8 Things You Need to Know About Earth

It's probably best that we don't think too much about the Earth. After all, it's a tiny orb spinning more than 1000 mph at the equator while simultaneously zipping through space at 67,000 miles per hour. It circles a mysterious, 10,000°F fusion reactor that's more than 100 times its size, and spends most of its orbit narrowly (in a cosmic sense) avoiding collisions with giant chunks of rock that could practically wipe its surface clean. But if you're feeling brave, here are a few things you might not know about Earth. Mental Floss spoke to Josh Willis, a climate scientist at NASA's Jet Propulsion Laboratory, about the planet we call home.

1. EARTH, BY THE NUMBERS.

The Earth orbits the Sun at approximately 93 million miles. As you probably know, at this distance it takes one year for the Earth to complete a revolution, and 24 hours to complete one rotation. The surface of the Earth has temperatures ranging from -126°F to 136°F. The planet is about 7900 miles in diameter (though the deepest we've ever drilled is 7.6 miles). There are 332,519,000 cubic miles of water on the planet, which is enough that, if the water broke from the Earth and organized itself into a sphere, it would have a diameter of 860 miles—about 40 percent that of the Moon.

2. SEEING IS BELIEVING.

The first photograph of Earth from space was taken in 1946. It's a grainy, black-and-white shot of a tiny slice of our world, curved with the ink of space as a backdrop. In 1960, weather satellites began sending photographs back to Earth, images that were still hideously deformed but scientifically valuable, especially for meteorologists, who now had stunning views of cloud systems from which to work. NASA's ATS-III satellite in 1967 returned the first color images of the full Earth. Now at last, we could see our living world, ringed in space and wrapped in billowing clouds.

On Christmas Eve, 1968, Apollo 8 astronaut William Anders sent back "Earthrise," a now-iconic photograph of a fragile cerulean orb rising over the lunar surface. But the most famous photograph of the Earth, by far, was taken about four years later, on December 7, 1972: the "Blue Marble." You've probably seen it countless times, enough that when you think of the Earth, that's what you think of. You may be less familiar with how astronaut Harrison Schmitt described the sight to Mission Control: "I'll tell you, if there ever was a fragile-appearing piece of blue in space, it's the Earth right now."

3. WE HAVE A NATURAL SATELLITE.

The Earth is the first planet, moving outward from the Sun, that possesses a moon. We call our moon "The Moon" (which will be a real headache centuries from now, when we've colonized the solar system). Every 27.32 days, the Moon completes an orbit of the Earth, which is why it has phases. When the Earth is between the Sun and the Moon, we see the Moon in full illumination (a round orb). As it circles the Earth, less and less of its visible surface is illuminated, until at last the Moon is between the Sun and the Earth. At that point, the "far side" of the Moon is in full illumination, and from our perspective, the Moon is receiving no light at all. The cycle then repeats itself, with more of its disc being illuminated as the month elapses, until it is again full. Because the length of the Moon's orbit is just shy of a month, every so often a month (which, itself, derives from the word "moon") has two full Moons, the second of which is colloquially called a Blue Moon.

The moon does spin, but in synchronous rotation with the Earth. In other words, it spins at the same speed as its orbit. As a result, the Earth only ever gets to see one side of our only natural satellite. The best guess for the origin of the Moon involves an object the size of Mars smashing into the Earth 4.5 billion years ago, sending debris into space. This debris organized itself into a molten form of the alabaster orb we know and love. Within 100 million years, an early crust had begun to form. Today, the Moon influences the tides of the ocean and eases our axial wobble, keeping things (more or less) nice and stable—a perfect condition for life.

4. LIFE FINDS A WAY …

When it comes to life, there are a lot of maybes in the solar system. Maybe Mars supported life billions of years ago. Maybe Europa is teeming with life today. The problem is that there is no evidence anywhere of anything that wiggles, walks, or swims … except for one place. Earth is the only body in the universe known to harbor life. And it has been tough going! Four billion years ago, the Earth's surface was sterilized during the Late Heavy Bombardment, when asteroids pilloried the inner solar system. To get some idea of what things must have been like during the LHB, look at the Moon. Most of its craters were formed during that time. Life survived on Earth in large part thanks to the hydrothermal vents at the bottom of the ocean.

There have been five mass extinctions on Earth, the worst of which (the Permian-Triassic, or "P-T Event") was 250 million years ago, wiping out 96 percent of sea species and nearly three-quarters of land vertebrates. Sixty-six million years ago, the Chicxulub impact wiped out 75 percent of all life, and ended the reign of the dinosaurs. Things recovered nicely, though, and today, biologists think there are 8.7 million species of life on Earth. That's not bad considering the universe's apparent hostility to life, and makes what we have going here all the more special and worth preserving. And we'd better get on it: Many scientists argue that we're in the midst of a sixth mass extinction—and we can only partially blame it on cats.

5. … BUT WE'RE DOING A POOR JOB OF PRESERVING IT.

"Global warming is real, it's caused by people, and it's a big problem," Willis told Mental Floss. "Every year the impacts of human-caused climate change get bigger and bigger, and are felt more and more across the planet." We feel the effects of climate change today, but the worst is yet to come, both in terms of economic and social disruption. "Right now we have a choice about what kind of planet we want to have in the future. And the choice is: Do we want to continue to burn fossil fuels and heat up the Earth, or do we want to try and stabilize our climate and keep it more or less like we've had it for the last 10,000 years?"

6. THE WATER IS RISING.

Carl Sagan once observed that, to scale, the Earth's atmosphere is about as thick as the gloss coating on a globe. Our oceans, meanwhile, make Earth the only known planet with stable water at its surface. (Icy moons like Europa and Enceladus have subsurface oceans of liquid water, and Titan, in addition to a possible subsurface ocean of water, has vast lakes of liquid methane covering its surface.)

The problem is, we're causing those water levels to rise. NASA's Jason-3 spacecraft measures the height of the ocean with 1-inch accuracy. Every 10 days, it collects data on the entire ocean, revealing details about such things as ocean currents and how they change, tilts in the ocean's surface, and the average volume of the ocean. "The oceans are growing for two reasons," says Willis. "One is because they absorb heat trapped by the greenhouse gases, and the other is that the ice in places like Greenland and Antarctica and tiny glaciers all across the planet are all melting and adding extra water to the oceans. And so this satellite measures these things combined, and in a way it's really taking the pulse of our planet."

A decade ago, the ice sheets in Greenland and Antarctica were thought of as stable. They are the last remaining ice sheets that cover huge land masses, and today they are disappearing. In 50 years, their melting will be the dominant source of global sea level rise. "Every time a big discovery is made," says Willis, "it seems like the picture is worse than we thought it was. The possibility for really rapid ice loss and rapid sea level rise is greater than we thought."

7. THERE MAY BE ANSWERS UNDERWATER.

The oceans remain a giant unknown for scientists. Knowing more about them would answer many of our questions about life and the life of the Earth. "Two-thirds of the planet is covered with water, and you can't see through it. And you can't shoot microwaves through it, and radio waves, and all the other kinds of things that we use even to measure other planets," Willis says. "If you probe the ocean, there are still a lot of big mysteries down there."

To understand how oceans really work would explain, for example, where the heat from global warming is going. Though the oceans absorb 95 percent of the heat trapped by greenhouse gases, it's still a mystery where that heat energy actually goes. Similar questions exist as to how the oceans interact with ice sheets.

Considering the stakes, it seems like an intense study of the Earth and its oceans is in order. And yet the same people who claim there isn't enough evidence to explain climate change want to slash the budgets of missions designed to find the requested evidence. Among the missions set to be killed are the PACE satellite, over a decade in development and designed to study the interaction of the ocean and the atmosphere, and the CLARREO pathfinder mission, which would cut the time necessary to predict climate change in half. (An extra 20 years to prepare for climate change would save the world $10 trillion.)

8. THERE IS STILL HOPE FOR OUR PALE BLUE DOT.

But it will take a concerted effort to change our behavior—before it's too late. "We think of global warming as something that happens in our cities, and it is happening there, but really 95 percent of the heat that's being trapped is going in the oceans. And I don't think people realize that. It just seems like, well, we're getting the brunt of global warming here in Los Angeles—but that's not true, really. It's the sea life and the oceans that are getting the brunt of the change," says Willis.

"One thing we should keep in mind is that all hope is not lost," he continues. "We are beginning to see changes in our economy, we're beginning to see the growth of renewable energy, and the strong desire to move to a fuel source that doesn't cook us, and I think that's a good thing. A lot of it happens at local and state levels now, but it's beginning to have an impact for real around the world."

10 of the Best Indoor and Outdoor Heaters on Amazon

Mr. Heater/Amazon
Mr. Heater/Amazon

With the colder months just around the corner, you might want to start thinking about investing in an indoor or outdoor heater. Indoor heaters not only provide a boost of heat for drafty spaces, but they can also be a money-saver, allowing you to actively control the heat based on the rooms you’re using. Outdoor heaters, meanwhile, can help you take advantage of cold-weather activities like camping or tailgating without having to call it quits because your extremities have gone numb. Check out this list of some of Amazon’s highest-rated indoor and outdoor heaters so you can spend less time shivering this winter and more time enjoying what the season has to offer.

Indoor Heaters

1. Lasko Ceramic Portable Heater; $20

Lasko/Amazon

This 1500-watt heater from Lasko may only be nine inches tall, but it can heat up to 300 square feet of space. With 11 temperature settings and three quiet settings—for high heat, low heat, and fan only—it’s a dynamic powerhouse that’ll keep you toasty all season long.

Buy it: Amazon

2. Alrocket Oscillating Space Heater; $25

Alrocket/Amazon

Alrocket’s oscillating space heater is an excellent addition to any desk or nightstand. Using energy-saving ceramic technology, this heater is made of fire-resistant material, and its special “tip-over” safety feature forces it to turn off if it falls over (making it a reliable choice for homes with kids or pets). It’s extremely quiet, too—at only 45 dB, it’s just a touch louder than a whisper. According to one reviewer, this an ideal option for a “very quiet but powerful” heater.

Buy it: Amazon

3. De’Longhi Oil-Filled Radiator Space Heather; $79

De’Longhi/Amazon

If you prefer a space heater with a more old-fashioned vibe, this radiator heater from De’Longhi gives you 2020 technology with a vintage feel. De’Longhi’s heater automatically turns itself on when the temperatures drops below 44°F, and it will also automatically turn itself off if it starts to overheat. Another smart safety feature? The oil system is permanently sealed, so you won’t have to worry about accidental spills.

Buy it: Amazon

4. Aikoper Ceramic Tower Heater; $70

Aikoper/Amazon

Whether your room needs a little extra warmth or its own heat source, Aikoper’s incredibly precise space heater has got you covered. With a range of 40-95°F, it adjusts by one-degree intervals, giving you the specific level of heat you want. It also has an option for running on an eight-hour timer, ensuring that it will only run when you need it.

Buy it: Amazon

5. Isiler Space Heater; $37

Isiler/Amazon

For a space heater that adds a fun pop of color to any room, check out this yellow unit from Isiler. Made from fire-resistant ceramic, Isiler’s heater can start warming up a space within seconds. It’s positioned on a triangular stand that creates an optimal angle for hot air to start circulating, rendering it so effective that, as one reviewer put it, “This heater needs to say ‘mighty’ in its description.”

Buy it: Amazon

Outdoor Heaters

6. Mr. Heater Portable Buddy; $104

Mr. Heater/Amazon

Make outdoor activities like camping and grilling last longer with Mr. Heater’s indoor/outdoor portable heater. This heater can connect to a propane tank or to a disposable cylinder, allowing you to keep it in one place or take it on the go. With such a versatile range of uses, this heater will—true to its name—become your best buddy when the temperature starts to drop.

Buy it: Amazon

7. Hiland Pyramid Patio Propane Heater; Various

Hiland/Amazon

The cold’s got nothing on this powerful outdoor heater. Hiland’s patio heater has a whopping 40,000 BTU output, which runs for eight to 10 hours on high heat. Simply open the heater’s bottom door to insert a propane tank, power it on, and sit back to let it warm up your backyard. The bright, contained flame from the propane doubles as an outdoor light.

Buy it: Amazon

8. Solo Stove Bonfire Pit; $345

Solo Stove/Amazon

This one is a slight cheat since it’s a bonfire pit and not a traditional outdoor heater, but the Solo Stove has a 4.7-star rating on Amazon for a reason. Everything about this portable fire pit is meticulously crafted to maximize airflow while it's lit, from its double-wall construction to its bottom air vents. These features all work together to help the logs burn more completely while emitting far less smoke than other pits. It’s the best choice for anyone who wants both warmth and ambiance on their patio.

Buy it: Amazon

9. Dr. Infrared Garage Shop Heater; $119

Dr. Infrared/Amazon

You’ll be able to use your garage or basement workshop all season long with this durable heater from Dr. Infrared. It’s unique in that it includes a built-in fan to keep warm air flowing—something that’s especially handy if you need to work without wearing gloves. The fan is overlaid with heat and finger-protectant grills, keeping you safe while it’s powered on.

Buy it: Amazon

10. Mr. Heater 540 Degree Tank Top; $86

Mr. Heater/Amazon

Mr. Heater’s clever propane tank top automatically connects to its fuel source, saving you from having to bring any extra attachments with you on the road. With three heat settings that can get up to 45,000 BTU, the top can rotate 360 degrees to give you the perfect angle of heat you need to stay cozy. According to a reviewer, for a no-fuss outdoor heater, “This baby is super easy to light, comes fully assembled … and man, does it put out the heat.”

Buy it: Amazon

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The Northern Lights Could Be Visible Over Parts of the Northern U.S. This Week

Vincent Guth, Unsplash
Vincent Guth, Unsplash

You don't need to live north of the Arctic Circle to see the northern lights. On rare occasions, the phenomenon is visible from upper parts of the contiguous U.S. That will be the case this week, when the aurora borealis lights up skies above Maine, Michigan, and other states across the northern border.

As Thrillist reports, the Space Weather Prediction Center has forecast G1 and G2 geomagnetic storms for Sunday, September 27 through Tuesday, September 29. A geomagnetic storm occurs when activity on the sun shoots solar particles toward our planet. At high latitudes, those particles react with gas molecules in the Earth's atmosphere, resulting in waves of green, pink, blue, and purple light undulating in the night sky.

Normally auroras are limited to the poles, because that's where the concentration of magnetic energy is the strongest. It takes an especially potent solar storm to make the spectacle appear farther south, and that's exactly what's been predicted for early this week. The first storm, a G1 or minor level, is set to last from September 27 through the 28th. It will be followed immediately by a G2 or moderate-level solar storm on September 29.

Northern lights from the G1 storm have already been spotted in Minnesota, and the aurora from the G2 storm is expected to extend even lower. States that have a shot at catching the northern lights on Tuesday include Idaho, Iowa, Maine, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, South Dakota, Vermont, Washington, and Wisconsin.

If you don't live within the range of September's light show, there will still be plenty of reasons to look up in the coming weeks. Here are some celestial events to look for in October.

[h/t Thrillist]