Sit back, relax, and get ready to learn some science and engineering! Experts Sarah Stewart Johnson and Lauren DuCharme are here to talk about the July 30 launch of our Perseverance mission, women in STEM, and much more.
Our Answer Time starts now!
As our Cassini spacecraft enters its final 20 months before its plunge into Saturn, the mission’s science team has selected their top 10 images from 2015 (above), a year of historic discoveries, as well as the top science results (below). Take a look:
1. First Deep Seafloor Hydrothermal Vents Found Beyond Earth
Cassini found the first evidence of active hot-water chemistry beyond planet Earth. An extensive, four-year analysis of data from the spacecraft, computer simulations and laboratory experiments led researchers to the conclusion the tiny silica (SiCO2) grains most likely form when hot water containing dissolved minerals from the moon’s rocky interior travels upward, coming into contact with cooler water.
2. Global Ocean Beneath Enceladus’ Surface
A global ocean lies beneath the icy crust of Saturn’s geologically active moon Enceladus. Scientists analyzed more than seven years’ worth of images of Enceladus taken by the spacecraft, which has been orbiting Saturn since mid-2004. As a result, they found Enceladus has a tiny, but measurable wobble as it orbits Saturn. This proves that there must be a global layer of liquid separating the surface from the core.
3. Titan Observed Outside of Saturnian Magnetosphere
During Cassini’s flyby of Titan, the giant moon happened to be on the sunward side of Saturn when a powerful outburst of solar activity reached the planet. The strong surge in the solar wind so compressed the sun-facing side of Saturn’s magnetosphere that the bubble’s outer edge was pushed inside the orbit of Titan. This left the moon exposed to, and unprotected from, the raging stream of energetic solar particles. The region of space dominated by Saturn’s magnetic field is called the magnetosphere.
4. Density of a Ring Particles May Indicate Recent Origins
Saturn’s A ring was found to be warmer than expected at the planet’s equinox, and also had an unusually large thermal asymmetry about the equinox. This could be due to the A ring being mostly composed of denser particles made primarily of solid ice, with a thin top layer of fluffy regolith.
5. Titan Southern Polar Ice Cloud
Scientists have detected a monstrous new cloud of frozen compounds in Titan’s low- to mid-stratosphere – a stable atmospheric region above the troposphere, or active weather layer.
6. Curtain Vents on Enceladus?
New research using data from Cassini suggests most of the eruptions from Saturn’s moon Enceladus might actually be diffuse curtains rather than discrete jets. Many features that appear to be individuals jets of material erupting along the length of prominent “tiger stripe” fractures in the moon’s south polar region might be phantoms created by an optical illusion, according to the new study.
7. Discovery of Tethys Red Arcs
Like graffiti sprayed by an unknown artist, unexplained arc-shaped, reddish streaks are visible on the surface of Saturn’s icy moon Tethys. The origin of the features and their reddish color is a mystery to scientists.
8. Saturn’s 30-year Giant Storms Powered by Water Convection
Changes in temperature and the composition of the hydrogen-laden air within the remnants of a giant storm system on Saturn reveal that air was lofted more than 120 miles in altitude from the deeper water condensation levels.
9. Seasonal Change Seen at Saturn’s Poles
Saturn’s polar regions have displayed extreme seasonal changes during Cassini’s decade-long watch, providing the most comprehensive view ever obtained of seasonal change on a giant planet.
10. Huygens Probe Imaging Mosaic of Titan’s Surface and Descent Movie
Ten years ago, an explorer from Earth, the Huygens probe, was released from the Cassini spacecraft and parachuted into the haze of an alien moon toward an uncertain fate. After a gentle descent lasting more than two hours, it landed with a thud on a frigid floodplain on Titan, surrounded by icy cobblestones.
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who was your biggest inspiration, if any, and what events led you to follow this career choice?
Questions coming up from….
@maybeinanotherworld: JWST IS HAPPENING! How are all of you feeling about this?
@Anonymous: How powerful is this telescope, exactly?
@Anonymous: Why are the mirrors on it yellow?
@foeofcolor: How long is this estimated to last for? Like how long will it be able to function in space by estimates?
The boundary between Earth and space is complicated and constantly changing. Unlike the rest of the atmosphere, the upper atmosphere near the edge of space has a mix of both neutral particles similar to the air we breathe, as well as electrically charged particles called ions. Changes in this region are unpredictable, but they can affect satellites and garble signals, like GPS, that pass through this region. That’s why we’re launching ICON (the Ionospheric Connection Explorer) to get our first-ever comprehensive look at our interface to space.
About 60 miles above Earth’s surface, Earth’s atmosphere gives way to space. The change is gradual: The gases of the atmosphere get steadily thinner the higher you go. On the edge of space, the Sun’s radiation cooks some of those thin gases until they lose an electron (or two or three), creating a population of electrically charged particles swarming alongside the neutral particles. These charged particles make up the ionosphere.
Because the particles of the ionosphere are electrically charged, they respond uniquely to electric and magnetic fields. Dynamic conditions in space — including shifting fields and surges of charged particles, collectively called space weather — induce shifts in the ionosphere that can have far-reaching effects. The ionosphere is where space weather manifests on Earth, and it’s inextricably connected with the neutral upper atmosphere — so distortions in one part affect the other.
Changes in the ionosphere and upper atmosphere — including sudden shifts in composition, density, temperature, and conductivity — can affect satellites, building up electric charge that has the potential to disrupt instruments, and garble signals like those used by GPS satellites. Predicting these variances is hard, because the causes are so complex: They’re driven not only by space weather — usually a product of solar activity — but also by regular weather down near Earth’s surface.
Differences in pressure caused by events like hurricanes, or even something as simple as a sustained wind over a mountain range, can ripple upwards until they reach this region and trigger fluctuations. Weather’s influence on the upper atmosphere was only discovered in the past ten years or so — and ICON is the first mission designed specifically to look at that interaction.
ICON carries four types of instruments to study the ionosphere and upper atmosphere. Three of them rely on taking far-away pictures of something called airglow, a faint, global glow produced by reactive compounds in the upper atmosphere. The fourth type collects and analyzes particles directly.
MIGHTI (the Michelson Interferometer for Global High-resolution Thermospheric Imaging) uses Doppler shift — the same effect that makes a siren change pitch as an ambulance passes you — to precisely track the speed and direction of upper-atmosphere winds.
FUV (the Far Ultraviolet instrument) measures airglow produced by certain types of oxygen and nitrogen molecules on Earth’s day side, as well as oxygen ions on Earth’s night side.
EUV (the Extreme Ultraviolet instrument) measures shorter wavelengths of light than FUV. Airglow measured by EUV is produced by oxygen ions on Earth’s day side, which make up the lion’s share of Earth’s daytime ionosphere.
The two identical IVMs (Ion Velocity Meters) make very precise measurements of the angle at which ionized gas enters the instruments, helping us build up a picture of how this ionized gas around the spacecraft is moving.
We’re launching ICON on June 14 Eastern Time on an Orbital ATK Pegasus XL rocket from Kwajalein Atoll in the Marshall Islands, which will deploy from Orbital’s L-1011 Stargazer aircraft. NASA TV will cover the launch — stay tuned to nasa.gov/live for updates and follow the mission on Twitter and Facebook.
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To celebrate National Intern Day, we asked interns to share how they got their internship and their perspective and advice to the next generation of prospective NASA interns.
Meet our interns and check out their suggestions for the next generation.
Sarah is a summer Surface Tension Driven Convection Experiment Data Intern at NASA. Her inspiration for applying for an internship came from a passion for science from an early age. “I grew up in a family that liked, enjoyed and appreciated science and the fun of it all,” she recalls. “I grew up watching PBS, NOVA, and other science shows, so when I saw NASA had opportunities for students like me, I was very interested.”
Sarah’s advice to the next generation of NASA interns is one of perseverance and resilience.
Nicholas is a summer Attitude Control Engineering Intern at NASA. He wants to contribute to scientific innovation and discovery. “Overall, what inspired me to apply and come to work here was to contribute to the scientific exploration of space while learning about unique perspectives and innovative space discoveries.”
Nicholas’s advice for prospective NASA interns is to make the most out of your time here and to be a curious and eager learner.
“Use all the resources that are at your center and ask questions about projects you are working on. Don’t be afraid to talk to your mentor about your plans for the future and ask for any advice you may need, as they are more than willing to help you during your time here,” says Nicholas.
Nicholas and his mentor, Brent Faller, are using software to inform design decisions on a variety of spacecraft.
As an American Indian College Fund ambassador and a Navajo engineer, Nylana Murphy hopes her internship story will inspire others to pursue a career in aerospace.
After attending the American Indian Science Engineering Society Conference, Nylana secured an internship in the additive manufacturing research laboratory at NASA Marshall.
“My internships have helped me get to where I am,” she says, “There is a career for everyone, where their dreams can become reality. Those dreams WILL become a reality.”
You might be wondering: what happens after a NASA internship Here’s what two of our former interns did.
Lorel interned at NASA JPL in 2003, and at NASA Goddard in 2004. She earned science degrees from both the University of Kansas and Purdue University.
As a research and project engineer, O’Hara reported for duty in August 2017 and completed two years of training as an Astronaut Candidate. She is projected to fly in Soyuz missions as a NASA astronaut soon.
If she could go back in time, Loral says she would tell her younger self to enjoy the opportunities that come her way—and never stop looking for new ones. “Enjoy the whole journey of…figuring out what it is that you like to do and exploring all different kinds of things.”
The “7 Minutes of Terror” video piqued Jeff Carlson’s interest in working at JPL. He thought, "That's the coolest thing I've ever heard of. I've got to go be a part of that in some way." While interning at the Jet Propulsion Laboratory, he worked on Starshade, a sunflower-shaped device used to block starlight in order to reveal planets orbiting a star. Later, he went on to work on the team tasked with assembling and testing the “head” and “neck” (officially called the Remote Sensing Mast) for the Mars 2020 rover.
Want to join us in exploring the secrets of the universe? Visit intern.nasa.gov to learn more about open opportunities and requirements!
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Credits: Isabel Rodriguez, Glenn Research Center intern and Claire O'Shea, Johnson Space Center intern
We’ve just added two more science missions to our lineup! The two selected missions have the potential to open new windows on one of the earliest eras in the history of our solar system – a time less than 10 millions years after the birth of our sun.
The missions, known as Lucy and Psyche, were chosen from five finalists and will proceed to mission formulation.
Lucy, a robotic spacecraft, will visit a target-rich environment of Jupiter’s mysterious Trojan asteroids. Scheduled to launch in October 2021, the spacecraft is slated to arrive at its first destination, a main asteroid belt, in 2025.
Then, from 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.
Studying these Trojan asteroids will give us valuable clues to deciphering the history of the early solar system.
The Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the sun than is the Earth. The asteroid measures about 130 miles in diameter and, unlike most other asteroids that are rocky or icy bodies, it is thought to be comprised of mostly metallic iron and nickel, similar to Earth’s core.
Scientists wonder whether psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.
The mission will help scientists understand how planets and other bodies separated into their layers early in their histories. The Psyche robotic mission is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025.
Get even more information about these two new science missions HERE.
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As an astronaut who has been on a spacewalk before, what does the all-woman spacewalk mean to you?
Once in how much time does a solar eclipse happen?
It depends on where you are. You can check out our interactive map here https://eclipse2017.nasa.gov/sites/default/files/interactive_map/index.html
On Sept. 15, 2017, our Cassini spacecraft ended its epic exploration of Saturn with a planned dive into the planet’s atmosphere–sending back new science to the very last second. The spacecraft is gone, but the science continues!
New research emerging from the final orbits represents a huge leap forward in our understanding of the Saturn system -- especially the mysterious, never-before-explored region between the planet and its rings. Some preconceived ideas are turning out to be wrong while new questions are being raised. How did they form? What holds them in place? What are they made of?
Six teams of researchers are publishing their work Oct. 5 in the journal Science, based on findings from Cassini's Grand Finale. That's when, as the spacecraft was running out of fuel, the mission team steered Cassini spectacularly close to Saturn in 22 orbits before deliberately vaporizing it in a final plunge into the atmosphere in September 2017.
Knowing Cassini's days were numbered, its mission team went for gold. The spacecraft flew where it was never designed to fly. For the first time, it probed Saturn's magnetized environment, flew through icy, rocky ring particles and sniffed the atmosphere in the 1,200-mile-wide (2,000-kilometer-wide) gap between the rings and the cloud tops. Not only did the engineering push the spacecraft to its limits, the new findings illustrate how powerful and agile the instruments were.
Many more Grand Finale science results are to come, but today's highlights include:
Complex organic compounds embedded in water nanograins rain down from Saturn's rings into its upper atmosphere. Scientists saw water and silicates, but they were surprised to see also methane, ammonia, carbon monoxide, nitrogen and carbon dioxide. The composition of organics is different from that found on moon Enceladus – and also different from those on moon Titan, meaning there are at least three distinct reservoirs of organic molecules in the Saturn system.
For the first time, Cassini saw up close how rings interact with the planet and observed inner-ring particles and gases falling directly into the atmosphere. Some particles take on electric charges and spiral along magnetic-field lines, falling into Saturn at higher latitudes -- a phenomenon known as "ring rain." But scientists were surprised to see that others are dragged quickly into Saturn at the equator. And it's all falling out of the rings faster than scientists thought -- as much as 10,000 kg of material per second.
Scientists were surprised to see what the material looks like in the gap between the rings and Saturn's atmosphere. They knew that the particles throughout the rings ranged from large to small. They thought material in the gap would look the same. But the sampling showed mostly tiny, nanograin- and micron-sized particles, like smoke, telling us that some yet-unknown process is grinding up particles. What could it be? Future research into the final bits of data sent by Cassini may hold the answer.
Saturn and its rings are even more interconnected than scientists thought. Cassini revealed a previously unknown electric current system that connects the rings to the top of Saturn's atmosphere.
Scientists discovered a new radiation belt around Saturn, close to the planet and composed of energetic particles. They found that while the belt actually intersects with the innermost ring, the ring is so tenuous that it doesn’t block the belt from forming.
Unlike every other planet with a magnetic field in our Solar System, Saturn's magnetic field is almost completely aligned with its spin axis. Think of the planet and the magnetic field as completely separate things that are both spinning. Both have the same center point, but they each have their own axis about which they spin. But for Saturn the two axes are essentially the same – no other planet does that, and we did not think it was even possible for this to happen. This new data shows a magnetic-field tilt of less than 0.0095 degrees. (Earth's magnetic field is tilted 11 degrees from its spin axis.) According to everything scientists know about how planetary magnetic fields are generated, Saturn should not have one. It's a mystery physicists will be working to solve.
Cassini flew above Saturn's magnetic poles, directly sampling regions where radio emissions are generated. The findings more than doubled the number of reported crossings of radio sources from the planet, one of the few non-terrestrial locations where scientists have been able to study a mechanism believed to operate throughout the universe. How are these signals generated? That’s still a mystery researchers are looking to uncover.
For the Cassini mission, the science rolling out from Grand Finale orbits confirms that the calculated risk of diving into the gap -- skimming the upper atmosphere and skirting the edge of the inner rings -- was worthwhile.
Almost everything going on in that region turned out to be a surprise, which was the importance of going there, to explore a place we'd never been before. And the expedition really paid off!
Analysis of Cassini data from the spacecraft’s instruments will be ongoing for years to come, helping to paint a clearer picture of Saturn.
To read the papers published in Science, visit: URL to papers
To learn more about the ground-breaking Cassini mission and its 13 years at Saturn, visit: https://www.nasa.gov/mission_pages/cassini/main/index.html
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On May 22 Mars will be at opposition. That's when Mars, Earth and the sun all line up, with Earth directly in the middle. A few days later, Mars and Earth will reach the points in their orbits around the sun where they are nearest to each other. The closer Mars comes to Earth in its orbit, the larger and brighter it appears in the sky.
It's an opportunity for backyard skywatchers—and a good time to catch up on all the exploration now underway at the Red Planet. Here are a few things to know this week about Mars:
1. Red Star Rising
The best time to see Mars at its brightest is when it's highest in the sky, which is around midnight during May. Look toward the south in the constellation Scorpius (where right now you can also catch the planet Saturn). If you have a telescope, you may be able to pick out some of the features on its surface. But don't fall for Internet rumors claiming that Mars will appear as big as the full moon. Instead, it will look like a bright, reddish or orange star. Get Mars viewing tips HERE.
2. Roving Weather Reporter
Our Mars Curiosity mission has now been roving across the floor of Gale Crater for two full Martian years—that's four Earth years. This robotic geologist is a meteorologist, too, and its long journey has allowed it to observe the local weather for two full seasonal cycles. During that time, the rover's instruments have recorded temperatures ranging from 60.5 degrees Fahrenheit (15.9 degrees Celsius) on a summer afternoon, to minus 148 F (minus 100 C) on a winter night. They also detected an intriguing spike in methane gas—but it hasn't happened since.
3. Increasing Clouds, with a Chance of Dust Storms
The Mars Reconnaissance Orbiter keeps an eye on Martian weather, too, but on a global scale. Every week, you can see the latest weather report, including an animation showing storms and clouds across the face of Mars.
4. Walking the Ancient Shoreline
Mars explorers have studied evidence for years that the early history of the planet included times where liquid water flowed and pooled freely. But just how deep those ancient lakes were, and how long they lasted, remains a topic of debate. A new study offers a more detailed picture of the rise and fall of standing bodies of water.
5. Wish Upon a Star
It's true that Mars will be especially bright in the sky this week. But did you ever consider that Earth often shines for Mars as well? This image from the Curiosity rover shows our whole world as a single point of light. When people finally do stand on Mars, they'll be able to look at the twilight sky—and see home. Left: the Earth and the Moon in the evening sky of Mars, as seen by the Curiosity rover. Right: Mars rising over Salt Lake City. Mars credit: NASA/JPL-Caltech/MSSS/TAMU. Earth credit: Bill Dunford.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
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