Pluto Continues To Amaze

What in the Universe is an Exoplanet?

Simply put, an exoplanet is a planet that orbits another star. 

All of the planets in our solar system orbit around the Sun. Planets that orbit around other stars outside our solar system are called exoplanets.

Just because a planet orbits a star (like Earth) does not mean that it is automatically stable for life. The planet must be within the habitable zone, which is the area around a star in which water has the potential to be liquid…aka not so close that all the water would evaporate, and not too far away where all the water would freeze.

Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit. So, astronomers use other ways to detect and study these distant planets by looking at the effects these planets have on the stars they orbit.

One way to search for exoplanets is to look for "wobbly" stars. A star that has planets doesn’t orbit perfectly around its center. From far away, this off-center orbit makes the star look like it’s wobbling. Hundreds of planets have been discovered using this method. However, only big planets—like Jupiter, or even larger—can be seen this way. Smaller Earth-like planets are much harder to find because they create only small wobbles that are hard to detect.

How can we find Earth-like planets in other solar systems?

In 2009, we launched a spacecraft called Kepler to look for exoplanets. Kepler looked for planets in a wide range of sizes and orbits. And these planets orbited around stars that varied in size and temperature.

Kepler detected exoplanets using something called the transit method. When a planet passes in front of its star, it’s called a transit. As the planet transits in front of the star, it blocks out a little bit of the star's light. That means a star will look a little less bright when the planet passes in front of it. Astronomers can observe how the brightness of the star changes during a transit. This can help them figure out the size of the planet.

By studying the time between transits, astronomers can also find out how far away the planet is from its star. This tells us something about the planet’s temperature. If a planet is just the right temperature, it could contain liquid water—an important ingredient for life.

So far, thousands of planets have been discovered by the Kepler mission.

We now know that exoplanets are very common in the universe. And future missions have been planned to discover many more!

Next month, we’re launching an explorer-class planet finder — the Transiting Exoplanet Survey Satellite (TESS). This mission will search the entire sky for exoplanets — planets outside our solar system that orbit sun-like stars.

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Dark Matter 101: Looking for the missing mass

Here’s the deal — here at NASA we share all kinds of amazing images of planets, stars, galaxies, astronauts, other humans, and such, but those photos can only capture part of what’s out there. Every image only shows ordinary matter (scientists sometimes call it baryonic matter), which is stuff made from protons, neutrons and electrons. The problem astronomers have is that most of the matter in the universe is not ordinary matter – it’s a mysterious substance called dark matter.  

What is dark matter? We don’t really know. That’s not to say we don’t know anything about it – we can see its effects on ordinary matter. We’ve been getting clues about what it is and what it is not for decades. However, it’s hard to pinpoint its exact nature when it doesn’t emit light our telescopes can see. 

Misbehaving galaxies

The first hint that we might be missing something came in the 1930s when astronomers noticed that the visible matter in some clusters of galaxies wasn’t enough to hold the cluster together. The galaxies were moving so fast that they should have gone zinging out of the cluster before too long (astronomically speaking), leaving no cluster behind.

Simulation credit: ESO/L. Calçada

It turns out, there’s a similar problem with individual galaxies. In the 1960s and 70s, astronomers mapped out how fast the stars in a galaxy were moving relative to its center. The outer parts of every single spiral galaxy the scientists looked at were traveling so fast that they should have been flying apart.

Something was missing – a lot of it! In order to explain how galaxies moved in clusters and stars moved in individual galaxies, they needed more matter than scientists could see. And not just a little more matter. A lot . . . a lot, a lot. Astronomers call this missing mass “dark matter” — “dark” because we don’t know what it is. There would need to be five times as much dark matter as ordinary matter to solve the problem.  

Holding things together

Dark matter keeps galaxies and galaxy clusters from coming apart at the seams, which means dark matter experiences gravity the same way we do.

In addition to holding things together, it distorts space like any other mass. Sometimes we see distant galaxies whose light has been bent around massive objects on its way to us. This makes the galaxies appear stretched out or contorted. These distortions provide another measurement of dark matter.

Undiscovered particles?

There have been a number of theories over the past several decades about what dark matter could be; for example, could dark matter be black holes and neutron stars – dead stars that aren’t shining anymore? However, most of the theories have been disproven. Currently, a leading class of candidates involves an as-yet-undiscovered type of elementary particle called WIMPs, or Weakly Interacting Massive Particles.

Theorists have envisioned a range of WIMP types and what happens when they collide with each other. Two possibilities are that the WIMPS could mutually annihilate, or they could produce an intermediate, quickly decaying particle. In both cases, the collision would end with the production of gamma rays — the most energetic form of light — within the detection range of our Fermi Gamma-ray Space Telescope.

Tantalizing evidence close to home

A few years ago, researchers took a look at Fermi data from near the center of our galaxy and subtracted out the gamma rays produced by known sources. There was a left-over gamma-ray signal, which could be consistent with some forms of dark matter.

While it was an exciting finding, the case is not yet closed because lots of things at the center of the galaxy make gamma rays. It’s going to take multiple sightings using other experiments and looking at other astronomical objects to know for sure if this excess is from dark matter.

In the meantime, Fermi will continue the search, as it has over its 10 years in space. Learn more about Fermi and how we’ve been celebrating its first decade in space.

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What’s Up for December?

View Mars right now, and prepare for 2016, the best Mars viewing year since 2005! Last month early risers watched small, reddish Mars dance with brighter Jupiter and Venus just before sunrise. 

This month Mars rises earlier-by about 2 a.m. local time. Its reddish color is unmistakable, even without a telescope. It's easy to see below the Moon and Jupiter on December 4. You won't see many features this month, because the planet is almost 10 times smaller than nearby Jupiter appears and 350 times smaller than the Moon appears to us on Earth.

You should also be able to see Mars' north polar region this month, because it's currently tilted towards Earth. 

You'll be amazed at the changes you'll see during 2016. January through December are all prime Mars observing months. Between January and May next year, Mars triples in apparent diameter as its orbit around the sun brings it closer to Earth. You'll even be able to see the areas on Mars where NASA's Mars landers are located.

By October, Mars shrinks in apparent size to less than half its May diameter as it speeds away from Earth. Mars shrinks even further from October through December, returning to the same size we saw in January 2016 by year's end.

So put Mars viewing on your calendar for 2016. You won't see Mars this size again until 2018, when Mars will put on an even better show.

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Questions coming up from….

@maybeinanotherworld: JWST IS HAPPENING! How are all of you feeling about this?

@Anonymous: How powerful is this telescope, exactly?

@Anonymous: Why are the mirrors on it yellow?

@foeofcolor: How long is this estimated to last for? Like how long will it be able to function in space by estimates?

The Shakespearean Moons of Uranus

This weekend marks the 400th anniversary of Shakespeare’s death, and we’re highlighting the moons of Uranus; some of which are named after characters from his works.

While most of the moons orbiting other planets take their names from Greek mythology, Uranus’ moons are unique in bing named for Shakespearean characters, along with a couple of them being named for characters from the works of Alexander Pope.

Using the Hubble Space Telescope and improved ground-based telescopes, astronomers have discovered a total of 27 known moons around Uranus.

Here’s a sampling of some of the unique aspects of the moons:

Miranda

Shakespearean work: The Tempest

Miranda, the innermost and smallest of the five major satellites, has a surface unlike any other moon that’s been seen. It has a giant fault canyon as much as 12 times as deep as the Grand Canyon, terraced layers and surfaces that appear very old, and others that look much younger.

Ariel

Shakespearean work: The Tempest

Ariel has the brightest and possibly the youngest surface among all the moons of Uranus. It has a few large craters and many small ones, indicating that fairly recent low-impact collisions wiped out the large craters that would have been left by much earlier, bigger strikes. Intersecting valleys pitted with craters scars its surface.

Oberon

Shakespearean work: A Midsummer Night’s Dream

Oberon, the outermost of the five major moons, is old, heavily cratered and shows little signs of internal activity. Unidentified dark material appears on the floors of many of its craters.

Cordelia and Ophelia

Shakespearean works: Cordelia - King Lear; Ophelia - Hamlet

Cordelia and Ophelia are shepherd moons that keep Uranus’ thin, outermost “epsilon” ring well defined.

Between them and miranda is a swarm of eight small satellites unlike any other system of planetary moons. This region is so crowded that astronomers don’t yet understand how the little moons have managed to avoid crashing into each other. They may be shepherds for the planet’s 10 narrow rings, and scientists think there must be still more moons, interior to any known, to confine the edges of the inner rings.

Want to learn more about all of Uranus’s moons? Visit: http://solarsystem.nasa.gov/planets/uranus/moons

Check out THIS blog from our Chief Scientist Ellen Stofan, where she reflects on the life and legacy of William Shakespeare on the 400th anniversary of his death on April 23, 1616.

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Sing About NASA with Our Interns

Each semester, interns at Johnson Space Center (JSC) have the opportunity to contribute to our agency’s missions and help us lead the frontier of human space exploration. Interns at JSC also have the opportunity to enhance their experience through weekly meetings to discuss social and professional development topics, and can also get involved in many different committees.

The intern video committee from each semester comes up with ideas and carries out the entire process of creating a video that puts a creative, youthful spin on spreading NASA messages.

Here are a few highlights from some of the great intern videos that have been created:

Welcome to NASA

“Welcome to NASA” is based off of Flo Rida’s “My House” and was created to raise interest for our Journey to Mars. The lyrics and scenes in the video have been re-imagined in order to inform the public about the amazing work going on at NASA and the Johnson Space Center. 

Created in 2016

NASA is Good

This latest intern video is based off of Andy Grammer’s “Honey, I’m Good”. This video is designed as an outreach video to raise interest around the One-Year Mission aboard the International Space Station and the Pathways and Student Intern opportunities. 

Created in 2015

NASA Johnson Style

NASA Johnson Style was created as an educational parody of Psy’s "Gangnam Style". The intent of the video is to inform the public about the work being done at Johnson Space Center and throughout the agency. 

Created in 2012

I.S.S. Baby

A group of NASA interns collaborated to create the I.S.S Baby video based off of Vanilla Ice’s “Ice, Ice, Baby”. The video was designed as an outreach video to raise interest around the International Space Station. 

Created in 2008

There are plenty more JSC intern videos. You can watch more and learn about the work done at JSC and throughout the agency HERE.

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We Found the Perfect Spot to Land our Moon Rover

After an extensive selection process, we chose the mountainous area west of Nobile Crater at the Moon’s South Pole as the landing site for our first-ever robotic Moon rover. The Volatiles Investigating Polar Exploration Rover, or VIPER, will explore the Moon’s surface and subsurface in search of water and other resources beginning in late 2023. Thanks to past missions, such as satellites orbiting the Moon or impacting its surface, we know there is ice at the Moon’s poles. But how much? And where did it come from? VIPER aims to answer these questions and more by venturing into shadowed craters and visiting other areas of scientific interest over its 100-day mission. The findings will inform future landing sites under the Artemis program and help pave the way toward establishing a long-term human presence on the Moon. Here are five things to know:

The landing site is located just outside the western rim of Nobile Crater at the Moon’s South Pole.

The region has suitable lighting and terrain for our solar-powered rover to navigate.

VIPER will travel up to 15 miles in search of water and other resources.

Its traverse will change depending on what it finds, but it could look like this.

Drivers on Earth will tell the rover where to explore during its 100-day mission.

The VIPER mission is managed by our Ames Research Center in California's Silicon Valley. The approximately 1,000-pound rover will be delivered to the Moon by a commercial vendor as part of our Commercial Lunar Payload Services initiative, delivering science and technology payloads to and near the Moon.

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It’s kick-off time! Pilot Dean “Gucci” Neeley is reporting for duty with answers to your questions in today’s Tumblr Answer Time!

Observing the Ozone Hole from Space: A Science Success Story

Using our unique ability to view Earth from space, we are working together with NOAA to monitor an emerging success story – the shrinking ozone hole over Antarctica.

Thirty years ago, the nations of the world agreed to the landmark ‘Montreal Protocol on Substances that Deplete the Ozone Layer.’ The Protocol limited the release of ozone-depleting chlorofluorocarbons (CFCs) into the atmosphere.

Since the 1960s our scientists have worked with NOAA researchers to study the ozone layer. 

We use a combination of satellite, aircraft and balloon measurements of the atmosphere.

The ozone layer acts like a sunscreen for Earth, blocking harmful ultraviolet, or UV, rays emitted by the Sun.

In 1985, scientists first reported a hole forming in the ozone layer over Antarctica. It formed over Antarctica because the Earth’s atmospheric circulation traps air over Antarctica.  This air contains chlorine released from the CFCs and thus it rapidly depletes the ozone.

Because colder temperatures speed up the process of CFCs breaking up and releasing chlorine more quickly, the ozone hole fluctuates with temperature. The hole shrinks during the warmer summer months and grows larger during the southern winter. In September 2006, the ozone hole reached a record large extent.

But things have been improving in the 30 years since the Montreal Protocol. Thanks to the agreement, the concentration of CFCs in the atmosphere has been decreasing, and the ozone hole maximum has been smaller since 2006’s record.

That being said, the ozone hole still exists and fluctuates depending on temperature because CFCs have very long lifetimes. So, they still exist in our atmosphere and continue to deplete the ozone layer.

To get a view of what the ozone hole would have looked like if the world had not come to the agreement to limit CFCs, our scientists developed computer models. These show that by 2065, much of Earth would have had almost no ozone layer at all.

Luckily, the Montreal Protocol exists, and we’ve managed to save our protective ozone layer. Looking into the future, our scientists project that by 2065, the ozone hole will have returned to the same size it was thirty years ago.

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How has being in space changed your perspective of life on Earth?