Signs You Might Be Ready To Apply To Be A NASA Astronaut

What is the best and worst thing about being in a zero gravity environment?

The Shrinking Aral Sea

The Aral Sea was once the fourth-largest lake in the world. Fed primarily by snowmelt and precipitation flowing down from faraway mountains, it was a temperate oasis in an arid region. But in the 1960s, the Soviet Union diverted two major rivers to irrigate farmland, cutting off the inland sea from its source. As the Aral Sea dried up, fisheries collapsed, as did the communities that depended on them. The remaining water supply became increasingly salty and polluted with runoff from agricultural plots. Loss of the Aral Sea's water influenced regional climate, making the winters even colder and the summers much hotter.

While seasonal rains still bring water to the Aral Sea, the lake is roughly one-tenth of its original size. These satellite images show how the Aral Sea and its surrounding landscape has changed over the past few decades.

For more details about these images, read the full stories here: https://go.nasa.gov/2PqJ1ot

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Five Fun Facts for the 2015 Geminid Meteor Shower

The Geminid meteor shower peaks this weekend starting on Sunday, Dec. 13. Here are a few fun facts:

Fact #1:

The Geminid meteor shower can be seen from both the Northern and Southern hemispheres. Because they are pieces of an asteroid, Geminid meteoroids can penetrate deeper into Earth’s atmosphere than most other meteor showers, creating beautiful long arcs viewable for 1-2 seconds.

Fact #2:

Geminids are pieces of debris from an object called 3200 Phaethon. It was long thought to be an asteroid, but is now classified as an extinct comet.

Phaethon’s eccentric orbit around the sun brings it well inside the orbit of Mercury every 1.4 years. Traveling this close to the sun blasts Phaethon with solar heat that may boil jets of dust into the Geminid stream. Of all the debris streams Earth passes through each year, the Geminid shower is the most massive. When we add up the amount of dust in this stream, it outweighs other streams by factors of 5 to 500.

Fact #3:

Because they are usually bright, many people say Geminid meteors show color. In addition to glowing white, they have been described as appearing yellow, green, or blue.

Geminid meteoroids hit earth's atmosphere traveling 78,000 mph or 35 km/s. That may sound fast, but it is actually somewhat slow compared to other meteor showers.

Fact #4:

Geminids are named because the meteors seem to radiate from the constellation of Gemini. The shower lasts a couple of weeks, with meteors typically seen Dec. 4-17, peaking near Dec 13-14.

Fact #5:

The Geminids started out as a relatively weak meteor shower when first discovered in the early 19th century. Over time, it has grown into the strongest annual shower, with theoretical rates above 120 meteors per hour.

Join In:

This Sunday, Dec. 13, our Marshall Space Flight Center in Huntsville, Alabama, will host a live tweet chat highlighting the 2015 Geminid meteor shower. This online, social event will occur 11 p.m. EST Dec. 13, until 3 a.m. EST on Dec. 14. To join the conversation and ask questions, use #askNASA or @NASA_Marshall.

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Solar System: 5 Things To Know This Week

Our solar system is huge, so let us break it down for you. Here are 5 things to know this week:

1. Dancing with a Star

Our local star, better known as the sun, teems with activity. This month NASA has been tracking regions that burst with magnetic loops. The Solar Dynamics Observatory is one of several space-based assets that keep tabs on the sun daily, watching as charged particles trace the magnetic field, forming bright lines as they emit light in ultraviolet wavelengths.

2. An Idyll for Ida

On Nov. 24, the asteroid Ida makes its closest approach to Earth (at a very safe distance). Ida is the first asteroid found to have its own moon, and the second ever visited by a spacecraft. Its close encounter happened in 1993 as Galileo flew by en route to Jupiter.

3. Moonshine

On Nov. 23, the Cassini spacecraft will fly near Saturn's icy moon Tethys. Several instruments aboard Cassini will collect data, including an eight-frame color image mosaic. Between Nov. 27 and Dec. 2, Cassini will have very limited communications with Earth, because Cassini will enter solar conjunction, when Cassini and Saturn are on the other side of the Sun from Earth.

4. The Moon Will Occult Aldebaran

That may sound ominous, but all it means is that Earth's moon will pass in front of the giant red star Aldebaran on Nov. 26. Aldebaran is the bright "eye" of the constellation Taurus. The event will only be visible in some parts of North America. Details can be found HERE. 

5. One Wild Ride, One Year Later

What a year it's been for the Rosetta mission since the Philae lander came to rest on the surface of Comet 67P/Churyumov-Gerasimenko in November 2014. A steady flow of data from the orbiter, together with several days of information sent from the lander, is providing a detailed picture of this remnant from the creation of the solar system.

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What Scientists Are Learning from the Eclipse

While millions of people in North America headed outside to watch the eclipse on Aug. 21, 2017, hundreds of scientists got out telescopes, set up instruments, and prepared balloon launches – all so they could study the Sun and its complicated influence on Earth.

Total solar eclipses happen about once every 18 months somewhere in the world, but the August eclipse was rare because of its long path over land. The total eclipse lasted more than 90 minutes over land, from when it first reached Oregon to when it left the U.S. in South Carolina.

This meant that scientists could collect more data from land than during most eclipses, giving us new insight into our world and the star that powers it.

A moment in the Sun’s atmosphere

During a total solar eclipse, the Sun’s outer atmosphere, the corona, is visible from Earth. It’s normally too dim to see next to the Sun’s bright face, but, during an eclipse, the Moon blocks out the Sun, revealing the corona.

Image Credit: Peter Aniol, Miloslav Druckmüller and Shadia Habbal

Though we can study parts of the corona with instruments that create artificial eclipses, some of the innermost regions of the corona are only visible during total solar eclipses. Solar scientists think this part of the corona may hold the secrets to some of our most fundamental questions about the Sun: Like how the solar wind – the constant flow of magnetized material that streams out from the Sun and fills the solar system – is accelerated, and why the corona is so much hotter than the Sun’s surface below.  

Depending on where you were, someone watching the total solar eclipse on Aug. 21 might have been able to see the Moon completely obscuring the Sun for up to two minutes and 42 seconds. One scientist wanted to stretch that even further – so he used a pair of our WB-57 jets to chase the path of the Moon’s shadow, giving their telescopes an uninterrupted view of the solar corona for just over seven and half minutes.

These telescopes were originally designed to help monitor space shuttle launches, and the eclipse campaign was their first airborne astronomy project!

These scientists weren’t the only ones who had the idea to stretch out their view of the eclipse: The Citizen CATE project (short for Continental-America Telescopic Eclipse) did something similar, but with the help of hundreds of citizen scientists. 

Citizen CATE included 68 identical small telescopes spread out across the path of totality, operated by citizen and student scientists. As the Moon’s shadow left one telescope, it reached the next one in the lineup, giving scientists a longer look at the way the corona changes throughout the eclipse.

After accounting for clouds, Citizen CATE telescopes were able to collect 82 minutes of images, out of the 93 total minutes that the eclipse was over the US. Their images will help scientists study the dynamics of the inner corona, including fast solar wind flows near the Sun’s north and south poles.

The magnetized solar wind can interact with Earth’s magnetic field, causing auroras, interfering with satellites, and – in extreme cases – even straining our power systems, and all these measurements will help us better understand how the Sun sends this material speeding out into space.

Exploring the Sun-Earth connection

Scientists also used the eclipse as a natural laboratory to explore the Sun’s complicated influence on Earth.

High in Earth’s upper atmosphere, above the ozone layer, the Sun’s intense radiation creates a layer of electrified particles called the ionosphere. This region of the atmosphere reacts to changes from both Earth below and space above. Such changes in the lower atmosphere or space weather can manifest as disruptions in the ionosphere that can interfere with communication and navigation signals.

One group of scientists used the eclipse to test computer models of the ionosphere’s effects on these communications signals. They predicted that radio signals would travel farther during the eclipse because of a drop in the number of energized particles. Their eclipse day data – collected by scientists spread out across the US and by thousands of amateur radio operators – proved that prediction right.

In another experiment, scientists used the Eclipse Ballooning Project to investigate the eclipse’s effects lower in the atmosphere. The project incorporated weather balloon flights from a dozen locations to form a picture of how Earth’s lower atmosphere – the part we interact with and which directly affects our weather – reacted to the eclipse. They found that the planetary boundary layer, the lowest part of Earth’s atmosphere, actually moved closer to Earth during the eclipse, dropped down nearly to its nighttime altitude.

A handful of these balloons also flew cards containing harmless bacteria to explore the potential for contamination of other planets with Earth-born life. Earth’s stratosphere is similar to the surface of Mars, except in one main way: the amount of sunlight. But during the eclipse, the level of sunlight dropped to something closer to what you’d expect to see on Mars, making this the perfect testbed to explore whether Earth microbes could hitch a ride to the Red Planet and survive. Scientists are working through the data collected, hoping to build up better information to help robotic and human explorers alike avoid carrying bacterial hitchhikers to Mars.

Image: The small metal card used to transport bacteria.

Finally, our EPIC instrument aboard NOAA’s DSCOVR satellite provided awe-inspiring views of the eclipse, but it’s also helping scientists understand Earth’s energy balance. Earth’s energy system is in a constant dance to maintain a balance between incoming radiation from the Sun and outgoing radiation from Earth to space, which scientists call the Earth’s energy budget. The role of clouds, both thick and thin, is important in their effect on energy balance.

Like a giant cloud, the Moon during the total solar eclipse cast a large shadow across a swath of the United States. Scientists know the dimensions and light-blocking properties of the Moon, so they used ground- and space-based instruments to learn how this large shadow affects the amount of sunlight reaching Earth’s surface, especially around the edges of the shadow. Measurements from EPIC show a 10% drop in light reflected from Earth during the eclipse (compared to about 1% on a normal day). That number will help scientists model how clouds radiate the Sun’s energy – which drives our planet’s ocean currents, seasons, weather and climate – away from our planet.

For even more eclipse science updates, stay tuned to nasa.gov/eclipse.

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How Gravity Warps Light

Gravity is obviously pretty important. It holds your feet down to Earth so you don’t fly away into space, and (equally important) it keeps your ice cream from floating right out of your cone! We’ve learned a lot about gravity over the past few hundred years, but one of the strangest things we’ve discovered is that most of the gravity in the universe comes from an invisible source called “dark matter.” While our telescopes can’t directly see dark matter, they can help us figure out more about it thanks to a phenomenon called gravitational lensing.

The Gravity of the Situation

Anything that has mass is called matter, and all matter has gravity. Gravity pulls on everything that has mass and warps space-time, the underlying fabric of the universe. Things like llamas and doughnuts and even paper clips all warp space-time, but only a tiny bit since they aren’t very massive.

But huge clusters of galaxies are so massive that their gravity produces some pretty bizarre effects. Light always travels in a straight line, but sometimes its path is bent. When light passes close to a massive object, space-time is so warped that it curves the path the light must follow. Light that would normally be blocked by the galaxy cluster is bent around it, producing intensified — and sometimes multiple — images of the source. This process, called gravitational lensing, turns galaxy clusters into gigantic, intergalactic magnifying glasses that give us a glimpse of cosmic objects that would normally be too distant and faint for even our biggest telescopes to see.

Hubble “Sees” Dark Matter

Let’s recap — matter warps space-time. The more matter, the stronger the warp and the bigger its gravitational lensing effects. In fact, by studying “lensed” objects, we can map out the quantity and location of the unseen matter causing the distortion!

Thanks to gravitational lensing, scientists have measured the total mass of many galaxy clusters, which revealed that all the matter they can see isn’t enough to create the warping effects they observe. There’s more gravitational pull than there is visible stuff to do the pulling — a lot more! Scientists think dark matter accounts for this difference. It’s invisible to our eyes and telescopes, but it can’t hide its gravity!

The mismatch between what we see and what we know must be there may seem strange, but it’s not hard to imagine. You know that people can’t float in mid-air, so what if you saw a person appearing to do just that? You would know right away that there must be wires holding him up, even if you couldn’t see them.

Our Hubble Space Telescope observations are helping unravel the dark matter mystery. By studying gravitationally lensed galaxy clusters with Hubble, astronomers have figured out how much of the matter in the universe is “normal” and how much is “dark.” Even though normal matter makes up everything from pickles to planets, there’s about five times more dark matter in the universe than all the normal matter combined!

WFIRST Will Escalate the Search

One of our next major space telescopes, the Wide Field Infrared Survey Telescope (WFIRST), will take these gravitational lensing observations to the next level. WFIRST will be sensitive enough to use weak gravitational lensing to see how clumps of dark matter warp the appearance of distant galaxies. By observing lensing effects on this small scale, scientists will be able to fill in more of the gaps in our understanding of dark matter.

WFIRST will observe a sky area 100 times larger than Hubble does, but with the same awesome image quality. WFIRST will collect so much data in its first year that it will allow scientists to conduct in-depth studies that would have taken hundreds of years with previous telescopes.

WFIRST’s weak gravitational lensing observations will allow us to peer even further back in time than Hubble is capable of seeing. Scientists believe that the universe’s underlying dark matter structure played a major role in the formation and evolution of galaxies by attracting normal matter. Seeing the universe in its early stages will help scientists unravel how it has evolved over time and possibly provide clues to how it may continue to evolve. We don’t know what the future will hold, but WFIRST will help us find out.

This science is pretty mind-bending, even for scientists. Learn more as our current and future telescopes plan to help unlock these mysteries of the universe...

Hubble: https://www.nasa.gov/mission_pages/hubble/main/index.html WFIRST: https://wfirst.gsfc.nasa.gov/

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Science, Technology, Engineering and Math: STEM

Today is College Signing Day and we’re working with the White House to celebrate all graduating seniors and inspire more young people to Reach Higher and enroll in higher education.

Additionally, choosing a degree within a STEM (Science, Math, Engineering and Technology) field enables the United States to remain the global economic and technological leader. We feel that it’s our duty to help inspire the next generation of scientists, technologists, engineers and astronauts.

It’s important that each and every student feels empowered and equipped with the knowledge to solve tough problems, evaluate evidence and analyze information. These are all skills students can learn through studying a subjects in STEM.

College is one of the stepping stones to many careers, including becoming an astronaut! Here are a few of our astronauts on their college graduation day, along with their astronaut portrait. 

Astronaut Victor Glover

Undergraduate: California Polytechnic State University Graduate: Air University and Naval Postgraduate School Astronaut Class: 2013

Astronaut Reid Wiseman

Undergraduate: Rensselaer Polytechnic Institute Graduate: Johns hopkins University Astronaut Class: 2009

Astronaut Thomas Marshburn

Undergraduate: Davidson College Graduate: University of Virginia, Wake Forest University and University of Texas medical Branch Astronaut Class: 2004

Astronaut Karen Nyberg

Undergraduate: University of North Dakota Graduate: University of Texas at Austin Astronaut Class: 2000

Astronaut Bob Behnken

Undergraduate: Washington University Graduate: California Institute of Technology Astronaut Class: 2000

Astronaut Peggy Whitson

Undergraduate: Iowa Wesleyan College Graduate: Rice University Astronaut Class: 1996

Astronaut Joseph Acaba

Undergraduate: University of California Graduate: University of Arizona Astronaut Class: 2004

Astronaut Rex Walheim

Undergraduate: University of California, Berkeley Graduate: University of Houston Astronaut Class: 1996

Whether you want to be an astronaut, an engineer or the administrator of NASA, a college education opens a universe of possibilities:

Administrator Charles Bolden

Here, Administrator Bolden wears the jersey of Keenan Reynolds, a scholar athlete who graduates from the Naval Academy this year. His jersey is on its way to the college football hall of fame. Bolden holds a drawing of himself as a midshipman in the Navy. 

Deputy Administrator Dava Newman

Deputy Administrator Dava Newman sports her college shirt, along with Lisa Guerra, Technical Assistant to the Associate Administrator. Both women studied aerospace engineering at Notre Dame. 

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No, this red beam in space isn't a light saber! It's a galaxy, far, far away — 44 million light-years away, to be exact. 

We often imagine galaxies as having massive spiral arms or thick disks of dust, but not all galaxies are oriented face-on as viewed from Earth. From our viewpoint, our Spitzer Space Telescope can detect this galaxy's infrared light but can only view the entire galaxy on its side where we can't see its spiral features. We know it has a diameter of roughly 60,000 light-years — a little more than half the diameter of our own Milky Way galaxy.

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What’s Up for June 2016?

What's Up for June? Saturn at its best! Plus, good views of Mars, Jupiter and Jupiter's moons continue from dusk to dawn.

You don't have to stay up late to see Jupiter, Mars and Saturn this month, because they're all visible soon after sunset. Jupiter is the brightest of the three, visible in the western sky all evening. 

The four Galilean moons are easily visible in binoculars or telescopes. If you think you're seeing 5 moons on June 10th, you're not. One of them is a distant star in the constellation Leo.

For telescope viewers, the time near Mars' closest approach to Earth, May 30th this year, is the best time to try to see the two moons of Mars: Phobos and Deimos. It takes patience, very steady skies and good charts! Mars is still large and bright in early June, but it fades as speedy Earth, in its shorter orbit around the sun, passes it.

Saturn has been close to Mars recently. This month Saturn reaches opposition, when Saturn, Earth and the sun are in a straight line with Earth in the middle, providing the best and closest views of the ringed beauty and several of its moons. You'll be able to make out cloud bands on Saturn, in delicate shades of cream and butterscotch. They're fainter than the bands of Jupiter. Through a telescope you'll see Saturn's rings tilted about as wide as they get: 26 degrees.

You'll also have a ring-side view of the Cassini division, discovered by Giovanni Domenico Cassini, namesake of our Cassini spacecraft, orbiting Saturn since 2004 and continuing through September 2017. When you look at Saturn through a telescope, you can't help but see several of its 4 brightest moons, and maybe more. If you just see one, that's Titan, 50% larger than our own moon. A telescope can also reveal more moons, like Saturn's two-colored moon Iapetus. It takes 3 months to orbit Saturn, and it's fairly easy to see.

There's a bright comet visible this month, Comet PanSTARRS. It's best seen from the southern hemisphere, but it's also visible from the U.S. low in the morning sky. Comet PanSTARRS can be seen through a telescope near the beautiful Helix Nebula on June 4, but it is visible all month.

Watch the full June “What’s Up” video for more: https://youtu.be/M7RtIa9zBYA

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Why Bennu?

Our OSIRIS-REx spacecraft will travel to a near-Earth asteroid, called Bennu, where it will collect a sample to bring back to Earth for study. 

But why was Bennu chosen as the target destination asteroid for OSIRIS-REx? The science team took into account three criteria: accessibility, size and composition.

Accessibility: We need an asteroid that we can easily travel to, retrieve a sample from and return to Earth, all within a few years time. The closest asteroids are called near-Earth objects and they travel within 1.3 Astronomical Units (AU) of the sun. For those of you who don’t think in astronomical units…one Astronomical Unit is approximately equal to the distance between the sun and the Earth: ~93 million miles.

For a mission like OSIRIS-REx, the most accessible asteroids are somewhere between 0.08 – 1.6 AU. But we also needed to make sure that those asteroids have a similar orbit to Earth. Bennu fit this criteria! Check!

Size: We need an asteroid the right size to perform two critical portions of the mission: operations close to the asteroid and the actual sample collection from the surface of the asteroid. Bennu is roughly spherical and has a rotation period of 4.3 hours, which is in our size criteria. Check!

Composition: Asteroids are categorized by their spectral properties. In the visible and infrared light minerals have unique signatures or colors, much like fingerprints. Scientists use these fingerprints to identify molecules, like organics. For primitive, carbon-rich asteroids like Bennu, materials are preserved from over 4.5 billion years ago! We’re talking about the start of the formation of our solar system here! These primitive materials could contain organic molecules that may be the precursors to life here on Earth, or elsewhere in our solar system.

Thanks to telescopic observations in the visible and the infrared, as well as in radar, Bennu is currently the best understood asteroid not yet visited by a spacecraft.

All of these things make Bennu a fascinating and accessible asteroid for the OSIRIS-REx mission.

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