What’s Up For May 2016?

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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Solar System: Things to Know This Week

Our solar system is huge, let us break it down for you. Here are a few things to know this week:

1. The New New Horizons

Seven months after the  Pluto flyby, information and discoveries continue to flow from the New Horizons mission, as the spacecraft transmits more and more data to scientists on Earth.

2. A Longlasting Dawn

The Dawn orbiter is in good health as it carries out the ongoing reconnaissance of the dwarf planet Ceres, which is revealing some spectacular and mysterious landscapes.

3. Storm Watch: Saturn

This week the Cassini spacecraft will be watching for storms in Saturn’s turbulent atmosphere. On March 6, it will spend about 14 hours acquiring a movie of the narrow, braided F ring. Check out some past photos of Saturnian storms HERE.

4. The Next Flight to Mars Departs Soon

The ExoMars 2016 mission, a joint endeavor between the European Space Agency and the Russian space agency Roscosmos, is set to lift off in March. The 2016 mission consists of the Trace Gas Orbiter and the Schiaparelli Entry, Descent and Landing Demonstrator Module. We’re supplying some of the technology that will fly aboard the orbiter. In 2018, the ExoMars rover is slated to follow.

5. Early Encounter with a Comet

As we continue to marvel at the latest images from Rosetta, this week is a good time to remember the 30th anniversary of the Vega 1 Comet Halley flyby. This Russian spacecraft dropped off a balloon probe at Venus before continuing on to the comet, which is photographed and examined at close range by flying through its coma.

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

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For the second time in history, a human-made object has reached the space between the stars. Our Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.

Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.

Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.

Read more at https://go.nasa.gov/2QG2s16 or follow along with the mission @NASAVoyager on Twitter.

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What’s Up - January 2018

What’s Up For January? 

Quadrantid meteors, a West Coast-favoring total lunar eclipse and time to start watching Mars!

This month the new year's first meteor shower fizzles, Mars meets Jupiter in the morning sky and the U.S. will enjoy a total lunar eclipse!

Most meteor showers radiate from recognizable constellations. Like the Leonids, Geminids and Orionids.

But the Quadrantids are meteors that appear to radiate from the location of the former Quadrans Muralis constellation, an area that's now part of the constellation Bootes.

The Quadrantids' peak lasts for just a few hours, and sadly, this year their timing coincides with a very bright, nearly full moon that will wash out most of the meteors.

You can look in any direction to see all the meteor showers. When you see one of these meteors, hold a shoestring along the path it followed. The shoestring will lead you back to the constellation containing the meteor’s origin.

On the morning of January 6th, look in the south-southeast sky 45 minutes before sunrise to see Jupiter and fainter Mars almost as close as last month's Jupiter and Venus close pairing.

Mars is only one-sixth the apparent diameter of Jupiter, but the two offer a great binocular and telescopic view with a pretty color contrast. They remain in each other's neighborhood from January 5th through the 8th.

Finally, to end the month, a great total lunar eclipse favors the western U.S., Alaska, and Hawaii and British Columbia on January 31st. Australia and the Pacific Ocean are well placed to see a major portion of the eclipse--if not all of it.

Watch the full What’s Up for January Video: 

There are so many sights to see in the sky. To stay informed, subscribe to our What’s Up video series on Facebook. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.   

Discovering the Universe Through the Constellation Orion

Do you ever look up at the night sky and get lost in the stars? Maybe while you’re stargazing, you spot some of your favorite constellations. But did you know there’s more to constellations than meets the eye? They’re not just a bunch of imaginary shapes made up of stars — constellations tell us stories about the universe from our perspective on Earth.

What is a constellation?

A constellation is a named pattern of stars that looks like a particular shape. Think of it like connecting the dots. If you join the dots — stars, in this case — and use your imagination, the picture would look like an object, animal, or person. For example, the ancient Greeks believed an arrangement of stars in the sky looked like a giant hunter with a sword attached to his belt, so they named it after a famous hunter in their mythology, Orion. It’s one of the most recognizable constellations in the night sky and can be seen around the world. The easiest way to find Orion is to go outside on a clear night and look for three bright stars close together in an almost-straight line. These three stars represent Orion's belt. Two brighter stars to the north mark his shoulders, and two more to the south represent his feet.

Credit: NASA/STScI

Over time, cultures around the world have had different names and numbers of constellations depending on what people thought they saw. Today, there are 88 officially recognized constellations. Though these constellations are generally based on what we can see with our unaided eyes, scientists have also invented unofficial constellations for objects that can only be seen in gamma rays, the highest-energy form of light.

Perspective is everything

The stars in constellations may look close to each other from our point of view here on Earth, but in space they might be really far apart. For example, Alnitak, the star at the left side of Orion's belt, is about 800 light-years away. Alnilam, the star in the middle of the belt, is about 1,300 light-years away. And Mintaka, the star at the right side of the belt, is about 900 light-years away. Yet they all appear from Earth to have the same brightness. Space is three-dimensional, so if you were looking at the stars that make up the constellation Orion from another part of our galaxy, you might see an entirely different pattern!

The superstars of Orion

Now that we know a little bit more about constellations, let’s talk about the supercool cosmic objects that form them – stars! Though over a dozen stars make up Orion, two take center stage. The red supergiant Betelgeuse (Orion's right shoulder) and blue supergiant Rigel (Orion's left foot) stand out as the brightest members in the constellation.

Credit: Derrick Lim

Betelgeuse is a young star by stellar standards, about 10 million years old, compared to our nearly 5 billion-year-old Sun. The star is so huge that if it replaced the Sun at the center of our solar system, it would extend past the main asteroid belt between Mars and Jupiter! But due to its giant mass, it leads a fast and furious life.

Betelgeuse is destined to end in a supernova blast. Scientists discovered a mysterious dimming of Betelgeuse in late 2019 caused by a traumatic outburst that some believed was a precursor to this cosmic event. Though we don’t know if this incident is directly related to an imminent supernova, there’s a tiny chance it might happen in your lifetime. But don't worry, Betelgeuse is about 550 light-years away, so this event wouldn't be dangerous to us – but it would be a spectacular sight.

Rigel is also a young star, estimated to be 8 million years old. Like Betelgeuse, Rigel is much larger and heavier than our Sun. Its surface is thousands of degrees hotter than Betelgeuse, though, making it shine blue-white rather than red. These colors are even noticeable from Earth. Although Rigel is farther from Earth than Betelgeuse (about 860 light-years away), it is intrinsically brighter than its companion, making it the brightest star in Orion and one of the brightest stars in the night sky.

Credit: Rogelio Bernal Andreo

Buckle up for Orion’s belt

Some dots that make up constellations are actually more than one star, but from a great distance they look like a single object. Remember Mintaka, the star at the far right side of Orion's belt? It is not just a single star, but actually five stars in a complex star system.

Credit: X-ray: NASA/CXC/GSFC/M. Corcoran et al.; Optical: Eckhard Slawik

Sword or a stellar nursery?

Below the three bright stars of Orion’s belt lies his sword, where you can find the famous Orion Nebula. The nebula is only 1,300 light-years away, making it the closest large star-forming region to Earth. Because of its brightness and prominent location just below Orion’s belt, you can actually spot the Orion Nebula from Earth! But with a pair of binoculars, you can get a much more detailed view of the stellar nursery. It’s best visible in January and looks like a fuzzy “star” in the middle of Orion’s sword.

More to discover in constellations

In addition to newborn stars, Orion also has some other awesome cosmic objects hanging around. Scientists have discovered exoplanets, or planets outside of our solar system, orbiting stars there. One of those planets is a giant gas world three times more massive than Jupiter. It’s estimated that on average there is at least one planet for every star in our galaxy. Just think of all the worlds you may be seeing when you look up at the night sky!

It’s also possible that the Orion Nebula might be home to a black hole, making it the closest known black hole to Earth. Though we may never detect it, because no light can escape black holes, making them invisible. However, space telescopes with special instruments can help find black holes. They can observe the behavior of material and stars that are very close to black holes, helping scientists find clues that can lead them closer to discovering some of these most bizarre and fascinating objects in the cosmos.

Next time you go stargazing, remember that there’s more to the constellations than meets the eye. Let them guide you to some of the most incredible and mysterious objects of the cosmos — young stars, brilliant nebulae, new worlds, star systems, and even galaxies!

To keep up with the most recent stellar news, follow NASA Universe on Twitter and Facebook.

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How can citizens become more involved and informed about Earth sciences and developments? Are there mailing lists or accounts you suggest following?

Website: https://science.nasa.gov/citizenscience

Solar System: Things to Know This Week

We've been up close and personal with Saturn for 13 years now, thanks to the Cassini mission. 

From a tour of Saturn's many enthralling moons to an incredible view of Earth through its rings, the planet continues to captivate the imagination. This week, here are 10 things you need to know about our fascinating ringed neighbor.

1. Strange Sighting

When Galileo Galilei was observing Saturn in the 1600s, he noticed strange objects on each side of the planet. He drew in his notes a triple-bodied planet system with ears. These "ears" were later discovered to be the rings of Saturn.

2. Solar System Status

Saturn orbits our sun and is the sixth planet from the sun at an average distance of about 886 million miles or 9.5 AU.

3. Short Days

Time flies when you're on Saturn. One day on Saturn takes just 10.7 hours (the time it takes for Saturn to rotate or spin once). The planet makes a complete orbit around the sun (a year in Saturnian time) in 29 Earth years, or 10,756 Earth days. saturn.jpl.nasa.gov/news/2955/measuring-a-day

4. No Shoes Necessary

That's because you can't stand on Saturn—it's a gas-giant planet and doesn't have a solid surface. But you might want a jacket. The planet's temperatures can dip to -220 degrees F.

5. Few visitors

Only a handful of missions have made their way to Saturn: Pioneer 11, Voyager 1 and 2, and Cassini-Huygens, which is there now. Since 2004, Cassini has been exploring Saturn and its moons and rings—but will complete its journey on Sept. 15, 2017.

6. Saturn's Close-Up

This month is a great time to observe Saturn from Earth. Check out June's "What's Up?" video for a how-to guide.

7. Daring Dives

Saturn's spectacular ring system is made up of seven rings with several gaps and divisions between them. From now until September, the Cassini spacecraft is performing a set of daring dives every week between the planet and the rings. No other mission has ever explored this unique region before, and what we learn from these final orbits will help us understand of how giant planets—and planetary systems everywhere—form and evolve.

8. Many, Many Moons 

Saturn has a total of 62 moons: 53 known moons, with an additional nine moons awaiting confirmation.

9. Curious Shapes 

Saturn's moon Atlas looks like a flying saucer. See for yourself.

10. Would You Live on a Moon? 

Saturn can't support life as we know it, but some of its moons have conditions that might support life. Ocean worlds could be the answer to life in space and two of Saturn's moons—Titan and Enceladus—are on that list.

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

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We Found the Universe’s First Type of Molecule

For decades, astronomers searched the cosmos for what is thought to be the first kind of molecule to have formed after the Big Bang. Now, it has finally been found. The molecule is called helium hydride. It’s made of a combination of hydrogen and helium. Astronomers think the molecule appeared more than 13 billion years ago and was the beginning step in the evolution of the universe. Only a few kinds of atoms existed when the universe was very young. Over time, the universe transformed from a primordial soup of simple molecules to the complex place it is today — filled with a seemingly infinite number of planets, stars and galaxies. Using SOFIA, the world’s largest airborne observatory, scientists detected newly formed helium hydride in a planetary nebula 3,000 light-years away. It was the first ever detection of the molecule in the modern universe. Learn more about the discovery:

Helium hydride is created when hydrogen and helium combine. 

Since the 1970s, scientists thought planetary nebula NGC 7027—a giant cloud of gas and dust in the constellation Cygnus—had the right environment for helium hydride to exist. 

But space telescopes could not pick out its chemical signal from a medley of molecules. 

Enter SOFIA, the world’s largest flying observatory! 

By pointing the aircraft’s 106-inch telescope at the planetary nebula and using a tool that works like a radio receiver to tune in to the “frequency” of helium hydride, similar to tuning a radio to a favorite station…

…the molecule’s chemical signal came through loud and clear, bringing a decades-long search to a happy end.

The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe. SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Find out more about the mission at www.nasa.gov/SOFIA

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How to Connect with NASA

We're the nation’s space agency, but that doesn’t mean you have to travel to the depths of the universe to stay connected with the awesome stuff we’re doing. There are actually some really easy ways to stay updated on all things space. Check them out:

Apps

We have lots of apps for smartphones and tablets that will make it easier than ever to stay connected to space. Here are a few to pique your interest:  

NASA App: Showcases a huge collection of the latest content, including images, videos, mission information, stories, space station sighting opportunities and more! Download: Apple/Android

NASA Spinoff App: This application profiles the best examples of technology that have been transferred from NASA research and missions into commercial products. From life-saving satellite systems to hospital robots, our technologies benefit society. Download: Apple

NASA 3DV App: The 3DV mobile app allows you to examine several of our Deep Space Exploration projects that will take our space program to asteroids, Mars and beyond! Download: Apple/Android

Spacecraft 3D: This augmented reality (AR) application lets you learn about and interact with a variety of spacecraft that are used to explore our solar system, study Earth and observe the universe. Download: Apple/Android

Competitions and Challenges

NASA Solve is an invitation to members of the public to contribute their time and expertise to solving problems and potentially winning prizes as a result of their work. This is a great way for individual members of the public to be a part of the nation’s space program. For a complete list of current challenges and competitions, visit THIS page.

Citizen Science

You don’t have to be a NASA employee to engage in the fun of interpreting scientific data and imagery from our many spacecraft and missions. As part of our Open Government plan, our goal is to promote transparency, participation and collaboration. By expanding the research base and using open innovation, we are all able to benefit from the accumulated findings. You can find data from our missions, research and activities HERE.

Email and Social Media

We have a wide-range of social media accounts here at NASA. Everything from Earth Science to the Mars Curiosity Rover, you can stay updated on many of our missions on many popular social media sites. For a full list of our accounts, visit THIS page.

If you’d like to get space news delivered straight to your inbox, you can sign up for updates and manage preferences HERE.

NASA Socials

What is a NASA Social? We’re glad you asked! These programs provide opportunities for our social media followers to learn and share information about our missions, people and programs. NASA Social includes both special in-person events and social media credentials for individuals who share the news in a significant way. Social events provide the participants with the opportunity to go behind-the-scenes at our facilities and events and speak with scientists engineers, astronauts and managers. Visit THIS page for a list of upcoming NASA Social opportunities.

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Solar System: Things to Know This Week

1. See Shadows on Jupiter

Jupiter dominates the evening sky this month, rising at sunset and setting at dawn. On the nights of March 14 and 15, Jovian moons Io and Europa will cross the planet's disk. When the planet is at opposition and the sun shines on Jupiter's moons, we can see the moons' shadows crossing the planet. There are actually 11 of these double shadow transits in March.

2. One Year of Dawn at Ceres

NASA's Dawn spacecraft gently slid into orbit around Ceres just over one year ago, becoming the first spacecraft to reach a dwarf planet. Since then, the spacecraft has delivered a wealth of images and other data that open an exciting new window to this previously unexplored body in the asteroid belt.

3. The Latest from Saturn

Days ago, on Mar. 11, 2016, Cassini's Ultraviolet Imaging Spectrograph (UVIS) watched as the plume of gas and icy particles from the moon Enceladus passed in front of the central star in Orion's Belt. Such observations, known as stellar occultations, provide information about the density and composition of the plume.

4. The Equinox is Upon Us

March 20 is the vernal equinox--the start of spring in the northern hemisphere, and the start of fall in the southern hemisphere. During the two equinoxes each year, the line between day and night is vertical, so all over the planet, the length of the day and night are nearly equal. For the rest of the year, the Earth's tilt angles the line between day and night, culminating with the solstices, in which the poles receive weeks of unending sunshine or darkness depending on the time of year.

5. Up Close with a Comet

Before Rosetta crash lands into comet Comet 67P/Churyumov-Gerasimenko in September, 2016, it will continue taking pictures and detailed measurements of this mysterious comet to study the origin of comets and how they relate to the origin of the solar system.

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

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