green fireball
© Unknown
Astronomical observations are based on the detection of visible light as well as other energy forms all across the electromagnetic spectrum, from radio waves to gamma radiation. Although certain kinds of radiation, such as radio waves, may be converted electronically into sound waves, thus producing hissing and humming sounds detectable to the human ear, people do not tend to think of astronomers listening directly to the actual sounds emanating from heavenly bodies.

I thought so, too.

That is, until a couple of nights ago, when something strange was heard coming out of the night sky.

A close friend owns a vacation home near the summit of one of the tallest mountains in West Virginia. And of those tallest mountains, his house peers down from one of the few where privately owned habitable dwellings exist. The elevation of the house is 4,440 feet above sea level.

On Sunday night, we were observing planets, nebulae, star clusters and galaxies with his largest telescope. The views through it were tremendous thanks to the dark skies free from the garish glare from any tawdry and gaudy man-made outdoor lighting fixtures, the thinner drier air found at that altitude and by the light gathering power of the large 24-inch diameter telescope mirror.

I was up on a ladder soaking in the view when the image field suddenly faded to green. Looking away from the eyepiece I noticed the surroundings had suddenly become brightly illuminated as if during the daytime, yet bathed in an eerie bright green light. Not as bright as sunlight, the illumination was nevertheless many times brighter than the full moon.

Right away I knew it was a meteor, and I looked up.

It was brilliant.

Like a burning green emerald trailing a short tail of what appeared to be sizzling orange sparks as the meteoroid was being ablated by friction caused by the heat of entry into the Earth's atmosphere. It was traveling from east to west and was nearly straight overhead and the stars were all washed out due to its brilliance.

When it was over, I looked at my watch. It was 11:03 p.m. The whole thing lasted less than 10 seconds.

My friend and I both agreed we have never seen a fireball meteor as bright as this one. Although we have each seen several in the past, no previous sighting was nearly as bright as the one observed that night. The spectacle would make it a night to long remember.

After a minute or two, our excitement had abated. We returned to our regularly scheduled observations of spring galaxies and summer Milky Way objects.

Suddenly, we heard a noise from the direction where the meteor was last observed. It sounded like a distant rumbling boom and came two-to-three minutes after the fireball's disappearance.

It was a first for us. Not only was this the brightest fireball we'd ever seen, it was also the first one that generated a sound.

Upon returning to civilization, I checked some meteor tracking websites and discovered numerous posted reports from observers in several other states including Maryland, Pennsylvania, North Carolina and Ohio. Several of the West Virginia based observers also reported hearing noise associated with the meteor. They left various descriptions of the sound, including "a static sound," "a low boom," "a large explosion like boom," "a crashing sound," "loud boom, explosion" and "sound like loud rolling thunder."

It was the first time I actually heard an astronomical observation with my own ears. If you have experienced sound associated with an observed meteorite, please share it by sending me an email description.

Curtis Roelle is a member of the Astronomical Society. His column appears the first Sunday of each month. His website is www.starpoints.org, and he can be reached at StarPoints (at) gmail (dot) com.