How Do You Guys Help With Climate Change?

Say hello to globular cluster 47 Tucanae 👋

This glittery spray of ancient stars is about 16,700 light-years away from Earth toward the constellation Tucana. Globular clusters like this one are isolated star cities, home to hundreds of thousands of stars that are held together by their mutual gravity. And like the fast pace of cities, there's plenty of action in these stellar metropolises. The stars are in constant motion, orbiting around the cluster's center.

Past observations have shown that the heavyweight stars tend to crowd into the “downtown” core area, while lightweight stars reside in the less populated suburbs. But as heavyweight stars age, they rapidly lose mass, cool down and shut off their nuclear furnaces. After the purge, only the stars' bright, superhot cores – called white dwarfs – remain. This weight loss program causes the now lighter-weight white dwarfs to be nudged out of the downtown area through gravitational interactions with heftier stars.

Until these Hubble observations, astronomers had never seen the dynamic conveyor belt in action. The Hubble results reveal young white dwarfs amid their leisurely 40-million-year exodus from the bustling center of the cluster.

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

Galaxies: Cities of Stars

Galaxies are like cities made of oodles of stars, gas, and dust bound together by gravity. These beautiful cosmic structures come in many shapes and sizes. Though there are a slew of galaxies in the universe, there are only a few we can see with the unaided eye or backyard telescope.

How many types are out there, how’d so many of them wind up with weird names, and how many stars live inside them? Hold tight while we explore these cosmic metropolises.

Galaxies come in lots of different shapes, sizes, and colors. But astronomers have noticed that there are mainly three types: spiral, elliptical, and irregular.

Spiral galaxies, like our very own Milky Way, look similar to pinwheels! These galaxies tend to have a bulging center heavily populated by stars, with elongated, sparser arms of dust and stars that wrap around it. Usually, there’s a huge black hole hiding at the center, like the Milky Way’s Sagittarius A* (pronounced A-star). Our galactic neighbor, Andromeda (also known as Messier 31 or M31), is also a spiral galaxy!

Elliptical galaxies tend to be smooth spheres of gas, dust, and stars. Like spiral galaxies, their centers are typically bulges surrounded by a halo of stars (but minus the epic spiral arms). The stars in these galaxies tend to be spread out neatly throughout the galaxies and are some of the oldest stars in the universe! Messier 87 (M87) is one example of an elliptical galaxy. The supermassive black hole at its center was recently imaged by the Event Horizon Telescope.

Irregular galaxies are, well … a bit strange. They have one-of-a-kind shapes, and many just look like messy blobs. Astronomers think that irregular galaxies' uniqueness is a result of interactions with other galaxies, like collisions! Galaxies are so big, with so much distance between their stars, that even when they collide, their stars usually do not. Galaxy collisions have been important to the formation of our Milky Way and others. When two galaxies collide, clouds of gas, dust, and stars are violently thrown around, forming an entirely new, larger one! This could be the cause of some irregular galaxies seen today.

Now that we know the different types of galaxies, what about how many stars they contain? Galaxies can come in lots of different sizes, even among each type. Dwarf galaxies, the smallest version of spiral, elliptical, and irregular galaxies, are usually made up of 1,000 to billions of stars. Compared to our Milky Way’s 200 to 400 billion stars, the dwarf galaxy known as the Small Magellanic Cloud is tiny, with just a few hundred million stars! IC 1101, on the other hand, is one of the largest elliptical galaxies found so far, containing almost 100 trillion stars.

Ever wondered how galaxies get their names? Astronomers have a number of ways to name galaxies, like the constellations we see them in or what we think they resemble. Some even have multiple names!

A more formal way astronomers name galaxies is with two-part designations based on astronomical catalogs, published collections of astronomical objects observed by specific astronomers, observatories, or spacecraft. These give us cryptic names like M51 or Swift J0241.3-0816. Catalog names usually have two parts:

A letter, word, or short acronym that identifies a specific astronomical catalog.

A sequence of numbers and/or letters that uniquely identify the galaxy within that catalog.

For M51, the “M” comes from the Messier catalog, which Charles Messier started compiling in 1771, and the "51" is because it’s the 51st entry in that catalog. Swift J0241.3-0816 is a galaxy observed by the Swift satellite, and the numbers refer to its location in the sky, similar to latitude and longitude on Earth.

There’s your quick intro to galaxies, but there’s much more to learn about them. Keep up with NASA Universe on Facebook and Twitter where we post regularly about galaxies.

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

How did you deal with the disappointment of being medically disqualified for astronaut candidacy?

Using a fleet of research aircraft, our Operation IceBridge images Earth's polar ice to better understand connections between polar regions and the global climate system. IceBridge studies annual changes in thickness of sea ice, glaciers and ice sheets. IceBridge bridges the gap between the ICESat missions.

Seen here is a time-lapse view of a glacier-run from the cockpit of our P-3 Orion aircraft taken during a May 8, 2017 flight over Greenland's Southeast glaciers.

Video credit: NASA/Gerrit Everson

Take a look back at this season’s Arctic ice survey HERE.

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

How did your perspective on Earth & humanity change from space?

Stars Make Firework Supplies!

The next time you see fireworks, take a moment to celebrate the cosmic pyrotechnics that made them possible. From the oxygen and potassium that help fireworks burn to the aluminum that makes sparklers sparkle, most of the elements in the universe wouldn’t be here without stars.

From the time the universe was only a few minutes old until it was about 400 million years old, the cosmos was made of just hydrogen, helium and a teensy bit of lithium. It took some stellar activity to produce the rest of the elements!

Stars are element factories

Even after more than 13 billion years, the hydrogen and helium that formed soon after the big bang still make up over 90 percent of the atoms in the cosmos. Most of the other elements come from stars.

Stars began popping into the universe about 400 million years after the big bang. That sounds like a long time, but it’s only about 3% of the universe’s current age!

Our Nancy Grace Roman Space Telescope will study the universe’s early days to help us learn more about how we went from a hot, soupy sea of atoms to the bigger cosmic structures we see today. We know hydrogen and helium atoms gravitated together to form stars, where atoms could fuse together to make new elements, but we're not sure when it began happening. Roman will help us find out.

The central parts of atoms, called nuclei, are super antisocial – it takes a lot of heat and pressure to force them close together. Strong gravity in the fiery cores of the first stars provided just the right conditions for hydrogen and helium atoms to combine to form more elements and generate energy. The same process continues today in stars like our Sun and provides some special firework supplies.

Carbon makes fireworks explode, helps launch them into the sky, and is even an ingredient in the “black snakes” that seem to grow out of tiny pellets. Fireworks glow pink with help from the element lithium. Both of these elements are created by average, Sun-like stars as they cycle from normal stars to red giants to white dwarfs.

Eventually stars release their elements into the cosmos, where they can be recycled into later generations of stars and planets. Sometimes they encounter cosmic rays, which are nuclei that have been boosted to high speed by the most energetic events in the universe. When cosmic rays collide with atoms, the impact can break them apart, forming simpler elements. That’s how we get boron, which can make fireworks green, and beryllium, which can make them silver or white!

Since massive stars have even stronger gravity in their cores, they can fuse more elements – all the way up to iron. (The process stops there because instead of producing energy, fusing iron is so hard to do that it uses up energy.)

That means the sodium that makes fireworks yellow, the aluminum that produces silver sparks (like in sparklers), and even the oxygen that helps fireworks ignite were all first made in stars, too! A lot of these more complex elements that we take for granted are actually pretty rare throughout the cosmos, adding up to less than 10 percent of the atoms in the universe combined!

Fusion in stars only got us through iron on the periodic table, so where do the rest of our elements come from? It’s what happens next in massive stars that produces some of the even more exotic elements.

Dying stars make elements too!

Once a star many times the Sun’s mass burns through its fuel, gravity is no longer held in check, and its core collapses under its own weight. There, atoms are crushed extremely close together – and they don’t like that! Eventually it reaches a breaking point and the star explodes as a brilliant supernova. Talk about fireworks! These exploding stars make elements like copper, which makes fireworks blue, and zinc, which creates a smoky effect.

Something similar can happen when a white dwarf star – the small, dense core left behind after a Sun-like star runs out of fuel – steals material from a neighboring star. These white dwarfs can explode as supernovae too, spewing elements like the calcium that makes fireworks orange into the cosmos.

When stars collide

White dwarfs aren’t the only “dead” stars that can shower their surroundings with new elements. Stars that are too massive to leave behind white dwarfs but not massive enough to create black holes end up as neutron stars.

If two of these extremely dense stellar skeletons collide, they can produce all kinds of elements, including the barium that makes fireworks bright green and the antimony that creates a glitter effect. Reading this on a phone or computer? You can thank crashing dead stars for some of the metals that make up your device, too!

As for most of the remaining elements we know of, we've only seen them in labs on Earth so far.

Sounds like we’ve got it all figured out, right? But there are still lots of open questions. Our Roman Space Telescope will help us learn more about how elements were created and distributed throughout galaxies. That’s important because the right materials had to come together to form the air we breathe, our bodies, the planet we live on, and yes – even fireworks!

So when you’re watching fireworks, think about their cosmic origins!

Learn more about the Roman Space Telescope at: https://roman.gsfc.nasa.gov/

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

On June 19, engineers on the ground remotely operated the International Space Station’s robotic arm to remove the Roll-Out Solar Array (ROSA) from the trunk of SpaceX’s Dragon cargo vehicle. Here, you see the experimental solar array unfurl as the station orbits Earth.

Solar panels are an efficient way to power satellites, but they are delicate and large, and must be unfolded when a satellite arrives in orbit. The Roll-Out Solar Array (ROSA) is a new type of solar panel that rolls open in space like a party favor and is more compact than current rigid panel designs.

ROSA is 20% lighter and 4x smaller in volume than rigid panel arrays!

This experiment remained attached to the robotic arm over seven days to test the effectiveness of the advanced, flexible solar array that rolls out like a tape measure. During that time, they also measured power produced by the array and monitored how the technology handled retraction.

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

Stop. Drop. And Apply to #BeAnAstronaut!

Feel like your place is in the stars? Are you an adventure seeker, an explorer, a person passionate about science and space? We need you!!

Applications are OPEN for our newest class of #Artemis astronauts. Once chosen, you could be the next person to step foot on the Moon and eventually embark on missions to Mars!

Do you have a friend who should apply? Tag them. Do you know someone who's still in school? Encourage them to follow their dreams and aim high.

To give you a sneak peak of what life will be like if you decide to #BeAnAstronaut, we’re taking you behind-the-scenes of astronaut life over the course of March. 

APPLY NOW AND GET MORE INFORMATION HERE! 

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

What are Phytoplankton and Why Are They Important?

Breathe deep… and thank phytoplankton.

Why? Like plants on land, these microscopic creatures capture energy from the sun and carbon from the atmosphere to produce oxygen.

Phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Though tiny, these creatures are the foundation of the aquatic food chain. They not only sustain healthy aquatic ecosystems, they also provide important clues on climate change.

Let’s explore what these creatures are and why they are important for NASA research.

Phytoplankton are diverse

Phytoplankton are an extremely diversified group of organisms, varying from photosynthesizing bacteria, e.g. cyanobacteria, to diatoms, to chalk-coated coccolithophores. Studying this incredibly diverse group is key to understanding the health - and future - of our ocean and life on earth.

Their growth depends on the availability of carbon dioxide, sunlight and nutrients. Like land plants, these creatures require nutrients such as nitrate, phosphate, silicate, and calcium at various levels. When conditions are right, populations can grow explosively, a phenomenon known as a bloom.

Phytoplankton blooms in the South Pacific Ocean with sediment re-suspended from the ocean floor by waves and tides along much of the New Zealand coastline.

Phytoplankton are Foundational

Phytoplankton are the foundation of the aquatic food web, feeding everything from microscopic, animal-like zooplankton to multi-ton whales. Certain species of phytoplankton produce powerful biotoxins that can kill marine life and people who eat contaminated seafood.

Phytoplankton are Part of the Carbon Cycle

Phytoplankton play an important part in the flow of carbon dioxide from the atmosphere into the ocean. Carbon dioxide is consumed during photosynthesis, with carbon being incorporated in the phytoplankton, and as phytoplankton sink a portion of that carbon makes its way into the deep ocean (far away from the atmosphere).

Changes in the growth of phytoplankton may affect atmospheric carbon dioxide concentrations, which impact climate and global surface temperatures. NASA field campaigns like EXPORTS are helping to understand the ocean's impact in terms of storing carbon dioxide.

Phytoplankton are Key to Understanding a Changing Ocean

NASA studies phytoplankton in different ways with satellites, instruments, and ships. Upcoming missions like Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) - set to launch Jan. 2024 - will reveal interactions between the ocean and atmosphere. This includes how they exchange carbon dioxide and how atmospheric aerosols might fuel phytoplankton growth in the ocean.

Information collected by PACE, especially about changes in plankton populations, will be available to researchers all over the world. See how this data will be used.

The Ocean Color Instrument (OCI) is integrated onto the PACE spacecraft in the cleanroom at Goddard Space Flight Center. Credit: NASA

uhmm, can you tell me what exactly a black hole is? or what iy does? thanks, just really confused and curious on how it actually works.