The Great Red Spot in Jupiter Likely to be a Massive Heat Source in its upper atmosphere
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| Artist’s concept of the heating mechanism from Jupiter’s Great Red Spot Credits: Art by Karen Teramura, UH IfA with James O’Donoghue and Luke Moore |
A new research funded by NASA suggests that Jupiter’s Great Red Spot may be the mysterious heat source behind Jupiter’s surprisingly high upper atmospheric temperatures. The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made of molecular hydrogen and helium in roughly solar proportions; other chemical compounds are present only in small amounts and include methane, ammonia, hydrogen sulphide and water.
Here on Earth, sunlight heats the atmosphere at altitudes well above the surface—for example, at 400 kilometres above our planet where the International Space Station orbits. Scientists have been stumped as to why temperatures in Jupiter’s upper atmosphere are comparable to those found at Earth, yet Jupiter is more than five times the distance from the sun. They wanted to know: if the sun isn’t the heat source, then what is?
Researchers from Boston University’s Center for Space Physics set out to solve the mystery by mapping temperatures well above Jupiter’s cloud tops using observations from Earth. They analyzed data from the SpeX spectrometer at NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, a 3-meter infrared telescope operated for NASA by the University of Hawaii. By observing non-visible infrared light hundreds of miles above the gas giant, scientists found temperatures to be much higher in certain latitudes and longitudes in Jupiter’s southern hemisphere, where the spot is located.
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| NASA's Infrared Telescope Facility atop Mauna Kea, Hawaii Credit: NASA's Jet Propulsion Laboratory. Copyright Ernie Mastroianni |
“We could see almost immediately that our maximum temperatures at high altitudes were above the Great Red Spot far below—a weird coincidence or a major clue?” said Boston University’s James O’Donoghue, lead author of the study.
The study, in the July 27 issue of the journal Nature, concludes that the storm in the Great Red Spot produces two kinds of turbulent energy waves that collide and heat the upper atmosphere. Gravity waves are much like how a guitar string moves when plucked, while acoustic waves are compressions of the air (sound waves). Heating in the upper atmosphere 500 miles (800 kilometers) above the Great Red Spot is thought to be caused by a combination of these two wave types “crashing,” like ocean waves on a beach.
“The extremely high temperatures observed above the storm appear to be the ‘smoking gun’ of this energy transfer,” said O’Donoghue. “This tells us that planet-wide heating is a plausible explanation for the ‘energy crisis,’ a problem in which upper-atmospheric temperatures are measured hundreds of degrees hotter than can be explained by sunlight alone.”
This effect has been observed over the Andes Mountains here on Earth and may also be happening elsewhere in the outer solar system, though it has not been directly observed. Scientists believe this phenomenon also occurs on giant exoplanets orbiting other stars.
The Great Red Spot (GRS) has delighted and mystified since its discovery in the 17th Century by the English Scientist Robert Hooke With its swirl of reddish hues, it’s 2-3 times as wide as Earth and is seen by many as a “perpetual hurricane,” with winds peaking at about 650 kilometres per hour.
NASA's Juno spacecraft, which recently arrived at Jupiter, will have several opportunities during its 20-month mission to observe the Great Red Spot and the turbulent region surrounding it. Juno will peer hundreds of kilometres 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.
Sources: NASA, Wikipedia
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La gran mancha roja de Júpiter posible gran fuente de calor de su atmósfera superior
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| A visual comparison of Jupiter, Earth, and the Great Red Spot. Credit: Wikipedia |
Una nueva investigación financiada por la NASA sugiere que la gran mancha roja de Júpiter podría ser la misteriosa fuente de calor detrás de la sorprendentemente alta temperatura de su atmósfera superior. La atmósfera de Júpiter es la atmósfera planetaria de mayor tamaño en todo el Sistema Solar. Está compuesta principalmente por hidrógeno molecular y helio en una proporción comparable con la de una estrella; también se encuentran presentes otras sustancias químicas, aunque en pequeñas medidas, tales como el metano, amoníaco, ácido sulfhídrico y agua.
Aquí en la tierra, la luz solar calienta la atmosfera superior a altitudes muy superiores a la superficie— por ejemplo, a 400 kilómetros de altura donde orbita la Estación Especial Internacional. Los científicos están sorprendidos de cómo las temperaturas de la atmosfera superior de Júpiter son comparables a las que tenemos de la Tierra, aun estando a cinco veces más distancia del sol. Querían saber: ¿si el sol no es tal fuente de calor, entonces que lo es?
Investigadores del Centro de Física del Espacio de la Universidad de Boston han decidido resolver este misterio cartografiando temperaturas muy por encima de las nubes de Júpiter a través de observaciones desde la Tierra. Han analizado la información del Espectrómetro SpeX de las instalaciones del Telescopio Infrarrojo de la NASA (IRTF) en Mauna Kea, Hawái. Con la observación de luz infrarroja no visible a cientos de kilómetros por encima del gigante gaseoso, los científicos han encontrado que las temperaturas son mucho más altas en ciertas latitudes y longitudes del hemisferio sur de Jupiter, en donde se encuentra la gran mancha roja.
“Podíamos ver de forma casi inmediata que las máximas temperaturas en altitudes altas eran por encima de la gran mancha roja justo debajo—¿una extraña coincidencia o gran pista?” dijo James O’Donoghue de la Universidad de Boston, líder de las investigaciones.
The study, in the July 27 issue of the journal Nature, concludes that the storm in the Great Red Spot produces two kinds of turbulent energy waves that collide and heat the upper atmosphere. Gravity waves are much like how a guitar string moves when plucked, while acoustic waves are compressions of the air (sound waves). Heating in the upper atmosphere 500 miles (800 kilometers) above the Great Red Spot is thought to be caused by a combination of these two wave types “crashing,” like ocean waves on a beach.
“The extremely high temperatures observed above the storm appear to be the ‘smoking gun’ of this energy transfer,” said O’Donoghue. “This tells us that planet-wide heating is a plausible explanation for the ‘energy crisis,’ a problem in which upper-atmospheric temperatures are measured hundreds of degrees hotter than can be explained by sunlight alone.”
Este efecto ha sido observado sobre las montañas de los Andes aquí en la Tierra y quizás esté pasando en algún lugar más del Sistema Solar exterior, aun no habiéndose observado directamente. Los científicos creen que este fenómeno también ocurre en los exoplanetas gigantes que orbitan otras estrellas.
La Gran Mancha Roja (GMR) has encandilado y ha sido fuente de misterio desde su descubrimiento en el siglo 17 por el científico Ingles Robert Hooke. Con sus remolinos de tonos rojos, y que es de dos a tres veces el ancho de la Tierra y es visto por muchos como un “huracán perpetuo”, con vientos que alcanzan un máximo de casi 650 kilómetros por hora.
La misión de la NASA Juno, que recientemente ha llegado a Júpiter, tendrá varias oportunidades de observar la gran mancha roja y las turbulentas regiones que la rodean en su misión de 20 meses. Juno mirara cientos de kilómetros hacia abajo hacia la atmosfera con su radiómetro de microondas, que pasivamente detecta el calor desde la superficie de Júpiter y que emana del planeta. Esta capacidad hará que Juno revele la estructura profunda de la gran mancha roja, junto a otros destacados elementos jovianos, como lo son sus coloridas bandas.
Sources: NASA, Wikipedia
