Nothing has ever come closer than NASA’s Voyager 1, nearly 40 years ago. Last week, all that changed.
“Juno will peer hundreds of miles downward into the atmosphere with its microwave radiometer, which passively senses heat coming from within the planet. This capability will enable Juno to reveal the deep structure of the Great Red Spot, along with other prominent Jovian features, such as the colorful cloud bands.” –Tricia Talbert
Jupiter is the Solar System’s largest planet, with the largest continuously-raging storm ever known.
Jupiter’s Great Red Spot (GRS) was discovered in 1665, raging continuously from at least 1830 until today.
The spot appeared solid and larger in the early 20th century, but appeared smaller and more storm-like when Voyager 1 flew past in 1979.
At its maximum, the GRS was 40,000 kilometers across: more than three Earth diameters long.
It’s barely half that extent today; if the shrinking continues, it will be completely circular by 2040.
There are three theories as to why it’s red:
an organic compound,
or a reddish sulphur compound: ammonium hydrosulfide.
Juno, celebrating its one-year anniversary orbiting Jupiter, is equipped with cloud-penetrating instruments to find out.
The GRS is colder and higher in altitude (by about 8 kilometers) than the rest of Jupiter’s atmosphere.
In theory, chemical and atmospheric processes occurring below the cloud-tops powers this storm.
With 600+ km/hr winds, this storm is much faster than any winds ever known on Earth.
Juno observed the Great Red Spot last week, 9,000 kilometers up, with all 8 instruments and its JunoCam imager.
Contingent upon new data, many mysteries might finally be solved.
Mostly Mute Monday tells the astronomical story of an astronomical object, phenomenon or mission in images, visuals, video and no more than 200 words.