot.

4) A rogue planet could hit Earth.

Or instead of just passing by and disrupting Earth’s orbit, a drifting world could make a direct hit.

It wouldn’t be unprecedented. About 4.5 billion years ago, a small planet crashed into a larger planet in the solar system — forming Earth and its moon.

A new collision would similarly send debris flying all over the solar system and melt Earth 100% through. And while the new planet would eventually reform and cool down, it’s anyone’s guess if it’d be habitable.

A new collision would similarly send debris flying all over the solar system and melt Earth 100% through. And while the new planet would eventually reform and cool down, it’s anyone’s guess if it’d be habitable.

5) Asteroids could bombard the planet.

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Rocks from space can be pretty destructive — a big one probably wiped out the dinosaurs — though it would take a lot of asteroids to properly dispatch the entire planet.

Still, it could happen. Earth was heavily bombarded by asteroids for hundreds of millions of years after it formed.

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The impacts were so intense that the oceans boiled for a full year.

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All life was single-celled at that point, and only the most heat-tolerant microbes made it.

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Today’s larger lifeforms almost certainly wouldn’t make it. Air temperatures could reach more than 900 degrees Fahrenheit for several weeks if we suffered a similar pummeling.

6) The Earth could pass too close to a wandering black hole.

Spinning black hole in “Interstellar” 

They’re as mysterious as they are frightening. Even the name is ominous.

We don’t know much about them, but we do know they’re so dense that not even light can escape beyond a black hole’s event horizon.

And scientists think “recoiled” black holes are out there wandering through space, just like rogue planets. It’s not inconceivable that one could pass through the solar system.

A small black hole might harmlessly pass through the Earth, though anything larger than mass of the moon — and the size of a grain of sand — would cause big problems.

If light can’t escape, the Earth definitely won’t. There are two ideas about what could happen after the point of no return, given a big-enough rogue black hole.

Beyond the event horizon, atoms might stretch until they’re pulled apart entirely.

Other physicists have theorized we’d run right into the end of the universe, or end up in an entirely different one.

Even if a recoiled black hole misses Earth, it might pass closely enough to cause earthquakes and other devastation, kick us out of the solar system, or spiral us into the sun.

7) The Earth’s atmosphere could be obliterated in a gamma ray burst.

Gamma ray bursts, or GRBs, are one of the most powerful phenomena in the universe.

Most are the result of massive stars collapsing when they die. One short blast can emit more energy than our sun will over the course of its lifetime.

That energy has the potential to eradicate the ozone layer, flood the Earth with dangerous ultraviolet light, and trigger rapid global cooling.

In fact, a GRB pointed at Earth might have caused the first mass extinction 440 million years ago.

Luckily, David Thompson, deputy project director on the Fermi Gamma-ray Space Telescope, told National Geographic that GRBs aren’t really a big concern.

He told the magazine the risk was equivalent to “the danger I might face if I found a polar bear in my closet in Bowie, Maryland.”

8) The universe could go to pieces in its final “Big Rip.”

This is the thing that could actually end the whole universe, not just the Earth.

The idea: A mysterious force called dark energy is pushing the universe apart at a faster and faster rate.

If this keeps accelerating, as it seems to be doing now, perhaps 22 billion years from now the force that keeps atoms together will fail — and all matter in the universe will dissolve into radiation.

But assuming the “Big Rip” is a dud, who knows what might happen after a global calamity humans don’t survive?

It’s possible some microbes will survive to reseed more complex life.

But if our destruction is total, we could at least hope some other intelligent life exists out there, and can pay its respects.

What Is the Sun’s Role in Climate Change?

The Sun powers life on Earth; it helps keep the planet warm enough for us to survive. It also influences Earth’s climate: We know subtle changes in Earth’s orbit around the Sun are responsible for the comings and goings of the past ice ages. But the warming we’ve seen over the last few decades is too rapid to be linked to changes in Earth’s orbit, and too large to be caused by solar activity.

The Sun doesn’t always shine at perpetually the same level of brightness; it brightens and dims slightly, taking 11 years to complete one solar cycle. During each cycle, the Sun undergoes various changes in its activity and appearance. Levels of solar radiation go up or down, as does the amount of material the Sun ejects into space and the size and number of sunspots and solar flares. These changes have a variety of effects in space, in Earth’s atmosphere and on Earth’s surface.

The current solar cycle began January 4, 2008, and appears to be headed toward the lowest level of sunspot activity since accurate recordkeeping began in 1750. It’s expected to end sometime between now and late 2020. Scientists don’t yet know with confidence how strong the next solar cycle may be.

What Effect Do Solar Cycles Have on Earth’s Climate?

According to the United Nations’ Intergovernmental Panel on Climate Change (IPCC), the current scientific consensus is that long and short-term variations in solar activity play only a very small role in Earth’s climate. Warming from increased levels of human-produced greenhouse gases is actually many times stronger than any effects due to recent variations in solar activity.

For more than 40 years, satellites have observed the Sun’s energy output, which has gone up or down by less than 0.1 percent during that period. Since 1750, the warming driven by greenhouse gases coming from the human burning of fossil fuels is over 50 times greater than the slight extra warming coming from the Sun itself over that same time interval.

Are We Headed for a ‘Grand Minimum’? (And Will It Slow Down Global Warming?)

solar irradiance with branding
The above graph compares global surface temperature changes (red line) and the Sun’s energy that Earth receives (yellow line) in watts (units of energy) per square meter since 1880. The lighter/thinner lines show the yearly levels while the heavier/thicker lines show the 11-year average trends. Eleven-year averages are used to reduce the year-to-year natural noise in the data, making the underlying trends more obvious.

The amount of solar energy that Earth receives has followed the Sun’s natural 11-year cycle of small ups and downs with no net increase since the 1950s. Over the same period, global temperature has risen markedly. It is therefore extremely unlikely that the Sun has caused the observed global temperature warming trend over the past half-century. Credit: NASA/JPL-Caltech

As mentioned, the Sun is currently experiencing a low level of sunspot activity. Some scientists speculate that this may be the beginning of a periodic solar event called a “grand minimum,” while others say there is insufficient evidence to support that position. During a grand minimum, solar magnetism diminishes, sunspots appear infrequently and less ultraviolet radiation reaches Earth. Grand minimums can last several decades to centuries. The largest recent event happened during the “Little Ice Age” (13th to mid-19th century): the “Maunder Minimum,” an extended period of time between 1645 and 1715, when there were few sunspots.

Several studies in recent years have looked at the effects that another grand minimum might have on global surface temperatures. These studies have suggested that while a grand minimum might cool the planet as much as 0.3 degrees C, this would, at best, slow down (but not reverse) human-caused global warming. There would be a small decline of energy reaching Earth, and just three years of current carbon dioxide concentration growth would make up for it. In addition, the grand minimum would be modest and temporary, with global temperatures quickly rebounding once the event concluded.

Some people have linked the Maunder Minimum’s temporary cooling effect to decreased solar activity, but that change was more likely influenced by increased volcanic activity and ocean circulation shifts.

Moreover, even a prolonged “Grand Solar Minimum” or “Maunder Minimum” would only briefly and minimally offset human-caused warming.

The Solar Cycle

since the sun obviously plays such a role in the life of our planet, let’s spend a little more time dicussing it’s routine or cycle as it were.

The Sun is the worst place in the solar system when it comes to stormy weather. After all, at its heart, our Sun is a huge nuclear bomb!

Much of the Sun’s tempestuous nature comes from its core. At its core is dense, electrically charged gas. Electrically charged gas is a special form of matter called a plasma. This roiling, boiling plasma generates the Sun’s powerful magnetic field. Like Earth’s magnetic field, the Sun’s magnetic field has a north pole and a south pole. On the Sun, however, the magnetic fields are much messier and more disorganized than on Earth.

About every 11 years, the Sun’s magnetic field does a flip. In other words, the north pole becomes the south pole, and vice versa.

This flip is one aspect of the roughly 11-year activity cycle the Sun experiences as its magnetic field evolves slowly over time. As the cycle progresses, the Sun’s stormy behavior builds to a maximum, and that’s when the magnetic field reverses. Then the Sun settles back down to a minimum, only to start another cycle.

Evolution of the Sun in extreme ultraviolet light from 2010 through 2020, as seen from the telescope aboard Europe's PROBA2 spacecraft.

Evolution of the Sun in extreme ultraviolet light from 2010 through 2020, as seen from the telescope aboard Europe’s PROBA2 spacecraft. Credit: Dan Seaton/European Space Agency (Collage by NOAA/JPL-Caltech)

Sunspots

Sunspots are areas of particularly strong magnetic forces on the Sun’s surface. They appear darker than their surroundings because they are cooler. Even so, scientists have discovered that when there are lots of sunspots, the Sun is actually putting out MORE energy than when there are fewer sunspots. During solar maximum, there are the most sunspots, and during solar minimum, the fewest.

Image of Sun on left shows several dark spots. Image on right is closer view of sunspot area.

Through special filters, sunspots may look like the picture on the left. The sunspot groups are as big as the giant planet Jupiter! On the right is a closeup of some other sunspots. The larger sunspot on the right is bigger than Earth! Credit: SOHO (NASA & ESA) and the Royal Swedish Academy of Sciences

Solar Flares

Solar flares happen because of the constantly moving magnetic fields in the Sun’s atmosphere. As the Sun approaches solar maximum (the most active part of its 11-year cycle), its magnetic fields become more and more complex. The magnetic fields loop around, and cross over each other, cutting each other off, and reconnecting.

You have probably seen what happens when you sprinkle iron filings on a bar magnet. The iron filings line up along the magnetic lines of force.

Similarly, the hot plasma on the Sun’s surface is at the mercy of the magnetic lines of force. Sometimes the plasma gets disconnected from the magnetic fields when the fields interact with each other. Then particles in the hot, charged plasma can be accelerated to great speed and send powerful radiation into space. This is a solar flare.

The frequency of solar flares coincides with the Sun’s 11-year cycle. When the solar cycle is at a minimum, active regions are small and rare and few solar flares are detected. These increase in number as the Sun approaches the maximum part of its cycle.

Coronal Mass Ejections

Sometimes, the Sun throws off huge amounts of matter. These events are called coronal mass ejections, or CMEs. A CME can release up to 20 billion tons of this material. If that material were rock, it would make a mountain roughly 2.75 miles across and almost one-half mile high!

Cartoon mountain with labels 2.75 miles wide and .45 miles high, and the amount of material in one coronal mass ejection.

The ejected material can travel a million or more miles per hour (500 km/second). Solar flares and CMEs are the biggest, most violent “explosions” in our solar system, releasing the power of around one billion hydrogen bombs!

Fast CMEs occur more often near the peak of the 11-year solar cycle, and can trigger major disturbances in Earth’s magnetosphere. The Sun can eject matter in any direction, so only some of the CMEs will actually encounter Earth.

Lovely Space Weather

When Earth is in the path of a CME, we get “space weather.” The one nice effect is Northern Lights and Southern Lights around the magnetic poles. They occur when the charged solar particles follow the Earth’s magnetic lines of force right down into the atmosphere at the poles. The particles cause gases in the air to glow and shimmy like colorful, dancing draperies of light.

Bad Space Weather

But space weather can also cause a lot of damage to our technologies. Electrical power systems on the ground can be damaged. Astronauts in the International Space Station can be injured. Jets flying over the poles can expose passengers and crews to significant doses of radiation. Earth-orbiting satellites can be disabled.

To protect our technologies, high-altitude travelers, and astronauts, we need warning when bad space weather is on the way. Thankfully, we have satellites, such as NOAA’s Geostationary Operational Environmental Satellites (GOES), that keep an eye on the Sun and warn us of its violent outbursts.

These images of the sun were captured at the same time on January 29, 2017 by the six channels on the SUVI instrument on board GOES-16.

These images of the sun were captured at the same time on January 29, 2017 by the six channels on the SUVI instrument on board GOES-16. Each channel observes the sun at a different wavelength, allowing scientists to detect a wide range of solar phenomena important for space weather forecasting.

Are orbital changes causing global warming?

Nearly all of Earth’s atmospheric energy is ultimately derived from the sun, so it makes sense that the planet’s position and orientation relative to the sun would have an effect on climate.

The shape of the Earth’s orbit around the sun is not constant, and neither are the tilt of the Earth’s axis and the direction of the axis relative to fixed stars in the galaxy; see Figures 1-3 below.


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Figure 1. Eccentricity, caused by gravitational forces from other planets in our solar system, changes the shape of the orbit on a 100,000-year cycle from a circular to a more elliptical shape. Animation by NASA/JPL-Caltech (public domain).

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Figure 2. Obliquity is the change of the angle of Earth’s axis, which ranges from 22° to 24.5° from normal, and occurs on a 41,000-year cycle. Animation by NASA/JPL-Caltech (public domain).

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Figure 3. Precession, commonly called the “wobble” of Earth’s axis, affects the positions in Earth’s orbit at which the Northern and Southern Hemispheres experience summer and winter. Precession changes on an approximately 26,000-year cycle. Animation by NASA/JPL-Caltech (public domain).

These orbital and astronomical changes repeat on time scales ranging from 26,000 to 100,000 years, and one can calculate their effect on the amount of energy our planet receives from the sun. A scientist named Milutin Milankovitch worked out the theory behind these cycles in the early 20th century, and they are named Milankovitch Cycles after him.

Figure 4 shows the combined effect of all three cycles on the solar radiation reaching the Earth, from 800,000 years ago to today.


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Figure 4. Combined effect of all three cycles on solar radiation reaching the Earth. Data: Milankovitch Orbital Data Viewer, Colorado State University. Figure by Ingrid Zabel for PRI’s Earth@Home project (CC BY-NC-SA 4.0 license).


The effect of this changing solar input over time has been significant: it has pushed the Earth’s climate in and out of cold and warm phases. Figure 5 shows the Milankovitch cycles together with Antarctic temperature reconstructions from ice core records. Scientists think that the Milankovitch cycles were enough to push the climate from, say, a cold phase into the beginning of a warm phase, but they are not enough to explain the full amount of temperature warming.  But once the Earth started to warm, ice cover over the oceans started to melt, and the ocean’s waters warmed.  Warming was then amplified by changes in the physics, chemistry, and biology of the ocean that affected the exchange of carbon dioxide between the ocean and the atmosphere. More carbon dioxide in the atmosphere then led to more warming, until the Milankovitch cycles pushed the climate back toward a cooling phase.


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Figure 5. Milankovitch cycles plotted together with reconstructions of Antarctic surface temperature, from ice core records. Milankovitch data: Milankovitch Orbital Data Viewer, Colorado State University. Ice core data: Jouzel, J., et al. 2007. EPICA Dome C Ice Core 800KYr Deuterium Data and Temperature Estimates. IGBP PAGES/World Data Center for Paleoclimatology, Data Contribution Series # 2007-091. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. Figure by Ingrid Zabel for PRI’s Earth@Home project (CC BY-NC-SA 4.0 license).


Milankovitch cycles are not the cause of the warming that the Earth is experiencing today. Figure 4 shows that most recently—in the last 10,000 years—Milankovitch cycles have been in a phase of decreasing solar radiation reaching the Earth. This would lead to cooling, not warming, so some other factor must be influencing the climate more strongly in recent times—that factor is human activities. Also, Milankovitch cycles lead to climate changes on the order of a few degrees in thousands of years; this is much slower than the rapid changes we observe today.

‘Earth wobble’ theory vs. global climate change

Astronomers have determined that the Earth has been going through three orbital variations. These include shifts in its axis, the wobbling motion around the axis, and ever-moving continents that can affect oceans and atmospheric patterns when plate tectonics move and warmer waters flow from the equator to the poles.

The tilt shift ranges from 24.5 degrees to 22.1 degrees on 41,000-year cycles. Earth’s one full wobble, which looks like a slowly spinning top, happens every 10,000 to 23,000 years, according to astronomer Milutin Milankovic.

In 1976, in a landmark study, it was reported that over the past 80,000 years, carbon dioxide levels fluctuated between about 170 parts per million and 280 ppm. But carbon dioxide levels are much higher today as compared to the past fluctuations.

In May 2016, carbon dioxide levels in Antarctica hit 400 ppm, according to Climate Central. The warming effects of carbon dioxide will have big consequences, because even a small increase in Earth’s average temperature can lead to drastic changes.

For instance, Earth was only about 9 degrees F colder, on average, during the last ice age than it is today. If global warming causes both Greenland’s and Antarctica’s ice sheets to melt, the oceans will rise about 196 feet higher than they are now.

Human impact

Humans have no control over any of the variations caused by changes in the Earth’s axis or its wobble, which occurs over thousands of years. However, we can do our part to minimize damage caused by greenhouse gases and plastics just over decades.

Scientists have noticed that climatic changes in the last few decades have caused global temperatures to fluctuate by as much as 5 degrees F or more.

Our use of fossil fuels has tremendously increased carbon dioxide in the atmosphere, which has a warming effect on the environment. According to scientific data, currently we have about 410 ppm of carbon dioxide in the global atmosphere, and we’re adding 2 ppm per year thanks to more than a billion automobiles and thousands of factories and power plants.

I remember when people in Los Angeles, Mexico City and Tokyo wore masks so they could breathe. I recently read that in New Delhi, there was so much smog before COVID-19 that people couldn’t see the stars at night. Due to the lockdown on people and automobiles for five weeks, they can see clear skies and stars again.

At the current rate of carbon dioxide increase, we’ll have 474 ppm by 2050. Some climatologists believe 500 ppm of carbon dioxide will approach dangerous levels for humans. We need to reverse the trend soon. We can’t control when the Earth will shift its axis or wobble again in thousands of years. However, we can have some controls over global temperatures and the air we breathe within this century!

Resources

dmaindia.com, “Earth can be destroyed by 5 dangerous things in the universe.” B y Sayalee Rakh; businessinsider.com, “8 terrifying ways the world could actually end.” By Dave Mosher, Kelly Dickerson and Sarah Kramer; climate.nasa.gov, “What Is the Sun’s Role in Climate Change?”; scijinks.gov, “The Solar Cycle.”; earthathome.org, “Are orbital changes causing global warming?”; farmprogress.com, “‘Earth wobble’ theory vs. global climate change.” By Dave Nanda;

Bizarre Facts About The Moon That May Explain Why We Haven’t Gone Back

The world watched with awe as the United States landed the first man on the moon in 1969. But even though space travel seemingly opened up a whole new frontier, the U.S. hasn’t returned to the moon since 1972. Why is this? Perhaps it’s because lunar research has revealed some secrets that the general public rarely hears about. And this intriguing information could explain why no further visits are planned.

1. First Impression

No one knew exactly what the lunar surface was going to be like. That’s why NASA had its Apollo 11 astronauts train on a variety of different terrain all over the U.S. before launch. Upon landing, though, Neil Armstrong and Buzz Aldrin found that the moon wasn’t nearly as dangerous as they feared – at least for their short visit.

NASA

2. Learning From Above

After studying samples from the moon, scientists discovered that the satellite has a “crust, mantle, and core — just like Earth.” So astronauts can navigate the moon without breaking through its surface or spinning out of control from the lack of gravity. Yet although these similarities stirred up scientists’ curiosity, further analysis would leave them disappointed.

NASA / YouTube

3. Compared To Earth

We know, of course, that the moon is genetically similar to our planet in many ways. But the lack of iron and other significant elements on the moon leaves no atmospheric gas or water. That’s partly why the satellite is so barren. It’s also part of the reason that it’s without any form of life – or of further interest to science.null

NASA via Getty Images

4. Barren Moon

NASA / Wikimedia Commons

No living organisms have ever been found to inhabit the moon. It’s possible this could be due to the lack of breathable oxygen and fertile land from water. This is, after all, why astronauts have to wear their tightly sealed space suits to survive on the lunar surface. But there’s another reason why life on the moon may be impossible.

5. Preferable Conditions

NASA

Every living creature has its temperature and climate preferences. We human beings can handle a range of conditions – but we do have our limits. And the moon far exceeds the limits of us – or any known living creature. This is mainly due to something that the celestial body doesn’t have.

6. Can’t Handle The Heat

zKobeh / Reddit

The atmosphere around Earth protects it from burning solar rays and the freezing cold of space. But since the moon lacks this layer, there’s nothing to shield it against these outside forces. Temperatures typically range from -298 °F at night to 224 °F during the day. That’s not the best environment for any traveler!

7. Shaking Things Up

KTLA 5 / YouTube

One similarity that the moon has with Earth makes it dangerous in another regard. As quiet as the moon can be compared to Earth, this celestial body isn’t completely still. In fact – with its similar form of layered crust, mantle, and core – the moon has a tendency to shake up.

8. Shaken Up

NASA

Don’t confuse moonquakes with our planet’s earthquakes. These bad boys are on another level! Without water to soften the impact of moonquakes, they can last up to three times longer and the resulting devastation can be much worse. NASA studied moonquakes after the Apollo missions – and what they found was intense.

9. Measuring Chaos

NASA

The Apollo Space Program placed seismometers to measure the magnitude of the quakes. By the time the research project was retired in the late ’70s, NASA had counted 28 moonquakes of varying magnitudes. Unfortunately, in addition to these lunar events, there are far more natural catastrophes to look out for.

10. Attack From Above

NASA/Public Domain

Everyone knows that the moon is covered in craters. And while the playful idea of comparing the moon to cheese is always nice, it’s better to understand what that’s really about. It’s actually very simple: the moon is vulnerable to constant asteroid collisions.

11. Important Protection

NASA via Getty Images

We’d hate to sound like a broken record, but the lack of a protective atmosphere really does make a difference. Chances are that the Earth has the same amount of asteroid collisions as the moon – but you’d never know it. That’s because our atmosphere shields us from them. The constant changes on Earth’s surface also cover up most of the evidence.

12. Covering Up

Sophia Groves / Getty Images

Even when an asteroid or a meteorite makes a landing close to home, there won’t be any remains or craters left behind. Geological activity, such as weather and volcano eruptions, erode signs of impact on Earth. But since the moon has none of this, all the evidence is left on its crater-covered face. And even though astronauts have so far been able to evade these hazardous showers, there’s one peril that can’t be ignored on the moon.

13. Tiny Threats

NASA

Even if they avoided a great meteor or asteroid, astronauts still have to worry about micrometeorites and solar wind irradiation. These come about when the relentless conditions break up a deep layer of the moon’s soil. The solar wind doesn’t just sweep up gray dust and rock fragments, you see. It could also contain pieces of volcanic glass. Astronauts found that the aggressive pressure of these conditions was a lot to bear – to the point that even their equipment would suffer.

14. Space Mess

NASA

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Micrometeorites have previously broken up rocks and melted patches of ground. It also created small glass fragments that would go just about everywhere. The shards invaded nooks and crannies of the lunar module, the spacesuits of the astronauts, and even went through the seals of sample boxes. The material also had a “static cling” that made it a challenge to remove.

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15. A Haunting Relic

There is also the matter of the visible trash piles on the moon. And most of the debris is comprised of “space junk” — small bits of discarded satellites and machinery — that was actually created by man. This also includes backpacks, golf balls, cameras, and rockets. But the most chilling part? The ashes of a dead scientist lie somewhere on the moon’s surface. NASA took the remains of Eugene Shoemaker up there to honor his many contributions to space flight.

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16. Unreliable Technology

NASA

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But there’s one machine up there that’s in perfect working order. The Laser Ranging Retroreflector is a device that uses a set of mirrors to reflect laser pulses from Earth. This device has helped scientists measure the exact distance between Earth and the moon. The retroreflector’s big advantage is that it is really just mirrors, so it doesn’t require any power.

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17. Seeing From Afar

NASA

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Just like organisms, most machines don’t last too long in the brutal lunar environment. So scientists are grateful for the Laser Ranging Retroreflector. It’s improving their knowledge every day about the moon’s orbit and rotation. But it has also revealed a concerning reality.

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18. Galactic Shift

ScienceABC / YouTube

Thanks to the retroreflector, scientists started to notice a great change in distance between the Earth and the moon. They calculated that the satellite is floating further and further away from us — by about 1.5 inches every year. But while the rest of us are shocked by this revelation, one man knew it all along.

19. Called It

Stock Montage / Getty Images

Nearly 300 years ago, English astronomer Edmond Halley first suspected the moon was moving. His study of ancient eclipses aroused his suspicions – and they were eventually confirmed in the 1970s. Apparently, this phenomenon has been happening for longer than we could have guessed.

20. Pushing Away

Space Frontiers / Getty Images

For billions of years, gravity from Earth has forced the moon away. Simply put, rising tides slowing the Earth’s spin have caused the moon to spin faster and farther away from our planet. This poses great changes for our planet’s future. They also mean that another manned mission to the moon isn’t happening anytime soon.

21. Science Non-fiction

Heritage Space / Heritage Images / Getty Images

The hope for space travel hasn’t died, but the funding, for the most part, has. NASA has hopes to create a live-in space station, but the government support seemingly isn’t there. It’s not the thrilling sci-fi epic you might want to hear, but so long as Capitol Hill has its focus elsewhere, it may be some time before we can walk among the stars again. Still, there’s another celestial body that may be more practical to visit…

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