Every Day Is Asteroid Day At NASA

The Special Ingredients…of Earth!

With its blue skies, puffy white clouds, warm beaches and abundant life, planet Earth is a pretty special place. A quick survey of the solar system reveals nothing else like it. But how special is Earth, really?

One way to find out is to look for other worlds like ours elsewhere in the galaxy. Astronomers using our Kepler Space Telescope and other observatories have been doing just that! 

In recent years they’ve been finding other planets increasingly similar to Earth, but still none that appear as hospitable as our home world. For those researchers, the search goes on.

Another group of researchers have taken on an entirely different approach. Instead of looking for Earth-like planets, they’ve been looking for Earth-like ingredients. Consider the following:

Our planet is rich in elements such as carbon, oxygen, iron, magnesium, silicon and sulfur…the stuff of rocks, air, oceans and life. Are these elements widespread elsewhere in the universe? 

To find out, a team of astronomers led by the Japanese Aerospace Exploration Agency (JAXA), with our participation, used Suzaku. This Japanese X-ray satellite was used to survey a cluster of galaxies located in the direction of the constellation Virgo.

The Virgo cluster is a massive swarm of more than 2,000 galaxies, many similar in appearance to our own Milky Way, located about 54 million light years away. The space between the member galaxies is filled with a diffuse gas, so hot that it glows in X-rays. Instruments onboard Suzaku were able to look at that gas and determine which elements it’s made of.

Reporting their findings in the Astrophysical Journal Letters, they reported findings of iron, magnesium, silicon and sulfur throughout the Virgo galaxy cluster. The elemental ratios are constant throughout the entire volume of the cluster, and roughly consistent with the composition of the sun and most of the stars in our own galaxy.

When the Universe was born in the Big Bang 13.8 billon years ago, elements heavier than carbon were rare. These elements are present today, mainly because of supernova explosions. 

Massive stars cook elements such as, carbon, oxygen, iron, magnesium, silicon and sulfur in their hot cores and then spew them far and wide when the stars explode.

According to the observations of Suzaku, the ingredients for making sun-like stars and Earth-like planets have been scattered far and wide by these explosions. Indeed, they appear to be widespread in the cosmos. The elements so important to life on Earth are available on average and in similar relative proportions throughout the bulk of the universe. In other words, the chemical requirements for life are common.

Earth is still special, but according to Suzaku, there might be other special places too. Suzaku recently completed its highly successful mission.

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How long did it take to build the rover??

Three NASA Telescopes Look at an Angry Young Star Together

Science is a shared endeavor. We learn more when we work together. Today, July 18, we’re using three different space telescopes to observe the same star/planet system!

As our Transiting Exoplanet Survey Satellite (TESS) enters its third year of observations, it's taking a new look at a familiar system this month. And today it won't be alone. Astronomers are looking at AU Microscopii, a young fiery nearby star – about 22 million years old – with the TESS, NICER and Swift observatories.

TESS will be looking for more transits – the passage of a planet across a star – of a recently-discovered exoplanet lurking in the dust of AU Microscopii (called AU Mic for short). Astronomers think there may be other worlds in this active system, as well!

Our Neutron star Interior Composition Explorer (NICER) telescope on the International Space Station will also focus on AU Mic today. While NICER is designed to study neutron stars, the collapsed remains of massive stars that exploded as supernovae, it can study other X-ray sources, too. Scientists hope to observe stellar flares by looking at the star with its high-precision X-ray instrument.

Scientists aren't sure where the X-rays are coming from on AU Mic — it could be from a stellar corona or magnetic hot spots. If it's from hot spots, NICER might not see the planet transit, unless it happens to pass over one of those spots, then it could see a big dip!

A different team of astronomers will use our Neil Gehrels Swift Observatory to peer at AU Mic in X-ray and UV to monitor for high-energy flares while TESS simultaneously observes the transiting planet in the visible spectrum. Stellar flares like those of AU Mic can bathe planets in radiation.

Studying high-energy flares from AU Mic with Swift will help us understand the flare-rate over time, which will help with models of the planet’s atmosphere and the system’s space weather. There's even a (very) small chance for Swift to see a hint of the planet's transit!

The flares that a star produces can have a direct impact on orbiting planets' atmospheres. The high-energy photons and particles associated with flares can alter the chemical makeup of a planet's atmosphere and erode it away over time.

Another time TESS teamed up with a different spacecraft, it discovered a hidden exoplanet, a planet beyond our solar system called AU Mic b, with the now-retired Spitzer Space Telescope. That notable discovery inspired our latest poster! It’s free to download in English and Spanish.

Spitzer’s infrared instrument was ideal for peering at dusty systems! Astronomers are still using data from Spitzer to make discoveries. In fact, the James Webb Space Telescope will carry on similar study and observe AU Mic after it launches next year.

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May the Four Forces Be With You!

May the force be with you? Much to learn you still have, padawan. In our universe it would be more appropriate to say, “May the four forces be with you.”

There are four fundamental forces that bind our universe and its building blocks together. Two of them are easy to spot — gravity keeps your feet on the ground while electromagnetism keeps your devices running. The other two are a little harder to see directly in everyday life, but without them, our universe would look a lot different!

Let’s explore these forces in a little more detail.

Gravity: Bringing the universe together

If you jump up, gravity brings you back down to Earth. It also keeps the solar system together … and our galaxy, and our local group of galaxies and our supercluster of galaxies.

Gravity pulls everything together. Everything, from the bright centers of the universe to the planets farthest from them. In fact, you (yes, you!) even exert a gravitational force on a galaxy far, far away. A tiny gravitational force, but a force nonetheless.

Credit: NASA and the Advanced Visualization Laboratory at the National Center for Supercomputing and B. O'Shea, M. Norman

Despite its well-known reputation, gravity is actually the weakest of the four forces. Its strength increases with the mass of the two objects involved. And its range is infinite, but the strength drops off as the square of the distance. If you and a friend measured your gravitational tug on each other and then doubled the distance between you, your new gravitational attraction would just be a quarter of what it was. So, you have to be really close together, or really big, or both, to exert a lot of gravity.

Even so, because its range is infinite, gravity is responsible for the formation of the largest structures in our universe! Planetary systems, galaxies and clusters of galaxies all formed because gravity brought them together.

Gravity truly surrounds us and binds us together.

Electromagnetism: Lighting the way

You know that shock you get on a dry day after shuffling across the carpet? The electricity that powers your television? The light that illuminates your room on a dark night? Those are all the work of electromagnetism. As the name implies, electromagnetism is the force that includes both electricity and magnetism.

Electromagnetism keeps electrons orbiting the nucleus at the center of atoms and allows chemical compounds to form (you know, the stuff that makes up us and everything around us). Electromagnetic waves are also known as light. Once started, an electromagnetic wave will travel at the speed of light until it interacts with something (like your eye) — so it will be there to light up the dark places.

Like gravity, electromagnetism works at infinite distances. And, also like gravity, the electromagnetic force between two objects falls as the square of their distance. However, unlike gravity, electromagnetism doesn't just attract. Whether it attracts or repels depends on the electric charge of the objects involved. Two negative charges or two positive charges repel each other; one of each, and they attract each other. Plus. Minus. A balance.

This is what happens with common household magnets. If you hold them with the same “poles” together, they resist each other. On the other hand, if you hold a magnet with opposite poles together — snap! — they’ll attract each other.

Electromagnetism might just explain the relationship between a certain scruffy-looking nerf-herder and a princess.

Strong Force: Building the building blocks

Credit: Lawrence Livermore National Laboratory

The strong force is where things get really small. So small, that you can’t see it at work directly. But don’t let your eyes deceive you. Despite acting only on short distances, the strong force holds together the building blocks of the atoms, which are, in turn, the building blocks of everything we see around us.

Like gravity, the strong force always attracts, but that’s really where their similarities end. As the name implies, the force is strong with the strong force. It is the strongest of the four forces. It brings together protons and neutrons to form the nucleus of atoms — it has to be stronger than electromagnetism to do it, since all those protons are positively charged. But not only that, the strong force holds together the quarks — even tinier particles — to form those very protons and neutrons.

However, the strong force only works on very, very, very small distances. How small? About the scale of a medium-sized atom’s nucleus. For those of you who like the numbers, that’s about 10-15 meters, or 0.000000000000001 meters. That’s about a hundred billion times smaller than the width of a human hair! Whew.

Its tiny scale is why you don’t directly see the strong force in your day-to-day life. Judge a force by its physical size, do you? 

Weak Force: Keeping us in sunshine

If you thought it was hard to see the strong force, the weak force works on even smaller scales — 1,000 times smaller. But it, too, is extremely important for life as we know it. In fact, the weak force plays a key role in keeping our Sun shining.

But what does the weak force do? Well … that requires getting a little into the weeds of particle physics. Here goes nothing! We mentioned quarks earlier — these are tiny particles that, among other things, make up protons and neutrons. There are six types of quarks, but the two that make up protons and neutrons are called up and down quarks. The weak force changes one quark type into another. This causes neutrons to decay into protons (or the other way around) while releasing electrons and ghostly particles called neutrinos.

So for example, the weak force can turn a down quark in a neutron into an up quark, which will turn that neutron into a proton. If that neutron is in an atom’s nucleus, the electric charge of the nucleus changes. That tiny change turns the atom into a different element! Such reactions are happening all the time in our Sun, giving it the energy to shine.

The weak force might just help to keep you in the (sun)light.

All four of these forces run strong in the universe. They flow between all things and keep our universe in balance. Without them, we’d be doomed. But these forces will be with you. Always.

You can learn more about gravity from NASA’s Space Place and follow NASAUniverse on Twitter or Facebook to learn about some of the cool cosmic objects we study with light.

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Solar System: From TED Talks to Data Releases

Let us lead you on a journey of our solar system. Here are some things to know this week:

1. NASA-Funded Research

It’s all just a click way with the launch of a new public access site, which reflects our ongoing commitment to provide public access to science data.

Start Exploring!

2.  Red Planet Reconnaissance 

One of the top places in our solar system to look for signs of past or current life is Mars. Through our robotic missions, we have been on and around Mars for 40 years. These orbiters, landers and rovers are paving the way for human exploration.

Meet the Mars robots

3. Three Moons and a Planet that Could Have Alien Life

In a presentation at TED Talks Live, our director of planetary science, Jim Green, discusses the best places to look for alien life in our solar system.

Watch the talk

4. Setting Free a Dragon

Tune in to NASA TV on Friday, Aug. 26 at 5:45 a.m. EDT for coverage of the release of the SpaceX Dragon CRS-9 cargo ship from the International Space Station.

Watch live

5. Anniversary Ring(s)

Aug. 26 marks 35 years since Voyager probe flew by Saturn, delighting scientists with rich data and images. Today, thanks to our Cassini spacecraft, we know much more about the ringed planet.

Learn more about Cassini’s mission to Saturn

Learn more about Voyager 2

Discover the full list of 10 things to know about our solar system this week HERE.

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How does time work in a black hole?

5 Myths About Becoming a Flight Director

Have you ever wondered if you have what it takes to become a NASA Flight Director? 

They are historically well known for making difficult calls and guiding the crew through "Houston, we've had a problem" situations, but in all spaceflight operations, they are ultimately responsible for the success of the mission.

We're looking for a new class of Flight Directors to join our team, and there are a few things to know.

Here are a few myths about becoming a Flight Director:

MYTH: You have to have already been a flight controller in Mission Control at NASA to become a flight director.

FACT: Although many flight directors have previously been NASA flight controllers, that is not a prerequisite to apply. The necessary experience could come from the military, other spaceflight organizations or areas that operate in similar high-stakes conditions.

MYTH: You have to already have a special spaceship flying license to apply.

FACT: The only place to get certified is on the job at NASA. Once chosen, the new flight directors will receive training on flight control and vehicle systems, as well as operational leadership and risk management.

MYTH: All flight directors have advanced degrees like, a PhD.

FACT: While a Bachelor's degree in engineering, biological science, physical science, computer science or mathematics from an accredited university is necessary, an advanced degree is not required to become a flight director.

MYTH: Flight directors are required to have experience in the space industry.

FACT: While you need at least three years of related, progressively responsible professional experience to apply, it can come from a variety of industries as long as it represents time-critical decision-making experience in high-stress, high-risk environments.

MYTH: Only astronauts become flight directors and vice versa.

FACT: To date, only one astronaut, T.J. Creamer, has become a flight director, and no flight directors have become astronauts. However, members of the flight controller teams have become astronauts. The "capsule communicator," or CAPCOM, role in Mission Control is more often filled by astronauts because the CAPCOM is the one responsible for relaying the flight director's decisions to the astronauts in space.

Okay, but What are the requirements?

Basic Qualification Requirements

Applicants must meet the following minimum requirements before submitting an application:

Be a U.S. citizen.

Have a Bachelor's degree from an accredited institution in engineering, biological science, physical science, computer science or math.

Have at least three years of related, progressively responsible professional experience.

Applications for our next Flight Director class open on Dec. 3, 2021 and close Dec. 16, 2021! Visit: go.nasa.gov/FlightDirector

Learn more about what Flight Directors do with our Everything About Mission Control Houston video featuring Flight Director Mary Lawrence!

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NASA Spotlight: Astronaut Andrew Feustel

Andrew J. Feustel was selected by NASA in 2000. The Lake Orion, Michigan native has a Ph.D. in the Geological Sciences, specializing in Seismology, and is a veteran of three spaceflights. In 2009, Dr. Feustel served on space shuttle mission STS-125. That mission was the fifth and final mission to service the Hubble Space Telescope that improved the observatory’s capabilities through 2014! Feustel most recently served as Commander on the International Space Station from March 21 through October 4, 2018. In his free time, Dr. Feustel enjoys auto restoration, guitar, water and snow skiing and is a fan of automotive and motorcycle racing.  

He took some time from his job as a NASA astronaut to answer a few questions about his life and career! Enjoy:

While attending Oakland Community College, you worked as an auto mechanic. How does that job and the skills you learned relate to your job now as an astronaut?

I’ve often told people that I believe having this skillset is almost as important as my training in college and university. I relied on those skills almost every day in space and even on the ground while preparing for missions. That skillset has been really helpful in understanding how to maintain and repair equipment for spaceflight. In general, having those general skills of knowing how things fit together, what the structure is, and how things work, even without knowing anything about the particular item, is very helpful in life.

Has there ever been a time as a NASA Astronaut where you had to overcome self-doubt and if so, how did you?

Yes, probably the most impactful time I had to overcome self-doubt was on my very first mission as a rookie doing a spacewalk for the first time and having to make a repair on the Hubble Space Telescope. Since it was my first spacewalk, I didn’t know if I could do it and didn’t know how I would do. However, I had trained for that mission for three years and the training took over when I started the spacewalk. At that point, I didn’t focus on my self-doubt, I focused on my training and was able to carry out the tasks.

What are you most excited about for the upcoming Artemis Moon missions?

I am most excited about the possibility of humans establishing the ability to live off of our planet. To have the capability to exist on another surface. That, to me, is a start. Humans need that capability for us to live on the Moon then to go to Mars.

What did living in space teach you about community and teamwork?

Not just living in space, but working at NASA and training for space missions taught me a lot about community and teamwork. Living in space allows you to use the skills you learn about teamwork while training. While living in space you must rely on each other for everything. It’s important to recognize the value of working as a team. All of the astronauts have a very different mix of skills and that’s a great thing about the astronaut corps. Being successful and staying alive in space relies on community and teamwork.

What kind of impact did living and working in space have on how you view the Earth?

I am more aware of the fragility of our planet and species which is why humans should extend past the Earth. We are fragile as a planet and the Earth is vulnerable to the impacts of us living here. We cannot have zero impact on the planet, we will always have some impact, but the goal is to lessen the damage that we do to Earth to allow us to live here indefinitely if possible.

What or who inspired you to apply to be an astronaut?

I was inspired by reading the obituary of my great-great uncle. He was very successful in the utilities and railroad industry in the Midwest. Reading about his successes made me believe that I could do anything. I was also interested in space travel from a young age. I believed that I would be involved in the space industry. The motivation of understanding what family members had done before me really encouraged me to reach for my dreams and apply.

What book, movie, or show about space and/or astronauts is the most accurate? The least accurate? You wish was accurate?

I’m less concerned about the accuracy of space and space exploration portrayed in movies, but more interested with the creative thought behind them and I am fascinated with ideas and imagination of the people making these movies. Things portrayed as science fiction in the past become science fact in the future.

What's the most common misconception about astronauts / working at NASA?

The most common misconception about astronauts is that we go on spaceflights often. Over 95% of our job is spent working on the ground. People should come to this job because it’s important to space and space exploration. The job entails so much more than going into space yourself, but the good news is it’s all awesome. I have never been bored at my job. There are so many exciting parts of this work that contribute to NASA missions even if it doesn’t always mean being in space.

Can you share your favorite photo or video that you took in space?

My favorite photo is this one of Michigan and Canada. It captures my life – where I lived and everyone that I know and my family and friends – that’s where I consider home. It’s such a beautiful image.

That’s a wrap! Thank you Dr. Feustel for your time! 

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10 Things Einstein Got Right

One hundred years ago, on May 29, 1919, astronomers observed a total solar eclipse in an ambitious  effort to test Albert Einstein’s general theory of relativity by seeing it in action. Essentially, Einstein thought space and time were intertwined in an infinite “fabric,” like an outstretched blanket. A massive object such as the Sun bends the spacetime blanket with its gravity, such that light no longer travels in a straight line as it passes by the Sun.

This means the apparent positions of background stars seen close to the Sun in the sky – including during a solar eclipse – should seem slightly shifted in the absence of the Sun, because the Sun’s gravity bends light. But until the eclipse experiment, no one was able to test Einstein’s theory of general relativity, as no one could see stars near the Sun in the daytime otherwise.

The world celebrated the results of this eclipse experiment— a victory for Einstein, and the dawning of a new era of our understanding of the universe.

General relativity has many important consequences for what we see in the cosmos and how we make discoveries in deep space today. The same is true for Einstein's slightly older theory, special relativity, with its widely celebrated equation E=mc². Here are 10 things that result from Einstein’s theories of relativity:

1. Universal Speed Limit

Einstein's famous equation E=mc² contains "c," the speed of light in a vacuum. Although light comes in many flavors – from the rainbow of colors humans can see to the radio waves that transmit spacecraft data – Einstein said all light must obey the speed limit of 186,000 miles (300,000 kilometers) per second. So, even if two particles of light carry very different amounts of energy, they will travel at the same speed.

This has been shown experimentally in space. In 2009, our Fermi Gamma-ray Space Telescope detected two photons at virtually the same moment, with one carrying a million times more energy than the other. They both came from a high-energy region near the collision of two neutron stars about 7 billion years ago. A neutron star is the highly dense remnant of a star that has exploded. While other theories posited that space-time itself has a "foamy" texture that might slow down more energetic particles, Fermi's observations found in favor of Einstein.

2. Strong Lensing

Just like the Sun bends the light from distant stars that pass close to it, a massive object like a galaxy distorts the light from another object that is much farther away. In some cases, this phenomenon can actually help us unveil new galaxies. We say that the closer object acts like a “lens,” acting like a telescope that reveals the more distant object. Entire clusters of galaxies can be lensed and act as lenses, too.

When the lensing object appears close enough to the more distant object in the sky, we actually see multiple images of that faraway object. In 1979, scientists first observed a double image of a quasar, a very bright object at the center of a galaxy that involves a supermassive black hole feeding off a disk of inflowing gas. These apparent copies of the distant object change in brightness if the original object is changing, but not all at once, because of how space itself is bent by the foreground object’s gravity.

Sometimes, when a distant celestial object is precisely aligned with another object, we see light bent into an “Einstein ring” or arc. In this image from our Hubble Space Telescope, the sweeping arc of light represents a distant galaxy that has been lensed, forming a “smiley face” with other galaxies.

3. Weak Lensing

When a massive object acts as a lens for a farther object, but the objects are not specially aligned with respect to our view, only one image of the distant object is projected. This happens much more often. The closer object’s gravity makes the background object look larger and more stretched than it really is. This is called “weak lensing.”

Weak lensing is very important for studying some of the biggest mysteries of the universe: dark matter and dark energy. Dark matter is an invisible material that only interacts with regular matter through gravity, and holds together entire galaxies and groups of galaxies like a cosmic glue. Dark energy behaves like the opposite of gravity, making objects recede from each other. Three upcoming observatories -- Our Wide Field Infrared Survey Telescope, WFIRST, mission, the European-led Euclid space mission with NASA participation, and the ground-based Large Synoptic Survey Telescope --- will be key players in this effort. By surveying distortions of weakly lensed galaxies across the universe, scientists can characterize the effects of these persistently puzzling phenomena.

Gravitational lensing in general will also enable NASA’s James Webb Space telescope to look for some of the very first stars and galaxies of the universe.

4. Microlensing

So far, we’ve been talking about giant objects acting like magnifying lenses for other giant objects. But stars can also “lens” other stars, including stars that have planets around them. When light from a background star gets “lensed” by a closer star in the foreground, there is an increase in the background star’s brightness. If that foreground star also has a planet orbiting it, then telescopes can detect an extra bump in the background star’s light, caused by the orbiting planet. This technique for finding exoplanets, which are planets around stars other than our own, is called “microlensing.”

Our Spitzer Space Telescope, in collaboration with ground-based observatories, found an “iceball” planet through microlensing. While microlensing has so far found less than 100 confirmed planets,  WFIRST could find more than 1,000 new exoplanets using this technique.

5. Black Holes

The very existence of black holes, extremely dense objects from which no light can escape, is a prediction of general relativity. They represent the most extreme distortions of the fabric of space-time, and are especially famous for how their immense gravity affects light in weird ways that only Einstein’s theory could explain.

In 2019 the Event Horizon Telescope international collaboration, supported by the National Science Foundation and other partners, unveiled the first image of a black hole’s event horizon, the border that defines a black hole’s “point of no return” for nearby material. NASA's Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR), Neil Gehrels Swift Observatory, and Fermi Gamma-ray Space Telescope all looked at the same black hole in a coordinated effort, and researchers are still analyzing the results.

6. Relativistic Jets

This Spitzer image shows the galaxy Messier 87 (M87) in infrared light, which has a supermassive black hole at its center. Around the black hole is a disk of extremely hot gas, as well as two jets of material shooting out in opposite directions. One of the jets, visible on the right of the image, is pointing almost exactly toward Earth. Its enhanced brightness is due to the emission of light from particles traveling toward the observer at near the speed of light, an effect called “relativistic beaming.” By contrast, the other jet is invisible at all wavelengths because it is traveling away from the observer near the speed of light. The details of how such jets work are still mysterious, and scientists will continue studying black holes for more clues. 

7. A Gravitational Vortex

Speaking of black holes, their gravity is so intense that they make infalling material “wobble” around them. Like a spoon stirring honey, where honey is the space around a black hole, the black hole’s distortion of space has a wobbling effect on material orbiting the black hole. Until recently, this was only theoretical. But in 2016, an international team of scientists using European Space Agency's XMM-Newton and our Nuclear Spectroscopic Telescope Array (NUSTAR) announced they had observed the signature of wobbling matter for the first time. Scientists will continue studying these odd effects of black holes to further probe Einstein’s ideas firsthand.

Incidentally, this wobbling of material around a black hole is similar to how Einstein explained Mercury’s odd orbit. As the closest planet to the Sun, Mercury feels the most gravitational tug from the Sun, and so its orbit’s orientation is slowly rotating around the Sun, creating a wobble.

 8. Gravitational Waves

Ripples through space-time called gravitational waves were hypothesized by Einstein about 100 years ago, but not actually observed until recently. In 2016, an international collaboration of astronomers working with the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors announced a landmark discovery: This enormous experiment detected the subtle signal of gravitational waves that had been traveling for 1.3 billion years after two black holes merged in a cataclysmic event. This opened a brand new door in an area of science called multi-messenger astronomy, in which both gravitational waves and light can be studied.

For example, our telescopes collaborated to measure light from two neutron stars merging after LIGO detected gravitational wave signals from the event, as announced in 2017. Given that gravitational waves from this event were detected mere 1.7 seconds before gamma rays from the merger, after both traveled 140 million light-years, scientists concluded Einstein was right about something else: gravitational waves and light waves travel at the same speed.

9. The Sun Delaying Radio Signals

Planetary exploration spacecraft have also shown Einstein to be right about general relativity. Because spacecraft communicate with Earth using light, in the form of radio waves, they present great opportunities to see whether the gravity of a massive object like the Sun changes light’s path.  

In 1970, our Jet Propulsion Laboratory announced that Mariner VI and VII, which completed flybys of Mars in 1969, had conducted experiments using radio signals — and also agreed with Einstein. Using NASA’s Deep Space Network (DSN), the two Mariners took several hundred radio measurements for this purpose. Researchers measured the time it took for radio signals to travel from the DSN dish in Goldstone, California, to the spacecraft and back. As Einstein would have predicted, there was a delay in the total roundtrip time because of the Sun’s gravity. For Mariner VI, the maximum delay was 204 microseconds, which, while far less than a single second, aligned almost exactly with what Einstein’s theory would anticipate.

In 1979, the Viking landers performed an even more accurate experiment along these lines. Then, in 2003 a group of scientists used NASA’s Cassini Spacecraft to repeat these kinds of radio science experiments with 50 times greater precision than Viking. It’s clear that Einstein’s theory has held up! 

10. Proof from Orbiting Earth

In 2004, we launched a spacecraft called Gravity Probe B specifically designed to watch Einstein’s theory play out in the orbit of Earth. The theory goes that Earth, a rotating body, should be pulling the fabric of space-time around it as it spins, in addition to distorting light with its gravity.

The spacecraft had four gyroscopes and pointed at the star IM Pegasi while orbiting Earth over the poles. In this experiment, if Einstein had been wrong, these gyroscopes would have always pointed in the same direction. But in 2011, scientists announced they had observed tiny changes in the gyroscopes’ directions as a consequence of Earth, because of its gravity, dragging space-time around it.

BONUS: Your GPS! Speaking of time delays, the GPS (global positioning system) on your phone or in your car relies on Einstein’s theories for accuracy. In order to know where you are, you need a receiver – like your phone, a ground station and a network of satellites orbiting Earth to send and receive signals. But according to general relativity, because of Earth’s gravity curving spacetime, satellites experience time moving slightly faster than on Earth. At the same time, special relativity would say time moves slower for objects that move much faster than others.

When scientists worked out the net effect of these forces, they found that the satellites’ clocks would always be a tiny bit ahead of clocks on Earth. While the difference per day is a matter of millionths of a second, that change really adds up. If GPS didn’t have relativity built into its technology, your phone would guide you miles out of your way!

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One Hot Year after Another

Globally, 2020 was the hottest year on record, effectively tying 2016, the previous record. Overall, Earth’s average temperature has risen more than 2 degrees Fahrenheit since the 1880s.

Temperatures are increasing due to human activities, specifically emissions of greenhouse gases, like carbon dioxide and methane. 

Heat and the energy it carries are what drive our planet: winds, weather, droughts, floods, and more are expressions of heat. The right amount of heat is even one of the things that makes life on Earth possible. But too much heat is changing the way our planet’s systems act.

My World’s on Fire

Higher temperatures drive longer, more intense fire seasons. As rain and snowfall patterns change, some regions are getting drier and more vulnerable to damage, setting the stage for more fires.

2020 saw several record-breaking fires, both in Australia in the beginning of the year, and in the western U.S. through northern summer and fall. Smoke from fires in both regions reached so high into the atmosphere that it formed clouds and continues to travel around the globe today.

In the Siberian Arctic, unusually high temperatures helped drive at least 19 fires in the region. More than half of them were burning peat soil -- decomposed organic materials -- that stores a lot of carbon. Peat fires release vast amounts of carbon into the atmosphere, potentially leading to even more warming.

The Water’s Getting Warm

It wasn’t just fire seasons setting records. 2020 had more named tropical storms in the Atlantic and more storms making landfall in the U.S. than any hurricane season on record.

Hurricanes rely on warm ocean water as fuel, and this year, the Atlantic provided. 30 named storms weren’t the only things that made this year’s hurricane season notable.

Storms like Eta, Delta, and Iota quickly changed from smaller, weaker tropical storms into more destructive hurricanes. This rapid intensification is complicated, but it’s likely that warmer, more humid weather -- a result of climate change -- helps drive it.

The Ice Is Getting Thin

Add enough heat, and even the biggest chunk of ice will melt. That’s true whether we’re talking about the ice cubes in your glass or the vast sheets of ice at our planet’s poles. Right now, the Arctic region is warming about three times faster than the rest of our planet, which has some major effects both locally and globally.

This year, Arctic sea ice hit a near-record low. Sea ice is actually made of frozen ocean water, and it grows and thaws with the seasons, typically reaching an annual minimum extent in September.

Warmer ocean water led to more ice melting this year, and 2020’s annual minimum extent continued a long trend of shrinking Arctic sea ice extent.

A Long Trend

We study Earth and how it’s changing from the ground, the sky, and space. Using data from sensors all around the planet, we calculate the global average temperature, working with our partners at NOAA.

Many other organizations also track global temperature using their own instruments and methods, and they all match remarkably well. The last seven years were the hottest seven years on record. Earth is getting warmer.

We also study the effects of increasing temperatures, like the melting sea ice and longer fire seasons mentioned above. Additionally, we can study the cause of climate change from space, with a bird’s eye view of increasing carbon in the atmosphere.

The planet is changing because of human activities. We’re working together with other agencies to monitor changes and understand what this means for people in the future.

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