Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Large asteroid is two orbiting objects

24.10.2003


An asteroid that has eluded astronomers for decades turns out to be an unusual pair of objects traveling together in space, a UCLA planetary scientist and colleagues report.



The asteroid Hermes was rediscovered last week after being lost for 66 years. Now Jean-Luc Margot, a researcher in UCLA’s department of Earth and space sciences, has determined that the asteroid is, in fact, two objects orbiting each other. The two objects together would cover an area approximately the size of Disneyland.

Margot and colleagues are analyzing new radar measurements from the Arecibo Observatory, part of the National Astronomy and Ionosphere Center, which is operated by Cornell University under a cooperative agreement with the National Science Foundation. The researchers are scheduled to obtain additional measurements Oct. 25–26 from the observatory, located in Puerto Rico.


Hermes makes frequent close approaches to Earth, Venus and Mars, as well as Vesta, the third-largest asteroid in the main asteroid belt between Mars and Jupiter.

While several other asteroids have satellites, the other known binaries with trajectories that cross the orbit of the Earth consist of a large primary asteroid orbited by a much smaller one.

"Hermes is the first asteroid ever discovered in the near-Earth population where the two components are essentially equal in size," Margot said. "It’s a very unusual binary, a puzzle. It may have formed when it swung so close to a planet that it was ripped apart by gravitational forces, but we don’t know for sure. One of our goals is to learn more about the two components and how they rotate about each other in the hopes that we may be able to deduce how Hermes became a double asteroid.

"Because the components are close to each other, they raise appreciable tides in each other and each has slowed down the other’s spin significantly. They are now likely in a doubly synchronous state, where their spin period is equal to their orbital period. This means they constantly present the same face to each other, just like Pluto and its satellite Charon."

A fast-moving bright object was observed in 1937, named Hermes, and went undetected until last week, although it had revolved around the Sun almost 31 times since then, escaping notice, said Brian Marsden, of the Minor Planet Center in Cambridge, Mass.

On Oct. 15, Brian Skiff of the Lowell Observatory Near-Earth-Object Search sighted the mysterious object; Timothy Spahr at the Minor Planet Center identified similarities with the 1937 observations; and Steven Chesley and Paul Chodas at NASA’s Jet Propulsion Laboratory (JPL) linked the observations to Hermes.

The same day, Margot and his team proposed to observe the asteroid with the Arecibo Observatory’s high-powered radar system -- a proposal that was accepted within hours.

The goals of the proposal were to measure precisely the distance and velocity of this object, to improve the knowledge of its trajectory and help trace back its history, to characterize Hermes’ physical properties, and to search for satellites.

Margot and collaborators have been given five sessions at Arecibo and sessions at the Goldstone radar in California to observe Hermes. Due to the urgent nature of the proposal, Margot observed from his home computer while Mike Nolan, Victor Negron, Alice Hine and Don Campbell were at the Arecibo telescope.

Hermes gets as close as 378 000 miles from Earth -- which, in astronomical terms, is quite close, about 1.6 times the distance between Earth and the moon. Orbits can change appreciably over time due to gravitational influences of the planets, noted Mike Nolan, an Arecibo Observatory scientist and member of the team.

Hermes travels on an elliptical orbit and reaches deep into the inner solar system, crossing Venus’ orbit. The new research has made it possible to extend the time interval over which the trajectory can be computed reliably, said Jon Giorgini, a senior engineer at JPL and member of the team.

"As far as impact risk, there is no cause for worry in our lifetimes," Giorgini said. "Over hundreds of thousands, or millions of years, Hermes could impact the Earth, but only if it doesn’t hit Venus first."

Margot and colleagues described their observations and data in an International Astronomical Union Circular this week. Margot’s research is funded by NASA. His co-authors are Michael Nolan, Victor Negron, Alice Hine, Donald Campbell and Ellen Howell at the National Astronomy and Ionosphere Center; Lance Benner, Steven Ostro and Jon Giorgini at JPL; and Brian Marsden at the Minor Planet Center.

Stuart Wolpert | EurekAlert!
Further information:
http://www2.ess.ucla.edu/~jlmargot/NEAs/Hermes

More articles from Physics and Astronomy:

nachricht Discovery of an Extragalactic Hot Molecular Core
29.09.2016 | National Astronomical Observatory of Japan

nachricht Swiss space research reaches for the sky
29.09.2016 | Schweizerischer Nationalfonds SNF

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: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>