Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A sea otter-shaped rubble pile in space

02.06.2006


Hayabusa mission offers an intimate portrait of asteroid Itokawa


This news release is also available in Japanese.


True to its name, the Japanese spacecraft Hayabusa, which means "falcon" in Japanese, hovered over the near-Earth asteroid Itokawa last fall, taking up-close measurements and photographs. Then it swooped down for a brief landing and the first-ever sample attempt on an asteroid.

The first peer-reviewed set of scientific results from this mission appears in the 2 June 2006 issue of the journal Science, published by AAAS, the nonprofit science society. These findings will help researchers understand the structure and composition of the "near-Earth asteroids" that periodically whiz past our planet.



"Asteroids are relics from our early solar system and provide critical information on its early evolution and some represent the early building blocks of Earth. Some in Earth-crossing orbits may pose significant future threats," said Brooks Hanson, Science’s deputy managing editor, physical sciences.

"The Hayabusa results appearing in Science give us an intimate look at a near-Earth asteroid and provide information on its makeup and relation to collected meteorites. The Hayabusa misson also opens up a new frontier of space research in which we investigate other asteroids," he said.

Asteroid Itokawa, named after Japanese rocket scientist Hideo Itokawa, was chosen as Hayabusa’s "prey" in part because it is one of the most common types of rocky near-Earth asteroids, the so-called "S-type" asteroids. The relatively tiny asteroid is only 500 meters long.

"The results obtained for Itokawa make a good benchmark for this type of asteroid. We could say that we have seen real images of the most common type of asteroid in the near-Earth region," said lead Science author Akira Fujiwara of the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA).

Some of the photographs taken by Hayabusa’s camera even show the spacecraft’s shadow, revealing how close the spacecraft came to the asteroid during its hover.

In a special issue of journal devoted to the Hayabusa mission, Fujiwara and his colleagues report that asteroid Itokawa has two parts, a smaller "head" and larger "body," giving it the shape of a sea otter, and appears to consist of rubble.

Asteroid structure has been a puzzle for scientists thus far. In theory, because of the pummeling that asteroids receive by other objects, they should be clusters of fragments that have re-accreted. Previously studied asteroids, however, generally appear to be lumps of solid rock.

"Although it is still unknown why these other asteroids do not show a rubble pile structure, at least now we have the first example of a rubble pile asteroid," said Fujiwara.

The rubble is very loosely packed and porous, just barely held together by the asteroid’s own gravity. If an object collided with Itokawa, it would probably be like a rock landing in a bucket of sand. The signs of impacts with small space rocks get erased as the rubble shifts after the impact, so there are very few craters on Itokawa.

The asteroid’s head-and-body structure might have arisen as the rubble shifted in response to impacts. Or, the head and body may once have been separate rubble piles that gradually merged.

Fujiwara and his colleagues report that, unlike previously explored asteroids, Itokawa’s surface has patches of both rough, boulder-strewn terrain and "seas" of uniformly sized, finer gravel particles, which appear velvety-smooth in the photographs from the mission. Hayabusa’s touchdown took place on one such smooth patch called "Muses Sea." (This is a play on words; Hayabusa was originally called MUSES-C).

Because it was designed to take samples from its destination and return them to Earth, the Hayabusa mission has also offered important engineering lessons. The spacecraft used an electronic ion propulsion system, whose efficiency should be critical to future missions in deep space, and autonomous navigation technology for its delicate approach and landing. Hayabusa also attempted a "touch and go" sampling effort intended to bring the first asteroid material back to Earth, but it may not have been successful.

The spacecraft, now low on fuel, is slowly gliding back to Earth, where it may drop its cargo capsule into the Australian desert in 2010.

The mission encountered several major technical difficulties, which Erik Asphaug of the University of California, Santa Cruz notes in a "Perspective" article that accompanies the research.

"Yet despite these heartbreaking setbacks, Hayabusa has been a stunning success for asteroid science and deep space concept testing, as reported in an exciting set of mission reports in this issue. These are the culmination of heroic efforts to make things go right in the face of multiple setbacks. Failures are not uncommon in deep space, and in this case ingenuity and perseverance paid off in remarkable ways," Asphaug writes.

Natasha Pinol | EurekAlert!
Further information:
http://www.sciencemag.org
http://www.aaas.org
http://www.eurekalert.org

More articles from Physics and Astronomy:

nachricht Tangled magnetic fields power cosmic particle accelerators
14.12.2018 | DOE/SLAC National Accelerator Laboratory

nachricht In search of missing worlds, Hubble finds a fast evaporating exoplanet
14.12.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>