Last month, the aerospace company SpaceX made history by sending an orbital rocket into space and then landing it back on the ground. No one else in the history of aerospace engineering has performed such a feat.

Watching a rocket touch down after a launch is something we hope to get used to as the decades of the 21st century march forward, but right now we can't get enough of this incredibly novel sight.

On Tuesday, SpaceX unveiled never-before-seen footage of December's rocket landing, shown below:

As you can see, the touch down is flawless. The landing legs deploy a few seconds before touch down as the 14-story-tall Falcon 9 rocket booster empties the last of its fuel reserves to slow down for a safe, soft landing.

The rocket landing was a moment that marked a critical milestone for SpaceX, which has been working toward for years and could pave the way for a new era of spaceflight that runs on reusable rockets, or rockets that can fly more than once.

SpaceX will be attempting another rocket landing this weekend, but the attempt will take place on one of their drone ships adrift offshore in the Pacific as opposed to on land, like the December touch down.

Check out the full video that SpaceX uploaded to YouTube below:

READ MORE: NASA is accepting astronaut applications, and this quiz will tell you if you qualify

SEE ALSO: This 1-minute animation will change your perception of life in the universe

Join the conversation about this story »

NOW WATCH: This is how Elon Musk wants to drastically reduce the cost of space flight

There's a rumor circulating that physicists may have finally discovered ripples in the fabric of spacetime known as "gravitational waves."

Scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO)— a lab in California that is hunting these waves — have not announced or confirmed anything, though.

"We will share results when ready but have nothing yet — it takes months to analyze the data, interpret results and review them," Gabriela Gonzalez, physicist and spokesperson for LIGO, told Tech Insider in an email.

But the possibility has many scientists thrilled.

Here's why the discovery of gravitational waves would be one of the biggest breakthroughs in physics we've seen in 100 years.

What are gravitational waves?

We know from Albert Einstein's theory of general relativity, published in 1915, that really massive objects can curve the fabric of spacetime around them.

In some ways, it's similar to a bowling ball sinking into and deforming a taut sheet.

So we know spacetime can be warped, and this has some crazy implications.

When a big object suddenly accelerates, for example, it should create ripples through spacetime, called gravitational waves, that are similar to the ripples raindrops create on the surface of a lake.

Physicists think we should be able to spot these ripples when a star explodes, or when two massive objects collide, like when two black holes merge.

How do we detect them?

Physicists have used increasingly complex instruments in hopes of finding them.

LIGO — a huge, L-shaped, laser-powered detector — has been looking for gravitational waves since it opened in 2002, to no avail:

However, a more powerful, advanced LIGO went online in September 2015.

If gravitational ripples are passing by Earth, these instruments should detect disturbances in a very sensitive laser beam setup. (But it's not easy. Even a truck driving by or a farmer plowing a field can disturb the laser beams.)

Where are we looking for them?

Scientists at LIGO are searching around exploding stars, merging black holes, and neutron stars to detect signs of gravitational waves.

Other physicists, like those with the BICEP2 experiment, are searching for signs of gravitational waves from the Big Bang at the edge of the observable universe.

According to the theory of inflation, the universe expanded during the Big Bang at around 100 trillion trillion times in a fraction of a second in its first moments of existence. That kind of cataclysmic disturbance should have created gravitational waves through spacetime.

When the universe began to cool after its rapid inflation, it left behind a faint pattern of temperature fluctuations on the edge of the observable universe. We call it the cosmic microwave background (CMB).

Some physicists think we should be able to spot gravitational waves hiding in the CMB.

What would it mean to find them?

If the new-and-improved LIGO found evidence of gravitational waves, it would be more confirmation that Einstein's theory of relativity is correct.

It would also mean that astronomers finally have a way to track all the objects in the universe that don't emit any kind of visible light, like black holes and neutron stars — and perhaps objects that physicists haven't yet dreamed up or discovered.

And if we find gravitational waves at the edge of the observable universe, it would lend a lot of support to the theory of inflation. It would also give us a better picture of how the universe came to be.

Gravitational waves might also bridge quantum physics (the physics of the very small) with classical physics (the physics of the very large) and get us closer to one unified "theory of everything."

Right now those two branches of science don't get along; physicists can't figure out how the two ideas are supposed to fit together. But if gravitational waves (classical physics) are linked to inflation (quantum physics), we'll know that the two theories can and do work together.

The revelation could usher in a whole new era of physics, astronomical observatories, and perhaps some practical applications, too.

Join the conversation about this story »

NOW WATCH: This 18-year-old just won a $400,000 prize for creating a video on Einstein’s theory of relativity

On Sunday at 1:42 pm ET, SpaceX is scheduled to launch one of its Falcon 9 rockets out of Vandenberg Air Force Base in California. Click here to watch it live.

Tucked away inside the cone of the rocket's head is precious cargo: the Jason-3 satellite, which is designed to measure ocean height across the globe and track sea level rise.

Here you can see the cone on the left as SpaceX rolled its rocket from the hangar toward the launch pad late last week:

The two-stage Falcon 9 rocket stands 224 feet tall— about 14 stories — with a reusable first stage, which SpaceX plans to land on a drone ship located off shore in the Pacific, 186 miles south of the launch site, shortly after the launch on Sunday.

You can clearly see the different sections of the rocket in the photo below, including the interstage module, which connects the first and second rocket stages. Take note of the human on the lower right in the image below for a sense of how big this rocket really is:

To help guide the first stage toward its landing point, SpaceX engineers use grid fins located near the top of the reusable rocket.

During ascent, the grid fins stay tucked parallel to the side of the rocket, as shown below. It's only after the rocket starts to fall back to Earth that the fins fold outward:

As you can see here, SpaceX has already attached its rocket to the launch tower — all of that scaffolding beneath the rocket is the launch tower:

After rolling it toward the launch pad, all that's left for SpaceX engineers to do is orient the massive machine upright in preparation for fueling and launch.

The launch is scheduled to take place during a 30-second window starting at 1:42 pm ET on Sunday.

SpaceX told Business Insider that the launch and landing attempt will be broadcast live, so don't miss out! You can watch all of the action unfold here.

RELATED: SpaceX will attempt its most challenging feat today — here's how to watch live

SEE ALSO: SpaceX just released never-before-seen footage of its epic rocket landing last month

Join the conversation about this story »

NOW WATCH: Couples therapist reveals the key to having a good sex life

Last week, NASA announced the creation of a new office that will take charge in such a scenario.

The Planetary Defense Coordination Office (PDCO) will help to track near-Earth asteroids, develop asteroid deflection strategies, and plan response efforts in case a threat arises.

"While there are no known impact threats at this time," John Grunsfeld from NASA's Science Mission Directorate said in a statement, "the 2013 Chelyabinsk super-fireball and the recent 'Halloween Asteroid' close approach remind us of why we need to remain vigilant and keep our eyes to the sky."

Should a threat arise in outer space (not the alien kind, there's a separate office for that), the PDCO's job will be to coordination communications with the public, assess whether there's anything we can do about it, and coordinate response efforts with FEMA.

Technically NASA would have done all those things anyway, but the new organizational structure formalizes who is in charge in case of an asteroid emergency.

So far we're in no grave danger. NASA estimates that it has found 90 percent of the kilometer-sized, dinosaur-killing asteroids in our general vicinity. The medium-sized asteroids on the order of 450-feet in diameter are harder to spot, but can still cause significant damage.

We've found about 40 percent of those so far, according to Paul Chodas from NASA's Near Earth Asteroid program. With recent increases in funding, NASA's goal is to track down 90 percent of these medium-sized asteroids by 2020.

SEE ALSO: 13 science-backed signs you're smarter than average

Join the conversation about this story »

NOW WATCH: We drove NASA’s monster Mars car with moves that’ll blow Ferrari out of the water

On Sunday, Jan. 17, SpaceX saw a successful lift off of its Falcon 9 rocket out of Vandenberg Air Force Base in California at 1:42 p.m. ET:

Nearly one hour later, the rocket had successfully achieved its primary mission goal, which was to deploy the Jason-3 weather satellite, which will use radar technology to measure ocean height across the globe to track sea level rise.

The second objective was to retrieve the first-stage of the Falcon 9 rocket to prove its reuse capabilities. However, that plan didn't go as well as planned. Click here to learn what happened.

Within 10 minutes after launch, the Falcon 9's first stage performed a series of engine burns while using GPS tracking to safely guide itself toward one of SpaceX's un-crewed drone ships.

But just seconds before viewers were anticipating to see the rocket touch down, the camera on the drone ship froze, leaving everyone in gut-wrenching limbo.

You may remember that SpaceX has already attempted this landing twice — first in January of last year and then again last April. Both landings ended in a spectacular rocket explosion, but SpaceX is hoping that won't be the case this time around.

DON'T MISS: SpaceX just released never-before-seen footage of its epic rocket landing last month

LEARN MORE: Elon Musk's rocket landing could make space travel costs cheaper than a penthouse in NYC

Join the conversation about this story »

NOW WATCH: Watch never-before-seen footage of SpaceX's monumental rocket landing

After a successful mission on Sunday afternoon out of Vandenberg Air Force Base in California, SpaceX attempted to land the first stage of its un-crewed two-stage Falcon 9 rocket for a second time in a row, but the attempt was unsuccessful.

"Unfortunately we are not standing upright on a drone ship," a SpaceX spokesperson announced during a live broadcast of the event.

Click here for the first footage of the aftermath.

While the landing attempt was not successful, SpaceX achieved its primary goal, which was to deploy its cargo into orbit — the Jason-3 weather satellite, designed to measure ocean height across the globe and track sea level rise.

The problem with the landing was a technical issue concerning one of the landing legs: 

SpaceX Falcon 9 rockets are equipped with four landing legs that deploy seconds before touch down and are what keep the rocket stable and upright after landing. Here's what that looked like during SpaceX's last, successful, rocket landing in December:

Seconds before the rocket was to reach the ship's platform on Sunday, the camera on the drone ship froze, which means footage of the landing is pending at the moment.

After successfully boosting the second stage and its cargo off the planet, the first stage booster turned itself around for re-entry, performing a series of engine burns to slow down. Upon descent grid fins and GPS tracking helped guide the rocket to a drone ship floating 186 miles south of the launch site in the middle of the Pacific.

It sounds like everything was working well — the engine burns, the descent, and the navigation — up until the rocket landed on the platform. One of the legs didn't lock into place. Without all four legs working, the 14-story-tall rocket wasn't stable, and after touch down, it tipped over.

One of the earlier suspicions was that the rocket was coming in too fast (see SpaceX founder Elon Musk's tweet below from right after touch down was expected), but upon further investigations it looks like touch down was good. If the leg had locked as it was supposed to, the landing might have been a success.

This second attempt at two landings in a row would have proven that SpaceX's first rocket landing — performed on Dec. 21 of last year — wasn't a one-and-done deal. Now, it's back to the drawing board.

To be fair, Sunday's landing attempt is more difficult than last month's because it happened on a floating target: One of SpaceX's un-crewed autonomous drone ships.

Last year, SpaceX attempted this same landing twice, and did not succeed in retrieving the rocket. Both times the first stage exploded after reaching the platform, shown below:

Musk said that landing rockets on drone ships is critical for high-velocity missions, which refer to mainly commercial satellite missions, wherein the Falcon 9 has to transport its payload higher above Earth's surface than it would on a cargo transport mission to the International Space Station, for example.

Commercial satellite missions make up a substantial amount of SpaceX launches, therefore, we can likely expect to see more rocket landing attempts like this in the future.

CHECK OUT: NASA is upping the competition on SpaceX

SEE ALSO: 9 ways Elon Musk has already upended the spaceflight industry

Join the conversation about this story »

NOW WATCH: Here's Elon Musk back in 2011, explaining how ridiculously hard it would be for SpaceX to land its first reusable rocket

SpaceX was unsuccessful in its attempt to land its Falcon 9 rocket on a drone ship in the Pacific ocean on Sunday January 17.

The rocket did successfully launch the Jason 3 satellite, but on its return trip to Earth it came in harder than expected and one of its landing legs broke.

This is the third time SpaceX has failed to stick the rocket landing at sea.

Unfortunately the live feed of the landing cut out.

But SpaceX said it will release footage of the landing attempt soon.

The launch of the satellite into orbit however, which was the primary objective of the mission, was successful.

In December last year, the company successfully pulled off a land-based landing, but landing a rocket at sea is much more difficult. The target is smaller and isn’t completely still as it’s tossed about in the waves.

On Monday, Musk tweeted that these kind of drone ship landings are "needed for high velocity missions."

High-velocity missions are mainly commercial launches, when the Falcon 9 has to carry a payload higher than it would on a cargo mission to the International Space Station (ISS). This Jason 3 satellite launch is a high-velocity mission, so that's why SpaceX had to attempt to land the rocket at sea.

Join the conversation about this story »

NOW WATCH: 7 proven strategies to become more charismatic

On Monday, theoretical physicist Laurence Krauss sent the scientific community on Twitter reeling when he suggested that researchers may have detected, for the first time, an astrophysical phenomenon called gravitational waves.

Right now, the rumor is just that. The scientists to which the rumor refers work at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and told Business Insider that there is no basis for such a claim, yet.

"We are still taking data, and we won't finish analyzing and reviewing results until at least a month or two later," Gabriela Gonzalez, LIGO spokesperson and Louisiana State University physics and astronomy professor, told Business Insider.

She added: "The instruments are working great, but ... I don't have any news with analysis results to share, yet."

But what if the rumor turns out to be real? Well, the prospect of what that would mean for science is what earned Krauss's Tweet 4,250% more retweets than his usual 40 or so — overnight.

What are gravitational waves and why do they matter?

Albert Einstein first predicted the existence of gravitational waves in 1916.

According to his theory of general relativity, a number of incredibly powerful cosmic systems across the universe will generate measurable ripples in the fabric of space-time called gravitational waves.

One example is two black holes orbiting one another that are eventually destined to collide.

When a smaller black hole meets a larger one, the two attract one another through tremendous gravitational forces. As the smaller black hole inches toward its inevitable doom, is accelerates through space at an ever-increasing rate toward the larger black hole, and, in so doing, generates gravitational waves.

Over 30 years ago, a pair of scientists using the radio telescope in Puerto Rico made the first indirect detection of gravitational waves by observing the behavior of a distant pulsar binary — a pair of rapidly rotating neutron stars (the densest objects in the universe next to black holes). This indirect detection gave fuel for larger projects, like LIGO and the BICEP2 telescope.

In 2014, the BICEP2 team reported the discovery of gravitational waves, but the discovery was later disproved.

To this day, scientists have yet to confirm the existence of gravitational waves with direct, observational evidence, which is why projects like LIGO are so important.

"The detection of gravitational waves would be a game changer for astronomers in the field,"Clifford Will, a distinguished profess of physics at the University of Florida who studied under famed astrophysicist Kip Thorne told Business Insider in 2015. "We would be able to test aspects of general relativity that have not been tested."

Not only that, the ability to observe gravitational waves would open a whole new frontier of astronomy. The same way that astronomers today use light waves to study the universe, they could also use gravitational waves to see cosmic objects — such as colliding black holes — like never before.

How to snag a gravitational wave

LIGO first began sniffing for gravitational waves in 2002. And between 2002 and 2010, the $620 million experiment came up empty handed.

To better the odds, engineers began upgrading LIGO to make it eventually 10 times more sensitive to gravitational waves.

Last September, scientists turned the new-and-improved machine on and began taking data with, what is now called Advanced LIGO.

The way Advanced LIGO works is that it consists of two identical machines that are located 1,865 miles apart — one is in Livingston, Louisiana and the other is in Hanford, Washington.

At each detector, there are two equally-long tunnels with a mirror at the end (one of the mirrors is shown in the image above). Scientists split a laser beam in two and then fire each half down one of the two tunnels. When the beams reflects off the mirror, the two beams should return at the same time, since they're both traveling at the speed of light.

However, if a gravitational wave passes through the detector the same time the laser is traveling through the two tunnels, scientists expect to see a slight difference in time between when the first and second halves of the beam return.

Compared to the length of light waves we see with our eyes, which are micrometers in size (about the width of a human hair), gravitational waves are huge. This is why the distance between each LIGO detector is over 1800 miles, because that's about how long LIGO scientists think the gravitational waves they're searching for should be.

Therefore, if one detector observes a gravitational wave, it should mean the other detector should measure the same signal, offering immediate confirmation that the observation at the first detector isn't a fluke.

Scientists at LIGO aren't taking any chances with this experiment — they don't want another BICEP2 incident. Before they announce a discovery, the data will have been fully vetted twice-over by their expert peers.

But if they do succeed, it will revolutionize astronomy as we know it.

READ MORE: This revolutionary discovery could help scientists see black holes for the first time

SEE ALSO: 11 mind-melting photos will make you realize how shockingly small the Earth is

Join the conversation about this story »

NOW WATCH: Watch never-before-seen footage of SpaceX's monumental rocket landing

Tim Peake is the first official British astronaut to walk in space.

The former Army Air Corps officer has spent a month in space, after blasting off on a Russian Soyuz rocket to the International Space Station on December 15 last year, but the spacewalk will doubtless be his most gruelling test.

But what exactly will he be going through, during his remarkable spell aboard the space station?

Space travel leads to many changes in the human body, many of which have been investigated since Yuri Gargarin made the first manned spaceflight in 1961– and an extensive team provides guidance and preparation for astronauts before, during and after any spaceflight. But if you’re planning an out-of-this-world trip, here are some of the things to expect.

SEE ALSO: SpaceX breaks a leg and misses chance at a successful rocket landing

1) You get weaker

The skeletal muscle system is the largest organ system of the human body. Hundreds of muscles are used for maintaining posture – sitting, standing – and performing a wide range of movements, with different loading conditions imposed by the forces of gravity on Earth.

Skeletal muscles have the ability to adapt to different purposes and the different loads placed on them, a quality known as plasticity. But like inactivity, space flight leads to loss of both skeletal muscle mass (atrophy) and strength.

During long spaceflights on the ISS, research found that 37 crew members experienced a decrease in mean isokinetic strength of between 8% and 17%. Men and women were similarly affected. In fact, this degradation occurs even when astronauts follow a strict exercise regime, meaning that it has profound implications for humans embarking on even longer journeys, such as to Mars. Data suggests that around 30% of muscle strength is lost after spending 110 to 237 days in microgravity.

2) So does your heart

Many parts of the cardiovascular system (including the heart) are influenced by gravity. On Earth, for example, the veins in our legs work against gravity to get blood back to the heart. Without gravity, however, the heart and blood vessels change – and the longer the flight, the more severe the changes.

 NASA astronauts Scott Kelly and Tim Kopra prepare for a spacewalk, December 2015.ESA/NASA, CC BY

The size and shape of the heart, for example, changes with microgravity and the right and left ventricles decrease in mass. This may be because of a decrease in fluid volume (blood) and changes in myocardial mass. A human heart rate (number of beats per minute) is lower in space than on Earth, too. In fact, it has been found that the heart rate of individuals standing upright on the ISS is similar to their rate while lying down pre-flight on Earth. Blood pressure is also lower in space than on Earth.

The cardiac output of the heart – the amount of blood pumped out of the heart each minute – decreases in space, too. Without gravity, there is also a redistribution of the blood– more blood stays in the legs and less blood is returned to the heart, which leads to less blood being pumped out of the heart. Muscle atrophy also contributes to reduced blood flow to the lower limbs.

This reduced blood flow to the muscles, combined with the loss of muscle mass, impacts aerobic capacity (below).

3) Fitness suffers

Aerobic capacity is a measure of aerobic fitness – the maximum amount of oxygen that the body can use during exercise. This can be measured by VO2max and VO2peak tests. Changes to both the muscles and cardiovascular system caused by spaceflight contribute to reduced aerobic fitness.

After nine to 14 days of spaceflight, for example, research shows that aerobic capacity (VO2peak) is reduced by 20%-25%. But the trends are interesting. During longer spells in space – say, five to six months – after the initial reduction in aerobic capacity, the body appears to compensate and the numbers begin improving– although they never return to pre-trip levels.

On Sunday, SpaceX tried and was unsuccessful at landing the first stage of its second-stage rocket on a drone ship floating in the Pacific. SpaceX had planned to broadcast the landing attempt live, but just seconds before touchdown was expected, the camera froze.

Now, SpaceX founder and CEO Elon Musk has just released the first footage of the wreckage, while staying optimistic about future landing attempts:

 And a photo on Twitter:

Indeed, like Musk said, the residual pieces of the crash are bigger this time compared to the first two similar landing attempts last year, which ended in a giant explosion and lots of small rocket pieces scattered across the ship's deck and nearby seafloor.

From the looks of it, a good chunk of the rocket survived. The problem with the landing was a technical issue concerning one of the landing legs.

After successfully boosting the second stage and its cargo off the planet earlier Sunday afternoon, the first stage Falcon 9 booster turned itself around for re-entry, performing a series of engine burns and autonomous navigation calculations to slow down and get to the drone ship's landing platform.

It sounds like everything was working well — the engine burns, the descent, and the navigation — up until the rocket landed on the platform. One of the legs didn't lock into place. Without all four legs working, the 14-story-tall rocket wasn't stable, and after touch down, it tipped over.

If the leg had locked as it was supposed to, the landing might have been a success. As Musk said, however, this won't be the last drone ship landing attempt we'll see. This was the third time SpaceX attempted to land one of its rockets on a drone ship, and each time the company keeps getting one step closer.

While the landing attempt didn't go as planned, SpaceX achieved its primary goal, which was to deploy its cargo into orbit — the Jason-3 weather satellite, designed to measure ocean height across the globe and track sea level rise. Therefore, the overall mission has been deemed a success.

Join the conversation about this story »

NOW WATCH: Turns out exercise might not be a cure for weight gain

On Sunday afternoon, SpaceX successfully launched the Jason 3 weather satellite into orbit. About 10 minutes after lift off the first stage of SpaceX two-stage Falcon 9 rocket headed back toward Earth for an attempt at landing on a drone ship floating 186 miles south of the launch site, in the Pacific. 

Though SpaceX had planned to broadcast the landing attempt live, camera footage cut out seconds before touch down. But now, SpaceX founder and CEO has released the first video footage of the landing, which shows just how close the company came to a second successful landing today:

 As you can see, the rocket touched down just as it should have. The only problem was the one of the landing legs, which help stabilize the rocket after landing, did not lock, and therefore, gave into the massive weight upon it. This caused the rocket to tip over, and upon impact, explode. 

While this might not be an entirely successful landing attempt, it's the closest that SpaceX has ever come to touching one of their Falcon 9 first stage boosters onto a drone ship. A feat that Musk says is critical to ensuring SpaceX's reusable rocket fleet. 

Join the conversation about this story »

NOW WATCH: Watch never-before-seen footage of SpaceX's monumental rocket landing

Right now Earth is surrounded by over 13,500 chunks of space rock, and if one of them bumps into us, the damage could be enough to flatten cities, wipe countries off the map, or even cause global extinctions.

"We are in a shooting gallery," Nahum Melamed, a project manager with the Aerospace Corp., recently said during an event for the American Institute of Aeronautics and Astronautics in California.

Now NASA is getting serious about the potential threat by creating the Planetary Defense Coordination Office (PDCO). The office will track the potentially dangerous objects, warn us of any close passes, and continue working with the Federal Emergency Management Agency (FEMA) and the US Department of Defense to figure out what we'll do if one ever heads directly for Earth.

Right now NASA keeps tabs on these threats through its near-Earth object (NEO) observation program. If an asteroid, comet, or other celestial rock passes within 1.3 astronomical units of the sun — 1 au is 93 million miles, or the distance from the Earth to the sun — then NASA tags it as an NEO. If it comes within 0.05 au of Earth — a little more than 4.5 million miles — then it's labeled as a potentially hazardous NEO.

NASA has already recorded over 13,500 NEOs, and over 1,600 are potentially hazardous.

You can tell why Melamed says we're in a shooting gallery in the map of near-Earth objects by the Armagh Observatory below. These NEOs are orbiting the sun, but they move faster than Earth and their orbits are less stable, so they could potentially come careening in our direction.

At the center of the yellow circled area is Earth — the yellow dot in the center is the sun. All the green dots represent asteroids at a safe distance, while red and yellow dots represent a ring of potentially dangerous asteroids:

Luckily, all of the NEOs we've found have less than a 0.01% chance of hitting Earth within the next century, according to NASA, and the next potentially dangerous — though still not at all likely — encounter won't happen until 2027.

But sometimes NASA misses an NEO, like the one that unexpectedly flew past Earth on Halloween in 2015. And even though there's a low likelihood that Earth will get hit, asteroids come hurtling toward Earth at hundreds of miles per hour, and the potential damage is not something to take lightly. Remember what happened to the dinosaurs?

We know that these impacts have happened regularly, if not often, throughout Earth's history because there's evidence buried in rock layers on the planet. But impacts are incredibly difficult to predict. They don't happen in any kind of predictable pattern or strike in a predictable spot. And if one ever heads right for us, we don't have a plan.

"While there are no known impact threats at this time, the 2013 Chelyabinsk super-fireball and the recent 'Halloween Asteroid' close approach remind us of why we need to remain vigilant and keep our eyes to the sky," John Grunsfeld said in a NASA press release.

Most importantly, the newly formed PDCO will be working on a way to redirect a dangerous asteroid should one ever head for Earth.

One potential plan is NASA's Asteroid Redirect Mission concept. This plan would use the gravity of another object to tug the incoming NEO slightly off its original orbital path. Other possible plans that PDCO will work on include a spacecraft that will fire at an NEO to deflect it.

If all else fails, then NASA will be in direct contact with FEMA to get us as prepared as possible.

"Even if intervention is not possible, NASA would provide expert input to FEMA about impact timing, location and effects to inform emergency response operations,"according to a NASA post. "In turn, FEMA would handle the preparations and response planning related to the consequences of atmospheric entry or impact to U.S. communities."

Join the conversation about this story »

NOW WATCH: Tesla's rival just unveiled its first car — and it looks like a futuristic Batmobile

Earth feels pretty large, and we feel pretty tiny living on it.

But we rarely, if ever, stop to think about the vast beyond. And we should!

Former astronomer Carl Sagan wrote in his book "Pale Blue Dot: A Vision of the Human Future in Space":

There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

So just how small is Earth compared with the rest of outer space? These photos will help put our planet in perspective.

This humbling photo, taken by NASA's Cassini spacecraft in 2013, shows what Earth, indicated by the tiny white arrow, looks like from 898 million miles away.

NASA Goddard Spaceflight Center

Here, North America is superimposed next to Jupiter's Great Red Spot. As you can see in this to-scale image, Jupiter's giant storm would completely swallow the entire continent.

Courtesy of John Brady, who founded the blog Astronomy Central.

Saturn's rings are a beautiful spectacle of the cosmos, but they look much better on Saturn than on Earth.

Courtesy of John Brady, who founded the blog Astronomy Central.

Every job comes with its own unique perks, but NASA astronauts seem to have the best perk of all: the opportunity to visit space.

That's not the only bonus, however, according to NASA astronaut Andrew J. Feustel.

"The other wonderful thing about this job is the opportunity to go and talk to people about what we do — especially kids," Feustel told Business Insider during a press event at NASA's Johnson Spaceflight Center in December.

Feustel first signed on to be a NASA astronaut in July 2000 and is now one of the 47 active astronauts at NASA today. He's spent over 40 hours in the unprotected confines of outer space, performing space walks that included upgrades to prolong the life of the famous Hubble Space Telescope.

"I hope that over the 15 years that I've been an astronaut and in the years to follow, I will continue to be able to inspire children," he said at the event which was to promote the Digital HD and Blu-ray/DVD release of the sci-fi film "The Martian." Both are now available.

For Feustel, there was no question growing up that space was going to be a part of his future. He was born in 1965, right in the middle of the great space race between the US and USSR, and it was this feverish thirst for space exploration that inspired Feustel, along with an entire generation, to reach for the stars.

But it's not the drive to become an astronaut that Feustel tries to inspire in the generations to come. He envisions something grander.

"I hope that every time I go to talk to a school, youth organization, or university that there's somebody there that heard what I said and was inspired personally to go off and pursue whatever goal they had. It doesn't have to be space exploration," he said.

He continued: "It doesn't have to be to become an astronaut, but that they were inspired to follow the dream that they had and pursue that and be successful."

SEE ALSO: One key fact you should know before becoming a NASA astronaut

DON'T MISS: 11 mind-melting photos will make you realize how shockingly small Earth is

Join the conversation about this story »

NOW WATCH: We drove NASA’s monster Mars car with moves that’ll blow Ferrari out of the water

2015 marked 50 years of successful NASA missions to Mars which started with Mariner 4 in 1965. These are the NASA rovers and satellites currently exploring the planet.

Produced by Ruchika Agarwal

Follow BI Video: On Facebook

Join the conversation about this story »

When Albert Einstein first predicted that light travels the same speed everywhere in our universe, he essentially stamped a speed limit on it: 670,616,629 miles per hour — fast enough to circle the entire Earth eight times every second.

But that's not the entire story. In fact, it's just the beginning.

Before Einstein, mass — the atoms that make up you, me, and everything we see — and energy were treated as separate entities. But in 1905, Einstein forever changed the way physicists view the universe.

Einstein's Special Theory of Relativity permanently tied mass and energy together in the simple yet fundamental equation E=mc². This little equation predicts that nothing with mass can move as fast as light, or faster.

The closest humankind has ever come to reaching the speed of light is inside of powerful particle accelerators like the Large Hadron Collider and the Tevatron.

These colossal machines accelerate subatomic particles to more than 99.99% the speed of light, but as Physics Nobel laureate David Gross explains, these particles will never reach the cosmic speed limit.

To do so would require an infinite amount of energy and, in the process, the object's mass would become infinite, which is impossible. (The reason particles of light, called photons, travel at light speeds is because they have no mass.)

Since Einstein, physicists have found that certain entities can reach superluminal (that means "faster-than-light") speeds and still follow the cosmic rules laid down by special relativity. While these do not disprove Einstein's theory, they give us insight into the peculiar behavior of light and the quantum realm.

The light equivalent of a sonic boom

When objects travel faster than the speed of sound, they generate a sonic boom. So, in theory, if something travels faster than the speed of light, it should produce something like a "luminal boom."

In fact, this light boom happens on a daily basis in facilities around the world — you can see it with your own eyes. It's called Cherenkov radiation, and it shows up as a blue glow inside of nuclear reactors, like in the Advanced Test Reactor at the Idaho National Laboratory in the image to the right.

Cherenkov radiation is named for Soviet scientist Pavel Alekseyevich Cherenkov, who first measured it in 1934 and was awarded the Nobel Physics Prize in 1958 for his discovery.

Cherenkov radiation glows because the core of the Advanced Test Reactor is submerged in water to keep it cool. In water, light travels at 75 % the speed it would in the vacuum of outer space, but the electrons created by the reaction inside of the core travel through the water faster than the light does.

Particles, like these electrons, that surpass the speed of light in water, or some other medium such as glass, create a shock wave similar to the shock wave from a sonic boom.

When a rocket, for example, travels through air, it generates pressure waves in front that move away from it at the speed of sound, and the closer the rocket reaches that sound barrier, the less time the waves have to move out of the object's path. Once it reaches the speed of sound, the waves bunch up creating a shock front that forms a loud sonic boom.

Similarly, when electrons travel through water at speeds faster than light speed in water, they generate a shock wave of light that sometimes shines as blue light, but can also shine in ultraviolet.

While these particles are traveling faster than light does in water, they're not actually breaking the cosmic speed limit of 670,616,629 miles per hour.

When the rules don't apply

Keep in mind that Einstein's Special Theory of Relativity states that nothing with mass can go faster than the speed of light, and as far as physicists can tell, the universe abides by that rule. But what about something without mass?

Photons, by their very nature, cannot exceed the speed of light, but particles of light are not the only massless entity in the universe. Empty space contains no material substance and therefore, by definition, has no mass.

"Since nothing is just empty space or vacuum, it can expand faster than light speed since no material object is breaking the light barrier," said theoretical astrophysicist Michio Kaku on Big Think. "Therefore, empty space can certainly expand faster than light."

This is exactly what physicists think happened immediately after the Big Bang during the epoch called inflation, which was first hypothesized by physicists Alan Guth and Andrei Linde in the 1980s. Within a trillionth of a trillionth of a second, the universe repeatedly doubled in size and as a result, the outer edge of the universe expanded very quickly, much faster than the speed of light.

Quantum entanglement makes the cut

Quantum entanglement sounds complex and intimidating but at a rudimentary level entanglement is just the way subatomic particles communicate with each other.

"If I have two electrons close together, they can vibrate in unison, according to the quantum theory," Kaku explains on Big Think. Now, separate those two electrons so that they're hundreds or even thousands of light years apart, and they will keep this instant communication bridge open.

"If I jiggle one electron, the other electron 'senses' this vibration instantly, faster than the speed of light. Einstein thought that this therefore disproved the quantum theory, since nothing can go faster than light," Kaku wrote.

In fact, in 1935, Einstein, Boris Podolsky and Nathan Rosen, attempted to disprove quantum theory with a thought experiment on what Einstein referred to as "spooky actions at a distance."

Ironically, their paper laid the foundation for what today is called the EPR (Einstein-Podolsky-Rosen) paradox, a paradox that describes this instantaneous communication of quantum entanglement — an integral part of some of the world's most cutting-edge technologies, like quantum cryptography.

Dreaming of wormholes

Since nothing with mass can travel faster than light, you can kiss interstellar travel goodbye — at least, in the classical sense of rocketships and flying.

Although Einstein trampled over our aspirations of deep-space roadtrips with his Theory of Special Relativity, he gave us a new hope for interstellar travel with his General Theory of Relativity in 1915.

While Special Relativity wed mass and energy, General Relativity wove space and time together.

"The only viable way of breaking the light barrier may be through General Relativity and the warping of space time," Kaku writes. This warping is what we colloquially call a "wormhole," which theoretically would let something travel vast distances instantaneously, essentially enabling us to break the cosmic speed limit by traveling great distances in a very short amount of time.

In 1988, theoretical physicist Kip Thorne — the science consultant and executive producer for the recent film "Interstellar"— used Einstein's equations of General Relativity to predict the possibility of wormholes that would forever be open for space travel.

But in order to be traversable, these wormholes need some strange, exotic matter holding them open.

"Now it is an amazing fact that exotic matter can exist, thanks to weirdnesses in the laws of quantum physics," Thorne writes in his book "The Science of Interstellar."

And this exotic matter has even been made in laboratories here on Earth, but in very tiny amounts. When Thorne proposed his theory of stable wormholes in 1988 he called upon the physics community to help him determine if enough exotic matter could exist in the universe to support the possibility of a wormhole.

"This triggered a lot of research by a lot of physicists; but today, nearly thirty years later, the answer is still unknown." Thorne writes. At the moment, it's not looking good, "But we are still far from a final answer," he concludes.

CHECK OUT: Why a rumor about the discovery of something Einstein predicted 100 years ago is going viral

SEE ALSO: NASA is upping the competition on SpaceX

Join the conversation about this story »

NOW WATCH: We drove NASA’s monster Mars car with moves that’ll blow Ferrari out of the water

Everything that we see around us — planets, stars, nebulas, and so on — only makes up about 15% of the matter in the universe.

The other 85% of matter is missing. Scientists call this invisible stuff "dark matter" because we can't see it and, so far, no one has directly detected it.

We know dark matter exists only because all the matter that we actually can see can't explain the motion of stars and galaxies in the universe. Not even close.

It's become one of the biggest mysteries in physics. There are a lot of differing theories about what dark matter is made of, and how we might actually find it.

From deep underground caverns to laboratories in space, here are five of the coolest dark matter experiments that are attempting to solve this cosmic mystery.

No one knows what dark matter is or how to detect it. The race is on to find it.

One lab in South Dakota is hot on the trail. It's called the Large Underground Xenon (LUX) experiment.

Source

LUX scientists are trying to detect dark matter by catching it bumping into visible matter.

Source

Saturn flaunts the most majestic planetary rings in the solar system, but those are not the only things that make this beautiful gas giant unique. It's also the farthest planet from Earth that we can see with the naked eye.

From 746 million miles away, however, we can't observe Saturn like NASA's Cassini spacecraft, which has been orbiting the ringed planet since 2004.

While some of Cassini's photos portray Saturn as a tranquil giant floating in space, others reveal the dynamic, stormy nature of its windy atmosphere. 

Here's a collection of some of the most incredible images Cassini has captured so far. You can learn more about each image by clicking the link provided in each photo's caption in the lower right.

LEARN MORE: The 2 most dangerous numbers in the universe are threatening the end of physics

SEE ALSO: I drove the 6,600-lb 'car' that NASA designed for astronauts on Mars, and I'll never see space exploration the same way again

The sun is located directly behind Saturn in this image taken from 1.3 million miles away. The light from the sun passes through Saturn's rings, revealing the never-before-seen E ring, which is the faint, outer-most ring below.

Shown here is a beautifully detailed look at Saturn's four inner rings. The closest to the planet is the D ring, and extending outward from there are the C, B, and A rings. Each ring is separated by a thin, empty gap.

This image highlights Saturn's North Pole, which displays a six-sided hurricane that's 60 miles deep and a whopping 1,250 miles across.

For the first time, a zinnia flower has bloomed in space, aboard the International Space Station (ISS). Successfully growing flowers brings cosmic explorers closer to growing flowering food crops, like tomatoes, on longer space missions in the future.  

On Saturday, American astronaut Scott Kelly, who has been working since March 2015 on the space laboratory and has become its resident gardner, gleefully announced on Twitter that he successfully coaxed the brightly colored zinnia to blossom.

This wasn’t the first time flowering plants have blossomed in space, though. There have been many, according to NASA, from wheat, to barley, to brassicas and peas, grown more than a decade ago on the Russian Mir space station and on the ISS.

Regardless, the zinnia bloom was a big accomplishment, as less than a month ago, the plants were moldy and shriveled.

But even the space mold held some interest to researchers, so it was collected and frozen so it can be returned to Earth for study. 

For NASA scientists back on Earth, the flowering experiment, called “Veggie,” will allow them to better understand how plants grow in microgravity. For the astronauts in space, growing the quick-sprouting zinnias is important practice for growing produce on a future mission to Mars.

“I think having this fresh food source available is going to be critical,” Gioia Massa, a project scientist at NASA Kennedy Space Center and the brainchild behind Veggie, told The Christian Science Monitor in a phone interview in November.

Astronauts eat mostly food that has been freeze-dried for long storage. Fresh fruits and vegetables do show up occasionally at the space station with other supply deliveries, but they run out quickly.

 "The farther and longer humans go away from Earth, the greater the need to be able to grow plants for food, atmosphere recycling and psychological benefits," Massa said in a NASA announcement.

Astronauts started experimenting with Veggie in 2014, when they grew red romaine lettuce in the same system that’s now growing the zinnias: trays of water with bags of seeds in a type of calcined clay used on baseball fields, used to increase aeration to help the plants grow. The growing plants are lit by LED lights and fertilized by an automatic release.

The first batch of lettuce didn’t grow due to “drought stress,” as the Veggie team reported. But astronauts learned from their watering mistakes and grew another batch of lettuce successfully in summer 2015. Scott Kelly and Kjell Lindgren of NASA, with Kimiya Yui of the Japan Aerospace Exploration Agency, celebrated in August by indulging in their freshly harvested space lettuce.

The lettuce experiment was an important precursor to the flowering zinnia, which is more challenging to cultivate.

“The zinnia plant is very different from lettuce,” said Trent Smith, Veggie project manager, in a NASA blog post.

“It is more sensitive to environmental parameters and light characteristics. It has a longer growth duration, between 60 and 80 days. Thus, it is a more difficult plant to grow, and allowing it to flower, along with the longer growth duration, makes it a good precursor to a tomato plant,” he said.

Astronauts are planning to try growing tomatoes in 2018.

Until then, they will keep experimenting with other crops. This year a SpaceX spacecraft will deliver seeds for two sets of Chinese cabbage, and one set of red romaine lettuce, said NASA.

Join the conversation about this story »

NOW WATCH: Your brain probably can't remember this color

From Earth, the sun appears as a distant, fuzzy ball of warmth that gives us all life.

But in reality the sun is a violent clump of magnetism and energy, and its surface is constantly erupting and shooting out jets of plasma and radiation.

Now NASA's Solar Dynamics Observatory has captured a video of one of these explosions that happened as an arch of plasma collapsed and set off a cascade of flares that twisted and bent around the sun's magnetic field before collapsing back onto the surface.

You can see the explosion happen at the beginning of the clip in the upper right corner:

That explosion likely set off the chain of what are called magnetic arches— bursts of the sun's hot plasma blow off the surface of the sun and twist along sun's magnetic field lines.

You can see them rippling in the middle of the video like a giant wave washing over the sun. There's a minor glitch that happens in the middle of the video:

The arches glow as they emit ultraviolet light, which normally isn't visible to the human eye, but NASA has colored it bronze in the video.

Every once in a while, the sun will unleash a particularly powerful burst of solar material. Sometimes these are so intense that they leave the sun, barrel through space, and pummel objects in their path with hot plasma and radiation.

Luckily the explosion in the video happened back in December and didn't cause any damage, since the solar material collapsed back onto the sun's surface.

NASA and government officials are working on a plan that will protect Earth should one of these huge bursts of energy ever head directly for Earth. A big enough blast could fry power grids and knock out communication systems.

You can watch the whole cascade in the video below:

Join the conversation about this story »

NOW WATCH: Five teenagers invented a suitcase that solves the biggest problem with luggage