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Solar System: Things To Know This Week

Weather permitting, you can observe the Moon most nights, unless it's a new moon, when the lighted side of the Moon faces away from Earth. The Moon is by far the brightest object in the night sky and there's plenty to see. But this week is special...

...October 28 is International Observe the Moon Night (also known as InOMN).

Here's all you need to know to join in and celebrate:

1. One Planet. One Moon. One Night.

Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event and uniting on one day each year to look at and learn about the Moon together.

2. What's Up?

October's night skies are full of sights, from the first quarter Moon on InOMN to Saturn making a cameo appearance above the Moon October 23 and 24. Watch our What's Up video for details.

3. Be Social

Hundreds of events are planned around the globe. Click the top link on this page for a handy map. You can also register your own event.

4. Don't Just Stand There

Here are some activities for enhanced Moon watching.

5. Impress Your Friends with Moon Knowledge

Download InOMN flyers and handouts, Moon maps and even some pre-made presentations. There's even a certificate to mark your participation.

6. Guide to the Face of the Moon

Almost dead center on the Earth-facing side of the Moon is the Surveyor 6 robotic spacecraft impact side. Apollo 12 and 14 are a bit to the left. And Apollo 11 - the first steps on the moon - are to the right. This retro graphic tells the whole story.

7. Moon Shots

NASA photographers have done some exceptional work capturing views of the Moon from Earth. Here are a few galleries:

You can't have a solar eclipse without the Moon.

The 2016 "Supermoon" was pretty spectacular.

The Moon gets eclipsed, too.

That IS a Moon - AND the International Space Station.

The Moon is always a great photo subject.

Some spooky shots of the 2014 "Supermoon."

And 2013.

Tips from a NASA pro for photographing the Moon.

8. Walking on the Moon

Twelve human beings walked on the face of the Moon. Here are some of the best shots from the Apollo program.

9. Moon Watch

Our Lunar Reconnaissance Orbiter is up there right now, mapping the moon and capturing some spectacular high-resolution shots.

10. Keep Exploring

Make our Moon portal your base for further lunar exploration.

Check out the full version of ‘Ten Things to Know This Week’ HERE.

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Download Software Used to Get Rovers to the Red Planet

Watching our Perseverance rover safely land on the surface of Mars is the kind of historic feat that gets our adventure-loving hearts racing.

Launching and landing rovers on Mars requires overcoming challenges like defying gravity on two planets, surviving the extreme heat of atmospheric entry, and avoiding rocky obstacles. This takes more than just rocket science – it takes incredible software too.

Did you know that some of the same tried and tested software that helped ensure a safe arrival for Perseverance (and its predecessor, Curiosity) can be downloaded – by you...for free...right now?

Our 2021-22 Software Catalog is full of codes made for space that can be used by entrepreneurs, teachers, gamers, or just about anyone. Whether you are curious about the Martian atmosphere, want to visualize the inside of a volcano, or have an application we’ve never even considered, our software may be able to help. Check out our full site, updated regularly with the latest codes available for download.

Here are a few examples of what you could do with our software!

1. Simulate the Martian atmosphere to prepare spacecrafts for landing

To prepare for exactly what a spacecraft will face on landing day, no matter the location scientists choose, we created software that simulates the Martian atmosphere. The code, Mars (GRAM), is now available to anyone.

We also have a version that simulates Earth's atmosphere, allowing users (especially those in the world of drone design) a way to replicate and design for, potentially dangerous conditions without ever stepping away from the computer.

2. Explore the Red Planet virtually from home with help from the Curiosity rover team

Originally developed for scientists and engineers working on the Curiosity rover mission, OnSight allowed the team a virtual way to walk on and look around Mars. Using an immersive display, such as a virtual reality headset, scientists could see the Red Planet the way a rover would.

This software can also be used to provide virtual experiences of places here on Earth, such as caves and lava fields.

3. Dodge disasters with a risk management tool made for space missions

When preparing for complex space missions, like the upcoming Mars Sample Return mission, it’s crucial to examine how different elements, independently and collectively, impact the probability of success.

But risk management has become an important tool for businesses of all disciplines, from engineering to accounting – and the Space Mission Architecture and Risk Analysis Tool (SMART) could help.

Sound interesting? The NASA software catalog has these and more than 800 additional codes ready for download.

You can also follow our Technology Transfer program on Twitter to learn more about software and technology that can be put to use on Earth.

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Frozen: Ice on Earth and Well Beyond

Icy Hearts: A heart-shaped calving front of a glacier in Greenland (left) and Pluto's frozen plains (right). Credits: NASA/Maria-Jose Viñas and NASA/APL/SwRI

From deep below the soil at Earth’s polar regions to Pluto’s frozen heart, ice exists all over the solar system...and beyond. From right here on our home planet to moons and planets millions of miles away, we’re exploring ice and watching how it changes. Here’s 10 things to know:

1. Earth’s Changing Ice Sheets

An Antarctic ice sheet. Credit: NASA

Ice sheets are massive expanses of ice that stay frozen from year to year and cover more than 6 million square miles. On Earth, ice sheets extend across most of Greenland and Antarctica. These two ice sheets contain more than 99 percent of the planet’s freshwater ice. However, our ice sheets are sensitive to the changing climate.

Data from our GRACE satellites show that the land ice sheets in both Antarctica and Greenland have been losing mass since at least 2002, and the speed at which they’re losing mass is accelerating.

2. Sea Ice at Earth’s Poles

Earth’s polar oceans are covered by stretches of ice that freezes and melts with the seasons and moves with the wind and ocean currents. During the autumn and winter, the sea ice grows until it reaches an annual maximum extent, and then melts back to an annual minimum at the end of summer. Sea ice plays a crucial role in regulating climate – it’s much more reflective than the dark ocean water, reflecting up to 70 percent of sunlight back into space; in contrast, the ocean reflects only about 7 percent of the sunlight that reaches it. Sea ice also acts like an insulating blanket on top of the polar oceans, keeping the polar wintertime oceans warm and the atmosphere cool.

Some Arctic sea ice has survived multiple years of summer melt, but our research indicates there’s less and less of this older ice each year. The maximum and minimum extents are shrinking, too. Summertime sea ice in the Arctic Ocean now routinely covers about 30-40 percent less area than it did in the late 1970s, when near-continuous satellite observations began. These changes in sea ice conditions enhance the rate of warming in the Arctic, already in progress as more sunlight is absorbed by the ocean and more heat is put into the atmosphere from the ocean, all of which may ultimately affect global weather patterns.

3. Snow Cover on Earth

Snow extends the cryosphere from the poles and into more temperate regions.

Snow and ice cover most of Earth’s polar regions throughout the year, but the coverage at lower latitudes depends on the season and elevation. High-elevation landscapes such as the Tibetan Plateau and the Andes and Rocky Mountains maintain some snow cover almost year-round. In the Northern Hemisphere, snow cover is more variable and extensive than in the Southern Hemisphere.

Snow cover the most reflective surface on Earth and works like sea ice to help cool our climate. As it melts with the seasons, it provides drinking water to communities around the planet.

4. Permafrost on Earth

Tundra polygons on Alaska's North Slope. As permafrost thaws, this area is likely to be a source of atmospheric carbon before 2100. Credit: NASA/JPL-Caltech/Charles Miller

Permafrost is soil that stays frozen solid for at least two years in a row. It occurs in the Arctic, Antarctic and high in the mountains, even in some tropical latitudes. The Arctic’s frozen layer of soil can extend more than 200 feet below the surface. It acts like cold storage for dead organic matter – plants and animals.

In parts of the Arctic, permafrost is thawing, which makes the ground wobbly and unstable and can also release those organic materials from their icy storage. As the permafrost thaws, tiny microbes in the soil wake back up and begin digesting these newly accessible organic materials, releasing carbon dioxide and methane, two greenhouse gases, into the atmosphere.

Two campaigns, CARVE and ABoVE, study Arctic permafrost and its potential effects on the climate as it thaws.

5. Glaciers on the Move

Did you know glaciers are constantly moving? The masses of ice act like slow-motion rivers, flowing under their own weight. Glaciers are formed by falling snow that accumulates over time and the slow, steady creep of flowing ice. About 10 percent of land area on Earth is covered with glacial ice, in Greenland, Antarctica and high in mountain ranges; glaciers store much of the world's freshwater.

Our satellites and airplanes have a bird’s eye view of these glaciers and have watched the ice thin and their flows accelerate, dumping more freshwater ice into the ocean, raising sea level.

6. Pluto’s Icy Heart

The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Pluto's surrounding uplands. NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto’s most famous feature – that heart! – is stone cold. First spotted by our New Horizons spacecraft in 2015, the heart’s western lobe, officially named Sputnik Planitia, is a deep basin containing three kinds of ices – frozen nitrogen, methane and carbon monoxide.

Models of Pluto’s temperatures show that, due the dwarf planet’s extreme tilt (119 degrees compared to Earth’s 23 degrees), over the course of its 248-year orbit, the latitudes near 30 degrees north and south are the coldest places – far colder than the poles. Ice would have naturally formed around these latitudes, including at the center of Sputnik Planitia.

New Horizons also saw strange ice formations resembling giant knife blades. This “bladed terrain” contains structures as tall as skyscrapers and made almost entirely of methane ice, likely formed as erosion wore away their surfaces, leaving dramatic crests and sharp divides. Similar structures can be found in high-altitude snowfields along Earth’s equator, though on a very different scale.

7. Polar Ice on Mars

This image, combining data from two instruments aboard our Mars Global Surveyor, depicts an orbital view of the north polar region of Mars. Credit: NASA/JPL-Caltech/MSSS

Mars has bright polar caps of ice easily visible from telescopes on Earth. A seasonal cover of carbon dioxide ice and snow advances and retreats over the poles during the Martian year, much like snow cover on Earth.

This animation shows a side-by-side comparison of CO2 ice at the north (left) and south (right) Martian poles over the course of a typical year (two Earth years). This simulation isn't based on photos; instead, the data used to create it came from two infrared instruments capable of studying the poles even when they're in complete darkness. This data were collected by our Mars Reconnaissance Orbiter, and Mars Global Surveyor. Credit: NASA/JPL-Caltech

During summertime in the planet's north, the remaining northern polar cap is all water ice; the southern cap is water ice as well, but remains covered by a relatively thin layer of carbon dioxide ice even in summertime.

Scientists using radar data from our Mars Reconnaissance Orbiter found a record of the most recent Martian ice age in the planet's north polar ice cap. Research indicates a glacial period ended there about 400,000 years ago. Understanding seasonal ice behavior on Mars helps scientists refine models of the Red Planet's past and future climate.

8. Ice Feeds a Ring of Saturn

Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturn's moon Enceladus into the E ring, while the moon's active south polar jets continue to fire away. Credit: NASA/JPL/Space Science Institute

Saturn’s rings and many of its moons are composed of mostly water ice – and one of its moons is actually creating a ring. Enceladus, an icy Saturnian moon, is covered in “tiger stripes.” These long cracks at Enceladus’ South Pole are venting its liquid ocean into space and creating a cloud of fine ice particles over the moon's South Pole. Those particles, in turn, form Saturn’s E ring, which spans from about 75,000 miles (120,000 kilometers) to about 260,000 miles (420,000 kilometers) above Saturn's equator. Our Cassini spacecraft discovered this venting process and took high-resolution images of the system.

Jets of icy particles burst from Saturn’s moon Enceladus in this brief movie sequence of four images taken on Nov. 27, 2005. Credit: NASA/JPL/Space Science Institute

9. Ice Rafts on Europa

View of a small region of the thin, disrupted, ice crust in the Conamara region of Jupiter's moon Europa showing the interplay of surface color with ice structures. Credit: NASA/JPL/University of Arizona

The icy surface of Jupiter’s moon Europa is crisscrossed by long fractures. During its flybys of Europa, our Galileo spacecraft observed icy domes and ridges, as well as disrupted terrain including crustal plates that are thought to have broken apart and "rafted" into new positions. An ocean with an estimated depth of 40 to 100 miles (60 to 150 kilometers) is believed to lie below that 10- to 15-mile-thick (15 to 25 km) shell of ice.

The rafts, strange pits and domes suggest that Europa’s surface ice could be slowly turning over due to heat from below. Our Europa Clipper mission, targeted to launch in 2022, will conduct detailed reconnaissance of Europa to see whether the icy moon could harbor conditions suitable for life.

10. Crater Ice on Our Moon

The image shows the distribution of surface ice at the Moon’s south pole (left) and north pole (right), detected by our Moon Mineralogy Mapper instrument. Credit: NASA

In the darkest and coldest parts of our Moon, scientists directly observed definitive evidence of water ice. These ice deposits are patchy and could be ancient. Most of the water ice lies inside the shadows of craters near the poles, where the warmest temperatures never reach above -250 degrees Fahrenheit. Because of the very small tilt of the Moon’s rotation axis, sunlight never reaches these regions.

A team of scientists used data from a our instrument on India’s Chandrayaan-1 spacecraft to identify specific signatures that definitively prove the water ice. The Moon Mineralogy Mapper not only picked up the reflective properties we’d expect from ice, but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice.

With enough ice sitting at the surface – within the top few millimeters – water would possibly be accessible as a resource for future expeditions to explore and even stay on the Moon, and potentially easier to access than the water detected beneath the Moon’s surface.

11. Bonus: Icy World Beyond Our Solar System!

With an estimated temperature of just 50K, OGLE-2005-BLG-390L b is the chilliest exoplanet yet discovered. Pictured here is an artist's concept. Credit: NASA

OGLE-2005-BLG-390Lb, the icy exoplanet otherwise known as Hoth, orbits a star more than 20,000 light years away and close to the center of our Milky Way galaxy. It’s locked in the deepest of deep freezes, with a surface temperature estimated at minus 364 degrees Fahrenheit (minus 220 Celsius)!

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

Not a question, but I just want to say that today is my daughter Erin's 7th birthday and she's wearing her NASA shirt and I want to thank you so much for being such an amazing inspiration to my daughter, myself, and women and girls everywhere. <3

Adorable! Please continue to encourage her to reach for the stars. 

Solar System: Things to Know This Week

Our Dawn mission to the asteroid belt is no ordinary deep space expedition. 

Instead of traditional chemical rockets, the spacecraft uses sophisticated ion engines for propulsion. This enabled Dawn to become the first mission to orbit not one, but two different worlds — first the giant asteroid Vesta and now the dwarf planet Ceres. Vesta and Ceres formed early in the solar system's history, and by studying them, the mission is helping scientists go back in time to the dawn of the planets. To mark a decade since Dawn was launched on Sept. 27, 2007, here are 10 things to know about this trailblazing mission.

1. Ion Engines: Not Just for Sci-Fi Anymore

Most rocket engines use chemical reactions for propulsion, which tend to be powerful but short-lived. Dawn's futuristic, hyper-efficient ion propulsion system works by using electricity to accelerate ions (charged particles) from xenon fuel to a speed seven to 10 times that of chemical engines. Ion engines accelerate the spacecraft slowly, but they're very thrifty with fuel, using just milligrams of xenon per second (about 10 ounces over 24 hours) at maximum thrust. Without its ion engines, Dawn could not have carried enough fuel to go into orbit around two different solar system bodies. Try your hand at an interactive ion engine simulation.

2. Time Capsules 

Scientists have long wanted to study Vesta and Ceres up close. Vesta is a large, complex and intriguing asteroid. Ceres is the largest object in the entire asteroid belt, and was once considered a planet in its own right after it was discovered in 1801. Vesta and Ceres have significant differences, but both are thought to have formed very early in the history of the solar system, harboring clues about how planets are constructed. Learn more about Ceres and Vesta—including why we have pieces of Vesta here on Earth.

3. Portrait of a Dwarf Planet

This view of Ceres built from Dawn photos is centered on Occator Crater, home of the famous "bright spots." The image resolution is about 460 feet (140 meters) per pixel.

Take a closer look.

4. What's in a Name? 

Craters on Ceres are named for agricultural deities from all over the world, and other features carry the names of agricultural festivals. Ceres itself was named after the Roman goddess of corn and harvests (that's also where the word "cereal" comes from). The International Astronomical Union recently approved 25 new Ceres feature names tied to the theme of agricultural deities. Jumi, for example, is the Latvian god of fertility of the field. Study the full-size map.

5. Landslides or Ice Slides? 

Thanks to Dawn, evidence is mounting that Ceres hides a significant amount of water ice. A recent study adds to this picture, showing how ice may have shaped the variety of landslides seen on Ceres today.

6. The Lonely Mountain 

Ahuna Mons, a 3-mile-high (5-kilometer-high) mountain, puzzled Ceres explorers when they first found it. It rises all alone above the surrounding plains. Now scientists think it is likely a cryovolcano — one that erupts a liquid made of volatiles such as water, instead of rock. "This is the only known example of a cryovolcano that potentially formed from a salty mud mix, and that formed in the geologically recent past," one researcher said. Learn more.

7. Shining a Light on the Bright Spots 

The brightest area on Ceres, located in the mysterious Occator Crater, has the highest concentration of carbonate minerals ever seen outside Earth, according to studies from Dawn scientists. Occator is 57 miles (92 kilometers) wide, with a central pit about 6 miles (10 kilometers) wide. The dominant mineral of this bright area is sodium carbonate, a kind of salt found on Earth in hydrothermal environments. This material appears to have come from inside Ceres, and this upwelling suggests that temperatures inside Ceres are warmer than previously believed. Even more intriguingly, the results suggest that liquid water may have existed beneath the surface of Ceres in recent geological time. The salts could be remnants of an ocean, or localized bodies of water, that reached the surface and then froze millions of years ago. See more details.

8. Captain's Log 

Dawn's chief engineer and mission director, Marc Rayman, provides regular dispatches about Dawn's work in the asteroid belt. Catch the latest updates here.

9. Eyes on Dawn 

Another cool way to retrace Dawn's decade-long flight is to download NASA's free Eyes on the Solar System app, which uses real data to let you go to any point in the solar system, or ride along with any spacecraft, at any point in time—all in 3-D.

10. No Stamp Required

Send a postcard from one of these three sets of images that tell the story of dwarf planet Ceres, protoplanet Vesta, and the Dawn mission overall.

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Solar System 10 Things: Two Years of Juno at Jupiter

Our Juno mission arrived at the King of Planets in July 2016. The intrepid robotic explorer has been revealing Jupiter's secrets ever since. 

Here are 10 historic Juno mission highlights:

1. Arrival at a Colossus

After an odyssey of almost five years and 1.7 billion miles (2.7 billion kilometers), our Juno spacecraft fired its main engine to enter orbit around Jupiter on July 4, 2016. Juno, with its suite of nine science instruments, was the first spacecraft to orbit the giant planet since the Galileo mission in the 1990s. It would be the first mission to make repeated excursions close to the cloud tops, deep inside the planet’s powerful radiation belts.

2. Science, Meet Art

Juno carries a color camera called JunoCam. In a remarkable first for a deep space mission, the Juno team reached out to the general public not only to help plan which pictures JunoCam would take, but also to process and enhance the resulting visual data. The results include some of the most beautiful images in the history of space exploration.

3. A Whole New Jupiter

It didn’t take long for Juno—and the science teams who hungrily consumed the data it sent home—to turn theories about how Jupiter works inside out. Among the early findings: Jupiter's poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together. Jupiter's iconic belts and zones were surprising, with the belt near the equator penetrating far beneath the clouds, and the belts and zones at other latitudes seeming to evolve to other structures below the surface.

4. The Ultimate Classroom

The Goldstone Apple Valley Radio Telescope (GAVRT) project, a collaboration among NASA, JPL and the Lewis Center for Educational Research, lets students do real science with a large radio telescope. GAVRT data includes Jupiter observations relevant to Juno, and Juno scientists collaborate with the students and their teachers.

5. Spotting the Spot

Measuring in at 10,159 miles (16,350 kilometers) in width (as of April 3, 2017) Jupiter's Great Red Spot is 1.3 times as wide as Earth. The storm has been monitored since 1830 and has possibly existed for more than 350 years. In modern times, the Great Red Spot has appeared to be shrinking. In July 2017, Juno passed directly over the spot, and JunoCam images revealed a tangle of dark, veinous clouds weaving their way through a massive crimson oval.

“For hundreds of years scientists have been observing, wondering and theorizing about Jupiter’s Great Red Spot,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “Now we have the best pictures ever of this iconic storm. It will take us some time to analyze all the data from not only JunoCam, but Juno’s eight science instruments, to shed some new light on the past, present and future of the Great Red Spot.”

6. Beauty Runs Deep

Data collected by the Juno spacecraft during its first pass over Jupiter's Great Red Spot in July 2017 indicate that this iconic feature penetrates well below the clouds. The solar system's most famous storm appears to have roots that penetrate about 200 miles (300 kilometers) into the planet's atmosphere.

7. Powerful Auroras, Powerful Mysteries

Scientists on the Juno mission observed massive amounts of energy swirling over Jupiter’s polar regions that contribute to the giant planet’s powerful auroras – only not in ways the researchers expected. Examining data collected by the ultraviolet spectrograph and energetic-particle detector instruments aboard Juno, scientists observed signatures of powerful electric potentials, aligned with Jupiter’s magnetic field, that accelerate electrons toward the Jovian atmosphere at energies up to 400,000 electron volts. This is 10 to 30 times higher than the largest such auroral potentials observed at Earth. 

Jupiter has the most powerful auroras in the solar system, so the team was not surprised that electric potentials play a role in their generation. What puzzled the researchers is that despite the magnitudes of these potentials at Jupiter, they are observed only sometimes and are not the source of the most intense auroras, as they are at Earth.

8. Heat from Within

Juno scientists shared a 3D infrared movie depicting densely packed cyclones and anticyclones that permeate the planet’s polar regions, and the first detailed view of a dynamo, or engine, powering the magnetic field for any planet beyond Earth (video above). Juno mission scientists took data collected by the spacecraft’s Jovian InfraRed Auroral Mapper (JIRAM) instrument and generated a 3D fly-around of the Jovian world’s north pole. 

Imaging in the infrared part of the spectrum, JIRAM captures light emerging from deep inside Jupiter equally well, night or day. The instrument probes the weather layer down to 30 to 45 miles (50 to 70 kilometers) below Jupiter's cloud tops.

9. A Highly Charged Atmosphere

Powerful bolts of lightning light up Jupiter’s clouds. In some ways its lightning is just like what we’re used to on Earth. In other ways,it’s very different. For example, most of Earth’s lightning strikes near the equator; on Jupiter, it’s mostly around the poles.

10. Extra Innings

In June, we approved an update to Juno’s science operations until July 2021. This provides for an additional 41 months in orbit around. Juno is in 53-day orbits rather than 14-day orbits as initially planned because of a concern about valves on the spacecraft’s fuel system. This longer orbit means that it will take more time to collect the needed science data, but an independent panel of experts confirmed that Juno is on track to achieve its science objectives and is already returning spectacular results. The spacecraft and all its instruments are healthy and operating nominally. ​

Read the full web version of this week’s ‘Solar System: 10 Things to Know’ article HERE. 

For regular updates, follow NASA Solar System on Twitter and Facebook. 

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When you went into space for the first time, what was it like? Were you nervous?

The Search for Starless Planets

While it’s familiar to us, our solar system may actually be a bit of an oddball. Our Milky Way galaxy is home to gigantic worlds with teeny-tiny orbits and planets that circle pairs of stars. We’ve even found planets that don’t orbit stars at all! Instead, they drift through the galaxy completely alone (unless they have a moon to keep them company). These lonely island worlds are called rogue planets.

Where do rogue planets come from?

The planet-building process can be pretty messy. Dust and gas around a star clump together to form larger and larger objects, like using a piece of play-dough to pick up other pieces.

Sometimes collisions and close encounters can fling a planet clear out of the gravitational grip of its parent star. Rogue planets may also form out in space on their own, like the way stars grow.

Seeing the invisible

We’ve discovered more than 4,000 exoplanets, but only a handful are rogue planets. That’s because they’re superhard to find! Rogue planets are almost completely invisible to us because they don’t shine like stars and space is inky black. It’s like looking for a black cat in a dark room without a flashlight.

Some planet-finding methods involve watching to see how orbiting planets affect their host star, but that doesn’t work for rogue planets because they’re off by themselves. Rogue planets are usually pretty cold too, so infrared telescopes can’t use their heat vision to spot them either.

So how can we find them? Astronomers use a cool cosmic quirk to detect them by their effect on starlight. When a rogue planet lines up with a more distant star from our vantage point, the planet bends and magnifies light from the star. This phenomenon, called microlensing, looks something like this:

Imagine you have a trampoline, a golf ball, and an invisible bowling ball. If you put the bowling ball on the trampoline, you could see how it made a dent in the fabric even if you couldn’t see the ball directly. And if you rolled the golf ball near it, it would change the golf ball’s path.

A rogue planet affects space the way the bowling ball warps the trampoline. When light from a distant star passes by a rogue planet, it curves around the invisible world (like how it curves around the star in the animation above). If astronomers on Earth were watching the star, they’d notice it briefly brighten. The shape and duration of this brightness spike lets them know a planet is there, even though they can’t see it.

Telescopes on the ground have to look through Earth’s turbulent atmosphere to search for rogue planets. But when our Nancy Grace Roman Space Telescope launches in the mid-2020s, it will give us a much better view of distant stars and rogue planets because it will be located way above Earth’s atmosphere — even higher than the Moon!

Other space telescopes would have to be really lucky to spot these one-in-a-million microlensing signals. But Roman will watch huge patches of the sky for months to catch these fleeting events.

Lessons from cosmic castaways

Scientists have come up with different models to explain how different planetary systems form and change over time, but we still don’t know which ones are right. The models make different predictions about rogue planets, so studying these isolated worlds can help us figure out which models work best.

When Roman spots little microlensing starlight blips, astronomers will be able to get a pretty good idea of the mass of the object that caused the signal from how long the blip lasts. Scientists expect the mission to detect hundreds of rogue planets that are as small as rocky Mars — about half the size of Earth — up to ones as big as gas giants, like Jupiter and Saturn.

By design, Roman is only going to search a small slice of the Milky Way for rogue planets. Scientists have come up with clever ways to use Roman’s future data to estimate how many rogue planets there are in the whole galaxy. This information will help us better understand whether our solar system is pretty normal or a bit of an oddball compared to the rest of our galaxy.

Roman will have such a wide field of view that it will be like going from looking at the cosmos through a peephole to looking through a floor-to-ceiling window. The mission will help us learn about all kinds of other cool things in addition to rogue planets, like dark energy and dark matter, that will help us understand much more about our place in space.

Learn more about the Roman Space Telescope at: https://roman.gsfc.nasa.gov/

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Blowing Bubbles in the Gamma-ray Sky

Did you know our Milky Way galaxy is blowing bubbles? Two of them, each 25,000 light-years tall! They extend above and below the disk of the galaxy, like the two halves of an hourglass. We can’t see them with our own eyes because they’re only apparent in gamma-ray light, the highest-energy light in the universe.

We didn’t even know these humongous structures were smack in the middle of our galaxy until 2010. Scientists found them when they analyzed the first two years of data from NASA’s Fermi Gamma-ray Space Telescope. They dubbed them the “Fermi bubbles” and found that in addition to being really big and spread out, they seem to have well-defined edges. The bubbles’ shape and the light they give off led scientists to think they were created by a rapid release of energy. But by what? And when?

One possible explanation is that they could be leftovers from the last big meal eaten by the supermassive black hole at the center of our galaxy. This monster is more than 4 million times the mass of our own Sun. Scientists think it may have slurped up a big cloud of hydrogen between 6 and 9 million years ago and then burped jets of hot gas that we see in gamma rays and X-rays.

Another possible explanation is that the bubbles could be the remains of star formation. There are massive clusters of stars at very the center of the Milky Way — sometimes the stars are so closely packed they’re a million times more dense than in the outer suburb of the galaxy where we live. If there was a burst of star formation in this area a few million years ago, it could have created the surge of gas needed to in turn create the Fermi bubbles.

It took us until 2010 to see these Fermi bubbles because the sky is filled with a fog of other gamma rays that can obscure our view. This fog is created when particles moving near light speed bump into gas, dust, and light in the Milky Way. These collisions produce gamma rays, and scientists had to factor out the fog to unveil the bubbles.

Scientists continue to study the possible causes of these massive bubbles using the 10 years of data Fermi has collected so far. Fermi has also made many other exciting discoveries — like the the collision of superdense neutron stars and the nature of space-time. Learn more about Fermi and how we’ve been celebrating its first decade in space.

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Sending Science to Space (and back) 🔬🚀

This season on our NASA Explorers video series, we’ve been following Elaine Horn-Ranney Ph.D and Parastoo Khoshaklagh Ph.D. as they send their research to the space station.

From preparing the experiment in the lab….

To training the astronauts to perform the science…

To watching it launch to space…

To conducting the science aboard the space station, we’ve been there every step of the way.

Now you can follow along with the whole journey!

Binge watch all of NASA Explorers season 4: Microgravity HERE

Want to keep up with space station research? Follow ISS Research on Twitter.

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