Instead of traditional chemical rockets, the spacecraft uses sophisticated ion engines for propulsion. This enabled Dawn to become the first mission to orbit not one, but two different worlds — first the giant asteroid Vesta and now the dwarf planet Ceres. Vesta and Ceres formed early in the solar system’s history, and by studying them, the mission is helping scientists go back in time to the dawn of the planets. To mark a decade since Dawn was launched on Sept. 27, 2007, here are 10 things to know about this trailblazing mission.
Most rocket engines use chemical reactions for propulsion, which tend to be powerful but short-lived. Dawn’s futuristic, hyper-efficient ion propulsion system works by using electricity to accelerate ions (charged particles) from xenon fuel to a speed seven to 10 times that of chemical engines. Ion engines accelerate the spacecraft slowly, but they’re very thrifty with fuel, using just milligrams of xenon per second (about 10 ounces over 24 hours) at maximum thrust. Without its ion engines, Dawn could not have carried enough fuel to go into orbit around two different solar system bodies. Try your hand at an interactive ion engine simulation.
Scientists have long wanted to study Vesta and Ceres up close. Vesta is a large, complex and intriguing asteroid. Ceres is the largest object in the entire asteroid belt, and was once considered a planet in its own right after it was discovered in 1801. Vesta and Ceres have significant differences, but both are thought to have formed very early in the history of the solar system, harboring clues about how planets are constructed. Learn more about Ceres and Vesta—including why we have pieces of Vesta here on Earth.
This view of Ceres built from Dawn photos is centered on Occator Crater, home of the famous “bright spots.” The image resolution is about 460 feet (140 meters) per pixel.
Take a closer look.
Craters on Ceres are named for agricultural deities from all over the world, and other features carry the names of agricultural festivals. Ceres itself was named after the Roman goddess of corn and harvests (that’s also where the word “cereal” comes from). The International Astronomical Union recently approved 25 new Ceres feature names tied to the theme of agricultural deities. Jumi, for example, is the Latvian god of fertility of the field. Study the full-size map.
Thanks to Dawn, evidence is mounting that Ceres hides a significant amount of water ice. A recent study adds to this picture, showing how ice may have shaped the variety of landslides seen on Ceres today.
Ahuna Mons, a 3-mile-high (5-kilometer-high) mountain, puzzled Ceres explorers when they first found it. It rises all alone above the surrounding plains. Now scientists think it is likely a cryovolcano — one that erupts a liquid made of volatiles such as water, instead of rock. “This is the only known example of a cryovolcano that potentially formed from a salty mud mix, and that formed in the geologically recent past,” one researcher said. Learn more.
The brightest area on Ceres, located in the mysterious Occator Crater, has the highest concentration of carbonate minerals ever seen outside Earth, according to studies from Dawn scientists. Occator is 57 miles (92 kilometers) wide, with a central pit about 6 miles (10 kilometers) wide. The dominant mineral of this bright area is sodium carbonate, a kind of salt found on Earth in hydrothermal environments. This material appears to have come from inside Ceres, and this upwelling suggests that temperatures inside Ceres are warmer than previously believed. Even more intriguingly, the results suggest that liquid water may have existed beneath the surface of Ceres in recent geological time. The salts could be remnants of an ocean, or localized bodies of water, that reached the surface and then froze millions of years ago. See more details.
Dawn’s chief engineer and mission director, Marc Rayman, provides regular dispatches about Dawn’s work in the asteroid belt. Catch the latest updates here.
Another cool way to retrace Dawn’s decade-long flight is to download NASA’s free Eyes on the Solar System app, which uses real data to let you go to any point in the solar system, or ride along with any spacecraft, at any point in time—all in 3-D.
Send a postcard from one of these three sets of images that tell the story of dwarf planet Ceres, protoplanet Vesta, and the Dawn mission overall.
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How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. This star is the brightest object located just above the gas front in the above image. Close inspection of images taken recently with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the bottom of the image, stars are still forming in the associated emission nebula NGC 6357, including several that appear to be breaking out and illuminating a spectacular cocoon.
Credit: NASA, ESA and J. M. Apellániz (IAA, Spain)
(CNN) On October 19, the Pan-STARRS 1 telescope in Hawaii spotted something strange zooming through our solar system. It turned out to be a visitor from beyond our solar system, and it's unlike anything astronomers have seen before.
Should there be a holiday called Astronomy Day?
Where lights are to be turned off for the entire night so everyone could see the stars?
A false-color image of the mid-infrared emission from the Great Galaxy in Andromeda, as seen by Nasa’s WISE space telescope.
Credit: NASA/JPL-Caltech/WISE Team
False color image of Uranus taken with the Hale Telescope and the Palomar Observatory. The rings are the red pieces.
Image credit: Palomar Observatory & Hale telescope
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.
Image Credit: Ball Aerospace
JPSS-1 is the primary satellite launching, but four tiny satellites will also be hitchhiking a ride into Earth orbit. These shoebox-sized satellites (part of our CubeSat Launch Initiative) were developed in partnership with university students and used for education, research and development. Here are 4 reasons why MiRaTA, one of the hitchhikers, is particularly interesting…
Miniaturized Weather Satellite Technology
The Microwave Radiometer Technology Acceleration (MiRaTA) CubeSat is set to orbit the Earth to prove that a small satellite can advance the technology necessary to reduce the cost and size of future weather satellites. At less than 10 pounds, these nanosatellites are faster and more cost-effective to build and launch since they have been constructed by Principal Investigator Kerri Cahoy’s students at MIT Lincoln Laboratory (with lots of help). There’s even a chance it could be put into operation with forecasters.
The Antenna? It’s a Measuring Tape
That long skinny piece coming out of the bottom right side under MiRaTA’s solar panel? That’s a measuring tape. It’s doubling as a communications antenna. MiRaTA will measure temperature, water vapor and cloud ice in Earth’s atmosphere. These measurements are used to track major storms, including hurricanes, as well as everyday weather. If this test flight is successful, the new, smaller technology will likely be incorporated into future weather satellites – part of our national infrastructure.
Tiny Package Packing a Punch MiRaTA will also test a new technique using radio signals received from GPS satellites in a higher orbit. They will be used to measure the temperature of the same volume of atmosphere that the radiometer is viewing. The GPS satellite measurement can then be used for calibrating the radiometer. “In physics class, you learn that a pencil submerged in water looks like it’s broken in half because light bends differently in the water than in the air,” Principal Investigator Kerri Cahoy said. “Radio waves are like light in that they refract when they go through changing densities of air, and we can use the magnitude of the refraction to calculate the temperature of the surrounding atmosphere with near-perfect accuracy and use this to calibrate a radiometer.”
What’s Next?
In the best-case scenario, three weeks after launch MiRaTA will be fully operational, and within three months the team will have obtained enough data to study if this technology concept is working. The big goal for the mission—declaring the technology demonstration a success—would be confirmed a bit farther down the road, at least half a year away, following the data analysis. If MiRaTA’s technology validation is successful, Cahoy said she envisions an eventual constellation of these CubeSats orbiting the entire Earth, taking snapshots of the atmosphere and weather every 15 minutes—frequent enough to track storms, from blizzards to hurricanes, in real time.
Learn more about MiRaTA
The mission is scheduled to launch this month (no sooner than Nov. 14), with JPSS-1 atop a United Launch Alliance (ULA) Delta II rocket lifting off from Space Launch Complex 2 at Vandenberg Air Force Base in California. You’ll be able to watch on NASA TV or at nasa.gov/live.
Watch the launch live HERE on Nov. 14, liftoff is scheduled for Tuesday, 4:47 a.m.!
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This stunning multi-mission picture shows off the many sides of the supernova remnant Cassiopeia A. It is made up of images taken by three of NASA’s Great Observatories, using three different wavebands of light. Infrared data from the Spitzer Space Telescope are colored red; visible data from the Hubble Space Telescope are yellow; and X-ray data from the Chandra X-ray Observatory are green and blue.
Image credit: NSA/JPL
A wispy and filamentary cloud of gas and dust, the Crab nebula is the remnant of a supernova explosion that was observed by Chinese astronomers in the year 1054.
The image combines Hubble’s view of the nebula at visible wavelengths, obtained using three different filters sensitive to the emission from oxygen and sulphur ions and is shown here in blue. Herschel’s far-infrared image reveals the emission from dust in the nebula and is shown here in red.
Credit: NASA/ESA/Hubble
Flying Monsters of Scorpius | Yuriy Toropin
Image of Titan taken by the Cassini spacecraft
NASA/JPL-Caltech/SSI/Kevin M. Gill
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