VOA科学技术2024--Severe Solar Storm Hits Earth, Causing Colorful Light Shows（在线收听）

Earth was recently hit by the most powerful solar storm in more than 20 years.

The storm caused some colorful light shows in some parts of the world, but no major damage was reported. Solar storms can hurt the operation of some equipment on Earth that uses radio waves. This includes GPS services, electrical systems and satellites.

The U.S. National Oceanic and Atmospheric Administration (NOAA) issued warnings about the storm before it reached Earth on May 10. In a statement, NOAA said it had observed heavy solar storm activity in the days before. Based on the activity, the agency issued a Geomagnetic Storm Warning.

Solar storms can involve two different processes. One is called a solar flare, while the other is a coronal mass ejection (CME). Both involve huge releases from the sun of magnetic field energy and a substance called plasma. The American space agency NASA explains that plasma is a form of matter made up of ionized particles. This means the particles have taken in so much energy that it causes electrons to separate from their atoms.

Solar flares travel at the speed of light in all directions. They can reach Earth in about eight minutes. But CMEs travel much slower. They reach Earth in one to three days. NOAA said a strong "solar flare event" had led to the latest CMEs hitting Earth.

NASA says its observatories see solar flares as flashes of light on the sun, while CMEs are seen as large explosions spreading out into space. The agency examines data from its Parker Solar Probe on plasma flowing out of the sun's corona.

Because the latest CME explosions were directed at Earth, they caused geomagnetic storms. NOAA's Space Weather Prediction Center issued a warning, calling the storm activity "an unusual and potentially historic event."

NOAA noted that such storms can cause problems for some communication systems. The agency informed major power operators and NASA officials about the storm activity. The electric power grid can also be affected, or disrupted, along with radio, satellite and spacecraft operations.

NOAA noted that severe geomagnetic storms can also produce intense, colorful light shows, or displays, in the sky. Such shows are also known as auroras.

Colorful displays could be seen overnight in different parts of the world. Reuters news agency reported on several areas in Latin America experiencing auroras after the solar storm activity. In Mexico's desert city of Mexicali, pink and purple light could be seen lighting up the night sky last Friday and Saturday.

In Chile, Reuters reported local media and social media users shared photos of the sky in the city of Punta Arenas, where the lights took on red and purple tones. Local media in Argentina also reported similar displays in the Patagonian city of Ushuaia.

The French news agency AFP reported social media services were filled up with people publishing images of auroras from areas including northern Europe and Australasia.

Iain Mansfield lives in Hertford, Britain. He told AFP, "We've just woken the kids to go watch the Northern Lights in the back garden! Clearly visible with the naked eye."

Other people also compared the intense color shows to the Northern Lights. Sometimes also called aurora borealis, the Northern Lights are natural, colored light displays that sometimes appear in the night sky in the most northern parts of the world.

From Australia's island state of Tasmania, photographer Sean O' Riordan published a message on X explaining what he saw. "Absolutely biblical skies in Tasmania at 4am this morning. I'm leaving today and knew I could not pass up this opportunity."

People in the United States were also able to see colorful auroras, including parts of the West Coast and as far south as Alabama.

The most intense solar storm in recorded history happened in 1859. It mainly produced auroras in Central America. A severe geomagnetic storm in 2003 cut power in Sweden and damaged power transformers in South Africa.

Storm activity coming from the sun generally intensifies as it reaches the height of a repeating, 11-year solar cycle. The activity increases as the sun experiences magnetic field changes that affect its polar areas

Words in This Story

potential - adj. possible when the necessary conditions exist

grid - n. a system of wires through which electricity is connected to different power stations across a particular area

tone - n. a form or degree of color

garden - n. a piece of land, usually in a yard next to a house, where things are grown

the naked eye - n. something that can be seen with just the eyes, without the need for devices or special equipment

opportunity - n. the chance to do something