Our Space Launch System Rocket’s “Green Run” Engine Testing By The Numbers

Watch Mercury Transit the Sun on Nov. 11

On Nov. 11, Earthlings will be treated to a rare cosmic event — a Mercury transit.

For about five and a half hours on Monday, Nov. 11 — from about 7:35 a.m. EST to 1:04 p.m. EST — Mercury will be visible from Earth as a tiny black dot crawling across the face of the Sun. This is a transit and it happens when Mercury lines up just right between the Sun and Earth.

Mercury transits happen about 13 times a century. Though it takes Mercury only about 88 days to zip around the Sun, its orbit is tilted, so it's relatively rare for the Sun, Mercury and Earth to line up perfectly. The next Mercury transit isn't until 2032 — and in the U.S., the next opportunity to catch a Mercury transit is in 2049!

How to watch

Our Solar Dynamics Observatory satellite, or SDO, will provide near-real time views of the transit. SDO keeps a constant eye on the Sun from its position in orbit around Earth to monitor and study the Sun's changes, putting it in the front row for many eclipses and transits.

Visit mercurytransit.gsfc.nasa.gov to tune in!

Our Solar Dynamics Observatory also saw Mercury transit the Sun in 2016.

If you're thinking of watching the transit from the ground, keep in mind that it is never safe to look directly at the Sun. Even with solar viewing glasses, Mercury is too small to be easily seen with the unaided eye. Your local astronomy club may have an opportunity to see the transit using specialized, properly-filtered solar telescopes — but remember that you cannot use a regular telescope or binoculars in conjunction with solar viewing glasses.

Transits in other star systems

Transiting planets outside our solar system are a key part of how we look for exoplanets.

Our Transiting Exoplanet Survey Satellite, or TESS, is NASA’s latest planet-hunter, observing the sky for new worlds in our cosmic neighborhood. TESS searches for these exoplanets, planets orbiting other stars, by using its four cameras to scan nearly the whole sky one section at a time. It monitors the brightness of stars for periodic dips caused by planets transiting those stars.

This is similar to Mercury’s transit across the Sun, but light-years away in other solar systems! So far, TESS has discovered 29 confirmed exoplanets using transits — with over 1,000 more candidates being studied by scientists!

Discover more transit and eclipse science at nasa.gov/transit, and tune in on Monday, Nov. 11, at mercurytransit.gsfc.nasa.gov.

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Astronaut Journal Entry - Pre-Launch

Currently, six humans are living and working on the International Space Station, which orbits 250 miles above our planet at 17,500mph. Below you will find a real journal entry written by NASA astronaut Scott Tingle.

To read more entires from this series, visit our Space Blogs on Tumblr.

Our crew just finished the final training event before the launch. Tomorrow, at 13:20 local time (Baikonur), we will strap the Soyuz MS-07 spacecraft to our backs and fly it to low Earth orbit. We will spend 2.5 days in low Earth orbit before docking to the MRM-1 docking port on the International Space Station (ISS). There we will begin approximately 168 days of maintenance, service and science aboard one of the greatest engineering marvels that humans have ever created.

Today was bittersweet. Ending a 2-year process of intense training was welcomed by all of us. We are very tired. Seeing our families for the last time was difficult. I am pretty lucky, though. My wife, Raynette, and the kids have grown up around military service and are conditioned to endure the time spent apart during extended calls-to-duty. We are also very much anticipating the good times we will have upon my return in June. Sean and Amy showed me a few videos of them mucking it up at Red Square before flying out to Baikonur. Eric was impressed with the Russian guards marching in to relieve the watch at Red Square. Raynette was taking it all in stride and did not seem surprised by any of it. I think I might have a family of mutants who are comfortable anywhere. Nice! And, by the way, I am VERY proud of all of them!

Tomorrow’s schedule includes a wake-up at 04:00, followed by an immediate medical exam and light breakfast. Upon returning to our quarters, we will undergo a few simple medical procedures that should help make the 2.5-day journey to ISS a little more comfortable. I’ve begun prepping with motion sickness medication that should limit the nausea associated with the first phases of spaceflight. I will continue this effort through docking. This being my first flight, I’m not sure how my body will respond and am taking all precautions to maintain a good working capability. The commander will need my help operating the vehicle, and I need to not be puking into a bag during the busy times. We suit up at 09:30 and then report to the State Commission as “Готовы к Полёту”, or “Ready for Flight”. We’ll enter the bus, wave goodbye to our friends and family, and then head out to the launch pad. Approximately 2 kilometers from the launch pad, the bus will stop. 

The crew will get out, pee on the bus’s tire, and then complete the last part of the drive to the launch pad. This is a traditional event first done by Yuri Gagarin during his historic first flight and repeated in his honor to this day. We will then strap in and prepare the systems for launch. Next is a waiting game of approximately 2 hours. Ouch. The crew provided five songs each to help pass the time. My playlist included “Born to Run” (Springsteen), “Sweet Child O’ Mine” (Guns and Roses), “Cliffs of Dover” (Eric Johnson), “More than a Feeling” (Boston), and “Touch the Sky” (Rainbow Bridge, Russian). Launch will happen precisely at 13:20.

I think this sets the stage. It’s 21:30, only 6.5 hours until duty calls. Time to get some sleep. If I could only lower my level of excitement!

Find more ‘Captain’s Log’ entries HERE.

Follow NASA astronaut Scott Tingle on Instagram and Twitter.

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When Dwarfs Meet Giants, and Other True Cosmic Fairy Tales

It’s easy to get lost in fantasy worlds through science-fiction movies and novels, but did you know that some of your favorite fairy tale characters actually exist in cosmic form? From dwarfs and giants to shape-shifters and buried treasure, the universe is home to a multitude of mystical objects.

White Dwarf Stars

You’ve probably heard of dwarfs like Happy and Sneezy (or Gimli and Thorin), but it’s unlikely you’re familiar with the space-dwelling dwarfs with names like Sirius B and ASASSN-16oh. White dwarf stars like these are typically about the size of Earth, which is pretty small as far as stars go. They represent one of three final stages of stellar evolution, along with neutron stars and black holes. Each star’s mass determines which one it will ultimately become. Stars much more massive than the Sun typically become neutron stars or black holes, and lower-mass stars end up as white dwarfs.

Our Sun will eventually become a white dwarf after it exhausts its fuel, but don’t worry — we’ve got several billion years to go! Before it is reduced to a white dwarf it will actually expand into a red giant, swelling out to encompass Earth’s orbit. But we don’t have to wait billions of years to see stellar giants … some already peek out at us from the cosmic deep.

Giants and Supergiants

The red giant star Aldebaran, located about 65 light-years away, is about 5,000 times bigger than Earth. Our Cassini spacecraft imaged Aldebaran through Saturn’s rings in 2006, but you can see it for yourself during northern winter. Just look for the brightest star in the constellation Taurus.

Fairy tale giants may be taller than trees, but these supergiant stars can be over 100,000 times “taller” than our entire planet! Supergiant stars are likely becoming more rare as time goes on. While scientists believe they used to be more common, our whole galaxy now contains just a small smattering of supergiants.

These massive stars grace the galaxy for a relatively small amount of time. They burn through their fuel extremely quickly — in just a few million years, as opposed to hundreds of billions of years for the smallest stars! Supergiants often end their lives in dramatic explosions called supernovae.

Betelgeuse — the bright, reddish star marking the shoulder of Orion — is nearing the end of its life and has expanded to become a red supergiant star. It is destined to explode as a supernova, which might happen tonight … or within the next few hundred thousand years.

Ghostly Solar Neutrinos

Even an average star like our Sun has some seemingly magical qualities. Each second, it sends billions of phantom-like neutrino particles out into space. They travel almost as fast as light and don’t usually interact with normal matter. Billions of them are zipping harmlessly straight through your body while you read this. Even at night they go through the entire Earth before reaching you!

But that’s not all … these ghostly particles are shape-shifters, too! Neutrinos can change characteristics over time, morphing between different versions of themselves. Spooky!

Buried Treasure in the Heart of the Galaxy

Extensive clouds of dust enshroud the heart of our Milky Way galaxy, hiding it from our view — at least when it comes to visible light. The dust isn’t as big a problem for infrared light, however, which has allowed us to get a glimpse of our galaxy’s chaotic core thanks to our Hubble and Spitzer space telescopes.

Future missions may peer into the galactic core in search of buried treasure — thousands of planets orbiting distant stars!

Want to learn about more cosmic objects? Find them here!

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Zoom to the Moon! Astronauts will blast off to the Moon in the Orion spacecraft with NASA’s Space Launch System, the world’s most powerful rocket ever built. Help #AstronautSnoopy launch into deep space, farther than any human or bird has ever gone before. https://www.nasa.gov/feature/peanuts-toys-and-books-commemorate-50th-anniversary-of-apollo/

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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HBCU Students Make Moves with NASA Tech

In September 2023, students at HBCUs participated in a hackathon at the National HBCU Week Conference, where they used NASA’s technologies to create solutions to problems that affect Black communities. The winning team, Team Airtek, proposed a nano-sensor array for medical diagnoses that would give students on HBCU campuses a non-invasive, non-intensive way to test themselves for precursors for diseases and illnesses like diabetes and COVID.

The hackathon they participated in is a modified version of the full NASA Minority University Research and Education Project Innovation and Tech Transfer Idea Competition (MITTIC) that takes place each fall and spring semester at NASA’s Johnson Space Center in Houston.

No matter what you’re studying, you can join the MITTIC competition and come up with new and innovative tech to help your community and the world.

MITTIC could be the beginning of your career pathway: Teams can go on exclusive NASA tours and network with industry experts. Show off your entrepreneurial skills and your team could earn money—and bragging rights.

Don’t wait too long to apply or to share with someone who should apply! The deadline for proposals is Oct. 16, 2023. Apply here: https://microgravityuniversity.jsc.nasa.gov/nasamittic.

What’s Up for November?

November weather can be challenging for backyard astronomers, but the moon is a reliable target, even when there are clouds.

Did you know that the moon takes about 29 days to go around the Earth once? It also takes the moon about 29 days to spin on its axis. This causes the same side of the moon to always face Earth.

On Nov. 3, the moon reaches last quarter when it rises at midnight and sets at noon. This is a great time to see the moon in the morning sky.

On Nov. 11, the new moon isn’t visible, because it’s between Earth and the sun, and the unlit side faces Earth. In the days after the new moon, the slender crescent gets bigger and brighter. Look just after sunset on Nov. 13 and 14 near the setting sun in the western sky.

The next phase on Nov. 19 is called the first quarter, because the moon has traveled one quarter of its 29-day orbit around Earth. The moon rises at noon and sets at midnight, so you can see it in the afternoon sky. It will rise higher in the sky after dark. That’s when you can look for the areas where four of the six Apollo missions landed on the moon! You won’t see the landers, flag or footprints, but it’s fun and easy to see these historic places with your own eyes or with binoculars.

To see the area: Look for three dark, smooth maria, or seas. The middle one is the Sea of Tranquility. Apollo 11 landed very near a bright crater on the edge of this mare in 1969. The Apollo 15, 16 and 17 landing areas form the points of a triangle above and below the Apollo 11 site.

On Nov. 25, you can see the full moon phase, which occurs on the 14th day of the lunar cycle. The moon will rise at sunset and will be visible all night long, setting at sunrise.

On Thanksgiving (Nov. 26), the 15-day-old moon will rise an hour after sunset. You may even see some interesting features! And this is a great time to see the impact rays of some of the larger craters.

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

Jack Hathaway

Jack Hathaway, a distinguished naval aviator, was born and raised in South Windsor, Connecticut. An Eagle Scout, Hathaway volunteers as an assistant scoutmaster for the Boy Scouts. https://go.nasa.gov/4bU8QbI

Make sure to follow us on Tumblr for your regular dose of space!

Our Galaxy is Caught Up in a Giant Cosmic Cobweb! 🕸️

If we could zoom waaaay out, we would see that galaxies and galaxy clusters make up large, fuzzy threads, like the strands of a giant cobweb. But we'll work our way out to that. First let's start at home and look at our planet's different cosmic communities.

Our home star system

Earth is one of eight planets — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune — that orbit the Sun. But our solar system is more than just planets; it also has a lot of smaller objects.

An asteroid belt circles the Sun between Mars and Jupiter. Beyond Neptune is a doughnut-shaped region of icy objects called the Kuiper Belt. This is where dwarf planets like Pluto and Makemake are found and is likely the source of short-period comets (like Haley’s comet), which orbit the Sun in less than 200 years.

Scientists think that even farther out lies the Oort Cloud, also a likely source of comets. This most distant region of our solar system is a giant spherical shell storing additional icy space debris the size of mountains, or larger! The outer edge of the Oort Cloud extends to about 1.5 light-years from the Sun — that’s the distance light travels in a year and a half (over 9 trillion miles).

Sometimes asteroids or comets get ejected from these regions and end up sharing an orbit with planets like Jupiter or even crossing Earth’s orbit. There are even interstellar objects that have entered the inner solar system from even farther than the Oort Cloud, perhaps coming all the way from another star!

Our home galaxy

Let's zoom out to look at the whole Milky Way galaxy, which contains more than 100 billion stars. Many are found in the galaxy’s disk — the pancake-shaped part of a spiral galaxy where the spiral arms lie. The brightest and most massive stars are found in the spiral arms, close to their birth places. Dimmer, less massive stars can be found sprinkled throughout the disk. Also found throughout the spiral arms are dense clouds of gas and dust called nebulae. The Sun lies in a small spiral arm called the Orion Spur.

The Milky Way’s disk is embedded in a spherical “halo” about 120,000 light-years across. The halo is dotted with globular clusters of old stars and filled with dark matter. Dark matter doesn’t emit enough light for us to directly detect it, but we know it’s there because without its mass our galaxy doesn’t have enough gravity to hold together!

Our galaxy also has several orbiting companion galaxies ranging from about 25,000 to 1.4 million light-years away. The best known of these are the Large and Small Magellanic Clouds, which are visible to the unaided eye from Earth’s Southern Hemisphere.

Our galactic neighborhood

The Milky Way and Andromeda, our nearest neighboring spiral galaxy, are just two members of a small group of galaxies called the Local Group. They and the other members of the group, 50 to 80 smaller galaxies, spread across about 10 million light-years.

The Local Group lies at the outskirts of an even larger structure. It is just one of at least 100 groups and clusters of galaxies that make up the Virgo Supercluster. This cluster of clusters spans about 110 million light-years!

Galaxies aren’t the only thing found in a galaxy cluster, though. We also find hot gas, as shown above in the bright X-ray light (in pink) that surrounds the galaxies (in optical light) of cluster Abell 1413, which is a picturesque member of a different supercluster. Plus, there is dark matter throughout the cluster that is only detectable through its gravitational interactions with other objects.

The Cosmic Web

The Virgo Supercluster is just one of many, many other groups of galaxies. But the universe’s structure is more than just galaxies, clusters, and the stuff contained within them.

For more than two decades, astronomers have been mapping out the locations of galaxies, revealing a filamentary, web-like structure. This large-scale backbone of the cosmos consists of dark matter laced with gas. Galaxies and clusters form along this structure, and there are large voids in between.

The scientific visualizations of this “cosmic web” look a little like a spider web, but that would be one colossal spider! <shudder>

And there you have the different communities that define Earth’s place in the universe. Our tiny planet is a small speck on a crumb of that giant cosmic web!

Want to learn even more about the structures in the universe? Check out our Cosmic Distance Scale!

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That’s a wrap! Thank you for all the great questions.

Keep up with Nick’s journey on and off the station by following him on Twitter at @AstroHague. Follow NASA on Tumblr for your regular dose of space!