The Great Conjunction Of Jupiter And Saturn

The Moon in Motion

Happy New Year! And happy supermoon! Tonight, the Moon will appear extra big and bright to welcome us into 2018 – about 6% bigger and 14% brighter than the average full Moon. And how do we know that? Well, each fall, our science visualizer Ernie Wright uses data from the Lunar Reconnaissance Orbiter (LRO) to render over a quarter of a million images of the Moon. He combines these images into an interactive visualization, Moon Phase and Libration, which depicts the Moon at every day and hour for the coming year. 

Want to see what the Moon will look like on your birthday this year? Just put in the date, and even the hour (in Universal Time) you were born to see your birthday Moon.

Our Moon is quite dynamic. In addition to Moon phases, our Moon appears to get bigger and smaller throughout the year, and it wobbles! Or at least it looks that way to us on Earth. This wobbling is called libration, from the Latin for ‘balance scale’ (libra). Wright relies on LRO maps of the Moon and NASA orbit calculations to create the most accurate depiction of the 6 ways our Moon moves from our perspective.

1. Phases

The Moon phases we see on Earth are caused by the changing positions of the Earth and Moon relative to the Sun. The Sun always illuminates half of the Moon, but we see changing shapes as the Moon revolves around the Earth. Wright uses a software library called SPICE to calculate the position and orientation of the Moon and Earth at every moment of the year. With his visualization, you can input any day and time of the year and see what the Moon will look like!

2. Shape of the Moon

Check out that crater detail! The Moon is not a smooth sphere. It’s covered in mountains and valleys and thanks to LRO, we know the shape of the Moon better than any other celestial body in the universe. To get the most accurate depiction possible of where the sunlight falls on the lunar surface throughout the month, Wright uses the same graphics software used by Hollywood design studios, including Pixar, and a method called ‘raytracing’ to calculate the intricate patterns of light and shadow on the Moon’s surface, and he checks the accuracy of his renders against photographs of the Moon he takes through his own telescope.

3. Apparent Size 

The Moon Phase and Libration visualization shows you the apparent size of the Moon. The Moon’s orbit is elliptical, instead of circular - so sometimes it is closer to the Earth and sometimes it is farther. You’ve probably heard the term “supermoon.” This describes a full Moon at or near perigee (the point when the Moon is closest to the Earth in its orbit). A supermoon can appear up to 14% bigger and brighter than a full Moon at apogee (the point when the Moon is farthest from the Earth in its orbit). 

Our supermoon tonight is a full Moon very close to perigee, and will appear to be about 14% bigger than the July 27 full Moon, the smallest full Moon of 2018, occurring at apogee. Input those dates into the Moon Phase and Libration visualization to see this difference in apparent size!

4. East-West Libration

Over a month, the Moon appears to nod, twist, and roll. The east-west motion, called ‘libration in longitude’, is another effect of the Moon’s elliptical orbital path. As the Moon travels around the Earth, it goes faster or slower, depending on how close it is to the Earth. When the Moon gets close to the Earth, it speeds up thanks to an additional pull from Earth’s gravity. Then it slows down, when it’s farther from the Earth. While this speed in orbital motion changes, the rotational speed of the Moon stays constant. 

This means that when the Moon moves faster around the Earth, the Moon itself doesn’t rotate quite enough to keep the same exact side facing us and we get to see a little more of the eastern side of the Moon. When the Moon moves more slowly around the Earth, its rotation gets a little ahead, and we see a bit more of its western side.

5. North-South Libration

The Moon also appears to nod, as if it were saying “yes,” a motion called ‘libration in latitude’. This is caused by the 5 degree tilt of the Moon’s orbit around the Earth. Sometimes the Moon is above the Earth’s northern hemisphere and sometimes it’s below the Earth’s southern hemisphere, and this lets us occasionally see slightly more of the northern or southern hemispheres of the Moon! 

6. Axis Angle

Finally, the Moon appears to tilt back and forth like a metronome. The tilt of the Moon’s orbit contributes to this, but it’s mostly because of the 23.5 degree tilt of our own observing platform, the Earth. Imagine standing sideways on a ramp. Look left, and the ramp slopes up. Look right and the ramp slopes down. 

Now look in front of you. The horizon will look higher on the right, lower on the left (try this by tilting your head left). But if you turn around, the horizon appears to tilt the opposite way (tilt your head to the right). The tilted platform of the Earth works the same way as we watch the Moon. Every two weeks we have to look in the opposite direction to see the Moon, and the ground beneath our feet is then tilted the opposite way as well.

So put this all together, and you get this:

Beautiful isn’t it? See if you can notice these phenomena when you observe the Moon. And keep coming back all year to check on the Moon’s changing appearance and help plan your observing sessions.

Follow @NASAMoon on Twitter to keep up with the latest lunar updates. 

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

NASA’s New Planet Hunter Reveals a Sky Full of Stars

NASA’s newest planet-hunting satellite — the Transiting Exoplanet Survey Satellite, or TESS for short — has just released its first science image using all of its cameras to capture a huge swath of the sky! TESS is NASA’s next step in the search for planets outside our solar system, called exoplanets.

This spectacular image, the first released using all four of TESS’ cameras, shows the satellite’s full field of view. It captures parts of a dozen constellations, from Capricornus (the Sea Goat) to Pictor (the Painter’s Easel) — though it might be hard to find familiar constellations among all these stars! The image even includes the Large and Small Magellanic Clouds, our galaxy’s two largest companion galaxies.

The science community calls this image “first light,” but don’t let that fool you — TESS has been seeing light since it launched in April. A first light image like this is released to show off the first science-quality image taken after a mission starts collecting science data, highlighting a spacecraft’s capabilities.

TESS has been busy since it launched from NASA’s Kennedy Space Center in Cape Canaveral, Florida. First TESS needed to get into position, which required a push from the Moon. After nearly a month in space, the satellite passed about 5,000 miles from the Moon, whose gravity gave it the boost it needed to get into a special orbit that will keep it stable and maximize its view of the sky.

During those first few weeks, we also got a sneak peek of the sky through one of TESS’s four cameras. This test image captured over 200,000 stars in just two seconds! The spacecraft was pointed toward the constellation Centaurus when it snapped this picture. The bright star Beta Centauri is visible at the lower left edge, and the edge of the Coalsack Nebula is in the right upper corner.

After settling into orbit, scientists ran a number of checks on TESS, including testing its ability to collect a set of stable images over a prolonged period of time. TESS not only proved its ability to perform this task, it also got a surprise! A comet named C/2018 N1 passed through TESS’s cameras for about 17 hours in July.

The images show a treasure trove of cosmic curiosities. There are some stars whose brightness changes over time and asteroids visible as small moving white dots. You can even see an arc of stray light from Mars, which is located outside the image, moving across the screen.

Now that TESS has settled into orbit and has been thoroughly tested, it’s digging into its main mission of finding planets around other stars. How will it spot something as tiny and faint as a planet trillions of miles away? The trick is to look at the star!

So far, most of the exoplanets we’ve found were detected by looking for tiny dips in the brightness of their host stars. These dips are caused by the planet passing between us and its star – an event called a transit. Over its first two years, TESS will stare at 200,000 of the nearest and brightest stars in the sky to look for transits to identify stars with planets.

TESS will be building on the legacy of NASA’s Kepler spacecraft, which also used transits to find exoplanets. TESS’s target stars are about 10 times closer than Kepler’s, so they’ll tend to be brighter. Because they're closer and brighter, TESS’s target stars will be ideal candidates for follow-up studies with current and future observatories.

TESS is challenging over 200,000 of our stellar neighbors to a staring contest! Who knows what new amazing planets we’ll find?

The TESS mission is led by MIT and came together with the help of many different partners. You can keep up with the latest from the TESS mission by following mission updates.

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

6 Things You Didn’t Know About Our ‘First’ Space Flight Center

When NASA began operations on Oct. 1, 1958, we consisted mainly of the four laboratories of our predecessor, the National Advisory Committee for Aeronautics (NACA). Hot on the heels of NASA’s first day of business, we opened the Goddard Space Flight Center. Chartered May 1, 1959, and located in Greenbelt, Maryland, Goddard is home to one of the largest groups of scientists and engineers in the world. These people are building, testing and experimenting their way toward answering some of the universe’s most intriguing questions.

To celebrate 60 years of exploring, here are six ways Goddard shoots for the stars.

For the last 60 years, we’ve kept a close eye on our home planet, watching its atmosphere, lands and ocean.

Goddard instruments were crucial in tracking the hole in the ozone layer over Antarctica as it grew and eventually began to show signs of healing. Satellites and field campaigns track the changing height and extent of ice around the globe. Precipitation missions give us a global, near-real-time look at rain and snow everywhere on Earth. Researchers keep a record of the planet’s temperature, and Goddard supercomputer models consider how Earth will change with rising temperatures. From satellites in Earth’s orbit to field campaigns in the air and on the ground, Goddard is helping us understand our planet.

We seek to answer the big questions about our universe: Are we alone? How does the universe work? How did we get here?

We’re piecing together the story of our cosmos, from now all the way back to its start 13.7 billion years ago. Goddard missions have contributed to our understanding of the big bang and have shown us nurseries where stars are born and what happens when galaxies collide. Our ongoing census of planets far beyond our own solar system (several thousand known and counting!) is helping us hone in on which ones might be potentially habitable.

We study our dynamic Sun.

Our Sun is an active star, with occasional storms and a constant outflow of particles, radiation and magnetic fields that fill the solar system out far past the orbit of Neptune. Goddard scientists study the Sun and its activity with a host of satellites to understand how our star affects Earth, planets throughout the solar system and the nature of the very space our astronauts travel through.

We explore the planets, moons and small objects in the solar system and beyond. 

Goddard instruments (well over 100 in total!) have visited every planet in the solar system and continue on to new frontiers. What we’ve learned about the history of our solar system helps us piece together the mysteries of life: How did life in our solar system form and evolve? Can we find life elsewhere?

Over 60 years, our communications networks have enabled hundreds of NASA spacecraft to “phone home.”

Today, Goddard communications networks bring down 98 percent of our spacecraft data – nearly 30 terabytes per day! This includes not only science data, but also key information related to spacecraft operations and astronaut health. Goddard is also leading the way in creating cutting-edge solutions like laser communications that will enable exploration – faster, better, safer – for generations to come. Pew pew!

Exploring the unknown often means we must create new ways of exploring, new ways of knowing what we’re “seeing.” 

Goddard’s technologists and engineers must often invent tools, mechanisms and sensors to return information about our universe that we may not have even known to look for when the center was first commissioned.

Behind every discovery is an amazing team of people, pushing the boundaries of humanity’s knowledge. Here’s to the ones who ask questions, find answers and ask questions some more!

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

Black Holes are NICER Than You Think!

We’re learning more every day about black holes thanks to one of the instruments aboard the International Space Station! Our Neutron star Interior Composition Explorer (NICER) instrument is keeping an eye on some of the most mysterious cosmic phenomena.

We’re going to talk about some of the amazing new things NICER is showing us about black holes. But first, let’s talk about black holes — how do they work, and where do they come from? There are two important types of black holes we’ll talk about here: stellar and supermassive. Stellar mass black holes are three to dozens of times as massive as our Sun while supermassive black holes can be billions of times as massive!

Stellar black holes begin with a bang — literally! They are one of the possible objects left over after a large star dies in a supernova explosion. Scientists think there are as many as a billion stellar mass black holes in our Milky Way galaxy alone!

Supermassive black holes have remained rather mysterious in comparison. Data suggest that supermassive black holes could be created when multiple black holes merge and make a bigger one. Or that these black holes formed during the early stages of galaxy formation, born when massive clouds of gas collapsed billions of years ago. There is very strong evidence that a supermassive black hole lies at the center of all large galaxies, as in our Milky Way.

Imagine an object 10 times more massive than the Sun squeezed into a sphere approximately the diameter of New York City — or cramming a billion trillion people into a car! These two examples give a sense of how incredibly compact and dense black holes can be.

Because so much stuff is squished into such a relatively small volume, a black hole’s gravity is strong enough that nothing — not even light — can escape from it. But if light can’t escape a dark fate when it encounters a black hole, how can we “see” black holes?

Scientists can’t observe black holes directly, because light can’t escape to bring us information about what’s going on inside them. Instead, they detect the presence of black holes indirectly — by looking for their effects on the cosmic objects around them. We see stars orbiting something massive but invisible to our telescopes, or even disappearing entirely!

When a star approaches a black hole’s event horizon — the point of no return — it’s torn apart. A technical term for this is “spaghettification” — we’re not kidding! Cosmic objects that go through the process of spaghettification become vertically stretched and horizontally compressed into thin, long shapes like noodles.

Scientists can also look for accretion disks when searching for black holes. These disks are relatively flat sheets of gas and dust that surround a cosmic object such as a star or black hole. The material in the disk swirls around and around, until it falls into the black hole. And because of the friction created by the constant movement, the material becomes super hot and emits light, including X-rays.  

At last — light! Different wavelengths of light coming from accretion disks are something we can see with our instruments. This reveals important information about black holes, even though we can’t see them directly.

So what has NICER helped us learn about black holes? One of the objects this instrument has studied during its time aboard the International Space Station is the ever-so-forgettably-named black hole GRS 1915+105, which lies nearly 36,000 light-years — or 200 million billion miles — away, in the direction of the constellation Aquila.

Scientists have found disk winds — fast streams of gas created by heat or pressure — near this black hole. Disk winds are pretty peculiar, and we still have a lot of questions about them. Where do they come from? And do they change the shape of the accretion disk?

It’s been difficult to answer these questions, but NICER is more sensitive than previous missions designed to return similar science data. Plus NICER often looks at GRS 1915+105 so it can see changes over time.

NICER’s observations of GRS 1915+105 have provided astronomers a prime example of disk wind patterns, allowing scientists to construct models that can help us better understand how accretion disks and their outflows around black holes work.

NICER has also collected data on a stellar mass black hole with another long name — MAXI J1535-571 (we can call it J1535 for short) — adding to information provided by NuSTAR, Chandra, and MAXI. Even though these are all X-ray detectors, their observations tell us something slightly different about J1535, complementing each other’s data!

This rapidly spinning black hole is part of a binary system, slurping material off its partner, a star. A thin halo of hot gas above the disk illuminates the accretion disk and causes it to glow in X-ray light, which reveals still more information about the shape, temperature, and even the chemical content of the disk. And it turns out that J1535’s disk may be warped!

Image courtesy of NRAO/AUI and Artist: John Kagaya (Hoshi No Techou)

This isn’t the first time we have seen evidence for a warped disk, but J1535’s disk can help us learn more about stellar black holes in binary systems, such as how they feed off their companions and how the accretion disks around black holes are structured.

NICER primarily studies neutron stars — it’s in the name! These are lighter-weight relatives of black holes that can be formed when stars explode. But NICER is also changing what we know about many types of X-ray sources. Thanks to NICER’s efforts, we are one step closer to a complete picture of black holes. And hey, that’s pretty nice!

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

Space Station Science: Biological Research

Each month, we highlight a different research topic on the International Space Station. In August, our focus is biological research. Learning how spaceflight affects living organisms will help us understand potential health risks related to humans on long duration missions, including our journey to Mars.

Cells, microbes, animals and plants are affected by microgravity, and studying the processes involved in adaptation to spaceflight increases our fundamental understanding of biological processes on Earth. Results on Earth from biological research in space include the development of new medications, improved agriculture, advancements in tissue engineering and regeneration, and more. 

Take a look at a few of the biological research experiments performed on space station:

Biomolecule Sequencer

Living organisms contain DNA, and sequencing DNA is a powerful way to understand how they respond to changing environments. The Biomolecule Sequencer experiment hopes to demonstrate (for the first time) that DNA sequencing is feasible in an orbiting spacecraft. Why? 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.

Ant-stronauts

Yes, ant-stronauts…as in ants in space. These types of studies provide insights into how ants answer collective search problems. Watching how the colony adapts as a unit in the quest for resources in extreme environments, like space, provides data that can be used to build algorithms with varied applications. Understanding how ants search in different conditions could have applications for robotics.

TAGES

The TAGES experiment (Transgenic Arabidopsis Gene Expression System) looks to see how microgravity impacts the growth of plant roots. Fluorescent markers placed on the plant’s genes allow scientists to study root development of Arabidopsis (a cress plant) grown on the space station. Evidence shows that directional light in microgravity skews root growth to the right, rather than straight down from the light source. Root growth patters on station mimic that of plants grown at at 45% degree angle on Earth. Space flight appears to slow the rate of the plant’s early growth as well.

Heart Cells

Spaceflight can cause a suite of negative health effects, which become more problematic as crew members stay in orbit for long periods of time. Effects of Microgravity on Stem Cell-Derived Cardiomycytes (Heart Cells) studies the human heart, specifically how heart muscle tissue contracts, grows and changes in microgravity. Understanding how heart muscle cells change in space improves efforts for studying disease, screening drugs and conducting cell replacement therapy for future space missions.

Medaka Fish

Chew on these results…Jaw bones of Japanese Medaka fish in microgravity show decreased mineral density and increased volume of osteoclasts, cells that break down bone tissue. Results from this study improve our understanding of the mechanisms behind bone density and organ tissue changes in space.

These experiments, and many others, emphasize the importance of biological research on the space station. Understanding the potential health effects for crew members in microgravity will help us develop preventatives and countermeasures.

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

Spread your cosmic wings 🦋

The Butterfly Nebula, created by a dying star, was captured by the Hubble Space Telescope in this spectacular image. Observations were taken over a more complete spectrum of light, helping researchers better understand the “wings'' of gas bursting out from its center. The nebula’s dying central star has become exceptionally hot, shining ultraviolet light brightly over the butterfly’s wings and causing the gas to glow.

Learn more about Hubble’s celebration of Nebula November and see new nebula images, here.

You can also keep up with Hubble on Twitter, Instagram, Facebook, and Flickr!

Image credits: NASA, ESA, and J. Kastner (RIT)

Astronaut Journal Entry - Alarms

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 in space, by NASA astronaut Scott Tingle.

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

The smoke detectors have been setting off alarms. This happens routinely due to dust circulating in the modules, but every alarm is taken seriously. This is the third time that the alarm has sounded while I was using the Waste & Hygiene Compartment (toilet). I am starting to think that my actions are causing the alarms…. maybe I should change my diet?

Find more ‘Captain’s Log’ entries HERE.

Follow NASA astronaut Scott Tingle on Instagram and Twitter.

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

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.

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

We're using our unique vantage point in space to provide observations and data of Hurricane Irma and other tropical storms. Hurricanes Irma and Jose are seen here in a 12-hour long infrared loop. Scientists monitor storms in infrared to closely monitor clouds and storm intensity. We continue to provide satellite imagery for these storms, tracking its trajectory, force and precipitation to inform forecasters at the National Hurricane Center.

As these storms continue their westward drive in the coming days, they will be passing over waters that are warmer than 30 degrees Celsius (86 degrees Fahrenheit)—hot enough to sustain a category 5 storm. Warm oceans, along with low wind shear, are two key ingredients that fuel and sustain hurricanes. Get the latest imagery and data from us at www.nasa.gov/hurricane For information on making preparations for Hurricanes, visit the FEMA website at: ready.gov/hurricanes. Credit: NASA-SPoRT/NOAA 

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

What’s Up for August 2016

What’s up for August? How to spot Mercury, Venus,  Mars, Jupiter and Saturn, as well as the and the annual Perseid meteor shower. 

Here are some highlights in this month’s nighttime skies as picked by astronomer Jane Houston Jones from our Jet Propulsion Laboratory.

Spot Venus, Mercury and Jupiter and the moon low on the western horizon about 45 minutes after sunset from August 4 through 7. On August 11, look in the south-southwest sky for a second planetary dance as Mars and Saturn are high and easy to see and they are joined by the moon.

The famous and reliably active Perseid meteor shower peaks in the morning hours of August 12. The moon, which paired up so nicely with Mars and Saturn on the 11, is bright enough to blot out some of the meteors, but lucky for you it sets about 1 a.m. on the morning of the 12, just at the peak time for the best Perseid viewing.

But wait, there are more planets, dwarf planets and an asteroid visible this month! Uranus and Neptune and dwarf planet Ceres are visible before dawn in the southern sky. Uranus is visible through binoculars but Neptune and Ceres require a telescope.

Watch the full August “What’s Up” video for more: 

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