Category Archives: Asteroids & Comets

Dawn spacecraft enters orbit around Ceres

Today NASA’s Dawn spacecraft went into orbit around Ceres, the largest object in the asteroid belt and now classified as a dwarf planet.

Here is NASA’s announcement:

NASA Spacecraft Becomes First to Orbit a Dwarf Planet

NASA’s Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000) kilometers from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday.

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Ceres is seen from NASA’s Dawn spacecraft on March 1, just a few days before the mission achieved orbit around the previously unexplored dwarf planet. The image was taken at a distance of about 30,000 miles (about 48,000 kilometers). Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Mission controllers at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California received a signal from the spacecraft at 5:36 a.m. PST (8:36 a.m. EST) that Dawn was healthy and thrusting with its ion engine, the indicator Dawn had entered orbit as planned.

“Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet,” said Marc Rayman, Dawn chief engineer and mission director at JPL. “Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home.”

In addition to being the first spacecraft to visit a dwarf planet, Dawn also has the distinction of being the first mission to orbit two extraterrestrial targets. From 2011 to 2012, the spacecraft explored the giant asteroid Vesta, delivering new insights and thousands of images from that distant world. Ceres and Vesta are the two most massive residents of our solar system’s main asteroid belt between Mars and Jupiter.

The most recent images received from the spacecraft, taken on March 1 show Ceres as a crescent, mostly in shadow because the spacecraft’s trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres’ dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet.

“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.”

Dawn’s mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

For a complete list of mission participants, visit: dawn.jpl.nasa.gov/mission

For more information about Dawn, visit: www.nasa.gov/dawn

New images from Dawn spacecraft as it approaches the dwarf planet Ceres

The latest news about NASA’s Dawn spacecraft and its approach to Ceres:

NASA Spacecraft Nears Historic Dwarf Planet Arrival

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Ceres rotates in this sped-up movie comprised of images taken by NASA’s Dawn mission during its approach to the dwarf planet. The images were taken on Feb. 19, 2015, from a distance of nearly 29,000 miles (46,000 kilometers). Dawn observed Ceres for a full rotation of the dwarf planet, which lasts about nine hours. The images have a resolution of 2.5 miles (4 kilometers) per pixel. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA’s Dawn spacecraft has returned new images captured on approach to its historic orbit insertion at the dwarf planet Ceres. Dawn will be the first mission to successfully visit a dwarf planet when it enters orbit around Ceres on Friday, March 6.

“Dawn is about to make history,” said Robert Mase, project manager for the Dawn mission at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “Our team is ready and eager to find out what Ceres has in store for us.”

[ Update: Here is a NASA JPL video about the Dawn Ceres mission:

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Recent images show numerous craters and unusual bright spots that scientists believe tell how Ceres, the first object discovered in our solar system’s asteroid belt, formed and whether its surface is changing. 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, which would suggest current geological activity.

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

Dawn began its final approach phase toward Ceres in December. The spacecraft has taken several optical navigation images and made two rotation characterizations, allowing Ceres to be observed through its full nine-hour rotation. Since Jan. 25, Dawn has been delivering the highest-resolution images of Ceres ever captured, and they will continue to improve in quality as the spacecraft approaches.

Sicilian astronomer Father Giuseppe Piazzi spotted Ceres in 1801. As more such objects were found in the same region, they became known as asteroids, or minor planets. Ceres was initially classified as a planet and later called an asteroid. In recognition of its planet-like qualities, Ceres was designated a dwarf planet in 2006, along with Pluto and Eris.

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NASA’s Dawn spacecraft took these images of dwarf planet Ceres from about 25,000 miles (40,000 kilometers) away on Feb. 25, 2015. Ceres appears half in shadow because of the current position of the spacecraft relative to the dwarf planet and the sun. The resolution is about 2.3 miles (3.7 kilometers) per pixel. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Ceres is named for the Roman goddess of agriculture and harvests. Craters on Ceres will similarly be named for gods and goddesses of agriculture and vegetation from world mythology. Other features will be named for agricultural festivals.

Launched in September 2007, Dawn explored the giant asteroid Vesta for 14 months in 2011 and 2012, capturing detailed images and data about that body. Both Vesta and Ceres orbit the sun between Mars and Jupiter, in the main asteroid belt. This two-stop tour of our solar system is made possible by Dawn’s ion propulsion system, its three ion engines being much more efficient than chemical propulsion.

“Both Vesta and Ceres were on their way to becoming planets, but their development was interrupted by the gravity of Jupiter,” said Carol Raymond, deputy project scientist at JPL. “These two bodies are like fossils from the dawn of the solar system, and they shed light on its origins.”

Ceres and Vesta have several important differences. Ceres is the most massive body in the asteroid belt, with an average diameter of 590 miles (950 kilometers). Ceres’ surface covers about 38 percent of the area of the continental United States. Vesta has an average diameter of 326 miles (525 kilometers), and is the second most massive body in the belt. The asteroid formed earlier than Ceres and is a very dry body. Ceres, in contrast, is estimated to be 25 percent water by mass.

“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,” said Raymond. “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.”

“We would not be able to orbit and explore these two worlds without ion propulsion,” Mase said. “Dawn capitalizes on this innovative technology to deliver big science on a small budget.”

In addition to the Dawn mission, NASA will launch in 2016 its Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) spacecraft. This mission will study a large asteroid in unprecedented detail and return samples to Earth.

NASA also places a high priority on tracking and protecting Earth from asteroids. NASA’s Near-Earth Object (NEO) Program at the agency’s headquarters manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. NASA is pursuing an Asteroid Redirect Mission (ARM), which will identify, redirect and send astronauts to explore an asteroid. Among its many exploration goals, the mission could demonstrate basic planetary defense techniques for asteroid deflection.

Dawn’s mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft.

The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

For a complete list of mission participants, visit: dawn.jpl.nasa.gov/mission

For more information about Dawn, visit: dawn.jpl.nasa.gov

For more information on OSIRIS-REx and ARM visit: www.nasa.gov

Update 2: Here is a NASA briefing about the Dawn mission held on Monday, Mar.2:

Review: “Fury of the Fifth Angel” by Pat and Chris Hoffman

There have been a number of books and movies about the end of the earth when a not-so heavenly object descends with extreme prejudice upon our helpless little planet. In Fury of the Fifth AngelPat and Chris Hoffman depict a scenario short of total oblivion by a space salvo but devastating none the less. Coming from a background in the power industry, they give a realistic portrayal of how civilization quickly descends into chaos as our utilities and other services switch off during a catastrophic cosmic pelting.

This book, Part I in a series, introduces a large number of characters in a diversity of places and backgrounds who participate in several parallel subplots. They illustrate the many ways such an event would impact, so to speak, a complex modern society, which can revert surprisingly quickly to a raw primitive condition. Presumably Part II will follow these characters as they struggle to survive in the chaos following a cataclysm and to rebuild their society.

With so many characters, it’s not too surprising that most are one dimensional and only a few stretch into 2-D, while none have any great depth. But it is the disaster – before, during and afterwards – that is being depicted and the characters are drawn well enough to profile it in vivid 3-D.

There is a lengthy build up to the action from above and a focus in more than one of the subplots on efforts of the powers-that-be to keep quiet the approaching threat. In a day when most any celestial object that can be seen by one observer is quickly found by multiple observers all of whom race to be the first to report the discovery on line, the suggestion that such a finding could be suppressed is unrealistic. Furthermore, it is clearly nearly impossible to keep secrets these days in government and in large organizations, especially dramatic earth-shaking kinds of secrets.

That said, Fury of the Fifth Angel is a fun and thought-provoking read that provides a fine contribution to the celestial catastrophe genre.

Dawn sees double bright spots on Ceres

As the Dawn spacecraft closes in on the dwarf planet Ceres, it appears someone left the lights on:

‘Bright Spot’ on Ceres Has Dimmer Companion

Dwarf planet Ceres continues to puzzle scientists as NASA’s Dawn spacecraft gets closer to being captured into orbit around the object. The latest images from Dawn, taken nearly 29,000 miles (46,000 kilometers) from Ceres, reveal that a bright spot that stands out in previous images lies close to yet another bright area.

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This image was taken by NASA’s Dawn spacecraft of dwarf planet Ceres on Feb. 19 from a distance of nearly 29,000 miles (46,000 kilometers). It shows that the brightest spot on Ceres has a dimmer companion, which apparently lies in the same basin.

“Ceres’ bright spot can now be seen to have a companion of lesser brightness, but apparently in the same basin. This may be pointing to a volcano-like origin of the spots, but we will have to wait for better resolution before we can make such geologic interpretations,” said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

Using its ion propulsion system, Dawn will enter orbit around Ceres on March 6. As scientists receive better and better views of the dwarf planet over the next 16 months, they hope to gain a deeper understanding of its origin and evolution by studying its surface. The intriguing bright spots and other interesting features of this captivating world will come into sharper focus.

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These images of dwarf planet Ceres, processed to enhance clarity, were taken on Feb. 19, 2015, from a distance of about 29,000 miles (46,000 kilometers), by NASA’s Dawn spacecraft. Dawn observed Ceres completing one full rotation, which lasted about nine hours.

The images show the full range of different crater shapes that can be found at Ceres’ surface: from shallow, flattish craters to those with peaks at their centers. These views show sections of Ceres’ surface that are similar to those in PIA19056.

“The brightest spot continues to be too small to resolve with our camera, but despite its size it is brighter than anything else on Ceres. This is truly unexpected and still a mystery to us,” said Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research, Gottingen, Germany.

Dawn visited the giant asteroid Vesta from 2011 to 2012, delivering more than 30,000 images of the body along with many other measurements, and providing insights about its composition and geological history. Vesta has an average diameter of 326 miles (525 kilometers), while Ceres has an average diameter of 590 miles (950 kilometers). Vesta and Ceres are the two most massive bodies in the asteroid belt, located between Mars and Jupiter.

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NASA’s Dawn spacecraft obtained these uncropped images of dwarf planet Ceres on Feb. 19, 2015, from a distance of about 29,000 miles (46,000 kilometers). They are part of a series taken as Dawn observed Ceres completing one full rotation, which lasted about nine hours.

The images show the full range of different crater shapes that can be found at Ceres’ surface: from shallow, flattish craters to those with peaks at their centers. These views show sections of Ceres’ surface that are similar to those in PIA19056.

Dawn’s mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK, Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgements, visit: dawn.jpl.nasa.gov/mission

For information about NASA’s Dawn mission, visit: dawn.jpl.nasa.gov

Video: Rosetta’s closest encounter with Comet 67P/C-G

This ESA video reports on the recent Rosetta fly-by of  Comet 67P/Churyumov-Gerasemenko: Space in Videos – 2015 – 02 – Rosetta’s closest encounter – ESA

On 14 February 2015, Rosetta made its closest encounter with comet 67P/Churyumov-Gerasemenko at just 6 km from the surface. The spacecraft is no longer orbiting the comet, it is now performing a series of flybys to continue its science.

This video explains the next stage of the Rosetta mission, the science that will be done during 2015 by the orbiter’s flybys, and assesses the possibility of the Philae lander’s reactivation from hibernation. So far Rosetta has only mapped about seventy percent of the surface because the comet’s orbit and rotation kept certain areas in darkness.

This year new regions will come into view alongside new activity on the surface. When the comet is at the peak of its activity in the summer, Rosetta’s instruments will be there to observe, measure and record a spectacular event.

It contains interviews in English with Andrea Accomazzo, ESA Rosetta Flight Director, and Matt Taylor, ESA Rosetta Project Scientist.