Original (left) and new (right) spots.
The world has long been familiar with Jupiter's "Great Red Spot," a swirling storm twice as wide as Earth that's lasted for at least 300 years. Now it may have a rival. In 2000, scientists spotted a large, white-colored oval on Jupiter, the product of three smaller storms merging. But it took amateur astronomer Christopher Go of the Philippines to notice that the spot, dubbed Oval BA, morphed from white to grayish-brown in December. Since late February, it has taken on the rusty red hue of its larger sibling.
Scientists aren't sure of the reasons for the change, says astronomer Glenn Orton of the Jet Propulsion Lab in Pasadena, California. He and others hypothesize that particularly violent storms propel material from under Jupiter's clouds higher into the atmosphere, where the sun's radiation then sparks a chemical reaction to turn the material red. Other jovian white spots have temporarily turned red in the past; astronomers are curious to see if this one lasts.
CREDIT: CHRISTOPHER GO
