Why Did I Think Anyone Would Like This?

Roman’s Heat-Vision Eyes Are Complete!

Our Nancy Grace Roman Space Telescope team recently flight-certified all 24 of the detectors the mission needs. When Roman launches in the mid-2020s, the detectors will convert starlight into electrical signals, which will then be decoded into 300-megapixel images of huge patches of the sky. These images will help astronomers explore all kinds of things, from rogue planets and black holes to dark matter and dark energy.

Eighteen of the detectors will be used in Roman’s camera, while another six will be reserved as backups. Each detector has 16 million tiny pixels, so Roman’s images will be super sharp, like Hubble’s.

The image above shows one of Roman’s detectors compared to an entire cell phone camera, which looks tiny by comparison. The best modern cell phone cameras can provide around 12-megapixel images. Since Roman will have 18 detectors that have 16 million pixels each, the mission will capture 300-megapixel panoramas of space.

The combination of such crisp resolution and Roman’s huge view has never been possible on a space-based telescope before and will make the Nancy Grace Roman Space Telescope a powerful tool in the future.

Learn more about the Roman Space Telescope!

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

Stars, Sea, and Smoke from the ISS: Tournament Earth 2021

We started Tournament Earth with 32 photos taken by astronauts from the Interantional Space Station and now we are down to 8. All of the #1 seeds are gone. Two #8 seeds are dominating their groups. Who will win? Let's take a closer look at the competitors still in the game. Then remember to vote for your favorites. The champion will be announced on April 13, 2021.

Stars in Motion vs. Cleveland Volcano

This matchup pits smoke against stars, but both have interesting stories.

The International Space Station (ISS) is constantly in motion. For astronaut photographers on board, that motion has consequences. For one, it makes it challenging to take photos. The same motion makes it possible to shoot spectacular photos like the one above. The image is compiled from a series of photographs taken by astronaut Don Pettit while he was onboard the ISS in April 2012. This composite was made from more than 72 individual long-exposure photographs taken over several minutes as the ISS traveled over the Caribbean Sea, across South America, and over the South Atlantic Ocean.

Astronaut Jeff Williams was the first to witness activity at the Cleveland Volcano on May 3, 2006. The Cleveland Volcano is one of the most active in the Aleutian Islands, which extend west-southwest from the Alaska mainland. It is a stratovolcano composed of alternating layers of hardened lava, compacted volcanic ash, and volcanic rocks. The event proved to be short-lived; two hours later, the plume had completely detached from the volcano. The ash cloud height could have been as high as 6,000 meters (20,000 feet) above sea level.

Stargazing from the ISS vs. Cruising Past the Aurora Borealis

This is the most stellar matchup of the tournament, literally. Two beloved star pictures face off in what will be one of the most difficult choices of the tournament.

An astronaut took this broad, short-lens photograph of Earth’s night lights while looking out over the remote reaches of the central equatorial Pacific Ocean. The ISS was passing over the island nation of Kiribati at the time, about 2600 kilometers (1,600 miles) south of Hawaii. Scientists identified the pattern of stars in the photo as our Milky Way galaxy (looking toward its center). The dark patches are dense dust clouds in an inner spiral arm of our galaxy; such clouds can block our view of stars toward the center. The curvature of the Earth crosses the center of the image and is illuminated by a variety of airglow layers in orange, green, and red.

Commonly known as the northern lights, these colorful ribbons of light appear to dance in the sky over the planet’s high latitudes, attracting sky chasers and photographers. Astronaut Randy “Komrade” Bresnik shot this photograph on September 15, 2017, as the space station passed over Ontario, Canada. Curtains of green—the most familiar color of auroras—dominate the light show, with hints of purple and red.

Rolling Through the Appalachians vs. Castellanus Cloud Tower

The Susquehanna River cuts through the folds of the Valley-and-Ridge province of the Appalachian Mountains in this photograph taken from the International Space Station by astronaut Christina Koch. The Valley-and-Ridge province is a section of the larger Appalachian Mountain Belt between the Appalachian Plateau and the Blue Ridge physiographic provinces. The northeast-southwest trending ridges are composed of Early Paleozoic sedimentary rocks. The valleys between them were made of softer rocks (limestone and shales) that were more susceptible to erosion; they are now occupied by farms.

An astronaut aboard the International Space Station took this photograph of a massive vertical cloud formation—known to meteorologists as cumulus castellanus—above Andros Island. The cloud name castellanus comes from the similarity to the crenellated towers or turrets of medieval castles. These clouds develop due to strong vertical air movement typically associated with thunderstorms.

Lake Van, Turkey vs. Typhoon Maysak from the Space Station

While orbiting on the International Space Station, astronaut Kate Rubins shot this photograph of part of Lake Van in Turkey, the largest soda or alkaline lake on Earth. Generally, soda lakes are distinguished by high concentrations of carbonate species. Lake Van is an endorheic lake—it has no outlet, so its water disappears by evaporation—with a pH of 10 and high salinity levels.

This photograph of super typhoon Maysak was taken by European Space Agency astronaut Samantha Cristoforetti as the International Space Station passed near the storm on March 31, 2015. The category 4 typhoon was headed for a possible landfall in the Philippines by the end of the week. It was unusual for the western Pacific to see such a strong storm so early in the year.

See all of the images and vote HERE. Follow @NASAEarth on social media for updates.

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

Q: Is your mind organized?

A: yes and no. Quantum mechanical order, so to speak.

#laughsinquantummechanicalsuperpositionwhilecrying

From Seed to Market: How NASA brings food to the table

Did you know we help farmers grow some of your favorite fruits, veggies and grains?

Our Earth-observing satellites track rainfall amounts, soil moisture, crop health, and more. On the ground, we partner with agencies and organizations around the world to help farmers use that data to care for their fields.

Here are a few ways we help put food on the table, from planting to harvest.

Planting

Did you plant seeds in science class to watch them sprout and grow? They all needed water, right? Our data helps farmers “see” how moist the soil is across large fields.

“When you’re not sure when to water your flowers or your garden, you can look at the soil or touch it with your hands. We are sort of ‘feeling’ the soil, sensing how much water is in the soil – from a satellite,

685 kilometers (408 miles) above Earth,” said John Bolten, the associate program manager of water resources for NASA’s Applied Sciences Program.

This spring, we worked with the U.S. Department of Agriculture and George Mason University to release Crop-CASMA, a tool that shows soil moisture and vegetation conditions for the United States. Able to see smaller areas – about the size of a couple of golf courses – the USDA uses Crop-CASMA to help update farmers on their state’s soil moisture, crop health and growing progress.

Growing

It’s dangerous being a seedling.

Heavy spring rains or summer storms can flood fields and drown growing plants. Dry spells and droughts can starve them of nutrients. Insects and hail can damage them. Farmers need to keep a close eye on plants during the spring and summer months. Our data and programs help them do that.

For example, in California, irrigation is essential for agriculture. California’s Central Valley annually produces more than 250 types of crops and is one of the most productive agricultural regions in the country – but it’s dry. Some parts only get 6 inches of rain per year.

To help, Landsat data powers CropManage – an app that tells farmers how long to irrigate their fields, based on soil conditions and evapotranspiration, or how much water plants are releasing into the atmosphere. The warmer and drier the atmosphere, the more plants “sweat” and lose water that needs to be replenished. Knowing how long to irrigate helps farmers conserve water and be more efficient. In years like 2021, intense droughts can make water management especially critical.

Harvest

Leading up to harvest, farmers need to know their expected yields – and profits.

GEOGLAM, or the Group on Earth Observations Global Agricultural Monitoring Initiative, is a partnership between NASA Harvest, USDA’s Foreign Agricultural Service (FAS) and other global agencies to track and report on crop conditions around the world.

USDA FAS is one of the main users of a soil moisture measurement product developed by Bolten and his team at our NASA Goddard Space Flight Center to drive their crop forecasting system.

If you’re interested in more ways we support agriculture, stay tuned over the next few weeks to learn more about how satellites (and scientists) help put snacks on your table!

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

The Lives, Times, and Deaths of Stars

Who among us doesn’t covertly read tabloid headlines when we pass them by? But if you’re really looking for a dramatic story, you might want to redirect your attention from Hollywood’s stars to the real thing. From birth to death, these burning spheres of gas experience some of the most extreme conditions our cosmos has to offer.

All stars are born in clouds of dust and gas like the Pillars of Creation in the Eagle Nebula pictured below. In these stellar nurseries, clumps of gas form, pulling in more and more mass as time passes. As they grow, these clumps start to spin and heat up. Once they get heavy and hot enough (like, 27 million degrees Fahrenheit or 15 million degrees Celsius), nuclear fusion starts in their cores. This process occurs when protons, the nuclei of hydrogen atoms, squish together to form helium nuclei. This releases a lot of energy, which heats the star and pushes against the force of its gravity. A star is born.

Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)

From then on, stars’ life cycles depend on how much mass they have. Scientists typically divide them into two broad categories: low-mass and high-mass stars. (Technically, there’s an intermediate-mass category, but we’ll stick with these two to keep it straightforward!)

Low-mass stars

A low-mass star has a mass eight times the Sun’s or less and can burn steadily for billions of years. As it reaches the end of its life, its core runs out of hydrogen to convert into helium. Because the energy produced by fusion is the only force fighting gravity’s tendency to pull matter together, the core starts to collapse. But squeezing the core also increases its temperature and pressure, so much so that its helium starts to fuse into carbon, which also releases energy. The core rebounds a little, but the star’s atmosphere expands a lot, eventually turning into a red giant star and destroying any nearby planets. (Don’t worry, though, this is several billion years away for our Sun!)

Red giants become unstable and begin pulsating, periodically inflating and ejecting some of their atmospheres. Eventually, all of the star’s outer layers blow away, creating an expanding cloud of dust and gas misleadingly called a planetary nebula. (There are no planets involved.)

Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

All that’s left of the star is its core, now called a white dwarf, a roughly Earth-sized stellar cinder that gradually cools over billions of years. If you could scoop up a teaspoon of its material, it would weigh more than a pickup truck. (Scientists recently found a potential planet closely orbiting a white dwarf. It somehow managed to survive the star’s chaotic, destructive history!)

High-mass stars

A high-mass star has a mass eight times the Sun’s or more and may only live for millions of years. (Rigel, a blue supergiant in the constellation Orion, pictured below, is 18 times the Sun’s mass.)

Credit: Rogelio Bernal Andreo

A high-mass star starts out doing the same things as a low-mass star, but it doesn’t stop at fusing helium into carbon. When the core runs out of helium, it shrinks, heats up, and starts converting its carbon into neon, which releases energy. Later, the core fuses the neon it produced into oxygen. Then, as the neon runs out, the core converts oxygen into silicon. Finally, this silicon fuses into iron. These processes produce energy that keeps the core from collapsing, but each new fuel buys it less and less time. By the point silicon fuses into iron, the star runs out of fuel in a matter of days. The next step would be fusing iron into some heavier element, but doing requires energy instead of releasing it.  

The star’s iron core collapses until forces between the nuclei push the brakes, and then it rebounds back to its original size. This change creates a shock wave that travels through the star’s outer layers. The result is a huge explosion called a supernova.

What’s left behind depends on the star’s initial mass. Remember, a high-mass star is anything with a mass more than eight times the Sun’s — which is a huge range! A star on the lower end of this spectrum leaves behind a city-size, superdense neutron star. (Some of these weird objects can spin faster than blender blades and have powerful magnetic fields. A teaspoon of their material would weigh as much as a mountain.)

At even higher masses, the star’s core turns into a black hole, one of the most bizarre cosmic objects out there. Black holes have such strong gravity that light can’t escape them. If you tried to get a teaspoon of material to weigh, you wouldn’t get it back once it crossed the event horizon — unless it could travel faster than the speed of light, and we don’t know of anything that can! (We’re a long way from visiting a black hole, but if you ever find yourself near one, there are some important safety considerations you should keep in mind.)

The explosion also leaves behind a cloud of debris called a supernova remnant. These and planetary nebulae from low-mass stars are the sources of many of the elements we find on Earth. Their dust and gas will one day become a part of other stars, starting the whole process over again.

That’s a very brief summary of the lives, times, and deaths of stars. (Remember, there’s that whole intermediate-mass category we glossed over!) To keep up with the most recent stellar news, follow NASA Universe on Twitter and Facebook.

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

Sea Level Rise is on the Rise

As our planet warms, sea levels are rising around the world – and are doing so at an accelerating rate. Currently, global sea level is rising about an eighth of an inch every year.

That may seem insignificant, but it’s 30% more than when NASA launched its first satellite mission to measure ocean heights in 1992 – less than 30 years ago. And people already feel the impacts, as seemingly small increments of sea level rise become big problems along coastlines worldwide.

Higher global temperatures cause our seas to rise, but how? And why are seas rising at a faster and faster rate? There are two main reasons: melting ice and warming waters.

 The Ice We See Is Getting Pretty Thin

About two-thirds of global sea level rise comes from melting glaciers and ice sheets, the vast expanses of ice that cover Antarctica and Greenland. In Greenland, most of that ice melt is caused by warmer air temperatures that melt the upper surface of ice sheets, and when giant chunks of ice crack off of the ends of glaciers, adding to the ocean.

In Antarctica – where temperatures stay low year-round – most of the ice loss happens at the edges of glaciers. Warmer ocean water and warmer air meet at the glaciers’ edges, eating away at the floating ice sheets there.

NASA can measure these changes from space. With data from the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, scientists can measure the height of ice sheets to within a fraction of an inch. Since 2006, an average of 318 gigatons of ice per year has melted from Greenland and Antarctica’s ice sheets. To get a sense of how big that is: just one gigaton is enough to cover New York City’s Central Park in ice 1,000 feet deep – almost as tall as the Chrysler Building.

With the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission – a partnership with the German Research Centre for Geosciences – scientists can calculate the mass of ice lost from these vast expanses across Greenland and Antarctica.

It’s not just glaciers in Antarctica and Greenland that are melting, though. Nearly all glaciers have been melting in the last decade, including those in Alaska, High Mountain Asia, South America, and the Canadian Arctic. Because these smaller glaciers are melting quickly, they contribute about the same amount to sea level rise as meltwater from massive ice sheets.

The Water’s Getting Warm

As seawater warms, it takes up more space. When water molecules get warmer, the atoms in those molecules vibrate faster, expanding the volume they take up. This phenomenon is called thermal expansion. It’s an incredibly tiny change in the size of a single water molecule, but added across all the water molecules in all of Earth’s oceans – a single drop contains well over a billion billion molecules – it accounts for about a third of global sea level rise.

So Much to See

While sea level is rising globally, it’s not the same across the planet. Sea levels are rising about an eighth of an inch per year on average worldwide. But some areas may see triple that rate, some may not observe any changes, and some may even experience a drop in sea level. These differences are due to ocean currents, mixing, upwelling of cold water from the deep ocean, winds, movements of heat and freshwater, and Earth’s gravitational pull moving water around. When ice melts from Greenland, for example, the drop in mass decreases the gravitational pull from the ice sheet, causing water to slosh to the shores of South America.

That’s where our view from space comes in. We’re launching Sentinel-6 Michael Freilich, an international partnership satellite, to continue our decades-long record of global sea level rise.

The Great Conjunction of Jupiter and Saturn

Credits:  NASA/Bill Ingalls

Have you noticed two bright objects in the sky getting closer together with each passing night? It’s Jupiter and Saturn doing a planetary dance that will result in the Great Conjunction on Dec. 21. On that day, Jupiter and Saturn will be right next to each other in the sky – the closest they have appeared in nearly 400 years!

Skywatching Tips from NASA

Credits: NASA/JPL-Caltech

For those who would like to see this phenomenon for themselves, here’s what to do:

Find a spot with an unobstructed view of the sky, such as a field or park. Jupiter and Saturn are bright, so they can be seen even from most cities.

An hour after sunset, look to the southwestern sky. Jupiter will look like a bright star and be easily visible. Saturn will be slightly fainter and will appear slightly above and to the left of Jupiter until December 21, when Jupiter will overtake it and they will reverse positions in the sky.

The planets can be seen with the unaided eye, but if you have binoculars or a small telescope, you may be able to see Jupiter’s four large moons orbiting the giant planet.

How to Photograph the Conjunction

Credits: NASA/Bill Dunford

Saturn and Jupiter are easy to see without special equipment, and can be photographed easily on DSLR cameras and many cell phone cameras. Here are a few tips and tricks:

These planets are visible in the early evening, and you’ll have about 1-2 hours from when they are visible, to when they set. A photo from the same location can look completely different just an hour later!

Using a tripod will help you hold your camera steady while taking longer exposures. If you don’t have a tripod, brace your camera against something – a tree, a fence, or a car can all serve as a tripod for a several-second exposure.

The crescent Moon will pass near Jupiter and Saturn a few days before the conjunction. Take advantage of it in your composition!

Get more tips HERE.

Still have questions about the Great Conjunction?

Our NASA expert answered questions from social media on an episode of NASA Science Live on Thursday, Dec. 17. Watch the recording HERE.

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

Boo-tiful Ring Galaxies

A ghoulish secret lurks within each of these gorgeous galaxies. Their rings are dotted with stellar graveyards!

These objects are called ring galaxies, and scientists think most of them form in monster-sized crashes. Not just any galaxy collision will do the trick, though. To produce the treat of a ring, a smaller galaxy needs to ram through the center of a larger galaxy at just the perfect angle.

The collision causes ripples that disturb both galaxies. The gravitational shock causes dust, gas, and stars in the larger galaxy’s disk to rush outward. As this ring of material plows out from the galaxy’s center, gas clouds collide and trigger the birth of new stars.

In visible light, the blue areas in the galaxies’ rings show us where young, hot stars are growing up. Faint, pink regions around the ring mark stellar nurseries where even younger stars set hydrogen gas aglow.

The newborn stars come in a mix of sizes, from smaller ones like our Sun all the way up to huge stars with tens of times the Sun’s mass. And those massive stars live large!

While a star like our Sun will last many billions of years before running out of fuel, larger stars burn much brighter and faster. After just a few million years, the largest stars explode as supernovae. When massive stars die, they leave behind a stellar corpse, either a neutron star or black hole.

When we turn our X-ray telescopes to these ring galaxies, we see telltale signs of stellar remnants dotted throughout their ghostly circles. The purple dots in the X-ray image above are neutron stars or black holes that are siphoning off gas from a companion star, like a vampire. The gas reinvigorates stellar corpses, which heat up and emit X-rays. These gas-thirsty remains are beacons lighting the way to stellar graveyards.

Spiral galaxies — like our home galaxy, the Milky Way — have curved arms that appear to sweep out around a bright center. The dust and gas in those spiral arms press together, causing cycles of star formation that result in a more even mix of new stars and stellar corpses scattered throughout our galaxy. No creepy ring of stellar corpses here!  

To visit some other eerie places in the universe, check out the latest additions to the Galaxy of Horrors poster series and follow NASA Universe on Twitter and Facebook for news about black holes, neutron stars, galaxies, and all the amazing objects outside our solar system.

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