13
Oct 11

Amateur skywatchers help space hazards team

Source: ESA News


Detection of asteroid 2011 SF108.
Credits: ESA/TOTAS Survey Team

For the first time, observations coordinated by ESA's space hazards team have found an asteroid that comes close enough to Earth to pose an impact threat. The space rock was found by amateur astronomers, highlighting the value of 'crowd-sourcing' to science and planetary defense. (read more)

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1
Oct 11

WISE finds fewer asteroids near Earth

Source: NASA/WISE


Image credit: NASA/JPL-Caltech.

New observations by NASA's Wide-field Infrared Survey Explorer, or WISE, show there are significantly fewer  near-Earth asteroids in the mid-size range than previously thought. The findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998.

Astronomers now estimate there are roughly 19,500 -- not 35,000 -- mid-size near-Earth asteroids. Scientists say this improved understanding of the population may indicate the hazard to Earth could be somewhat less than previously thought. However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth.

The results come from the most accurate census to date of near-Earth asteroids, the space rocks that orbit within 120 million miles (195 million kilometers) of the sun into Earth's orbital vicinity. WISE observed infrared light from those in the middle to large-size category. The survey project, called NEOWISE, is the asteroid-hunting portion of the WISE mission. Study results appear in the Astrophysical Journal. (read more)

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25
Sep 11

Exploring an asteroid with the Desert RATS

Source: ESA


One of two vehicles used in Desert RATS.
Image credits: ESA - F. Didot.

Earlier this month, European scientists linked up with astronauts roaming over the surface of an asteroid. Desert RATS, NASA’s realistic simulation of a future mission, this year included a European dimension for the first time.(read more)

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19
Sep 11

WISE raises doubt about asteroid family believed responsible for dinosaur extinction

Source: NASA


Artist's impression about dinossaur extinction.
Image credit: HowStuffsWork.

 

Observations from NASA's Wide-field Infrared Survey Explorer (WISE) mission indicate the family of asteroids some believed was responsible for the demise of the dinosaurs is not likely the culprit, keeping the case open on one of Earth's greatest mysteries.

While scientists are confident a large asteroid crashed into Earth approximately 65 million years ago, leading to the extinction of dinosaurs and some other lifeforms on our planet, they do not know exactly where the asteroid came from or how it made its way to Earth.

A 2007 study using visible-light data from ground-based telescopes first suggested the remnant of a huge asteroid, known as Baptistina, as a possible suspect. According to that theory, Baptistina crashed into another asteroid in the main belt between Mars and Jupiter about 160 million years ago. The collision sent shattered pieces as big as mountains flying. One of those pieces was believed to have impacted Earth, causing the dinosaurs' extinction.

Since this scenario was first proposed, evidence developed that the so-called Baptistina family of asteroids was not the responsible party. With the new infrared observations from WISE, astronomers say Baptistina may finally be ruled out. (read more)

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16
Sep 11

NASA releases video about DAWN adn Vesta

Source: NASA/JPL


Go to video webpage.

NASA and JPL have just released a video about the close encounconter of space probe DAWN with asteroid Vesta. On the video one can notice that Vesta is not entirely lit up. There is no light in the high northern latitudes because, like Earth, Vesta has seasons. Currently it is northern winter on Vesta, and the northern polar region is in perpetual darkness. When we view Vesta's rotation from above the south pole, half is in darkness simply because half of Vesta is in daylight and half is in the darkness of night . (see video webpage).

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3
Sep 11

Dwarf Planet mysteries beckon to New Horizons

Source: NASA Science News


Artist's concept of New Horizons arriving to a minor planet.
Image credit: NASA.

Dwarf planet Pluto is a world of mystery waiting to be visited for the first time. NASA's New Horizons probe is racing across the solar system for a close encounter that could dramatically alter what researchers "know" about Pluto and other small worlds.(read more)

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16
Aug 11

NASA Plans to Visit a Near-Earth Asteroid

Source: NASA Science News

 
 

NASA is planning a daring new mission to visit a near-Earth asteroid. The spacecraft, named OSIRIS-REx, will orbit 1999 RQ36 for a year before gathering samples for return to Earth.(read more)

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1
Aug 11

Dawn's smooth orbital insertion at Vesta

Source: NASA Science News


Dawn's image of Vesta on July 24, 2011.
Image credits: NASA/Dawn.

When a NASA spacecraft goes into orbit around a new world for the first time, the control room is usually packed to capacity with scientists, engineers, and dignitaries ready to leap and shout when the retro-rockets fire. It's a big, noisy event.

July 15, 2011, was one of those days. NASA's Dawn spacecraft approached Vesta and became the first probe from Earth to orbit a main belt asteroid. Dawn's cameras revealed a desolate world of transcendent beauty, thrilling everyone who worked on the project.

Needless to say, the control room was .... silent?

This was because with Dawn all could be fuel controlled previously. (read more)

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28
Jul 11

Wise Mission finds first Trojan Asteroid sharing Earth's orbit

Source: NASA/WISE


Earth's New Trojan Friend.
Image credit: Paul Wiegert, University of Western Ontario, Canada.

Astronomers studying observations taken by NASA's Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known "Trojan" asteroid orbiting the sun along with Earth.

Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn's moons share orbits with Trojans.

Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth's point of view.(read more)

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19
Jul 11

Dawn spacecraft returns close-up Image of asteroid Vesta

Source: NASA/Dawn


Dawn spacecraft obtained this image on July 17, 2011.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA's Dawn spacecraft has returned the first close-up image after beginning its orbit around the giant asteroid Vesta. On Friday, July 15, Dawn became the first probe to enter orbit around an object in the main asteroid belt between Mars and Jupiter.

The image taken for navigation purposes shows Vesta in greater detail than ever before. When Vesta captured Dawn into its orbit, there were approximately 16 000 kilometers between the spacecraft and asteroid.

Vesta is 330 miles (530 kilometers) in diameter and the second most massive object in the asteroid belt. Ground- and space-based telescopes have obtained images of Vesta for about two centuries, but they have not been able to see much detail on its surface.(read more)

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18
Jul 11

DAWN spacecraft enters orbit around asteroid Vesta

Source: NASA/DAWN


Artist's impression of Dawn.
Image credit: NASA/JPL.

NASA's Dawn spacecraft on Saturday became the first probe ever to enter orbit around an object in the main asteroid belt between Mars and Jupiter.

Dawn will study the asteroid, named Vesta, for a year before departing for a second destination, a dwarf planet named Ceres, in July 2012. Observations will provide unprecedented data to help scientists understand the earliest chapter of our solar system. The data also will help pave the way for future human space missions.(read more)

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17
Jul 11

When minor planets Ceres and Vesta rock the Earth into chaos

Astronomy and Astrophysics is publishing a new study of the orbital evolution of minor planets Ceres and Vesta, a few days before the flyby of Vesta by the Dawn spacecraft. A team of astronomers found that close encounters among these bodies lead to strong chaotic behavior of their orbits, as well as of the Earth's eccentricity. This means, in particular, that the Earth's past orbit cannot be reconstructed beyond 60 million years.

Astronomy and Astrophysics is publishing numerical simulations of the long-term evolution of the orbits of minor planets Ceres and Vesta, which are the largest bodies in the asteroid belt, between Mars and Jupiter. Ceres is 6000 times less massive than the Earth and almost 80 times less massive than our Moon. Vesta is almost four times less massive than Ceres.

These two minor bodies, long thought to peacefully orbit in the asteroid belt, are found to affect their large neighbors and, in particular, the Earth in a way that had not been anticipated. This is showed in the new astronomical computations released by Jacques Laskar from Paris Observatory and his colleagues.

Although small, Ceres and Vesta gravitationally interact together and with the other planets of the Solar System. Because of these interactions, they are continuously pulled or pushed slightly out of their initial orbit. Calculations show that, after some time, these effects do not average out. Consequently, the bodies leave their initial orbits and, more importantly, their orbits are chaotic, meaning that we cannot predict their positions.

The two bodies also have a significant probability of impacting each other, estimated at 0.2% per billion year. Last but not least, Ceres and Vesta gravitationally interact with the Earth, whose orbit also becomes unpredictable after only 60 million years.

This means that the Earth's eccentricity, which affects the large climatic variations on its surface, cannot be traced back more than 60 million years ago. This is indeed bad news for Paleoclimate studies.

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15
Jul 11

Dawn Set to Orbit Giant Asteroid Vesta on July 15th

Source: NASA


Dawn's image of giant asteroid Vesta on July 9, 2011.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

 

On July 15, NASA's ion-propelled Dawn spacecraft will become the first mission to enter orbit around a main-belt asteroid. Dawn will orbit Vesta for one Earth-year, studying the giant space rock at close range to help scientists understand the earliest chapter of our solar system's history.(read more)

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7
Jul 11

Does Asteroid Vesta Have a Moon?

Source: NASA


Ida and Dactyl: Asteroid and Moon
Credit: Galileo Project, JPL, NASA

As NASA's ion-powered Dawn spacecraft approaches Vesta for orbital insertion in mid-July, Dawn's camera's will be scanning space around the giant asteroid for signs of an asteroid moon.(read more)

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25
Jun 11

Dawn nears position for year-long stay at giant asteroid

Source: NASA/Dawn


Artist's impression of Dawn. Image credit: NASA.

NASA's Dawn spacecraft is on track to begin the first extended visit to a large asteroid. The mission expects to go into orbit around Vesta on July 16 and begin gathering science data in early August. Vesta resides in the main asteroid belt and is thought to be the source of a large number of meteorites that fall to Earth.(read more)

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24
Jun 11

Asteroid misses Earth by little next Monday

Source: Skymania/Paul Sutherland

An asteroid with a diameter between 10meters and 50 meters was discovered on June 22nd and will pass Earth at a distance of  less than 17,700 km (11,000 miles) on Monday June 27, 2011. That’s about 23 times closer than the Moon. The size and location of the asteroid, named 2011 MD, should allow observers in certain locations to take a look at the space rock, even with small telescopes. It’s closest approach will be at 13:26 UTC on June 27.(read more)

 

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14
Jun 11

NASA spacecraft captures video of asteroid approach

Source: NASA/Dawn


Artist's impression of Dawn. Image credit: NASA.

Scientists working with NASA's Dawn spacecraft have created a new video showing the giant asteroid Vesta as the spacecraft approaches this unexplored world in the main asteroid belt.

The video loops 20 images obtained for navigation purposes on June 1. The images show a dark feature near Vesta's equator moving from left to right across the field of view as Vesta rotates. Images also show Vesta's jagged, irregular shape, hinting at the enormous crater known to exist at Vesta's south pole. (read more)

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11
May 11

Dawn spacecraft captures first image of nearing asteroid

Source: NASA-Dawn

Image processed to show the true size of the giant asteroid Vesta.
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Dawn spacecraft has obtained its first image of the giant asteroid Vesta, which will help fine-tune navigation during its approach. Dawn expects to achieve orbit around Vesta on July 16, when the asteroid is about 117 million miles from Earth.

The image from Dawn's framing cameras was taken on May 3 when the spacecraft began its approach and was approximately 752,000 miles (1.21 million km) from Vesta. The asteroid appears as a small, bright pearl against a background of stars. Vesta also is known as a protoplanet, because it is a large body that almost formed into a planet. (read more)

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6
May 11

NASA Selects Investigations For Future Key Planetary Mission

Source: NASA Discovery Program

NASA has selected three science investigations from which it will pick one potential 2016 mission to look at Mars' interior for the first time; study an extraterrestrial sea on one of Saturn's moons; or study in unprecedented detail the surface of a comet's nucleus.

Each investigation team will receive $3 million to conduct its mission's concept phase or preliminary design studies and analyses. After another detailed review in 2012 of the concept studies, NASA will select one to continue development efforts leading up to launch. The selected mission will be cost-capped at $425 million, not including launch vehicle funding.

NASA's Discovery Program requested proposals for spaceflight investigations in June 2010. A panel of NASA and other scientists and engineers reviewed 28 submissions. The selected investigations could reveal much about the formation of our solar system and its dynamic processes. Three technology developments for possible future planetary missions also were selected. (learn more)

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4
May 11

NASA Dawn Spacecraft Reaches Milestone Approaching Asteroid

Source: NASA News


Dawn spacecraft, illustrated in this artist's concept, is propelled by ion engines.
Image credit: NASA/JPL.

 

NASA's Dawn spacecraft has reached its official approach phase to the asteroid Vesta and will begin using cameras for the first time to aid navigation for an expected July 16 orbital encounter. The large asteroid is known as a protoplanet - a celestial body that almost formed into a planet.

At the start of this three-month final approach to this massive body in the asteroid belt, Dawn is 752,000 miles (1.21 million kilometers) from Vesta, or about three times the distance between the Earth and the moon. During the approach phase, the spacecraft's main activity will be thrusting with a special, hyper-efficient ion engine that uses electricity to ionize and accelerate xenon to generate thrust. The 12-inch-wide ion thrusters provide less thrust than conventional engines, but will provide propulsion for years during the mission and provide far greater capability to change velocity. (read more)

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