[meteorite-list] A "Strike" with a spare ball

[MexicoDoug]

A brief of this (current from space.com) was already posted to the list (Bob V. / Ron B.) as some onlookers mouths dropped in disbelief.  Personally it sounded like much fun and that there is plenty to learn from observing terminal velocitied meteoroid like objects smashing into the ground and studying the aftermath.
http://www.space.com/scienceastronomy/mystery_monday_040301.html
Bowling Ball Dropped from Airplane Simulates Meteor Impact

By Robert Roy Britt
Senior Science Writer
posted: 06:15 am ET
01 March 2004

On Feb. 13 a single-engine Cessna flew low over the Utah desert toward the Bonneville Seabase at 80 knots. Pilot Patrick Wiggins checked his altimeter. As planned, he was just 820 feet (250 meters) above the surface.

The mission's bombardier, Ann House, readied a 14-pound (6.5-kilogram) bowling ball in her lap and opened the right-side window. This was a test to see if she could safely manage getting the ball out the window. Wiggins called on the radio to make sure nobody was in the drop zone.

(Photo)
Patrick Wiggins and colleague Bruce Grim inspect the bowling ball, seen here as it ended up.

(Photo)
The bowling ball during less exciting times, along with acrylic spheres planned for use in future drops.

(Photo)
Bombardier Ann House with the bowling ball used in the drop from a Cessna.
"Then Ann opened the window and chucked the ball out."

Thus began an offbeat effort -- equal parts science and thrill seeking -- to learn what happens when space rocks hit the ground.

Do they bounce, stick or disappear? Nobody knows. An answer would help meteorite hunters figure out where and how to search for extraterrestrial material that rains down on the planet daily.

"It's perfectly legal, as long as you make sure nobody is going to get hurt," Wiggins said in a telephone interview last week after a night spent in his backyard observatory. "Admittedly there is an element of fun. I'm not going to deny that."

Wiggins is a volunteer "solar system ambassador" for NASA, working to spread good words about astronomy and the space program. But his colleagues -- other amateur astronomers and meteorite hunters with the Salt Lake Astronomical Society -- say he's involved in the current project more for the excitement of throwing things out of airplanes.

Indeed, next time Wiggins wants to don a parachute and jump out of the plane along with the bowling ball. More on the importance of that in a moment.

The idea

Space rocks hit Earth regularly. Small, iron-laden meteors can streak to the surface largely intact. Those made more of stone often vaporize. A car-sized asteroid can explode high up, only its fragments reaching the ground.

Space rocks as prized possessions. They are found, sold and traded by avid meteor hunters and collectors worldwide.

Scientists prize the chunks of iron and stone for the clues they carry to corners of the solar system that can't easily be studied directly. Meteorites can be chunks of primordial asteroids, or they can even come from Mars, from long ago asteroid collisions that kicked planetary bedrock dramatically into space.

Aerial bowling for science is partly the brainchild of Kim Hyatt, who works at an architectural firm by day.

Hyatt and others at the Salt Lake Astronomical Society think Utah's Bonneville Salt Flats -- a vast, dead, unchanging white sea of nothingness -- should be a good place to search for small, dark extraterrestrial rocks that have survived plunges through the atmosphere.

Perhaps, they figure, the meteorites will be pristine, sitting there for decades or centuries undisturbed and waiting to be studied for clues about the primitive solar system.

Preliminary rough searches of the salt flats, however, have not turned up much. Yet meteorites have been found in dry lakebeds elsewhere in Utah and in California, and also on the permanent ice of the arctic.

The bowling ball drop was the first of many planned schemes to understand what happens when falling objects hit the ground.

"If we determine it's going to bury in mud or punch through salt, then it might be a fruitless search," Hyatt told SPACE.com . "If we find that objects are just going to bounce on the salt or the mud flats, then they might sit there for centuries. Then we can get 20 to 30 people to space out, walk across the desert and see if we can pick some up."

Hyatt would also like to generate a science paper from the results of several drops.

The drop

The plan was hatched more than a year ago. When the Bureau of Land Management got wind that someone wanted to drop a bowling ball onto the salt flats, which it manages, officials were not pleased. Hyatt and his colleagues "have a challenge to present a formal proposal" that convinces the BLM the drops can be safe.

Meanwhile, Wiggins got permission to make a dent in the grounds of the privately run Bonneville Seabase. This sprawling but isolated destination for scuba divers is, as Wiggins describes it, "the only place in the desert where you can swim with sharks." And it is surrounded by unpopulated mud flats.

Wiggins checked with a local official of the Federal Aviation Administration, who said, "We don't need to be involved," then smiled and added, "unless something goes wrong."

The bowling ball hit the wet mud with a thud.

It was found partially embedded, its top half above the surface looking decidedly otherworldly. An ejecta blanket -- stuff kicked up by the collision -- spread 115 feet (35 meters) from the impact site. All the ejected material shot in one direction, indicating that the ball still had some horizontal velocity when it struck the ground.

Higher and more personal

The amateur researchers are eager to move to the salt flats for future drops. And they'd like to see if the bowling ball behaves differently when impacting dry mud.

They also plan to toss different sized spheres made of various materials, including lead, iron and acrylic, from the Cessna. One club member has a chunk of slag that is presumed to more closely resemble a real rock from beyond.

Wiggins hopes to make the next drop at more than a half-mile up (1,000 meters), from where an object should achieve "terminal velocity," or top vertical speed, zooming straight down and having lost all its horizontal movement induced by the airplane ride.

He also wants to jump with a bowling ball, reach his own terminal velocity -- he knows when that occurs -- and then drop the ball to observe its more streamlined shape race away from him.

It's not clear what scientific purpose that would serve, but it sounds like fun.

"We're pretty sure it's going to leave us in the dust," he says of the bowling ball. "We've done this before with pumpkins. People have trouble keeping up with pumpkins."

from our friends at Space.com