Every time you take a breath of fresh air, it’s easy to forget you can safely do so because of Earth’s atmosphere. Life on Earth could not exist without that protective cover that keeps us warm, allows us to breathe and protects us from harmful radiation—among other things.
1. On Earth, we live in the troposphere, the closest atmospheric layer to Earth’s surface. “Tropos” means “change,” and the name reflects our constantly changing weather and mixture of gases.
It’s 5 to 9 miles (8 to 14 kilometers) thick, depending on where you are on Earth, and it’s the densest layer of atmosphere. When we breathe, we’re taking in an air mixture of about 78 percent nitrogen, 21 percent oxygen and 1 percent argon, water vapor and carbon dioxide. More on Earth’s atmosphere›
2. Mars has a very thin atmosphere, nearly all carbon dioxide. Because of the Red Planet’s low atmospheric pressure, and with little methane or water vapor to reinforce the weak greenhouse effect (warming that results when the atmosphere traps heat radiating from the planet toward space), Mars’ surface remains quite cold, the average surface temperature being about -82 degrees Fahrenheit (minus 63 degrees Celsius). More on the greenhouse effect›
3. Venus’ atmosphere, like Mars’, is nearly all carbon dioxide. However, Venus has about 154,000 times more carbon dioxide in its atmosphere than Earth (and about 19,000 times more than Mars does), producing a runaway greenhouse effect and a surface temperature hot enough to melt lead. A runaway greenhouse effect is when a planet’s atmosphere and surface temperature keep increasing until the surface gets so hot that its oceans boil away. More on the greenhouse effect›
4. Jupiter likely has three distinct cloud layers (composed of ammonia, ammonium hydrosulfide and water) in its "skies" that, taken together, span an altitude range of about 44 miles (71 kilometers). The planet's fast rotation—spinning once every 10 hours—creates strong jet streams, separating its clouds into dark belts and bright zones wrapping around the circumference of the planet. More on Jupiter›
5. Saturn’s atmosphere—where our Cassini spacecraft ended its 13 extraordinary years of exploration of the planet—has a few unusual features. Its winds are among the fastest in the solar system, reaching speeds of 1,118 miles (1,800 kilometers) per hour. Saturn may be the only planet in our solar system with a warm polar vortex (a mass of swirling atmospheric gas around the pole) at both the North and South poles. Also, the vortices have “eye-wall clouds,” making them hurricane-like systems like those on Earth.
Another uniquely striking feature is a hexagon-shaped jet streamencircling the North Pole. In addition, about every 20 to 30 Earth years, Saturn hosts a megastorm (a great storm that can last many months). More on Saturn›
6. Uranus gets its signature blue-green color from the cold methane gas in its atmosphere and a lack of high clouds. The planet’s minimum troposphere temperature is 49 Kelvin (minus 224.2 degrees Celsius), making it even colder than Neptune in some places. Its winds move backward at the equator, blowing against the planet’s rotation. Closer to the poles, winds shift forward and flow with the planet’s rotation. More on Uranus›
7. Neptune is the windiest planet in our solar system. Despite its great distance and low energy input from the Sun, wind speeds at Neptune surpass 1,200 miles per hour (2,000 kilometers per hour), making them three times stronger than Jupiter’s and nine times stronger than Earth’s. Even Earth's most powerful winds hit only about 250 miles per hour (400 kilometers per hour). Also, Neptune’s atmosphere is blue for the very same reasons as Uranus’ atmosphere. More on Neptune›
8. WASP-39b, a hot, bloated, Saturn-like exoplanet (planet outside of our solar system) some 700 light-years away, apparently has a lot of water in its atmosphere. In fact, scientists estimate that it has about three times as much water as Saturn does. More on this exoplanet›
9. A weather forecast on “hot Jupiters”—blistering, Jupiter-like exoplanets that orbit very close to their stars—might mention cloudy nights and sunny days, with highs of 2,400 degrees Fahrenheit (about 1,300 degrees Celsius, or 1,600 Kelvin). Their cloud composition depends on their temperature, and studies suggest that the clouds are unevenly distributed. More on these exoplanets›
10. 55 Cancri e, a “super Earth” exoplanet (a planet outside of our solar system with a diameter between Earth’s and Neptune’s) that may be covered in lava, likely has an atmosphere containing nitrogen, water and even oxygen–molecules found in our atmosphere–but with much higher temperatures throughout. Orbiting so close to its host star, the planet could not maintain liquid water and likely would not be able to support life. More on this exoplanet›
Read the full version of this week’s Solar System 10 Things to Know HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
While the first exoplanets—planets beyond our solar system—were discovered using ground-based telescopes, the view was blurry at best. Clouds, moisture, and jittering air molecules all got in the way, limiting what we could learn about these distant worlds.
A superhero team of space telescopes has been working tirelessly to discover exoplanets and unveil their secrets. Now, a new superhero has joined the team—the James Webb Space Telescope. What will it find? Credit: NASA/JPL-Caltech
To capture finer details—detecting atmospheres on small, rocky planets like Earth, for instance, to seek potential signs of habitability—astronomers knew they needed what we might call “superhero” space telescopes, each with its own special power to explore our universe. Over the past few decades, a team of now-legendary space telescopes answered the call: Hubble, Chandra, Spitzer, Kepler, and TESS.
Much like scientists, space telescopes don't work alone. Hubble observes in visible light—with some special features (superpowers?)—Chandra has X-ray vision, and TESS discovers planets by looking for tiny dips in the brightness of stars.
Kepler and Spitzer are now retired, but we're still making discoveries in the space telescopes' data. Legends! All were used to tell us more about exoplanets. Spitzer saw beyond visible light into the infrared and was able to make exoplanet weather maps! Kepler discovered more than 3,000 exoplanets.
Three space telescopes studied one fascinating planet and told us different things. Hubble found that the atmosphere of HD 189733 b is a deep blue. Spitzer estimated its temperature at 1,700 degrees Fahrenheit (935 degrees Celsius). Chandra, measuring the planet’s transit using X-rays from its star, showed that the gas giant’s atmosphere is distended by evaporation.
Adding the James Webb Space Telescope to the superhero team will make our science stronger. Its infrared views in increased ranges will make the previously unseen visible.
Soon, Webb will usher in a new era in understanding exoplanets. What will Webb discover when it studies HD 189733 b? We can’t wait to find out! Super, indeed.
Make sure to follow us on Tumblr for your regular dose of space!
I’m sure you’re trained so that nothing in space is really a surprise, but: was there anything about spacewalking that surprised you when you did it for the first time?
With tumultuous winds peaking at 400 mph, the Great Red Spot has been swirling wildly over Jupiter’s skies for at least 150 years and possibly much longer. People saw a big spot on Jupiter as early as the 1600s when they started stargazing through telescopes, though it’s unclear whether they were looking at a different storm. Today, scientists know the Great Red Spot has been there for a while, but what causes its swirl of reddish hues remains to be discovered. More >
Despite its unofficial name, the Little Red Spot is about as wide as Earth. The storm reached its current size when three smaller spots collided and merged in the year 2000. More >
The planet’s rings might get most of the glory, but another shape’s been competing for attention: the hexagon. This jet stream is home to a massive hurricane tightly centered on the north pole, with an eye about 50 times larger than the average hurricane eye on Earth. Numerous small vortices spin clockwise while the hexagon and hurricane spin counterclockwise. The biggest of these vortices, seen near the lower right corner of the hexagon and appearing whitish, spans about 2,200 miles, approximately twice the size of the largest hurricane on Earth. More>
A tempest erupted in 2010, extending approximately 9,000 miles north-south large enough to eventually eat its own tail before petering out. The storm raged for 200 days, making it the longest-lasting, planet-encircling storm ever seen on Saturn. More >
Better cover your eyes. Dust storms are a frequent guest on the Red Planet, but one dust storm in 2001 larger by far than any seen on Earth raised a cloud of dust that engulfed the entire planet for three months. As the Sun warmed the airborne dust, the upper atmospheric temperature rose by about 80 degrees Fahrenheit. More >
Several large, dark spots on Neptune are similar to Jupiter’s hurricane-like storms. The largest spot, named the “Great Dark Spot” by its discoverers, contains a storm big enough for Earth to fit neatly inside. And, it looks to be an anticyclone similar to Jupiter’s Great Red Spot. More >
Not to be confused with Earth’s tornadoes, a stalk-like prominence rose up above the Sun, then split into about four strands that twisted themselves into a knot and dispersed over a two-hour period. This close-up shows the effect is one of airy gracefulness. More >
The storm blew across the equatorial region of Titan, creating large effects in the form of dark and likely “wet” from liquid hydrocarbons areas on the surface of the moon. The part of the storm visible here measures 750 miles in length east-to-west. The wings of the storm that trail off to the northwest and southwest from the easternmost point of the storm are each 930 miles long. More >
On March 9, 1989, a huge cloud of solar material exploded from the sun, twisting toward Earth. When this cloud of magnetized solar material called a coronal mass ejection reached our planet, it set off a chain of events in near-Earth space that ultimately knocked out an entire power grid area to the Canadian province Quebec for nine hours. More >
Back on Earth, Typhoon Tip of 1979 remains the biggest storm to ever hit our planet, making landfall in Japan. The tropical cyclone saw sustained winds peak at 190 mph and the diameter of circulation spanned approximately 1,380 miles. Fortunately, we now have plans to better predict future storms on Earth. NASA recently launched a new fleet of hurricane-tracking satellites, known as the Cyclone Global Navigation Satellite System (CYGNSS), which will use the same GPS technology you and I use in our cars to measure wind speed and ultimately improve how to track and forecast hurricanes. More >
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Our two long-running missions, Cassini and the Hubble Space Telescope, are providing new details about “ocean worlds,” specifically the moons of Jupiter and Saturn.
The details – discussed during our April 13 science briefing – included the announcement by the Cassini mission team that a key ingredient for life has been found in the ocean on Saturn's moon Enceladus.
Meanwhile, in 2016 Hubble spotted a likely plume erupting from Jupiter’s moon Europa at the same location as one in 2014, reenforcing the notion of liquid water erupting from the moon.
These observations are laying the groundwork for our Europa Clipper mission, planned for launch in the 2020s.
Shane Kimbrough and his Russian colleagues returned home safely after spending 173 days in space during his mission to the International Space Station.
Meanwhile, astronaut Peggy Whitson assumed command of the orbital platform and she and her crew await the next occupants of the station, which is slated to launch April 20.
We’ve announced the preliminary winner of the 2017 Student Launch Initiative that took place near our Marshall Space Fight Center, The final selection will be announced in May. The students showcased advanced aerospace and engineering skills by launching their respective model rockets to an altitude of one mile, deploying an automated parachute and safely landing them for re-use.
On April 11, a ground-breaking ceremony took place at our Langley Research Center for the new Systems Measurement Laboratory. The 175,000 square-foot facility will be a world class lab for the research and development of new measurement concepts, technologies and systems that will enable the to meet its missions in space explorations, science and aeronautics.
Space fans celebrated Yuri’s Night on April 12 at the Air and Space Museum and around the world. On April 12, 1961, cosmonaut Yuri Gagrin became the first person to orbit the Earth.
On April 12, 1981, John Young and Bob Crippin launched aboard Space Shuttle Columbia on STS-1 a two-day mission, the first of the Shuttle Program’s 30-year history.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
What is the weirdest thing you had to account for when building the perseverance rover?
Our Galileo spacecraft (1989-2003) detected the first evidence of an ocean beyond Earth under the ice of Jupiter's icy moon Europa.
There are signs that Mars and Venus once had oceans, but something catastrophic may have wiped them out. Earth's natural force field -- our magnetosphere -- acts like shield against the erosive force of the solar wind.
The search for life beyond Earth relies, in large part, on understanding our home planet. Among the newest Earth ocean explorers us the Cyclone Global Navigation Satellite System, or CYGNSS--a constellation of microsatellites that will make detailed measurements of wind speeds over Earth's oceans to help understand hurricanes. The spacecraft have moved into their science operations phase.
It's fitting the first mission to explore an alien ocean is named in honor of fast-sailing clipper ships of old. Our Europa Clipper spacecraft will seek signs of habitability on Jupiter's moon Europa.
Scientists expected Saturn's moon Enceladus to be a tiny, solid chunk of ice and rock. But, not long after arriving at Saturn, our Cassini spacecraft made a series of incremental discoveries, eventually confirming that a global subsurface ocean is venting into space, with signs of hydrothermal activity.
"The question of whether or not life exists beyond Earth, the question of whether or not biology works beyond our home planet, is one of humanity's oldest and yet unanswered questions. And for the first time in the history of humanity, we have the tools and technology and capability to potentially answer this question. And, we know where to go to find it. Jupiter's ocean world Europa." - Kevin Hand, NASA Astrobiologist
Scientists think Jupiter's giant moons Ganymede and Callisto also hide oceans beneath their surfaces. Elsewhere in the solar system, scientists hope to look for hidden oceans on far-flung worlds from Ceres in the main asteroid belt to Pluto in the Kuiper Belt.
Thanks to our Cassini orbiter we know the tiny moon Enceladus is venting its ocean into space in a towering, beautiful plume. The Hubble Space Telescope also has seen tantalizing hints of plumes on Jupiter's moon Europa. Plumes are useful because they provide samples of ocean chemistry for oceans that could be miles below the surface and difficult for spacecraft to reach. It's like they're giving out free samples!
Saturn's moon Titan not only has liquid hydrocarbon seas on its surface. It also shows signs of a global, subsurface saltwater ocean--making the giant moon a place to possibly look for life as we know it and life as we don't know it ... yet.
Several of the thousands of planets discovered beyond our solar system orbit their stars in zones where liquid surface water is possible--including Proxima-b, a rocky planet orbiting the star nearest to our own.
We invite everyone to help us celebrate Earth Day 2017 by virtually adopting a piece of Earth as seen from space. Your personalized adoption certificate will feature data from our Earth-observing satellites for a randomly assigned location, much of it ocean (it is 70 percent of the Earth's surface after all!). Print it and share it, then explore other locations with our interactive map and get even more Earth science data from NASA's Worldview website.
Visit go.nasa.gov/adopt to adopt your piece of the planet today!
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Planetary nebula NGC 6826 is located about 4,200 light years from Earth in Cygnus. When observers look directly at it through a small telescope, they typically see only the nebula’s sparkling-white central star. However, by averting one’s gaze, glancing away from the central star, the nebula’s bulbous dust clouds come into view. This optical trickery earned this planetary nebula the name the "Blinking Planetary.”
Over the next several thousand years, the nebula will gradually disperse into space, and then the central star will slowly cool as it radiates its energy for billions of years as a white dwarf.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Black holes, cosmic rays, neutron stars and even new kinds of physics — for 10 years, data from our Fermi Gamma-ray Space Telescope have helped unravel some of the biggest mysteries of the cosmos. And Fermi is far from finished!
On June 11, 2008, at Cape Canaveral in Florida, the countdown started for Fermi, which was called the Gamma-ray Large Area Space Telescope (GLAST) at the time.
The telescope was renamed after launch to honor Enrico Fermi, an Italian-American pioneer in high-energy physics who also helped develop the first nuclear reactor.
Fermi has had many other things named after him, like Fermi’s Paradox, the Fermi National Accelerator Laboratory, the Enrico Fermi Nuclear Generating Station, the Enrico Fermi Institute, and the synthetic element fermium.
Photo courtesy of Argonne National Laboratory
The Fermi telescope measures some of the highest energy bursts of light in the universe; watching the sky to help scientists answer all sorts of questions about some of the most powerful objects in the universe.
Its main instrument is the Large Area Telescope (LAT), which can view 20% of the sky at a time and makes a new image of the whole gamma-ray sky every three hours. Fermi’s other instrument is the Gamma-ray Burst Monitor. It sees even more of the sky at lower energies and is designed to detect brief flashes of gamma-rays from the cosmos and Earth.
This sky map below is from 2013 and shows all of the high energy gamma rays observed by the LAT during Fermi’s first five years in space. The bright glowing band along the map’s center is our own Milky Way galaxy!
Well, they’re a form of light. But light with so much energy and with such short wavelengths that we can’t see them with the naked eye. Gamma rays require a ton of energy to produce — from things like subatomic particles (such as protons) smashing into each other.
Here on Earth, you can get them in nuclear reactors and lightning strikes. Here’s a glimpse of the Seattle skyline if you could pop on a pair of gamma-ray goggles. That purple streak? That’s still the Milky Way, which is consistently the brightest source of gamma rays in our sky.
In space, you find that kind of energy in places like black holes and neutron stars. The raindrop-looking animation below shows a big flare of gamma rays that Fermi spotted coming from something called a blazar, which is a kind of quasar, which is different from a pulsar... actually, let’s back this up a little bit.
One of the sources of gamma rays that Fermi spots are pulsars. Pulsars are a kind of neutron star, which is a kind of star that used to be a lot bigger, but collapsed into something that’s smaller and a lot denser. Pulsars send out beams of gamma rays. But the thing about pulsars is that they rotate.
So Fermi only sees a beam of gamma rays from a pulsar when it’s pointed towards Earth. Kind of like how you only periodically see the beam from a lighthouse. These flashes of light are very regular. You could almost set your watch by them!
Quasars are supermassive black holes surrounded by disks of gas. As the gas falls into the black hole, it releases massive amount of energy, including — you guessed it — gamma rays. Blazars are quasars that send out beams of gamma rays and other forms of light — right in our direction.
When Fermi sees them, it’s basically looking straight down this tunnel of light, almost all the way back to the black hole. This means we can learn about the kinds of conditions in that environment when the rays were emitted. Fermi has found about 5,500 individual sources of gamma rays, and the bulk of them have been blazars, which is pretty nifty.
But gamma rays also have many other sources. We’ve seen them coming from supernovas where stars die and from star factories where stars are born. They’re created in lightning storms here on Earth, and our own Sun can toss them out in solar flares.
Gamma rays were in the news last year because of something Fermi spotted at almost the same time as the National Science Foundation (NSF)’s Laser Interferometer Gravitational-Wave Observatory (LIGO) and European Gravitational Observatory’s Virgo on August 17, 2017. Fermi, LIGO, Virgo, and numerous other observatories spotted the merger of two neutron stars. It was the first time that gravitational waves and light were confirmed to come from the same source.
Fermi has been looking at the sky for almost 10 years now, and it’s helped scientists advance our understanding of the universe in many ways. And the longer it looks, the more we’ll learn. Discover more about how we’ll be celebrating Fermi’s achievements all year.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Not long after midnight on Dec. 7, 1972, the last crewed mission to the Moon, Apollo 17, lifted off with three astronauts: Eugene Cernan, Harrison Schmitt, and Ronald Evans.
Experience the Apollo 17 launch and follow the mission in real time.
Let’s meet the astronauts who made the final Apollo trip to the Moon, including the first scientist-astronaut.
Gene Cernan: In 1972, Apollo 17 Mission Commander Eugene A. Cernan had two space flights under his belt, Gemini 9 in June 1966, and Apollo 10 in May 1969. He was a naval aviator, electrical and aeronautical engineer and fighter pilot.
Ron Evans: Apollo 17 Command Module Pilot Ronald E. Evans was selected as a member of the 4th group of NASA astronauts in 1966. Like Cernan, he was an electrical and aeronautical engineer, and naval aviator before his assignment to the Apollo 17 crew.
Harrison (Jack) Schmitt: Lunar Module Pilot Dr. Harrison (Jack) Schmitt joined NASA as a member of the first group of scientist-astronauts in 1965. Before working for NASA, Schmitt was a geologist at the USGS Astrogeology Center. He was on the backup crew for Apollo 15 before being selected for the prime crew of Apollo 17. He became the first of the scientist-astronauts to go to space and the 12th human to walk on the Moon.
“The Blue Marble,” one of the most reproduced images in history, was taken 50 years ago on Dec. 7, 1972 by the Apollo 17 crew as they made their way to the Moon.
NASA astronauts have an array of menu items to stay well fed and hydrated on missions. For Apollo 17, the menus allocated around 2,500 calories per day for each astronaut. They included:
Bacon Squares
Peanut Butter Sandwiches
Frankfurters
Lobster Bisque
Like anything going to space, weight and containment matter. That's why the Apollo 17 menu included plenty of soups and puddings.
On Dec. 11, 2022, the Artemis I mission will be splashing down on Earth after its 25.5-day mission. At 2:55 p.m. 50 years prior, the Apollo 17 lunar module (LM) landed on the Moon, with Commander Gene Cernan and LM Pilot Harrison Schmitt on board. Ron Evans remained in the Command and Service Module (CSM) orbiting the Moon.
Experience the landing.
One of the first tasks the Apollo 17 crew did on their first moonwalk was to plant the American flag. There’s no wind on the Moon, but that doesn’t mean the flag has to droop. Did you know that a horizontal rod with a latch makes the flag appear to be flying in the wind? Gene Cernan carefully composed this photo to get Schmitt, the flag, and the Earth in a single shot.
So, is the flag still there? Images of the Apollo 17 landing site from the Lunar Reconnaissance Orbiter Camera show that in 2011 the flag was still standing and casting a shadow!
During Apollo 17, the Lunar Rover Vehicle (LRV), nicknamed the Moon buggy, logged the farthest distance from the Lunar Module of any Apollo mission, about 4.7 miles (7.5 km).
As a precaution, the LRV had a walk-back limit in the event of an issue; astronauts had to have enough resources to walk back to the lunar module if need be.
The right rear fender extension of the LRV (Moon buggy) was torn off, kicking up dust as the crew drove, reducing visibility. The crew made a resourceful repair using duct tape and maps.
For LRV fans, visiting an LRV driven on the Moon is a bit difficult since all three LRVs used on the Apollo 15, 16, and 17 missions were left on the Moon. But you can find an LRV used for training at the National Air and Space Museum in Washington. Read more about the LRV.
After the first lunar EVA, Apollo 17 astronaut Harrison Schmitt reported that he suffered from “lunar hay fever” in reaction to the lunar dust. Unlike Earth’s dust particles which are rounded, Moon dust particles are sharp and abrasive, irritating astronaut eyes, nasal passages, and lungs.
Curious about how Moon dust feels and smells? Find out!
After his return to Earth, Apollo 17 astronaut Harrison Schmitt (on the right) described his time on the Moon:
“Working on the Moon is a lot of fun. It’s like walking around on a giant trampoline all the time and you’re just as strong as you were here on Earth, but you don’t weigh as much.”
After 12 days and 14 hours in space, the Apollo 17 astronauts splashed down in the Pacific Ocean at 2:25 p.m. EST on Dec. 19, 1972. It was the longest of all the Apollo missions, with the most photos taken. A recovery team was waiting on the USS Ticonderoga just 4 miles (6.4 km) away to pick up the astronauts, the lunar samples, and the Crew Module.
NASA’s Artemis Program has taken its first steps to sending humans back to the Moon with Artemis I, currently on its way back to Earth. The program plans to land humans, including the first women and person of color, on the Moon’s south polar region with its Artemis III mission, currently slated to launch in 2025.
Is aerospace history your cup of tea? Be sure to check out more from NASA’s past missions at www.nasa.gov/history.
Make sure to follow us on Tumblr for your regular dose of space!
Will Perseverance be near any other Rovers?
Explore the universe and discover our home planet with the official NASA Tumblr account
1K posts