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Author Topic: NASA'S Dawn nears Ceres – Approach images, movies and animations  (Read 458 times)
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« on: Mar 04, 2015, 07:50 AM »

Dawn nears Ceres – Approach images, movies and animations

March 3, 2015

NASA’s Dawn mission will arrive at Ceres on March 6, 2015, and will be the first spacecraft to explore a dwarf planet. Ceres is the largest body in the main asteroid belt. At the time of its discovery in 1801 it was considered a planet and later demoted.

Click to watch:

And here:

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« Reply #1 on: Mar 04, 2015, 08:07 PM »

". . . the first spacecraft to explore a dwarf planet . . ."

All I can say is:  WOW!!

Thanks, Rad, for posting this news item and the videos.

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« Reply #2 on: Mar 07, 2015, 06:36 AM »

Dawn has arrived at Ceres

March 6, 2015
Chuck Bednar for – @BednarChuck

After a journey of more than 7 1/2 years, NASA’s Dawn spacecraft was expected to enter orbit around Ceres, the largest object in the asteroid belt between Mars and Jupiter, this morning.

In a statement, the US space agency announced that Dawn was approximately 38,000 miles (61,000 kilometers) from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 am PST (7:39 am EST) Friday morning. NASA personnel received a signal from the spacecraft confirming that it was healthy and operational at 5:36 am PST (8:36 a.m. EST).

“We feel exhilarated,” said Chris Russell, principal investigator of the Dawn mission at the University of California, Los Angeles (UCLA). “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”

Reconnaissance of an entirely new world

According to BBC News, Dawn was expected to enter orbit around the planetoid at about 7:20 am EST on Friday, barring any unexpected issues. For the next 14 months, the probe will study Ceres, dwarf planet in the inner solar system and the first to be visited by a spacecraft.

Dawn’s study of Ceres should provide new insight into the origins of the solar system, and since it has been travelling at a relatively slow speed, it was anticipated to have a smooth entry into the gravitational field of the dwarf planet. At closest approach, Dawn will be approximately 40,000 kilometers (under 25,000 miles) from Ceres, the British news outlet added.

“This is a first reconnaissance of an entirely new world,” Marc Rayman, Dawn’s chief engineer and mission director, told USA Today. UCLA’s Christopher Russell, principal investigator of the mission, added that Ceres has been like a “secretive neighbor” and that everything that he and his colleagues have witnessed so far during the mission has been “unexpected.”

Figuring out the bright spots

Among the surprises revealed by the planetoid thus far was a pair of bright spots discovered by Dawn during its approach. The spots, which thus far have been too small for an in-depth analysis yet remain brighter than anything else on Ceres, could be ice, salt or volcanic activity.

“As the spacecraft spirals into closer and closer orbits around the dwarf planet, researchers will be looking for signs that these strange features are changing,” NASA said earlier this week in a statement. Such changes “would suggest current geological activity,” the agency noted.

“Studying Ceres allows us to do historical research in space, opening a window into the earliest chapter in the history of our solar system,” added Jim Green, director of the Planetary Science Division at the NASA headquarters in Washington. “Data returned from Dawn could contribute significant breakthroughs in our understanding of how the solar system formed.”

The final countdown

Dawn began its final approach phase toward Ceres in December, and during its journey it has captured several optical navigation images and made two rotation characterizations, NASA said. This has made it possible for scientists to observe the object throughout the entire course of its nine-hour rotation, and it will continue to provide increasingly quality high-resolution photos of Ceres throughout the course of its mission, agency officials added.

“Scientists know that Ceres once had an icy ocean at its core and probably still does. But it’s also possible that radioactivity inside the planet melted some of the ice, creating a lake or a sea. Dawn will look for a liquid ocean,” USA Today said. If they find it, science team member Mark Sykes said, it could indicate that Ceres is or once was capable of supporting subsurface life.

Interrupted by Jupiter

Ceres, which was discovered by Sicilian astronomer Father Giuseppe Piazzi in 1801, is the second destination for Dawn, which had previously visited the giant asteroid Vesta in 2011 and 2012. While in orbit around Vesta, the spacecraft captured more than 30,000 images and several measurements of the object, revealing new information about its composition and geology.

With an average diameter of 590 miles (950 kilometers), Ceres is much larger than Vesta, which has an average diameter of just 326 miles (525 kilometers). Ceres, which contains approximately one-third  of the entire asteroid belt’s mass, was initially classified as a planet and later called an asteroid before being re-designated a dwarf planet along with Pluto and Eris in 2006.

Carol Raymond, deputy principal investigator at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, explained that both Ceres and Vesta “were on their way to becoming planets, but their development was interrupted by the gravity of Jupiter. These two bodies are like fossils from the dawn of the solar system, and they shed light on its origins.”

“By studying Vesta and Ceres, we will gain a better understanding of the formation of our solar system, especially the terrestrial planets and most importantly the Earth,” she added. “These bodies are samples of the building blocks that have formed Venus, Earth and Mars. Vesta-like bodies are believed to have contributed heavily to the core of our planet, and Ceres-like bodies may have provided our water.”

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« Reply #3 on: Apr 17, 2015, 08:40 PM »

NASA Probe Sees North Pole of Dwarf Planet Ceres (Video)

by Elizabeth Howell, Contributor
April 17, 2015 01:36pm ET
After spending several weeks in the shadow of Ceres, NASA's Dawn spacecraft is finally getting a close-up glimpse of the dwarf planet.

Ceres' cratered north pole blazes through the darkness in new images captured by Dawn on April 10. The photos are the highest-resolution views of the world that Dawn has gotten since entering Ceres' orbit on March 6, NASA officials said.

Dawn was about 21,000 miles (33,000 kilometers) from the dwarf planet when the pictures were taken, and mission team members promise even better views of Ceres in the months to come.

Full science observations begin April 23, when lighting conditions will be better for Dawn and the probe will be even closer to Ceres — just 8,400 miles (13,500 km) above the surface. Dawn will begin moving even lower down on May 9.

In future weeks, NASA hopes the mission will help scientists better understand a key mystery of Ceres: strange bright spots on its surface that, in some cases, have different temperatures than the terrain surrounding them. Mission scientists still don't know what the spots are made of.

The $466 million Dawn mission, which launched in September 2007, aims to better characterize the solar system's early days by studying Ceres and Vesta, two intact protoplanets that are the largest denizens of the asteroid belt between Mars and Jupiter. The probe spent 14 months at the 330-mile-wide (530 km) Vesta in 2011 and 2012, then headed to Ceres.

Mission scientists said they expect that Ceres, which is about 590 miles (950 km) wide, will be wetter than Vesta, and made of different stuff. Some researchers think Ceres may even harbor liquid water beneath its surface, perhaps making the dwarf planet capable of hosting life as we know it.

Dawn will study Ceres for the next 14 months, mapping and measuring the cratered world from a series of successively closer-in orbits until June 2016, when the probe's fuel will run out and the mission will come to an end.
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« Reply #4 on: Jun 24, 2015, 02:18 PM »

Ceres Gets Weirder With More Bright Spots and Unexplained ‘Pyramid’

If you thought Ceres’ spots were weird, wait until you see its mystifying ‘pyramid.’

Indeed, Ceres has intrigued NASA scientists and worked fringe UFO bloggers into a frenzy since the Dawn spacecraft arrived for a close-up of the dwarf planet in March. Upon arrival, Dawn imaged a cluster of bright spots in a crater; now, a pyramid towering over a flat landscape serves as the latest addition to Ceres’ scrapbook of oddities.

Scientists have plenty of questions about Ceres’ features, but will we get answers? Maybe.

Space Oddity

Right now, Dawn is in its second orbiting phase roughly 2,700 miles above Ceres, which has given us a closer look at the now famous bright spots. We now know there are even more spots than we initially saw in early images.

Scientists believe a highly reflective substance — ice or salt are leading contenders — is responsible for the spots, but they are still considering other options (a thriving alien metropolis is probably not one of them). Thankfully, Dawn is equipped with an infrared mapping spectrometer that can identify minerals based on the way they reflect light. As scientists get more images and data from Dawn, they’ll certainly learn more about the composition of those spots.

And That Pyramid

Dawn also photographed a pyramid-shaped landform in its latest crop of photographs. Based on visual evidence, the mountain rises roughly 3 miles into the sky, and it’s smack-dab in the middle of a relatively flat area on Ceres’ surface. This shouldn’t come as too big of a surprise: Ceres bears all the telltale signs ancient, and perhaps present, geologic activity. Ceres has scars on its surface that hint at ancient lava flows, landslides and collapsed structures.

Ceres’ story is only going to get more interesting. Dawn will continue to orbit 2,700 miles above the dwarf planet’s surface until June 30. Then, it will edge even closer, entering orbit at an altitude of 900 miles sometime in August.

When that time comes, it’s safe to say another strange chapter will be added to the book of Ceres.
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