One fundamental difficulty is that we do not know exactly where the majority of meteorite specimens come from within the asteroidal main belt. For many years, astronomers failed to discover the parent body of the most common meteorites, the ordinary chondrites that represent 75% of all the collected meteorites.

To find the source asteroid of a meteorite, astronomers must compare the spectra of the meteorite specimen to those of asteroids. This is a difficult task because meteorites and their parent bodies underwent different processes after the meteorite was ejected. In particular, asteroidal surfaces are known to be altered by a process called “space weathering”, which is probably caused by micrometeorite and solar wind action that progressively transforms the spectra of asteroidal surfaces. Hence, the spectral properties of asteroids become different from those of their associated meteorites, making the identification of asteroidal parent body more difficult.

Collisions are the main process to affect asteroids. As a consequence of a strong impact, an asteroid can be broken up, its fragments following the same orbit as the primary asteroid. These fragments constitute what astronomers call “asteroid families”. Until recently, most of the known asteroid families have been very old (they were formed 100 million to billions of years ago). Indeed, younger families are more difficult to detect because asteroids are closer to each other [2]. In 2006, four new, extremely young asteroid families were identified, with an age ranging from 50000 to 600000 years. These fragments should be less affected than older families by space weathering after the initial breakup. Mothé-Diniz and Nesvorný then observed these asteroids, using the GEMINI telescopes (one located in Hawaii, the other in Chile), and obtained visible spectra. They compared the asteroids spectra to the one of an ordinary chondrite (the Fayetteville meteorite [3]) and found good agreement.

He’s in good company too, with rock and roll’s Frank Zappa just one of the famous names to make the list. Several Canadian cities and universities have also been honoured, including Saint Mary’s in Halifax, where Mr. Lane works as a systems administrator in the astronomy and physics department.

The difference is that these stars — asteroids orbiting the sun, to be precise — are far from some earthly sidewalk.

“It’s amazing,” Mr. Lane said Thursday of the special recognition he received last weekend at the national general assembly of the Royal Astronomical Society of Canada in Toronto.

“I know a few people who have asteroids named after them and it’s the kind of thing where, if you’re into astronomy, you kind of hope some day in your life that someone will name one after you,” he said. “You kind of have to wait until someone thinks of (you).”

Mr. Lane, also recently named president of the Royal Astronomical Society of Canada, has along with Atlantic Canadian amateur astronomer Paul Gray discovered a few supernovas, which are bright exploding stars. But he said scientists who discover asteroids never name their findings after themselves.

He was pleasantly surprised by the decision of David Levy, Wendee Levy and Tom Glinos to name their May 2004 asteroid discovery from the Jarnac Observatory in Arizona after him. The discoverers also cite Mr. Lane’s Earth Centered Universe software, “a brilliantly easy-to-use planetarium and telescope-control program,” as one of the reasons they think he’s out of this world.

The asteroid, named 117032 David-lane, can be found between the orbits of Mars and Jupiter.

Mr. Lane said it’s about five kilometres in diameter, “so it’s about the size of a city,” but said he can’t yet see it from Abbey Ridge Observatory, which is located in his backyard in Stillwater Lake, near Upper Tantallon.

“The Tunguska event just 100 years ago reminds us that the threat of an asteroid strike is real,” said Ray Williamson, Executive Director of the Secure World Foundation (SWF). “If that object had struck in New York City or London, it would have killed hundreds of thousands and created untold fear in human hearts. Yet, as near Earth object strikes go, it was relatively small,” he pointed out.

“We need to be much better prepared than we are today to deal with this important, if uncommon, threat by creating the international institutions and governance methods to find objects likely to strike Earth and devise the means to divert them from Earth’s path,” Williamson explained.

Action agenda

Thwarting the threat of Earth-colliding asteroids – is on the action agenda list for former Apollo astronaut, Russell L. (Rusty) Schweickart.

While a civilization-smashing impact from a space object is a low probability, it is not zero…and there are other trouble-makers out there too. They are the smaller asteroids, in far greater number and could wreak havoc on our world, but in a more localized way.

Speaking recently at a Secure World Foundation luncheon at the University of Colorado - Boulder, Schweickart emphasized that what is needed is an international protocol – “mission rules” — that deal with asteroids that are menacing to Earth. Such a plan could calls upon nations around the globe to consider and embrace steps that can help mitigate the destructive nature stemming from an asteroid striking our planet.

Tree of life

Schweickart’s talk drew from his chairman position of the Association of Space Explorers’ Committee on Near Earth Objects and as Chairman of the B612 Foundation, dedicated to detecting, tracking and deflecting near Earth objects (NEOs).

Coming to grips with the NEO challenge, Schweickart emphasized, is more a matter of humanity’s readiness not to be dinosaurs – thought by many scientists to have been the victims of a huge asteroid impact some 65 million years ago. And that’s why we on Earth, he added, are faced with a key question: “To be…or not to be?”

Indeed, over billions of years, the Tree of Life here on Earth has been whacked time and time again by what Schweickart labeled as “the crazy cosmic gardener.”

“The good news is that we can do something about this,” the former astronaut explained. “The marriage of we human beings and the machines that we’ve created are now at a level of capability which enables us to fire the crazy cosmic gardener. We can stop this process from occurring again.”

Now, a research team led by Brown University planetary geologist James Head has determined that volcanism played a central role in forming Mercury’s surface. In a paper that appears in the July 4 issue of Science, part of a special section describing the MESSENGER spacecraft’s first flyby of Mercury, the researchers have found evidence of past volcanic activity, suggesting that the planet underwent an intense bout of changes to its landscape about 3 to 4 billion years ago – and that the source for much of that reshaping was within.

“What this shows is that Mercury was not dead on arrival,” says Head, the paper’s lead author. “It had a pulse for a while. Now, we want to know when it had that pulse and what caused it to slow down and eventually stop.”

A major clue to Mercury’s geologic past came from the scientists’ finding of volcanic vents along the margins of the Caloris basin, one of the solar system’s largest and youngest impact basins. The group zeroed in on a kidney-shaped depression that was surrounded by a bright ring, lending a halo-like impression to the landscape. The scientists determined that the depression was a volcanic vent, and the bright ring around it was pyroclastic, remnants of lava that had been spewed outward, much like a volcanic fountain on Earth.

Another larger ring surrounding the vent and halo ring showed that another type of volcanism, called effusion, in which molten rock from within the planet oozes outward and covers the surface, had occurred. Together these deposits create a surface feature shaped like a volcanic shield – a clear sign to scientists that volcanic activity helped form the surrounding plains.

 They are deep and dense, and not even light can escape their grip. We’re talking about black holes, but they may not be as dark as you think.

“If you have binoculars, you might be able to make out a smudge, which would be the nearest galaxies,” says Jon Miller, an assistant professor of astronomy at the University of Michigan in Ann Arbor.

But what you won’t see — even with a telescope — black holes! In fact, Miller doesn’t even use one to study black holes. He uses his computer.

“I think it’s really for the best that NASA doesn’t let people like me drive billion-dollar satellites. So instead, we get data distributed through the computer networks,” Miller tells DBIS.

These data reveal just how complex black holes are. As gravity pulls matter into the hole, it is heated 1,000-times hotter than the sun and forms mega-heated gases. As the hole’s magnetic field pulls these gases into its center, it creates a light show.