Happy Martian New Year!

A Hitchhiker’s Ride to Space

This month, we are set to launch the latest weather satellite from the National Oceanic and Atmospheric Administration (NOAA). The Joint Polar Satellite System-1, or JPSS-1, satellite will provide essential data for timely and accurate weather forecasts and for tracking environmental events such as forest fires and droughts.

NASA Astronaut Scott Kelly shared this incredible video tonight, August 11, showing "our galactic home" with the stars of the Milky Way. Kelly is living and working off the Earth, for the Earth aboard the station for a yearlong mission. Traveling the world more than 220 miles above the Earth, and at 17,500 mph, he circumnavigates the globe more than a dozen times a day conducting research about how the body adapts and changes to living in space for a long duration.

Video credit: NASA

1,000 Days in Orbit: MAVEN’s Top 10 Discoveries at Mars

On June 17, our MAVEN (Mars Atmosphere and Volatile Evolution Mission) will celebrate 1,000 Earth days in orbit around the Red Planet.

Since its launch in November 2013 and its orbit insertion in September 2014, MAVEN has been exploring the upper atmosphere of Mars. MAVEN is bringing insight to how the sun stripped Mars of most of its atmosphere, turning a planet once possibly habitable to microbial life into a barren desert world.

Here’s a countdown of the top 10 discoveries from the mission so far:

10. Unprecedented Ultraviolet View of Mars

Revealing dynamic, previously invisible behavior, MAVEN was able to show the ultraviolet glow from the Martian atmosphere in unprecedented detail. Nightside images showed ultraviolet “nightglow” emission from nitric oxide. Nightglow is a common planetary phenomenon in which the sky faintly glows even in the complete absence of eternal light.

9. Key Features on the Loss of Atmosphere

Some particles from the solar wind are able to penetrate unexpectedly deep into the upper atmosphere, rather than being diverted around the planet by the Martian ionosphere. This penetration is allowed by chemical reactions in the ionosphere that turn the charged particles of the solar wind into neutral atoms that are then able to penetrate deeply.

8. Metal Ions

MAVEN made the first direct observations of a layer of metal ions in the Martian ionosphere, resulting from incoming interplanetary dust hitting the atmosphere. This layer is always present, but was enhanced dramatically by the close passage to Mars of Comet Siding Spring in October 2014.

7. Two New Types of Aurora

MAVEN has identified two new types of aurora, termed “diffuse” and “proton” aurora. Unlike how we think of most aurorae on Earth, these aurorae are unrelated to either a global or local magnetic field.

6. Cause of the Aurorae

These aurorae are caused by an influx of particles from the sun ejected by different types of solar storms. When particles from these storms hit the Martian atmosphere, they can also increase the rate of loss of gas to space, by a factor of ten or more.

5. Complex Interactions with Solar Wind

The interactions between the solar wind and the planet are unexpectedly complex. This results due to the lack of an intrinsic Martian magnetic field and the occurrence of small regions of magnetized crust that can affect the incoming solar wind on local and regional scales. The magnetosphere that results from the interactions varies on short timescales and is remarkably “lumpy” as a result.

4. Seasonal Hydrogen

After investigating the upper atmosphere of the Red Planet for a full Martian year, MAVEN determined that the escaping water does not always go gently into space. The spacecraft observed the full seasonal variation of hydrogen in the upper atmosphere, confirming that it varies by a factor of 10 throughout the year. The escape rate peaked when Mars was at its closest point to the sun and dropped off when the planet was farthest from the sun.

3. Gas Lost to Space

MAVEN has used measurements of the isotopes in the upper atmosphere (atoms of the same composition but having different mass) to determine how much gas has been lost through time. These measurements suggest that 2/3 or more of the gas has been lost to space.

2. Speed of Solar Wind Stripping Martian Atmosphere

MAVEN has measured the rate at which the sun and the solar wind are stripping gas from the top of the atmosphere to space today, along with details of the removal process. Extrapolation of the loss rates into the ancient past – when the solar ultraviolet light and the solar wind were more intense – indicates that large amounts of gas have been lost to space through time.

1. Martian Atmosphere Lost to Space

The Mars atmosphere has been stripped away by the sun and the solar wind over time, changing the climate from a warmer and wetter environment early in history to the cold, dry climate that we see today.

Maven will continue its observations and is now observing a second Martian year, looking at the ways that the seasonal cycles and the solar cycle affect the system.

For more information about MAVEN, visit: www.nasa.gov/maven

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How Do You Solve a Problem Like Dark Energy?

Here’s the deal — the universe is expanding. Not only that, but it’s expanding faster and faster due to the presence of a mysterious substance scientists have named “dark energy.”

But before we get to dark energy, let’s first talk a bit about the expanding cosmos. It started with the big bang — when the universe started expanding from a hot, dense state about 13.8 billion years ago. Our universe has been getting bigger and bigger ever since. Nearly every galaxy we look at is zipping away from us, caught up in that expansion!

The expansion, though, is even weirder than you might imagine. Things aren’t actually moving away from each other. Instead, the space between them is getting larger.

Imagine that you and a friend were standing next to each other. Just standing there, but the floor between you was growing. You two aren’t technically moving, but you see each other moving away. That’s what’s happening with the galaxies (and everything else) in our cosmos ... in ALL directions!

Astronomers expected the expansion to slow down over time. Why? In a word: gravity. Anything that has mass or energy has gravity, and gravity tries to pull stuff together. Plus, it works over the longest distances. Even you, reading this, exert a gravitational tug on the farthest galaxy in the universe! It’s a tiny tug, but a tug nonetheless.

As the space between galaxies grows, gravity is trying to tug the galaxies back together — which should slow down the expansion. So, if we measure the distance of faraway galaxies over time, we should be able to detect if the universe's growth rate slows down.  

But in 1998, a group of astronomers measured the distance and velocity of a number of galaxies using bright, exploding stars as their “yardstick.” They found out that the expansion was getting faster.

Not slowing down.

Speeding up.

⬆️ This graphic illustrates the history of our expanding universe. We do see some slowing down of the expansion (the uphill part of the graph, where the roller coaster is slowing down). However, at some point, dark energy overtakes gravity and the expansion speeds up (the downhill on the graph). It’s like our universe is on a giant roller coaster ride, but we’re not sure how steep the hill is!

Other researchers also started looking for signs of accelerated expansion. And they found it — everywhere. They saw it when they looked at individual stars. They saw it in large scale structures of the universe, like galaxies, galaxy groups and clusters. They even saw it when they looked at the cosmic microwave background (that’s what’s in this image), a "baby picture" of the universe from just a few hundred thousand years after the big bang.

If you thought the roller coaster was wild, hold on because things are about to get really weird.

Clearly, we were missing something. Gravity wasn’t the biggest influence on matter and energy across the largest scales of the universe. Something else was. The name we’ve given to that “something else” is dark energy.

We don’t know exactly what dark energy is, and we’ve never detected it directly. But we do know there is a lot of it. A lot. If you summed up all the “stuff” in the universe — normal matter (the stuff we can touch or observe directly), dark matter, and dark energy — dark energy would make up more than two-thirds of what is out there.

That’s a lot of our universe to have escaped detection!

Researchers have come up with a few dark energy possibilities. Einstein discarded an idea from his theory of general relativity about an intrinsic property of space itself. It could be that this bit of theory got dark energy right after all. Perhaps instead there is some strange kind of energy-fluid that fills space. It could even be that we need to tweak Einstein’s theory of gravity to work at the largest scales.  

We’ll have to stay tuned as researchers work this out.

Our Wide Field Infrared Survey Telescope (WFIRST) — planned to launch in the mid-2020s — will be helping with the task of unraveling the mystery of dark energy. WFIRST will map the structure and distribution of matter throughout the cosmos and across cosmic time. It will also map the universe’s expansion and study galaxies from when the universe was a wee 2-billion-year-old up to today. Using these new data, researchers will learn more than we’ve ever known about dark energy. Perhaps even cracking open the case!

You can find out more about the history of dark energy and how a number of different pieces of observational evidence led to its discovery in our Cosmic Times series. And keep an eye on WFIRST to see how this mystery unfolds.

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What's a day working at NASA like??

Is your only job helping astronauts and satellites or does NASA do other thing too?

How to Connect with NASA

We're the nation’s space agency, but that doesn’t mean you have to travel to the depths of the universe to stay connected with the awesome stuff we’re doing. There are actually some really easy ways to stay updated on all things space. Check them out:

Apps

We have lots of apps for smartphones and tablets that will make it easier than ever to stay connected to space. Here are a few to pique your interest:  

NASA App: Showcases a huge collection of the latest content, including images, videos, mission information, stories, space station sighting opportunities and more! Download: Apple/Android

NASA Spinoff App: This application profiles the best examples of technology that have been transferred from NASA research and missions into commercial products. From life-saving satellite systems to hospital robots, our technologies benefit society. Download: Apple

NASA 3DV App: The 3DV mobile app allows you to examine several of our Deep Space Exploration projects that will take our space program to asteroids, Mars and beyond! Download: Apple/Android

Spacecraft 3D: This augmented reality (AR) application lets you learn about and interact with a variety of spacecraft that are used to explore our solar system, study Earth and observe the universe. Download: Apple/Android

Competitions and Challenges

NASA Solve is an invitation to members of the public to contribute their time and expertise to solving problems and potentially winning prizes as a result of their work. This is a great way for individual members of the public to be a part of the nation’s space program. For a complete list of current challenges and competitions, visit THIS page.

Citizen Science

You don’t have to be a NASA employee to engage in the fun of interpreting scientific data and imagery from our many spacecraft and missions. As part of our Open Government plan, our goal is to promote transparency, participation and collaboration. By expanding the research base and using open innovation, we are all able to benefit from the accumulated findings. You can find data from our missions, research and activities HERE.

Email and Social Media

We have a wide-range of social media accounts here at NASA. Everything from Earth Science to the Mars Curiosity Rover, you can stay updated on many of our missions on many popular social media sites. For a full list of our accounts, visit THIS page.

If you’d like to get space news delivered straight to your inbox, you can sign up for updates and manage preferences HERE.

NASA Socials

What is a NASA Social? We’re glad you asked! These programs provide opportunities for our social media followers to learn and share information about our missions, people and programs. NASA Social includes both special in-person events and social media credentials for individuals who share the news in a significant way. Social events provide the participants with the opportunity to go behind-the-scenes at our facilities and events and speak with scientists engineers, astronauts and managers. Visit THIS page for a list of upcoming NASA Social opportunities.

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Six Answers to Questions You’re Too Embarrassed to Ask about the Hottest Year on Record

You may have seen the news that 2023 was the hottest year in NASA’s record, continuing a trend of warming global temperatures. But have you ever wondered what in the world that actually means and how we know?

We talked to some of our climate scientists to get clarity on what a temperature record is, what happened in 2023, and what we can expect to happen in the future… so you don’t have to!

1. Why was 2023 the warmest year on record?

The short answer: Human activities. The release of greenhouse gases like carbon dioxide and methane into the atmosphere trap more heat near Earth’s surface, raising global temperatures. This is responsible for the decades-long warming trend we’re living through.

But this year’s record wasn’t just because of human activities. The last few years, we’ve been experiencing the cooler phase of a natural pattern of Pacific Ocean temperatures called the El Niño Southern Oscillation (ENSO). This phase, known as La Niña, tends to cool temperatures slightly around the world. In mid-2023, we started to shift into the warmer phase, known as El Niño. The shift ENSO brought, combined with overall human-driven warming and other factors we’re continuing to study, pushed 2023 to a new record high temperature.

2. So will every year be a record now?

Almost certainly not. Although the overall trend in annual temperatures is warmer, there’s some year-to-year variation, like ENSO we mentioned above.

Think about Texas and Minnesota. On the whole, Texas is warmer than Minnesota. But some days, stormy weather could bring cooler temperatures to Texas while Minnesota is suffering through a local heat wave. On those days, the weather in Minnesota could be warmer than the weather in Texas. That doesn’t mean Minnesota is warmer than Texas overall; we’re just experiencing a little short-term variation.

Something similar happens with global annual temperatures. The globe will naturally shift back to La Niña in the next few years, bringing a slight cooling effect. Because of human carbon emissions, current La Niña years will be warmer than La Niña years were in the past, but they’ll likely still be cooler than current El Niño years.

3. What do we mean by “on record”?

Technically, NASA’s global temperature record starts in 1880. NASA didn’t exist back then, but temperature data were being collected by sailing ships, weather stations, and scientists in enough places around the world to reconstruct a global average temperature. We use those data and our modern techniques to calculate the average.

We start in 1880, because that’s when thermometers and other instruments became technologically advanced and widespread enough to reliably measure and calculate a global average. Today, we make those calculations based on millions of measurements taken from weather stations and Antarctic research stations on land, and ships and ocean buoys at sea. So, we can confidently say 2023 is the warmest year in the last century and a half.

However, we actually have a really good idea of what global climate looked like for tens of thousands of years before 1880, relying on other, indirect ways of measuring temperature. We can look at tree rings or cores drilled from ice sheets to reconstruct Earth’s more ancient climate. These measurements affirm that current warming on Earth is happening at an unprecedented speed.

4. Why does a space agency keep a record of Earth’s temperature?

It’s literally our job! When NASA was formed in 1958, our original charter called for “the expansion of human knowledge of phenomena in the atmosphere and space.” Our very first space missions uncovered surprises about Earth, and we’ve been using the vantage point of space to study our home planet ever since. Right now, we have a fleet of more than 20 spacecraft monitoring Earth and its systems.

Why we created our specific surface temperature record – known as GISTEMP – actually starts about 25 million miles away on the planet Venus. In the 1960s and 70s, researchers discovered that a thick atmosphere of clouds and carbon dioxide was responsible for Venus’ scorchingly hot temperatures.

Dr. James Hansen was a scientist at the Goddard Institute for Space Studies in New York, studying Venus. He realized that the greenhouse effect cooking Venus’ surface could happen on Earth, too, especially as human activities were pumping carbon dioxide into our atmosphere.

He started creating computer models to see what would happen to Earth’s climate as more carbon dioxide entered the atmosphere. As he did, he needed a way to check his models – a record of temperatures at Earth’s surface over time, to see if the planet was indeed warming along with increased atmospheric carbon. It was, and is, and NASA’s temperature record was born.

5. If last year was record hot, why wasn’t it very hot where I live?

The temperature record is a global average, so not everywhere on Earth experienced record heat. Local differences in weather patterns can influence individual locations to be hotter or colder than the globe overall, but when we average it out, 2023 was the hottest year.

Just because you didn’t feel record heat this year, doesn’t mean you didn’t experience the effects of a warming climate. 2023 saw a busy Atlantic hurricane season, low Arctic sea ice, raging wildfires in Canada, heat waves in the U.S. and Australia, and more.

And these effects don’t stay in one place. For example, unusually hot and intense fires in Canada sent smoke swirling across the entire North American continent, triggering some of the worst air quality in decades in many American cities. Melting ice at Earth’s poles drives rising sea levels on coasts thousands of miles away.

6. Speaking of which, why is the Arctic – one of the coldest places on Earth – red on this temperature map?

Our global temperature record doesn’t actually track absolute temperatures. Instead, we track temperature anomalies, which are basically just deviations from the norm. Our baseline is an average of the temperatures from 1951-1980, and we compare how much Earth’s temperature has changed since then. 

Why focus on anomalies, rather than absolutes? Let’s say you want to track if apples these days are generally larger, smaller, or the same size as they were 20 years ago. In other words, you want to track the change over time.

Apples grown in Florida are generally larger than apples grown in Alaska. Like, in real life, how Floridian temperatures are generally much higher than Alaskan temperatures. So how do you track the change in apple sizes from apples grown all over the world while still accounting for their different baseline weights? 

By focusing on the difference within each area rather than the absolute weights. So in our map, the Arctic isn’t red because it’s hotter than Bermuda. It’s red because it’s gotten relatively much warmer than Bermuda has in the same time frame.

Want to learn more about climate change? Dig into the data at climate.nasa.gov.

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The Legacy of Viking

On this day in 1976, we landed an ambitious mission on Mars –– the Viking 2 mission.

One of a pair of identical spacecraft, Viking found a place in history when it became the first U.S. mission to successfully land on Mars and return images of the surface.

Viking imaged and collected different types of data on the Martian surface. It also conducted experiments specifically designed to look for possible signs of life.

These experiments discovered unexpected chemical activity in the Martian soil but provided no clear evidence for the presence of living microorganisms.

Viking didn’t find unambiguous signs of life on Mars, but it made astrobiologists wonder if we devised the right tests. To this day, the results from Viking are helping to shape the development of life detection strategies at NASA.

So, what’s next in our search for life?

Our Mars 2020 Perseverance rover is the first mission designed to seek possible signs of past Martian life. For astrobiologists, the answers to questions about Mars’ habitability are in Perseverance’s “hands.” The robot astrobiologist and geologist launched earlier this year on July 30 and will touch down on Mars on Feb. 18, 2021.

Discover more about Viking and the history of exploration at Mars with our “Missions To Mars” graphic history novel here.

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Water, Water Everywhere; We Track Drops to Drink!

When we think about what makes a planet habitable, we’re often talking about water. With abundant water in liquid, gas (vapor) and solid (ice) form, Earth is a highly unusual planet. Almost 70% of our home planet’s surface is covered in water!

But about 97% of Earth’s water is salty – only a tiny amount is freshwater: the stuff humans, pets and plants need to survive.

Water on our planet is constantly moving, and not just geographically. Water shifts phases from ice to water to vapor and back, moving through the planet’s soils and skies as it goes.

That’s where our satellites come in.

Look at the Midwestern U.S. this spring, for example. Torrential rain oversaturated the soil and overflowed rivers, which caused severe flooding, seen by Landsat.

Our satellites also tracked a years-long drought in California. Between 2013 and 2014, much of the state turned brown, without visible green.  

It’s not just rain. Where and when snow falls – and melts – is changing, too. The snow that falls and accumulates on the ground is called snowpack, which eventually melts and feeds rivers used for drinking water and crop irrigation. When the snow doesn’t fall, or melts too early, communities go without water and crops don’t get watered at the right time.

Even when water is available, it can become contaminated by blooms of phytoplankton, like cyanobacteria . Also known as blue-green algae, these organisms can make humans sick if they drink the water. Satellites can help track algae from space, looking for the brightly colored blooms against blue water.

Zooming even farther back, Earth’s blue water is visible from thousands of miles away. The water around us makes our planet habitable and makes our planet shine blue among the darkness of space.

Knowing where the water is, and where it’s going, helps people make better decisions about how to manage it. Earth’s climate is changing rapidly, and freshwater is moving as a result. Some places are getting drier and some are getting much, much wetter. By predicting droughts and floods and tracking blooms of algae, our view of freshwater around the globe helps people manage their water.

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