Astronomy - June 2015

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measurements indicate that thousands of
pounds of these meteoric debris breach
our atmosphere each day and find their
way to the surface, where their organics
play a role in earthly biology. Most of this
cosmic dust is too small to create meteors.
Sometimes the rocks are large enough
to put on a show. Astronomers call these
night-sky streakers “fireballs” when they
f lare brighter than Venus.
And that’s the information New Mexico
State University scientists are after. As the
number of meteor observations increases,
their All Sky Camera Network aims to cre-
ate overlapping fields of view so that sev-
eral cameras can catch the same fireball,
allowing astronomers to find its speed and

height. With sufficient imaging, research-

ers can calculate the meteor’s original orbit

and help determine whether the object

began life as a comet or an asteroid.

“They’re hauling butt, so they’ve got a lot

of energy,” says Bill Cooke, who runs

NASA’s Meteoroid Environment Office at

the Marshall Space Flight Center in Ala-

bama. “A lot of people underestimate the

amount of energy meteors have.” While an

average fireball is typically about a milli-

meter to a centimeter in size, it’s entering

Earth’s atmosphere at anywhere from 25,000

mph (11 km/s) to 160,000 mph (72 km/s).

“If that hits you, it’s like I shot you with

a .357 magnum,” Cooke says. “That’s why

we worry about orbiting debris so much.

A particle smaller than a millimeter can go

right through a space suit.”

Part of the network’s initial funding and

goals also stem from a desire to show the

U.S. government’s satellites how to tell the

difference between natural and man-made

atmospheric explosions. In some cases, it

even can help meteorite hunters like Schoner

track down the rock if it survived the fall.

Shooting star survey

Schoner has been involved with this

network from his home in Flagstaff,

Arizona, since 2012. And his camera isn’t

just mounted on any rooftop; this is the

former home of Pluto discoverer Clyde

Tombaugh. So far, Schoner has caught five

The Chelyabinsk fireball lit up the skies over Russia

in 2013. Asteroid expert Mark Boslough and col-

leagues used witnesses’ photos to re-create its path

in this digital rendition made on a supercomputer.

3-D SIMULATION: M. BOSLOUGH AND B. CARVEY; TAIL COMPOSITE: A. CARVEY;

IMAGE: O. KRUGLOVA/SANDIA NATIONAL LABS