Pluto The Small Dwarf Planet

Which do you think you'll miss more after your first trip? Space when you're back on Earth or Earth when you're up in Space?

I think that I will miss space when I’m back on Earth. One astronaut when she returned said that gravity sucks, so I’m looking forward to finding out what that’s like.

A Space Odyssey: 21 Years of Searching for Another Earth

There are infinite worlds both like and unlike this world of ours. We must believe that in all worlds there are living creatures and plants and other things we see in this world. – Epicurus, c. 300 B.C.

Are we alone? Are there other planets like ours? Does life exist elsewhere in the universe?

These are questions mankind has been asking for years—since the time of Greek philosophers. But for years, those answers have been elusive, if not impossible to find.

The month of October marks the 21st anniversary of the discovery of the first planet orbiting another sun-like star (aka. an exoplanet), 51 Pegasi b or “Dimidium.” Its existence proved that there were other planets in the galaxy outside our solar system.*

Even more exciting is the fact that astronomers are in hot pursuit of the first discovery of an Earth-like exoplanet orbiting a star other than the sun. The discovery of the so-called "blue dot" could redefine our understanding of the universe and our place in it, especially if astronomers can also find signs that life exists on that planet's surface.

Astronomy is entering a fascinating era where we're beginning to answer tantalizing questions that people have pondered for thousands of years.

Are we alone?

In 1584, when the Catholic monk Giordano Bruno asserted that there were "countless suns and countless earths all rotating around their suns," he was accused of heresy.

But even in Bruno's time, the idea of a plurality of worlds wasn't entirely new. As far back as ancient Greece, humankind has speculated that other solar systems might exist and that some would harbor other forms of life.

Still, centuries passed without convincing proof of planets around even the nearest stars.

Are there other planets like ours?

The first discovery of a planet orbiting a star similar to the sun came in 1995. The Swiss team of Michel Mayor and Didier Queloz of Geneva announced that they had found a rapidly orbiting gas world located blisteringly close to the star 51 Pegasi.

This announcement marked the beginning of a flood of discoveries. Exotic discoveries transformed science fiction into science fact:

a pink planet

worlds with two or even three suns

a gas giant as light as Styrofoam

a world in the shape of an egg

a lava planet

But what about another Earth?

Our first exoplanet mission**, Kepler, launched in 2009 and revolutionized how astronomers understand the universe and our place in it. Kepler was built to answer the question—how many habitable planets exist in our galaxy?

And it delivered: Thousands of planet discoveries poured in, providing statistical proof that one in five sun-like stars (yellow, main-sequence G type) harbor Earth-sized planets orbiting in their habitable zones– where it’s possible liquid water could exist on their surface.

Now, our other missions like the Hubble and Spitzer space telescopes point at promising planetary systems (TRAPPIST-1) to figure out whether they are suitable for life as we know it.

Does life exist elsewhere in the universe?

Now that exoplanet-hunting is a mainstream part of astronomy, the race is on to build instruments that can find more and more planets, especially worlds that could be like our own.

Our Transiting Exoplanet Survey Satellite (TESS), set for launch in 2017-2018, will look for super-Earth and Earth-sized planets around stars much closer to home. TESS will find new planets the same way Kepler does—via the transit method—but will cover 400 times the sky area.

The James Webb Space Telescope, to launch in 2018, wil be our most powerful space telescope to date. Webb will use its spectrograph to look at exoplanet atmospheres, searching for signs of life.

We still don’t know where or which planets are in the habitable zones of the nearest stars­ to Earth. Searching out our nearest potentially habitable neighbors will be the next chapter in this unfolding story.

*The first true discovery of extrasolar planets was actually a triplet of dead worlds orbiting the remains of an exploded star, called a pulsar star. Two of three were found by Dr. Alexander Wolszczan in 1992– a full three years before Dimidium’s discovery. But because they are so strange, and can’t support life as we know it, most scientists would reserve the “first” designation for a planet orbiting a normal star.

** The French CoRoT mission, launched in 2006, was the first dedicated exoplanet space mission. It has contributed dozens of confirmed exoplanets to the ranks and boasts a roster of some of the most well-studied planets outside our solar system.

To stay up-to-date on our latest exoplanet discoveries, visit: https://exoplanets.nasa.gov

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Black Holes: Seeing the Invisible!

Black holes are some of the most bizarre and fascinating objects in the cosmos. Astronomers want to study lots of them, but there’s one big problem – black holes are invisible! Since they don’t emit any light, it’s pretty tough to find them lurking in the inky void of space. Fortunately there are a few different ways we can “see” black holes indirectly by watching how they affect their surroundings.

Speedy stars

If you’ve spent some time stargazing, you know what a calm, peaceful place our universe can be. But did you know that a monster is hiding right in the heart of our Milky Way galaxy? Astronomers noticed stars zipping superfast around something we can’t see at the center of the galaxy, about 10 million miles per hour! The stars must be circling a supermassive black hole. No other object would have strong enough gravity to keep them from flying off into space.

Two astrophysicists won half of the Nobel Prize in Physics last year for revealing this dark secret. The black hole is truly monstrous, weighing about four million times as much as our Sun! And it seems our home galaxy is no exception – our Hubble Space Telescope has revealed that the hubs of most galaxies contain supermassive black holes.

Shadowy silhouettes

Technology has advanced enough that we’ve been able to spot one of these supermassive black holes in a nearby galaxy. In 2019, astronomers took the first-ever picture of a black hole in a galaxy called M87, which is about 55 million light-years away. They used an international network of radio telescopes called the Event Horizon Telescope.

In the image, we can see some light from hot gas surrounding a dark shape. While we still can’t see the black hole itself, we can see the “shadow” it casts on the bright backdrop.

Shattered stars

Black holes can come in a smaller variety, too. When a massive star runs out of the fuel it uses to shine, it collapses in on itself. These lightweight or “stellar-mass” black holes are only about 5-20 times as massive as the Sun. They’re scattered throughout the galaxy in the same places where we find stars, since that’s how they began their lives. Some of them started out with a companion star, and so far that’s been our best clue to find them.

Some black holes steal material from their companion star. As the material falls onto the black hole, it gets superhot and lights up in X-rays. The first confirmed black hole astronomers discovered, called Cygnus X-1, was found this way.

If a star comes too close to a supermassive black hole, the effect is even more dramatic! Instead of just siphoning material from the star like a smaller black hole would do, a supermassive black hole will completely tear the star apart into a stream of gas. This is called a tidal disruption event.

Making waves

But what if two companion stars both turn into black holes? They may eventually collide with each other to form a larger black hole, sending ripples through space-time – the fabric of the cosmos!

These ripples, called gravitational waves, travel across space at the speed of light. The waves that reach us are extremely weak because space-time is really stiff.

Three scientists received the 2017 Nobel Prize in Physics for using LIGO to observe gravitational waves that were sent out from colliding stellar-mass black holes. Though gravitational waves are hard to detect, they offer a way to find black holes without having to see any light.

We’re teaming up with the European Space Agency for a mission called LISA, which stands for Laser Interferometer Space Antenna. When it launches in the 2030s, it will detect gravitational waves from merging supermassive black holes – a likely sign of colliding galaxies!

Rogue black holes

So we have a few ways to find black holes by seeing stuff that’s close to them. But astronomers think there could be 100 million black holes roaming the galaxy solo. Fortunately, our Nancy Grace Roman Space Telescope will provide a way to “see” these isolated black holes, too.

Roman will find solitary black holes when they pass in front of more distant stars from our vantage point. The black hole’s gravity will warp the starlight in ways that reveal its presence. In some cases we can figure out a black hole’s mass and distance this way, and even estimate how fast it’s moving through the galaxy.

For more about black holes, check out these Tumblr posts!

⚫ Gobble Up These Black (Hole) Friday Deals!

⚫ Hubble’s 5 Weirdest Black Hole Discoveries

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10 Things to Know About Explorer 1, America's First Satellite

Sixty years ago, the hopes of Cold War America soared into the night sky as a rocket lofted skyward above Cape Canaveral, a soon-to-be-famous barrier island off the Florida coast.

1. The Original Science Robot

Sixty years ago this week, the United States sent its first satellite into space on Jan. 31, 1958. The spacecraft, small enough to be held triumphantly overhead, orbited Earth from as far as 1,594 miles (2,565 km) above and made the first scientific discovery in space. It was called, appropriately, Explorer 1.

2. Why It's Important

The world had changed three months before Explorer 1's launch, when the Soviet Union lofted Sputnik into orbit on Oct. 4, 1957. That satellite was followed a month later by a second Sputnik spacecraft. All of the missions were inspired when an international council of scientists called for satellites to be placed in Earth orbit in the pursuit of science. The Space Age was on.

3. It...Wasn't Easy

When Explorer 1 launched, we (NASA) didn't yet exist. It was a project of the U.S. Army and was built by Caltech's Jet Propulsion Laboratory (JPL) in Pasadena, California. After the Sputnik launch, the Army, Navy and Air Force were tasked by President Eisenhower with getting a satellite into orbit within 90 days. The Navy's Vanguard Rocket, the first choice, exploded on the launch pad Dec. 6, 1957.

4. The People Behind Explorer 1

University of Iowa physicist James Van Allen, whose proposal was chosen for the Vanguard satellite, had made sure his scientific instrument—a cosmic ray detector—would fit either launch vehicle. Wernher von Braun, working with the Army Ballistic Missile Agency in Alabama, directed the design of the Redstone Jupiter-C launch rocket, while JPL Director William Pickering oversaw the design of Explorer 1 and other upper stages of the rocket. JPL was also responsible for sending and receiving communications from the spacecraft.

5. All About the Science

Explorer 1's science payload took up 37.25 inches (95 cm) of the satellite's total 80.75 inches (2.05 meters). The main instruments were a cosmic-ray detector; internal, external and nose-cone temperature sensors; a micrometeorite impact microphone; a ring of micrometeorite erosion gauges; and two transmitters. There were two antennas in the body of the satellite and its four flexible whips formed a turnstile antenna that extended with the rotation of the satellite. Electrical power was provided by batteries that made up 40 percent of the total payload weight.

6. At the Center of a Space Doughnut

The first scientific discovery in space came from Explorer 1. Earth is surrounded by radiation belts of electrons and charged particles, some of them moving at nearly the speed of light, about 186,000 miles (299,000 km) per second. The two belts are shaped like giant doughnuts with Earth at the center. Data from Explorer 1 and Explorer 3 (launched March 26, 1958) led to the discovery of the inner radiation belt, while Pioneer 3 (Dec. 6, 1958) and Explorer IV (July 26, 1958) provided additional data, leading to the discovery of the outer radiation belt. The radiation belts can be hazardous for spacecraft, but they also protect the planet from harmful particles and energy from the Sun.

7. 58,376 Orbits

Explorer 1's last transmission was received May 21, 1958. The spacecraft re-entered Earth's atmosphere and burned up on March 31, 1970, after 58,376 orbits. From 1958 on, more than 100 spacecraft would fall under the Explorer designation.

8. Find Out More!

Want to know more about Explorer 1? Check out the website and download the poster celebrating 60 years of space science. go.nasa.gov/Explorer1

9. Hold the Spacecraft In Your Hands

Create your own iconic Explorer 1 photo (or re-create the original), with our Spacecraft 3D app. Follow @NASAEarth this week to see how we #ExploreAsOne. https://go.nasa.gov/2BmSCWi

10. What's Next?

All of our missions can trace a lineage to Explorer 1. This year alone, we're going to expand the study of our home planet from space with the launch of two new satellite missions (GRACE-FO and ICESat-2); we're going back to Mars with InSight; and the Transiting Exoplanet Survey Satellite (TESS) will search for planets outside our solar system by monitoring 200,000 bright, nearby stars. Meanwhile, the Parker Solar Probe will build on the work of James Van Allen when it flies closer to the Sun than any mission before.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

NASA Spotlight: Astronaut Mike Hopkins

Michael S. Hopkins was selected by NASA as an astronaut in 2009. The Missouri native is currently the Crew-1 mission commander for NASA’s next SpaceX launch to the International Space Station on Nov. 14, 2020. Hopkin’s Crew-1 mission will mark the first-ever crew rotation flight of a U.S. commercial spacecraft with astronauts on board, and it secures the U.S.’s ability to launch humans into space from American soil once again.  Previously, Hopkins was member of the Expedition 37/38 crew and has logged 166 days in space. During his stay aboard the station, he conducted two spacewalks totaling 12 hours and 58 minutes to change out a degraded pump module. He holds a Bachelor of Science in Aerospace Engineering from the University of Illinois and a Master of Science in Aerospace Engineering. 

He took some time from being a NASA astronaut to answer questions about his life and career! Enjoy:

What do you hope people think about when you launch?

I hope people are thinking about the fact that we’re starting a new era in human spaceflight. We’re re-opening human launch capability to U.S. soil again, but it’s not just that. We’re opening low-Earth orbit and the International Space Station with commercial companies. It’s a lot different than what we’ve done in the past. I hope people realize this isn’t just another launch – this is something a lot bigger. Hopefully it’s setting the stage, one of those first steps to getting us to the Moon and on to Mars.

You served in the U.S. Air Force as a flight test engineer. What does that entail?

First off, just like being an astronaut, it involves a lot of training when you first get started. I went to the U.S. Air Force Test Pilot School and spent a year in training and just learning how to be a flight test engineer. It was one of the most challenging years I’ve ever had, but also one of the more rewarding years. What it means afterwards is, you are basically testing new vehicles or new systems that are going on aircraft. You are testing them before they get handed over to the operational fleet and squadrons. You want to make sure that these capabilities are safe, and that they meet requirements. As a flight test engineer, I would help design the test. I would then get the opportunity to go and fly and execute the test and collect the data, then do the analysis, then write the final reports and give those conclusions on whether this particular vehicle or system was ready to go.

What is one piece of life advice you wish somebody had told you when you were younger? 

A common theme for me is to just have patience. Enjoy the ride along the way. I think I tend to be pretty high intensity on things and looking back, I think things happen when they’re supposed to happen, and sometimes that doesn’t necessarily agree with when you think it should happen. So for me, someone saying, “Just be patient Mike, it’s all going to happen when it’s supposed to,” would be really good advice.

Is there a particular science experiment you enjoyed working on the most while aboard the space station?

There’s a lot of experiments I had the opportunity to participate in, but the ones in particular I liked were ones where I got to interact directly with the folks that designed the experiment. One thing I enjoyed was a fluid experiment called Capillary Flow Experiment, or CFE. I got to work directly with the principal investigators on the ground as I executed that experiment. What made it nice was getting to hear their excitement as you were letting them know what was happening in real time and getting to hear their voices as they got excited about the results. It’s just a lot of fun.

Space is a risky business. Why do it?

I think most of us when we think about whatever it is we do, we don’t think of it in those terms. Space is risky, yes, but there’s a lot of other risky jobs out there. Whether it’s in the military, farming, jobs that involve heavy machinery or dangerous equipment… there’s all kinds of jobs that entail risk. Why do it? You do it because it appeals to you. You do it because it’s what gets you excited. It just feels right. We all have to go through a point in our lives where we figure out what we want to do and what we want to be. Sometimes we have to make decisions based on factors that maybe wouldn’t lead you down that choice if you had everything that you wanted, but in this particular case for me, it’s exactly where I want to be. From a risk standpoint, I don’t think of it in those terms.

Can you describe your crew mate Soichi Noguchi in one sentence?

There are many facets to Soichi Noguchi. I’m thinking about the movie Shrek. He has many layers! He’s very talented. He’s very well-thought. He’s very funny. He’s very caring. He’s very sensitive to other people’s needs and desires. He’s a dedicated family man. I could go on and on and on… so maybe like an onion – full of layers!

Star Trek or Star Wars?

I love them both. But can I say Firefly? There’s a TV series out there called Firefly. It lasted one season – kind of a space cowboy-type show. They did have a movie, Serenity, that was made as well. But anyway, I love both Star Wars and Star Trek. We’ve really enjoyed The Mandalorian. I mean who doesn’t love Baby Yoda right? It’s all fun.

How many times did you apply to be an astronaut? Did you learn anything on your last attempt? 

I tried four times over the course of 13 years. My first three attempts, I didn’t even have references checked or interviews or anything. Remember what we talked about earlier, about patience? For my fourth attempt, the fact is, it happened when it was supposed to happen. I didn’t realize it at the time. I would have loved to have been picked on my first attempt like anybody would think, but at the same time, because I didn’t get picked right away, my family had some amazing experiences throughout my Air Force career. That includes living in Canada, living overseas in Italy, and having an opportunity to work at the Pentagon. All of those helped shape me and grow my experience in ways that I think helped me be a better astronaut.

Can you share your favorite photo or video that you took in space?

One of my favorite pictures was a picture inside the station at night when all of the lights were out. You can see the glow of all of the little LEDs and computers and things that stay on even when you turn off the overhead lights. You see this glow on station. It’s really one of my favorite times because the picture doesn’t capture it all. I wish you could hear it as well. I like to think of the station in some sense as being alive. It’s at that time of night when everybody else is in their crew quarters in bed and the lights are out that you feel it. You feel the rhythm, you feel the heartbeat of the station, you see it in the glow of those lights – that heartbeat is what’s keeping you alive while you’re up there. That picture goes a small way of trying to capture that, but I think it’s a special time from up there.

What personal items did you decide to pack for launch and why? 

My wedding bands. I’m also taking up pilot wings for my son. He wants to be a pilot so if he succeeds with that, I’ll be able to give him his pilot wings. Last time, I took one of the Purple Hearts of a very close friend. He was a Marine in World War II who earned it after his service in the Pacific.

Thank you for your time, Mike, and good luck on your historic mission! Get to know a bit more about Mike and his Crew-1 crew mates Victor Glover, Soichi Noguchi, and Shannon Walker in the video above.

Watch LIVE launch coverage beginning at 3:30 p.m. EST on Nov. 14 HERE. 

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Have a Happy Halloween with NASA

Attention ghouls and goblins of the galaxy! The season for scares and frights is upon us, so we’ve rounded up a few Halloween resources to capture that festive feeling. Read on for craft ideas, free decoration downloads, a creepy soundtrack, and even costume ideas.

Overdid it at the pumpkin patch this year? Get some creative inspiration and some pumpkin-building tips from our Jet Propulsion Laboratory engineers, carve a James Webb Space Pumpkin, or paint a pumpkin with space and weather themed designs. And yes – you can make a NASA pumpkin, too.

Speaking of design, check out our terrifying Galaxy of Horrors posters: decorate your walls with a an illustration of a galactic graveyard or of dark energy prowling through the universe…

If costumes are more your thing, see how the astronauts aboard the International Space Station have dressed up over the years.

Finally, our Sinister Sounds of the Solar System playlist will give you just the right soundtrack for a haunted house or a party – or for scaring yourself all alone.

Hi Mr Neeley, thank you for answering questions! I’ve got two things I want to know- how does the cockpit differ form a normal one? Are there special instruments in there? And do you get tired in long flights? What sort of system is in place to make sure you get sufficient rest if you are flying 12+ hours?

It's the International Day of Human Space Flight!

In this image, NASA astronaut Sunita Williams, Expedition 32 flight engineer, appears to touch the bright Sun during the mission's third spacewalk outside the International Space Station. Japan Aerospace Exploration Agency astronaut Aki Hoshide is visible in the reflection of Williams' helmet visor.

Today, April 12, is the International Day of Human Space Flight—marking Yuri Gagarin's first flight in 1961, and the first space shuttle launch in 1981.

As we honor global collaboration in exploration, we're moving forward to the Moon & Mars under the Artemis Accords.

Sign up to send your name around the Moon aboard Artemis I at go.nasa.gov/wearegoing.

Extraordinary Materials: Developed for Space, Useful for Just About Everything on Earth

Did you know technologies developed for space show up all over Earth? Our Technology Transfer Program has one major goal: bring our technology down to Earth. We patent space innovations developed for missions so that companies, startups and entrepreneurs can spin them off into new commercial products.

Our engineers and scientists create all sorts of materials and coatings—in fact, it is one of the most licensed technology categories in our patent portfolio. From materials that improve industrial and household products, to coatings and insulations that protect satellites, machinery and firefighters, our technologies offer smart solutions for modern challenges.

These are a few of our most in-demand technologies.

Dust-Resistant Coatings

Made by innovators at our Langley Research Center, this tech was first created for exploring dusty, dirty surfaces like the Moon, Mars and asteroids. Lunar dust has been shown to cause big problems with mechanical equipment, like clogging filters and damaging seals. This technology can be used in the production of films, coatings and surface treatments to create dust-resistant and self-cleaning products for biomedical devices, aircraft, cars and much more. This tech could be a game-changer when battling dirt and grime.

Smart, Environmentally-Friendly Coating System

Looking for a technology to ward off corrosion that’s also safe for the environment? Developed to protect our launch pads at Kennedy Space Center from extreme heat and exhaust from rockets, this “smart” coating can detect and prevent corrosion. It can even be painted on damaged surfaces to heal and protect them going forward. This tech has commercial potential in building safer bridges, automobiles and machinery.  While it may seem like magic, this technology will reduce maintenance cost and improve safety.

Multilayer Fire Protection System

Made to protect astronauts and vehicles during the dangerously hot task of reentry, scientists at Langley developed a flexible, lightweight and portable thermal protection system that can serve as a personal emergency fire shelter.

The flexible technology is made up of multilayer thermal blankets designed to handle external temperatures of up to 2,000°F – that’s as hot as magma found in some volcanos! The system can be formed as a sleeping bag, a tent, a blanket, a curtain, a flexible roll-up doorway or even for fire protection in housing structures.

Super-Strength Aluminums

This award-winning tech was initially developed by researchers at our Marshall Space Flight Center to help reduce vehicle exhaust emissions. This special alloy is flexible and strong—even at temperatures of over 500°F. That means it can withstand more wear and tear than other similar materials. Currently, this tech can be found improving motors on fishing boats as well as in all kinds of different engines.

Oil-Free Lubricants

Not all lubricants are liquids, for example, the non-stick coating on a frying pan. Truly in a class of its own, innovators at our Glenn Research Center have created solid lubricant materials to reduce friction and wear in mechanical parts, especially in extremely high heat. This tech could be useful in large engines, valves, turbines and power generation.

High-Strength Super Elastic Compounds

We needed a better material than iron or steel to prevent corrosion and rust in the International Space Station’s wastewater treatment system. Enter: our high-strength, super elastic compounds. Shock-proof, lightweight, durable and immune to rust, this durable tech has applications in ships, machines, industrial knives and cutters, and engine bearings here on Earth. They also don’t chemically degrade or break down lubricants, a common problem with existing bearing materials.

Interested in licensing the tech mentioned above? Follow the links to apply through our website, http://technology.nasa.gov.

You can also browse our entire materials and coatings portfolio at http://technology.nasa.gov/materials_and_coatings/.

Follow our NASA Technology Transfer Program on Twitter (@NASAsolutions) for the latest updates on technologies available for licensing.

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Solar System: Things to Know This Week

Has Cassini inspired you? Learn more about dwarf planet Ceres, get the latest images from the Keck Observatory and more!

1. Has Cassini Inspired You?

During nearly two decades in space, Cassini has been a source of inspiration to many. Has Cassini inspired you? Upload your artwork, photos, poems or songs to the social media platform of your choice, such as Instagram, YouTube, Facebook, Twitter or others. Tag it #CassiniInspires. Or, send it directly to: cassinimission@jpl.nasa.gov. We'll highlight some of the creations on this page. See examples and details at: saturn.jpl.nasa.gov/mission/cassiniinspires/

2. Dawn’s Shines a Light on Ceres

Our Dawn mission has found evidence for organic material on Ceres, a dwarf planet and the largest body in the main asteroid belt between Mars and Jupiter. Learn more: solarsystem.nasa.gov/news/2017/02/17/dawn-discovers-evidence-for-organic-material-on-ceres

3. Into the Vortex

A new device called the vortex coronagraph was recently installed inside NIRC2 (Near Infrared Camera 2) at the W.M. Keck Observatory in Hawaii and has delivered its first images, showing a ring of planet-forming dust around a star, and separately, a cool, star-like body, called a brown dwarf, lying near its companion star.

4. Enceladus: Cassini Cracks the Code of the Icy Moon

A puzzling sensor reading transformed our Cassini Saturn mission and created a new target in the search for habitable worlds beyond Earth, when on Feb. 17, 2005, Cassini made the first-ever close pass over Saturn’s moon. Since our two Voyager spacecraft made their distant flybys of Enceladus about 20 years prior, scientists had anticipated the little moon would be an interesting place to visit. Enceladus is bright white -- the most reflective object in the solar system, in fact -- and it orbits in the middle of a faint ring of dust-sized ice particles known as Saturn’s E ring. Scientists speculated ice dust was being kicked off its surface somehow. But they presumed it would be, essentially, a dead, airless ball of ice.

What Cassini saw didn't look like a frozen, airless body. Instead, it looked something like a comet that was actively emitting gas. The magnetometer detected that Saturn’s magnetic field, which envelops Enceladus, was perturbed above the moon's south pole in a way that didn't make sense for an inactive world. Could it be that the moon was actively replenishing gases it was breathing into space? Watch the video.

5. Descent Into a Frozen Underworld

Our planet's southernmost active volcano reaches 12,448 feet (3,794 meters) above Ross Island in Antarctica. It's a good stand-in for a frozen alien world, the kind we want to send robots to someday. Learn more: solarsystem.nasa.gov/news/2017/02/13/descent-into-a-frozen-underworld

Discover the full list of 10 things to know about our solar system this week HERE.

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