(via https://www.youtube.com/watch?v=QMs7sWGm9q0)
1. What a Long, Strange—and Revealing—Trip It’s Been
As the Cassini mission builds toward its climactic “Grand Finale,” we’re taking a look back at the epic story of its journey among Saturn’s mini-solar system of rings and moons.
+ Traverse the timeline
2. Our Very Own Moon
Unlike Saturn, Earth has only one moon. Let’s celebrate it! International Observe the Moon Night (InOMN) is a worldwide, public celebration of lunar science and exploration held annually. On Oct. 8, everyone on Earth is invited to observe and learn about the moon together, and to celebrate the cultural and personal connections we all have with it.
+ Join in
3. What’s Up, October?
Even more about Earth’s moon is the subject of this month’s video guide for sky watchers and includes a look at the moon’s phases and when to observe them. Also featured are a guide to upcoming meteor showers and tips on how to catch a glimpse of Saturn.
+ Take a look
4. Nine Lives
Dawn’s discoveries continue, even as the asteroid belt mission marks nine years in space. “For such an overachiever,” writes Dawn’s top scientist, “it’s fitting that now, on its ninth anniversary, the spacecraft is engaged in activities entirely unimagined on its eighth.”
+ Learn more
5. The Incredible Shrinking Mercury
It’s small, it’s hot, and it’s shrinking. Research funded by us suggests that Mercury is contracting even today. This means we now know that Mercury joins Earth as a tectonically active planet.
+ Get the small details
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The Andromeda Galaxy is 2 million light years away from us so what we see now is how it appeared 2 million years ago. It will collide with our Milky Way in 2 billions years from now. The two galaxies are heading towards each other at a rate of 430 km/hr. A billion years from now Andromeda will loom as a spectacular site, eventually swelling to fill half of the night sky.
This month (March 2016), in the journal Science, New Horizons scientists have authored the first comprehensive set of papers describing results from last summer’s Pluto system flyby. These detailed papers completely transform our view of Pluto and reveal the former “astronomer’s planet” to be a real world with diverse and active geology, exotic surface chemistry, a complex atmosphere, puzzling interaction with the sun and an intriguing system of small moons.
1. Pluto has been geologically active throughout the past 4 billion years. The age-dating of Pluto’s surface through crater counts has revealed that Pluto has been geologically active throughout the past 4 billion years. Further, the surface of Pluto’s informally-named Sputnik Planum, a massive ice plain larger than Texas, is devoid of any detectable craters and estimated to be geologically young – no more than 10 million years old.
2. Pluto’s moon Charon has been discovered to have an ancient surface. As an example, the great expanse of smooth plains on Charon is likely a vast cryovolcanic flow or flows that erupted onto Charon’s surface about 4 billion years ago. These flows are likely related to the freezing of an internal ocean that globally ruptured Charon’s crust.
3. Pluto’s surface has many types of terrain. The distribution of compositional units on Pluto’s surface – from nitrogen-rich, to methane-rich, to water-rich – has been found to be surprisingly complex, creating puzzles for understanding Pluto’s climate and geologic history. The variations in surface composition on Pluto are unprecedented elsewhere in the outer solar system.
4. Pluto’s atmosphere is colder than we thought. Pluto’s upper atmospheric temperature has been found to be much colder (by about 70 degrees Fahrenheit) than had been thought from Earth-based studies, with important implications for its atmospheric escape rate. Why the atmosphere is colder is a mystery.
5. We know what Pluto’s atmosphere is made of. The New Horizon spacecraft made observations of sunlight passing through Pluto’s atmosphere. We see absorption features that indicate an atmosphere made up of nitrogen (like Earth’s) with methane, acetylene and ethylene as minor constituents.
6. We might have an idea for how Pluto’s haze formed. For first time, a plausible mechanism for forming Pluto’s atmospheric haze layers has been found. This mechanism involves the concentration of haze particles by atmospheric buoyancy waves, created by winds blowing over Pluto’s mountainous topography. Pluto’s haze extends hundreds of kilometers into space, and embedded within it are over 20 very thin, but far brighter, layers.
7. There isn’t much dust around Pluto. Before the flyby, there was concern that a small piece of debris (even the size of a grain of sand) could cause great damage to (or even destroy) the spacecraft. But the Venetia Burney Student Dust Counter (an instrument on the New Horizons spacecraft) only counted a single dust particle within five days of the flyby. This is similar to the density of dust particles in free space in the outer solar system – about 6 particles per cubic mile – showing that the region around Pluto is, in fact, not filled with debris.
8. Pluto’s atmosphere is smaller than we expected. The uppermost region of Pluto’s atmosphere is slowly escaping to space. The hotter the upper atmosphere, the more rapid the gasses escape. The lower the planet’s mass, the lower the gravity, and the faster the atmospheric loss. As molecules escape, they are ionized by solar ultraviolet light. Once ionized, the charged molecules are carried away by the solar wind. As more Pluto-genic material is picked up by the solar wind, the more the solar wind is slowed down and deflected around Pluto. So - the net result is a region (the interaction region), which is like a blunt cone pointed toward the sun, where the escaping ionized gasses interact with the solar wind. The cone extends to a distance about 6 Pluto radii from Pluto toward the sun, but extend behind Pluto at least 400 Pluto radii behind Pluto - like a wake behind the dwarf planet.
9. Pluto’s moons are brighter than we thought. The high albedos (reflectiveness) of Pluto’s small satellites (moons) – about 50 to 80 percent – are entirely different from the much lower reflectiveness of the small bodies in the general Kuiper Belt population, which range from about 5 to 20 percent. This difference lends further support to the idea that these moons were not captured from the general Kuiper Belt population, but instead formed by the collection of material produced in the aftermath of the giant collision that created the entire Pluto satellite system.
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In case you don’t know, the Juno spacecraft entered orbit around the gas giant on July 4, 2016…about a year ago. Since then, it has been collecting data and images from this unique vantage point.
Juno is in a polar orbit around Jupiter, which means that the majority of each orbit is spent well away from the gas giant. But once every 53 days its trajectory approaches Jupiter from above its north pole, where it begins a close two-hour transit flying north to south with its eight science instruments collecting data and its JunoCam camera snapping pictures.
Space Fact: The download of six megabytes of data collected during the two-hour transit can take one-and-a-half days!
Juno and her cloud-piercing science instruments are helping us get a better understanding of the processes happening on Jupiter. These new results portray the planet as a complex, gigantic, turbulent world that we still need to study and unravel its mysteries.
Juno’s imager, JunoCam, has showed us that both of Jupiter’s poles are covered in tumultuous cyclones and anticyclone storms, densely clustered and rubbing together. Some of these storms as large as Earth!
These storms are still puzzling. We’re still not exactly sure how they formed or how they interact with each other. Future close flybys will help us better understand these mysterious cyclones.
Seen above, waves of clouds (at 37.8 degrees latitude) dominate this three-dimensional Jovian cloudscape. JunoCam obtained this enhanced-color picture on May 19, 2017, at 5:50 UTC from an altitude of 5,500 miles (8,900 kilometers). Details as small as 4 miles (6 kilometers) across can be identified in this image.
An even closer view of the same image shows small bright high clouds that are about 16 miles (25 kilometers) across and in some areas appear to form “squall lines” (a narrow band of high winds and storms associated with a cold front). On Jupiter, clouds this high are almost certainly comprised of water and/or ammonia ice.
Juno’s Microwave Radiometer is an instrument that samples the thermal microwave radiation from Jupiter’s atmosphere from the tops of the ammonia clouds to deep within its atmosphere.
Data from this instrument suggest that the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred kilometers. In the cut-out image below, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange.
Why does this ammonia matter? Well, ammonia is a good tracer of other relatively rare gases and fluids in the atmosphere…like water. Understanding the relative abundances of these materials helps us have a better idea of how and when Jupiter formed in the early solar system.
This instrument has also given us more information about Jupiter’s iconic belts and zones. Data suggest that the belt near Jupiter’s equator penetrates all the way down, while the belts and zones at other latitudes seem to evolve to other structures.
Prior to Juno, it was known that Jupiter had the most intense magnetic field in the solar system…but measurements from Juno’s magnetometer investigation (MAG) indicate that the gas giant’s magnetic field is even stronger than models expected, and more irregular in shape.
At 7.766 Gauss, it is about 10 times stronger than the strongest magnetic field found on Earth! What is Gauss? Magnetic field strengths are measured in units called Gauss or Teslas. A magnetic field with a strength of 10,000 Gauss also has a strength of 1 Tesla.
Juno is giving us a unique view of the magnetic field close to Jupiter that we’ve never had before. For example, data from the spacecraft (displayed in the graphic above) suggests that the planet’s magnetic field is “lumpy”, meaning its stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action (where the motion of electrically conducting fluid creates a self-sustaining magnetic field) closer to the surface, above the layer of metallic hydrogen. Juno’s orbital track is illustrated with the black curve.
Juno also observed plasma wave signals from Jupiter’s ionosphere. This movie shows results from Juno’s radio wave detector that were recorded while it passed close to Jupiter. Waves in the plasma (the charged gas) in the upper atmosphere of Jupiter have different frequencies that depend on the types of ions present, and their densities.
Mapping out these ions in the jovian system helps us understand how the upper atmosphere works including the aurora. Beyond the visual representation of the data, the data have been made into sounds where the frequencies and playback speed have been shifted to be audible to human ears.
The complexity and richness of Jupiter’s “southern lights” (also known as auroras) are on display in this animation of false-color maps from our Juno spacecraft. Auroras result when energetic electrons from the magnetosphere crash into the molecular hydrogen in the Jovian upper atmosphere. The data for this animation were obtained by Juno’s Ultraviolet Spectrograph.
During Juno’s next flyby on July 11, the spacecraft will fly directly over one of the most iconic features in the entire solar system – one that every school kid knows – Jupiter’s Great Red Spot! If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno.
Learn more about the Juno spacecraft and its mission at Jupiter HERE.
1. Amateur" Means “One Who Loves”
We release thousands of breathtaking solar system images every year and not all of them are the exclusive result of work by scientists. Amateur image processors around the world take raw data from deep space missions and turn it into striking visuals.
Amateur images from Cassini
Get current unprocessed images
2. Prepare to Weigh Anchor
OSIRIS-REx, our first spacecraft destined to rendezvous with, study and return a sample of an asteroid, will launch. The mission to asteroid Bennu will yield the largest sample returned from space since the Apollo era. Tune in four our media briefing about OSIRIS-REx for 2 p.m. EDT on Aug. 17.
Learn more and tune in.
3. Out for a Walk
Join us for live coverage on Aug. 19 as our astronauts Jeff Williams and Kate Rubins install a new gateway for American commercial crew spacecraft at the International Space Station.
Live coverage of the spacewalk.
4. The Weather Out There
Aug. 17 marks 50 years since the launch of Pioneer 7, a robotic spacecraft that lived up to its name by exploring the solar magnetic field, the solar wind and cosmic rays in deep space. Along with Pioneers 6, 8, and 9, the spacecraft formed a ring of solar weather stations spaced along Earth’s orbit. Measurements by the craft were used to predict solar storms for organizations ranging from commercial airlines to power companies.
Learn more.
5. Destination: The Red Planet
The European Space Agency’s ExoMars/Trace Gas Orbiter mission to Mars performed a critical engine burn to keep it on course. The maneuver was a success, and ExoMars remains on target for an October arrival.
Learn more.
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A map of our galaxy the Milky Way, showing pulsars (red), planetary nebulae (blue), globular clusters (yellow), and the orbits of several stars
The title says it all...MAKING Video Games...FOR NASA! :)
Dark, cold and whipped by supersonic winds, Neptune is the last of the hydrogen and helium gas giants in our solar system. More than 30 times as far from the sun as Earth, the planet takes almost 165 Earth years to orbit our sun! In fact, in 2011, Neptune completed its first orbit since its discovery in 1846.
Here are a few things you might not know about the windiest planet:
If the sun were as tell as a typical front door, the Earth would be the size of a nickel and Neptune would be about as big as a baseball.
Neptune orbits our sun, a star. Neptune is the eighth planet from the sun at a distance of about 4.5 billion km (2.8 billion miles) or 30.07 AU.
One day on Neptune takes about 16 hours (the time it takes for Neptune to rotate or spin once)
Neptune makes a complete orbit around the sun (a year in Neptunian time) in about 165 Earth years (60,190 Earth days)
Neptune has six rings
Voyager 2 is the only spacecraft to have visited Neptune
Neptune has 13 moons. They are named after various sea gods and nymphs in Greek mythology
Did you know that Neptune has storms?
Similar to Jupiter, Neptune has storms that create gigantic spots in its atmosphere…well, it did. When Voyager 2 flew past Neptune in 1989, it tracked and imaged the “Great Dark Spot” — a storm larger than the entire Earth! When the Hubble Space Telescope imaged Neptune the spot had disappeared, only to be replaced with two smaller storms, which in turn also disappeared.
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A 3D tour of the path taken by Mark Watney in “The Martian” was recently added to the Mars Trek page. It includes commentary from NASA experts. Use the tutorial to learn how to navigate. @NASAEPDC