‘Question-mark-shaped cloud’ left after meteor streaks across California sky
A bright object that streaked across the sunset sky in the San Francisco Bay Area in California left a trail that some described as resembling a shining question mark, with many locals confused about what could have caused it.
- The National Weather Service and Lick Observatory both suggested a meteor caused the strange cloud
- The curled shape with a gleaming tail stayed visible in the sky for some time
- NASA said meteor smoke could make strange clouds called noctilucent clouds
Numerous Bay Area residents captured video and photos of the object and the gleaming trail it left behind in the sky, and posted to social media with questions about what they were.
It left behind a curled shape with a luminous tail trailing after it that stayed visible in the sky for some time as the sun was setting, and looked distinctly like a giant question mark.
Images captured minutes after a meteor streaked across the sky showed a strangely shaped cloud. (Photo: @GoGoSirico via Storyful)
The local National Weather Service (NWS) tweeted a photo of the light and said it thought the object that caused the unusual cloud formation could have been a meteor.
@NWSBayArea: Anyone else see this interesting cloud feature? We saw it here at the office.
@NWSBayArea: Still not 100% certain, but evidence is growing the object seen was a meteor. A meteor can create a very high level cloud called a noctilucent cloud.
The Lick Observatory in San Jose, however, was more certain.
“A bright meteor was visible in the skies over the Bay Area shortly after sunset this evening, leaving a bright trail that was visible for many minutes in the western sky,” it said in a statement on Facebook.
According to NASA, smoke from meteors can create unusual “noctilucent” clouds that shine in twilight or night-time skies.
“Anyone who’s ever seen a noctilucent cloud or ‘NLC’ would agree: They look alien,” it said it a statement on its website.
“The electric-blue ripples and pale tendrils of NLCs reaching across the night sky resemble something from another world.”
According to NASA, noctilucent cloud-spotting has dated back to the late 19th century.
They were first noticed in 1885, about two years after the eruption of Indonesian volcano Krakatoa, when ash caused such dramatic sunsets that watching the sky in the evening became a global pastime.
A German man named TW Backhouse is often credited with first discovering NLCs, NASA said, after he noticed wispy filaments glowing electric blue against the sky on some evenings.
Scientists at the time thought they were remnants of volcanic dust, but they did not dissipate after the ash from the Krakatoa eruption finally settled.
Researchers now believe it is space dust that causes the unusual cloud formations, NASA said.
In the 19th century, NLCs were mostly spotted in higher latitude countries such as Canada, and those throughout Scandinavia.
More recently though, NASA said, they have been seen further south in Colorado, Utah, Nebraska — and now, it seems, California.