Answer Time From Space!

Cape Town was on the verge of running out of water. The South African city of 3.7 million people had suffered years of drought. But after nearly running dry earlier this year, the reservoirs are now rising thanks to rain, conservation efforts, and engineering fixes.

The city’s largest reservoir—Theewaterskloof—holds 40 percent of Cape Town’s water storage capacity, so it's a good barometer for the amount of water available. Natural-color images, captured by Landsat 8, show the change in water levels at Theewaterskloof between July 22, 2017, and July 9, 2018.

Read more HERE.

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@danizzzxix: Does being in space take a toll on your body?

Confirmed: Summer 2023 Hottest in NASA’s Record

All three months of summer 2023 broke records. July 2023 was the hottest month ever recorded, and the hottest July. June 2023 was the hottest June, and August 2023 was the hottest August.

NASA’s temperature record, GISTEMP, starts in 1880, when consistent, modern recordkeeping became possible. Our record uses millions of measurements of surface temperature from weather stations, ships and ocean buoys, and Antarctic research stations. Other agencies and organizations who keep similar global temperature records find the same pattern of long-term warming.

Global temperatures are rising from increased emissions of greenhouse gasses, like carbon dioxide and methane. Over the last 200 years, humans have raised atmospheric CO2 by nearly 50%, primarily through the burning of fossil fuels.

Drivers of climate change, both natural and human-caused, leave distinct fingerprints. Through observations and modeling, NASA researchers confirm that the current warming is the result of human activities, particularly increased greenhouse gas emissions.

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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🌊🌊🌊 This natural-color image captured May 17 near the coast of Guinea-Bissau in West Africa shows estuaries branching out like a network of roots from a plant. Crossfading to a data visualization helps reveals water clarity due to dissolved organic matter in Guinea-Bissau. 

With their long tendrils, the rivers meander through the country’s lowland plains to join the Atlantic Ocean. On the way, they carry water, nutrients, but also sediments out from the land. These estuaries play an important role in agriculture for this small country that is mostly made up of flat terrain. While the coastal valleys can flood often during the rainiest part of the year in the summer, the rain makes the valleys good locations for farming, especially rice cultivation. Using satellite data, researchers continue to observe the country's change in terrain and as a result, they're documenting a regrowth of previously eroded coastal areas.

Learn more

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Great Scott, it’s Back to the Future Day – Oct. 21, 2015

What would a time traveler from 1985 discover about   NASA today?

It’s Back to the Future Day, the date in the second film that Marty and Doc traveled to in the future. When they arrived in 2015, it looked much different than today’s reality. Although we may not have self-drying jackets or flying cars, we do have some amazing spacecraft and technologies that were not around back when the film was made.

For example, in 1985 we did not have the capability to capture an image like this of our Earth. This full-Earth view captured Monday (10/19/15) by our camera on the Deep Space Climate Observatory, or DSCOVER, was not previously possible. The DSCOVR mission captures a daily sequence of images that show the Earth as it rotates, revealing the whole globe over the course of a day. These images will allow scientists to study daily variations over the entire globe in such features as vegetation, ozone, aerosols and cloud height and reflectivity.

So, we might not be cruising down the street on hover boards, but the movies didn’t get it all wrong in terms of how advanced we’d be in 2015.

When you were a kid, what technologies did you dream we’d have in the future that we may or may not have today? Here’s what two astronauts said:

NASA is much different than it was in 1985. Could we have dreamed these amazing accomplishments that have changed our world and understanding of the universe?

1. “There will be an orbiting laboratory where astronauts from around the world will live and work together.”

When Back to the Future II was set, the International Space Station didn’t exist yet. The first piece of the space station was launched in 1998, and the first crew arrived in 2000. Since November 2000, the station has been continuously occupied by humans. 

2. "We will find planets orbiting in the habitable zone of a star, and possibly suited for life."

The first exoplanet, or planet orbiting around a star, was found in 1995. Since then, we’ve discovered around a dozen habitable zone planets in the Earth-size range. While we aren’t able to zoom in to these planets that are light-years away, we’re still closer to finding another Earth-like planet in 2015 than we were in 1985. 

3. “Mars will become more populated.”

No, not by humans...yet. But, since the release of Back to the Future II, Mars has become a bit more populated with rovers and orbiters. These scientific spacecraft have played an important role in learning about the Red Planet. We currently have six missions at Mars. With the most recent news of liquid water on the surface of Mars, we can look forward to future missions returning even more data and images. The historical log of all Mars missions, both domestic and international can be found HERE. 

4. “We will launch a telescope into orbit that’s capable of looking at locations more than 13.4 billion light years from Earth.”

When Back to the Future II was released, our Hubble Space Telescope had not yet launched into orbit -- something that wouldn’t happen until April 1990. Since then, Hubble has made more than 1.2 million observations, and has traveled more than 3 billion miles along a circular low Earth orbit. For updates on Hubble’s findings, check HERE.

For more information about the technology that we’re developing at NASA, visit: http://www.nasa.gov/topics/technology

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Two New Missions to Explore the Early Solar System

We’ve got big science news…!

We’ve just added two more science missions to our lineup! The two selected missions have the potential to open new windows on one of the earliest eras in the history of our solar system – a time less than 10 millions years after the birth of our sun.

The missions, known as Lucy and Psyche, were chosen from five finalists and will proceed to mission formulation.

Let’s take a dive into each mission…

Lucy

Lucy, a robotic spacecraft, will visit a target-rich environment of Jupiter’s mysterious Trojan asteroids. Scheduled to launch in October 2021, the spacecraft is slated to arrive at its first destination, a main asteroid belt, in 2025. 

Then, from 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.

Studying these Trojan asteroids will give us valuable clues to deciphering the history of the early solar system.

Psyche

The Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the sun than is the Earth. The asteroid measures about 130 miles in diameter and, unlike most other asteroids that are rocky or icy bodies, it is thought to be comprised of mostly metallic iron and nickel, similar to Earth’s core.

Scientists wonder whether psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.

The mission will help scientists understand how planets and other bodies separated into their layers early in their histories. The Psyche robotic mission is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025.

Get even more information about these two new science missions HERE. 

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From Frozen Antarctica to the Cold Vacuum of Space

A new experiment that will collect tiny charged particles known as galactic cosmic rays will soon be added to the International Space Station. The Cosmic Ray Energetics And Mass for the International Space Station payload, nicknamed ISS-CREAM, will soon be installed in its new home on the Station’s Japanese Experiment Module Exposed Facility. ISS-CREAM will help scientists understand more about galactic cosmic rays and the processes that produce them.

Wait, what are cosmic rays?

Cosmic rays are pieces of atoms that move through space at nearly the speed of light. Galactic cosmic rays come from beyond our solar system. 

They provide us with direct samples of matter from distant places in our galaxy.

Why do these things go so fast?

Galactic cosmic rays have been sped up by extreme processes. When massive stars die, they explode as supernovas. The explosion’s blast wave expands into space along with a cloud of debris. 

Particles caught up in this blast wave can bounce around in it and slowly pick up speed. Eventually they move so fast they can escape the blast wave and race away as a cosmic ray.

Where can we catch cosmic rays?

Cosmic rays are constantly zipping through space at these super-fast speeds, running into whatever is in their path -- including Earth.  

But Earth’s atmosphere is a great shield, protecting us from 99.9 percent of the radiation coming from space, including most cosmic rays.  This is good news for life on Earth, but bad news for scientists studying cosmic rays.  

So… how do you deal with that?

Because Earth has such an effective shield against cosmic rays, the best place for scientists to study them is above our atmosphere -- in space.  Since the 1920s, scientists have tried to get their instruments as close to space as possible. One of the simplest ways to do this is to send these instruments up on balloons the size of football stadiums. These balloons are so large because they have to be able to both lift their own weight and that of their cargo, which can be heavier than a car. Scientific balloons fly to 120,000 feet or more above the ground -- that’s at least three times higher than you might fly in a commercial airplane!  

Credit: Isaac Mognet (Pennsylvania State University)

Earlier versions of ISS-CREAM’s instruments were launched on these giant balloons from McMurdo Station in Antarctica seven times, starting in 2004, for a total of 191 days near the top of the atmosphere.  Each of these flights helped the team test their hardware and work towards sending a cutting-edge cosmic ray detector into space!  

How is going to space different than flying balloons?

Balloon flights allowed the team to collect a lot of cosmic rays, but even at 120,000 feet, a lot of the particles are still blocked. Scientists at the University of Maryland, College Park, who operate ISS-CREAM, expect to get about 10 times as much data from their new home on the International Space Station. 

That’s because it will be both above the atmosphere and fly far longer than is possible with a balloon. As you might imagine, there are large differences between flying something on a balloon and launching it into space. The science instruments and other systems had to be changed so ISS-CREAM could safely launch on a rocket and work in space.

What will ISS-CREAM do?

While on the space station, ISS-CREAM will collect millions of cosmic rays -- electrons, protons and atomic nuclei representing the elements found in the solar system. These results will help us understand why cosmic rays reach the wicked-fast speeds they do and, most important, what limits those speeds.

ISS-CREAM launches to the International Space Station aboard the latest SpaceX Dragon spacecraft, targeted to launch August 14. Want to learn more about ISS-CREAM and some of our scientific balloons? Check out our recent feature, NASA’s Scientific Balloon Program Reaches New Heights.

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Vote for Your Favorite Astronaut Picture: Tournament Earth 2021

It is that time of year again…Tournament Earth is back! This year, NASA Earth Observatory has chosen a new theme for the tournament: astronaut photography. Choose your favorite image here.

For more than 20 years, astronauts have been shooting photos of Earth from the International Space Station that highlight the planet’s beauty, complexity, and vulnerabilities. So which are the most unforgettable ones? Over the next five weeks (March 8-April 13), you can help decide.

How can you get involved? It's easy as 1…2…3!

1. Read and Vote.

Not sure which image to vote for because they are ALL so captivating? Read the intriguing stories behind the images to help you decide! You can access the stories by clicking on the image headlines on the voting page: https://earthobservatory.nasa.gov/tournament-earth

For instance, the Stars in Motion image is actually a compilation of 72 photographs. And some of the night lights around Bangkok, Thailand, actually show fishing boats as well as city lights.

2. Fill out your bracket.

Think you know which photo will win it all? Fill out a #TournamentEarth bracket with your predictions and challenge friends! Then share your predictions with NASAEarth on our blog, Twitter, Facebook, Instagram, or right here on Tumblr!

We can't offer a trip to the Moon, but bragging rights are forever if you can pick the champion. Download a more print-friendly version of the bracket here.

3. View the results…and vote again!

Tournament Earth will have five rounds, and round one is currently underway. Voting for the following rounds begins on Tuesdays and will be open for six days. We will update our social media channels (including right here on Tumblr!) with the newest matchups. Check this space to see how your favorite images did. Then vote until we crown a champion on April 13, 2021.

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

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A Tour of Cosmic Temperatures

We often think of space as “cold,” but its temperature can vary enormously depending on where you visit. If the difference between summer and winter on Earth feels extreme, imagine the range of temperatures between the coldest and hottest places in the universe — it’s trillions of degrees! So let’s take a tour of cosmic temperatures … from the coldest spots to the hottest temperatures yet achieved.

First, a little vocabulary: Astronomers use the Kelvin temperature scale, which is represented by the symbol K. Going up by 1 K is the same as going up 1°C, but the scale begins at 0 K, or -273°C, which is also called absolute zero. This is the temperature where the atoms in stuff stop moving. We’ll measure our temperatures in this tour in kelvins, but also convert them to make them more familiar!

We’ll start on the chilly end of the scale with our CAL (Cold Atom Lab) on the International Space Station, which can chill atoms to within one ten billionth of a degree above 0 K, just a fraction above absolute zero.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

Just slightly warmer is the Resolve sensor inside XRISM, pronounced “crism,” short for the X-ray Imaging and Spectroscopy Mission. This is an international collaboration led by JAXA (Japan Aerospace Exploration Agency) with NASA and ESA (European Space Agency). Resolve operates at one twentieth of a degree above 0 K. Why? To measure the heat from individual X-rays striking its 36 pixels!

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

Resolve and CAL are both colder than the Boomerang Nebula, the coldest known region in the cosmos at just 1 K! This cloud of dust and gas left over from a Sun-like star is about 5,000 light-years from Earth. Scientists are studying why it’s colder than the natural background temperature of deep space.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

Let’s talk about some temperatures closer to home. Icy gas giant Neptune is the coldest major planet. It has an average temperature of 72 K at the height in its atmosphere where the pressure is equivalent to sea level on Earth. Explore how that compares to other objects in our solar system!

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

How about Earth? According to NOAA, Death Valley set the world’s surface air temperature record on July 10, 1913. This record of 330 K has yet to be broken — but recent heat waves have come close. (If you’re curious about the coldest temperature measured on Earth, that’d be 183.95 K (-128.6°F or -89.2°C) at Vostok Station, Antarctica, on July 21, 1983.)

We monitor Earth's global average temperature to understand how our planet is changing due to human activities. Last year, 2023, was the warmest year on our record, which stretches back to 1880.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

The inside of our planet is even hotter. Earth’s inner core is a solid sphere made of iron and nickel that’s about 759 miles (1,221 kilometers) in radius. It reaches temperatures up to 5,600 K.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

We might assume stars would be much hotter than our planet, but the surface of Rigel is only about twice the temperature of Earth’s core at 11,000 K. Rigel is a young, blue star in the constellation Orion, and one of the brightest stars in our night sky.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger 

We study temperatures on large and small scales. The electrons in hydrogen, the most abundant element in the universe, can be stripped away from their atoms in a process called ionization at a temperature around 158,000 K. When these electrons join back up with ionized atoms, light is produced. Ionization is what makes some clouds of gas and dust, like the Orion Nebula, glow.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

We already talked about the temperature on a star’s surface, but the material surrounding a star gets much, much hotter! Our Sun’s surface is about 5,800 K (10,000°F or 5,500°C), but the outermost layer of the solar atmosphere, called the corona, can reach millions of kelvins.

Our Parker Solar Probe became the first spacecraft to fly through the corona in 2021, helping us answer questions like why it is so much hotter than the Sun's surface. This is one of the mysteries of the Sun that solar scientists have been trying to figure out for years.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

Looking for a hotter spot? Located about 240 million light-years away, the Perseus galaxy cluster contains thousands of galaxies. It’s surrounded by a vast cloud of gas heated up to tens of millions of kelvins that glows in X-ray light. Our telescopes found a giant wave rolling through this cluster’s hot gas, likely due to a smaller cluster grazing it billions of years ago.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

Now things are really starting to heat up! When massive stars — ones with eight times the mass of our Sun or more — run out of fuel, they put on a show. On their way to becoming black holes or neutron stars, these stars will shed their outer layers in a supernova explosion. These layers can reach temperatures of 300 million K!

Credit: NASA's Goddard Space Flight Center/Jeremy Schnittman

We couldn’t explore cosmic temperatures without talking about black holes. When stuff gets too close to a black hole, it can become part of a hot, orbiting debris disk with a conical corona swirling above it. As the material churns, it heats up and emits light, making it glow. This hot environment, which can reach temperatures of a billion kelvins, helps us find and study black holes even though they don’t emit light themselves.

JAXA’s XRISM telescope, which we mentioned at the start of our tour, uses its supercool Resolve detector to explore the scorching conditions around these intriguing, extreme objects.

Credit: NASA's Goddard Space Flight Center/CI Lab

Our universe’s origins are even hotter. Just one second after the big bang, our tiny, baby universe consisted of an extremely hot — around 10 billion K — “soup” of light and particles. It had to cool for a few minutes before the first elements could form. The oldest light we can see, the cosmic microwave background, is from about 380,000 years after the big bang, and shows us the heat left over from these earlier moments.

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

We’ve ventured far in distance and time … but the final spot on our temperature adventure is back on Earth! Scientists use the Large Hadron Collider at CERN to smash teensy particles together at superspeeds to simulate the conditions of the early universe. In 2012, they generated a plasma that was over 5 trillion K, setting a world record for the highest human-made temperature.

Want this tour as a poster? You can download it here in a vertical or horizontal version!

Credit: NASA's Goddard Space Flight Center/Scott Wiessinger

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