What Have We Learned About Pluto?

This month (March 2016), in the journal Science, New Horizons scientists have authored the first comprehensive set of papers describing results from last summer’s Pluto system flyby. These detailed papers completely transform our view of Pluto and reveal the former “astronomer’s planet” to be a real world with diverse and active geology, exotic surface chemistry, a complex atmosphere, puzzling interaction with the sun and an intriguing system of small moons.

Here’s a breakdown of what we’ve learned about Pluto:

1. Pluto has been geologically active throughout the past 4 billion years. The age-dating of Pluto’s surface through crater counts has revealed that Pluto has been geologically active throughout the past 4 billion years. Further, the surface of Pluto’s informally-named Sputnik Planum, a massive ice plain larger than Texas, is devoid of any detectable craters and estimated to be geologically young – no more than 10 million years old.

2. Pluto’s moon Charon has been discovered to have an ancient surface. As an example, the great expanse of smooth plains on Charon is likely a vast cryovolcanic flow or flows that erupted onto Charon’s surface about 4 billion years ago. These flows are likely related to the freezing of an internal ocean that globally ruptured Charon’s crust.

3. Pluto’s surface has many types of terrain. The distribution of compositional units on Pluto’s surface – from nitrogen-rich, to methane-rich, to water-rich – has been found to be surprisingly complex, creating puzzles for understanding Pluto’s climate and geologic history. The variations in surface composition on Pluto are unprecedented elsewhere in the outer solar system.

4. Pluto’s atmosphere is colder than we thought. Pluto’s upper atmospheric temperature has been found to be much colder (by about 70 degrees Fahrenheit) than had been thought from Earth-based studies, with important implications for its atmospheric escape rate. Why the atmosphere is colder is a mystery.

5. We know what Pluto’s atmosphere is made of. The New Horizon spacecraft made observations of sunlight passing through Pluto’s atmosphere. We see absorption features that indicate an atmosphere made up of nitrogen (like Earth’s) with methane, acetylene and ethylene as minor constituents.

6. We might have an idea for how Pluto’s haze formed. For first time, a plausible mechanism for forming Pluto’s atmospheric haze layers has been found. This mechanism involves the concentration of haze particles by atmospheric buoyancy waves, created by winds blowing over Pluto’s mountainous topography. Pluto’s haze extends hundreds of kilometers into space, and embedded within it are over 20 very thin, but far brighter, layers.

7. There isn’t much dust around Pluto. Before the flyby, there was concern that a small piece of debris (even the size of a grain of sand) could cause great damage to (or even destroy) the spacecraft. But the Venetia Burney Student Dust Counter (an instrument on the New Horizons spacecraft) only counted a single dust particle within five days of the flyby. This is similar to the density of dust particles in free space in the outer solar system – about 6 particles per cubic mile – showing that the region around Pluto is, in fact, not filled with debris.

8. Pluto’s atmosphere is smaller than we expected. The uppermost region of Pluto’s atmosphere is slowly escaping to space. The hotter the upper atmosphere, the more rapid the gasses escape. The lower the planet’s mass, the lower the gravity, and the faster the atmospheric loss. As molecules escape, they are ionized by solar ultraviolet light. Once ionized, the charged molecules are carried away by the solar wind. As more Pluto-genic material is picked up by the solar wind, the more the solar wind is slowed down and deflected around Pluto. So - the net result is a region (the interaction region), which is like a blunt cone pointed toward the sun, where the escaping ionized gasses interact with the solar wind. The cone extends to a distance about 6 Pluto radii from Pluto toward the sun, but extend behind Pluto at least 400 Pluto radii behind Pluto - like a wake behind the dwarf planet.

9. Pluto’s moons are brighter than we thought. The high albedos (reflectiveness) of Pluto’s small satellites (moons) – about 50 to 80 percent – are entirely different from the much lower reflectiveness of the small bodies in the general Kuiper Belt population, which range from about 5 to 20 percent. This difference lends further support to the idea that these moons were not captured from the general Kuiper Belt population, but instead formed by the collection of material produced in the aftermath of the giant collision that created the entire Pluto satellite system.

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Fun Moments with Our Record Breaking Astronaut

Astronaut Scott Kelly has broken the record for longest time spent in space by a U.S. astronaut. He has spent a cumulative of 383 days in space over the course of four missions. What better way to celebrate than to highlight some of his fun moments on the internet:

A question from the president during a recent TweetChat:

Astronaut Scott Kelly occasionally hosts TweetChats from the International Space Station. During a recent chat, he happened to get a question from someone who lives at 1600 Pennsylvania Avenue! HERE’s a recap from a similar chat from the station.

Tackling the tough questions during interviews:

During an interview with Katie Couric, Kelly explained what a day on the space station is really like...including the chores he can and can’t do.

The pros and cons of having roommates:

The International Space Station is an orbiting laboratory where an international crew live, work and conduct valuable research.

Getting supplies from cargo ships:

Living on the space station requires food, water and supplies. All of these things, plus experiments and other essentials are delivered to the crew via cargo ship. Learn more about our commercial resupply program HERE.

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7 years ago

Solar System: 10 Things to Know This Week

Rockets We Love-Saturn V

Fifty years ago, with President Kennedy’s Moon landing deadline looming, the powerful Saturn V had to perform. And perform it did—hurling 24 humans to the Moon.

The race to land astronauts on the Moon was getting tense 50 years ago this week. Apollo 6, the final uncrewed test flight of America’s powerful Moon rocket, launched on April 4, 1968. Several technical issues made for a less-than-perfect launch, but the test flight nonetheless convinced NASA managers that the rocket was up to the task of carrying humans. Less than two years remained to achieve President John F. Kennedy’s goal to put humans on the Moon before the decade was out, meaning the Saturn V rocket had to perform.

1—“The only chance to get to the Moon before the end of 1969.”

After the April 1968 Apollo 6 test flight (pictured above), the words of Deke Slayton (one of the original Mercury 7 astronauts) and intense competition with a rival team in the Soviet Union propelled a 12-member panel to unanimously vote for a Christmas 1968 crewed mission to orbit the Moon.

2—Four Hundred Elephants...

The Saturn V rocket stood about the height of a 36-story-tall building, and 60 feet (18 meters) taller than the Statue of Liberty. Fully fueled for liftoff, the Saturn V weighed 6.2 million pounds (2.8 million kilograms), or the weight of about 400 elephants.

3—...and Busloads of Thrust

Stand back, Ms. Frizzle. The Saturn V generated 7.6 million pounds (34.5 million newtons) of thrust at launch, creating more power than 85 Hoover Dams. It could launch about 130 tons (118,000 kilograms) into Earth orbit. That's about as much weight as 10 school buses. The Saturn V could launch about 50 tons (43,500 kilograms) to the Moon. That's about the same as four school buses.

4—Christmas at the Moon

On Christmas Eve 1968, the Saturn V delivered on engineers’ promises by hurling Frank Borman, Jim Lovell and Bill Anders into lunar orbit. The trio became the first human beings to orbit another world. The Apollo 8 crew broadcast a special holiday greeting from lunar orbit and also snapped the iconic earthrise image of our home planet rising over the lunar landscape.

5—Gumdrop and Spider

The crew of Apollo 9 proved that they could pull the lunar module out of the top of the Saturn V’s third stage and maneuver it in space (in this case high above Earth). The crew named their command module “Gumdrop.” The Lunar Module was named “Spider.”

6—The Whole Enchilada

Saturn-V AS-505 provided the ride for the second dry run to the Moon in 1969. Tom Stafford, Gene Cernan and John Young rode Command Module “Charlie Brown” to lunar orbit and then took Lunar Module “Snoopy” on a test run in lunar orbit. Apollo 10 did everything but land on the Moon, setting the stage for the main event a few months later. Young and Cernan returned to walk on the Moon aboard Apollo 16 and 17 respectively. Cernan, who died in 2017, was the last human being (so far) to set foot on the Moon.

7—The Main Event

The launch of Apollo 11—the first mission to land humans on the Moon—provided another iconic visual as Saturn-V AS-506 roared to life on Launch Pad 39A at Kennedy Space Center in Florida. Three days later, Neil Armstrong and Buzz Aldrin made the first of many bootprints in the lunar dust (supported from orbit by Michael Collins).

8—Moon Men

Saturn V rockets carried 24 humans to the Moon, and 12 of them walked on its surface between 1969 and 1972. Thirteen are still alive today. The youngest, all in their early 80s, are moonwalkers Charles Duke (Apollo 16) and Harrison Schmitt (Apollo 17) and Command Module Pilot Ken Mattingly (Apollo 16, and also one of the heroes who helped rescue Apollo 13). There is no single image of all the humans who have visited the Moon.

9—The Flexible Saturn V

The Saturn V’s swan song was to lay the groundwork for establishing a permanent human presence in space. Skylab, launched into Earth orbit in 1973, was America’s first space station, a precursor to the current International Space Station. Skylab’s ride to orbit was a Saturn IV-B 3rd stage, launched by a Saturn 1-C and SII Saturn V stages.

This was the last launch of a Saturn V, but you can still see the three remaining giant rockets at the visitor centers at Johnson Space Center in Texas and Kennedy Space Center in Florida and at the United States Space and Rocket Center in Alabama (near Marshall Space Flight Center, one of the birthplaces of the Saturn V).

10—The Next Generation

The Saturn V was retired in 1973. Work is now underway on a fleet of rockets. We are planning an uncrewed flight test of Space Launch System (SLS) rocket to travel beyond the Moon called Exploration Mission-1 (EM-1). “This is a mission that truly will do what hasn’t been done and learn what isn’t known,” said Mike Sarafin, EM-1 mission manager at NASA Headquarters in Washington.

Read the web version of this 10 Things to Know article HERE.

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7 years ago

What’s Up November 2017

What’s Up For November?

Dawn pairing of Jupiter and Venus, Moon shines near star clusters, meteor activity all month long!

This month binoculars will come in handy--to view the moon, star clusters, and a close pairing of Venus and Jupiter.

You can’t miss bright Venus in the predawn sky. This month Venus pairs up with Jupiter on the morning of November 13th.

The Leonids peak on a moonless November 17th. Expect no more than 10 meteors an hour around 3:00 a.m., the height of the shower.

The Northern and Southern sub-branches of the Taurid meteor shower offer sparse counts of about 5 meteors per hour, but slow, bright meteors are common.

The nearby November Orionids peak on the 28th. In contrast to the Taurids, the Orionids are swift. But don’t expect more than 3 meteors per hour.

The moon glides by three beautiful star clusters in the morning sky this month, and a pair of binoculars will allow you to see the individual stars in the clusters. Aim your binoculars at the Pleiades and the moon on the 5th.

Then aim at the Messier or M-35 cluster and the moon on the 7th and the Beehive cluster and the moon on the 10th.

Meanwhile, at dusk, catch Saturn as it dips closer to the western horizon and pairs up with Mercury on the 24th through the 28th.

Also, Comet C/2017 O1 should still be a binocular-friendly magnitude 7 or 8 greenish object in November. Use Polaris, the North Star as a guide. Look in the East to Northeast sky in the late evening.

Watch the full What’s Up for November Video:

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6 years ago

Weathering the Storm with our Global Precipitation Measurement Mission

How much rain falls in a hurricane? How much snow falls in a nor’easter? What even is a nor’easter? These are the sorts of questions answered by our Global Precipitation Measurement Mission, or GPM.

GPM measures precipitation: Rain, snow, sleet, freezing rain, hail, ice pellets. It tells meteorologists the volume, intensity and location of the precipitation that falls in weather systems, helping them improve their forecasting, gather information about extreme weather and better understand Earth’s energy and water cycles.

And putting all that together, one of GPM’s specialties is measuring storms.

GPM is marking its fifth birthday this year, and to celebrate, we’re looking back on some severe storms that the mission measured in its first five years.

1. The Nor’easter of 2018

A nor’easter is a swirling storm with strong northeasterly winds and often lots of snow. In January 2018, the mission’s main satellite, the Core Observatory, flew over the East Coast in time to capture the development of a nor’easter. The storm dumped 18 inches of snow in parts of New England and unleashed winds up to 80 miles per hour!

2. Hurricane Harvey

Hurricane Harvey came to a virtual halt over eastern Texas in August 2017, producing the largest rain event in U.S. history. Harvey dropped up to 5 feet of rain, causing $125 billion in damage. The Core Observatory passed over the storm several times, using its radar and microwave instruments to capture the devastating deluge.

3. Typhoon Vongfong

In October 2014, GPM flew over one of its very first Category 5 typhoons – tropical storms with wind speeds faster than 157 miles per hour. The storm was Typhoon Vongfong, which caused $48 million in damage in Japan, the Philippines and Taiwan. We were able to see both the pattern and the intensity of Vongfong’s rain, which let meteorologists know the storm’s structure and how it might behave.

4. Near Real-Time Global Precipitation Calculations

The Core Observatory isn’t GPM’s only satellite! A dozen other satellites from different countries and government agencies come together to share their microwave measurements with the Core Observatory. Together, they are called the GPM Constellation, and they create one of its most impressive products, IMERG.

IMERG stands for “Integrated Multi-satellitE Retrievals for GPM,” and it uses the info from all the satellites in the Constellation to calculate global precipitation in near real time. In other words, we can see where it’s raining anywhere in the world, practically live.

5. Hurricane Ophelia

Hurricane Ophelia hit Ireland and the United Kingdom in October 2017, pounding them with winds up to 115 miles per hour, reddening the skies with dust from the Sahara Desert and causing more than $79 million in damages. Several satellites from the Constellation passed over Ophelia, watching this mid-latitude weather system develop into a Category 3 hurricane – the easternmost Category 3 storm in the satellite era (since 1970).

From the softest snow to the fiercest hurricanes, GPM is keeping a weather eye open for precipitation around the world. And we’re on cloud nine about that.

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7 years ago

What caused this outburst of this star named V838 Mon? For reasons unknown, this star’s outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before – supernovas and novas expel matter out into space.

Although the V838 Mon flash appears to expel material into space, what is seen in the above GIF from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash.

In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter.

Credit: NASA, ESA

To discover more, visit: https://www.nasa.gov/multimedia/imagegallery/image_feature_2472.html

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7 years ago

Is it safe to look at the eclipse if it isn't fully covered by the sun? Say 75%

Not without proper eye wear. There will still be too much light that could burn your eyes. But you can have a ton of fun viewing the Sun using a https://eclipse.aas.org/eye-safety/projection. In fact, there is a sunspot that is now on the Sun that you should be able to see using this indirect method!

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8 years ago

Living and Working Aboard Station

Join us on Facebook Live for a conversation with astronaut Kate Rubins and the director of the National Institutes for Health on Tuesday, October 18 at 11:15 a.m. ET.

Astronaut Kate Rubins has conducted out of this world research aboard Earth’s only orbiting laboratory. During her time aboard the International Space Station, she became the first person to sequence DNA in space. On Tuesday, she’ll be live on Facebook with National Institute of Health director Francis Collins, who led the effort to map the human genome. You can submit questions for Kate using the hashtag #SpaceChat on Twitter, or during the live event. Here’s a primer on the science this PhD astronaut has been conducting to help inspire your questions:

Kate has a background in genomics (a branch of molecular genetics that deals with the study of genomes,specifically the identification and sequencing of their constituent genes and the application of this knowledge in medicine, pharmacy,agriculture, and other fields). When she began her tenure on the station, zero base pairs of DNA had been sequenced in space. Within just a few weeks, she and the Biomolecule Sequencer team had sequenced their one billionth base of DNA aboard the orbital platform.

“I [have a] genomics background, [so] I get really excited about that kind of stuff,” Rubins said in a downlink shortly after reaching the one billion base pairs sequenced goal.

Learn more about this achievement:

+First DNA Sequencing in Space a Game Changer

+Science in Short: One Billion Base Pairs Sequenced

Why is DNA Sequencing in Space a Big Deal?

A space-based DNA sequencer could identify microbes, diagnose diseases and understand crew member health, and potentially help detect DNA-based life elsewhere in the solar system.

+Why Sequencing DNA in Space is a Big Deal

https://youtu.be/1N0qm8HcFRI

Miss the Reddit AMA on the subject? Here’s a transcript:

+NASA AMA: We just sequenced DNA in space for the first time. Ask us anything!

NASA and Its Partnerships

We’re not doing this alone. Just like the DNA sequencing was a collaborative project with industry, so is the Eli Lilly Hard to Wet Surfaces investigation, which is a partnership between CASIS and Eli Lilly Co. In this experiment aboard the station, astronauts will study how certain materials used in the pharmaceutical industry dissolve in water while in microgravity. Results from this investigation could help improve the design of tablets that dissolve in the body to deliver drugs, thereby improving drug design for medicines used in space and on Earth. Learn more about what we and our partners are doing:

+Eli Lilly Hard to Wet Surfaces – been happening the last week and a half or so

Researchers to Test How Solids Dissolve in Space to Design Better Tablets and Pills on Earth

With our colleagues at the Stanford University School of Medicine, we’re also investigating the effects of spaceflight on stem cell-derived heart cells, specifically how heart muscle tissue, contracts, grows and changes in microgravity and how those changes vary between subjects. Understanding how heart muscle cells change in space improves efforts for studying disease, screening drugs and conducting cell replacement therapy for future space missions. Learn more:

+Heart Cells

+Weekly Recap From the Expedition Lead Scientist for Aug. 18, 2016

It’s Not Just Medicine

Kate and her crew mates have also worked on the combustion experiments.

Kate has also worked on the Bigelow Expandable Activity Module (BEAM), an experimental expandable capsule that docks with the station. As we work on our Journey to Mars, future space habitats are a necessity. BEAM, designed for Mars or other destinations, is a lightweight and relatively simple to construct solution. Kate has recently examined BEAM, currently attached to the station, to take measurements and install sensors.

Kate recently performed a harvest of the Plant RNA Regulation experiment, by removing seed cassettes and stowing them in cold stowage.

The Plant RNA Regulation investigation studies the first steps of gene expression involved in development of roots and shoots. Scientists expect to find new molecules that play a role in how plants adapt and respond to the microgravity environment of space, which provides new insight into growing plants for food and oxygen supplies on long-duration missions. Read more about the experiment:

+Plant RNA Harvest

NASA Astronaut Kate Rubins is participating in several investigations examining changes in her body as a result of living in space. Some of these changes are similar to issues experienced by our elderly on Earth; for example, bone loss (osteoporosis), cardiovascular deconditioning, immune dysfunction, and muscle atrophy. Understanding these changes and how to prevent them in astronauts off the Earth may help improve health for all of us on the Earth. In additional, the crew aboard station is also working on more generalized studies of aging.

+ Study of the effects of aging on C. elegans, a model organism for a range of biological studies.

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7 years ago

On Monday, August 21, 2017, our nation will be treated to a total eclipse of the Sun. The eclipse will be visible – weather permitting – across all of North America. The entire continent will experience at least a partial eclipse lasting two to three hours. Halfway through the event, anyone within a 60 to 70 mile-wide path from Oregon to South Carolina will experience a total eclipse. During those brief moments when the moon completely blocks the Sun's bright face for 2+ minutes, day will turn into night, making visible the otherwise hidden solar corona, the Sun's outer atmosphere. Bright stars and planets will become visible as well. This is truly one of nature's most awesome sights. The eclipse provides a unique opportunity to study the Sun, Earth, Moon and their interaction because of the eclipse's long path over land coast to coast.

Scientists will be able to take ground-based and airborne observations over a period of about 90 minutes to complement the wealth of data provided by NASA assets.

Watch this and other eclipse videos on our YouTube channel: https://youtu.be/8jaxiha8-rY?list=PL_8hVmWnP_O2oVpjXjd_5De4EalioxAUi

To learn all about the 2017 Total Eclipse: https://eclipse2017.nasa.gov/

Music credit: Ascending Lanterns by Philip Hochstrate

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8 years ago

Solar System: Things to Know This Week

With only four months left in the mission, Cassini is busy at Saturn. The upcoming cargo launch, anniversaries and more!

As our Cassini spacecraft made its first-ever dive through the gap between Saturn and its rings on April 26, 2017, one of its imaging cameras took a series of rapid-fire images that were used to make this movie sequence. Credits: NASA/JPL-Caltech/Space Science Institute/Hampton University

1-3. The Grand Finale

Our Cassini spacecraft has begun its final mission at Saturn. Some dates to note:

May 28, 2017: Cassini makes its riskiest ring crossing as it ventures deeper into Saturn's innermost ring (D ring).

June 29, 2017: On this day in 2004, the Cassini orbiter and its travel companion the European Space Agency's Huygens probe arrived at Saturn.

September 15, 2017: In a final, spectacular dive, Cassini will plunge into Saturn - beaming science data about Saturn's atmosphere back to Earth to the last second. It's all over at 5:08 a.m. PDT.

More about the Grand Finale

4. Cargo Launch to the International Space Station

June 1, 2017: Target date of the cargo launch. The uncrewed Dragon spacecraft will launch on a Falcon 9 from Launch Complex 39A at our Kennedy Space Center in Florida. The payload includes NICER, an instrument to measure neutron stars, and ROSA, a Roll-Out Solar Array that will test a new solar panel that rolls open in space like a party favor.

5. Sojourner

July 4, 2017: Twenty years ago, a wagon-sized rover named Sojourner blazed the trail for future Mars explorers - both robots and, one day, humans. Take a trip back in time to the vintage Mars Pathfinder websites:

6. Voyager

August 20, 2017: Forty years and still going strong, our twin Voyagers mark 40 years since they left Earth.

August 21, 2017: All of North America will be treated to a rare celestial event: a total solar eclipse. The path of totality runs from Oregon to South Carolina.

8. From Science Fiction to Science Fact

Light a candle for the man who took rocketry from science fiction to science fact. On this day in 1882, Robert H. Goddard was born in Worcester, Massachusetts.