2017.12.12:ついに来たーっ!木星の大赤斑に突入の動画公開

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ついにNASAが木星の大赤斑に大赤斑に突入した映像を、しかも動画で公開しました。

といってもイメージ動画ですが、なかなかのものです。

大赤斑は木星の大気の奥深くに発生源があると考えていた人が多かったのですが、驚いたことに木星大気の表面のごく浅いところに存在している巨大嵐なのかもしれません。

This animation takes the viewer on a simulated flight into, and then out of, Jupiter’s upper atmosphere at the location of the Great Red Spot. It was created by combining an image from the JunoCam imager on NASA’s Juno spacecraft with a computer-generated animation.
この動画は木星の大赤斑上空から、内部に突入してから外に出てくるまでをシミュレーションした画像で構成したものです。ジュノー搭載のジュノーカムで撮影した画像とCGとを組み合わせて動画にしています。

木星の大赤斑の謎にせまる

NASA’s Juno Probes the Depths of Jupiter’s Great Red Spot

This looping animation simulates the motion of clouds in Jupiter’s Great Red Spot. The animation was made by applying a wind movement model to a mosaic of JunoCam images.
Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/Justin Cowart
このGIFアニメーションは木星の大赤斑の雲の動きをシミュレートしています。ジュノーカムで撮影した画像を組合せてアニメーションにしたものです。

画像クリックで拡大表示します

This graphic shows a new radiation zone Juno detected surrounding Jupiter, located just above the atmosphere near the equator. Also indicated are regions of high-energy, heavy ions Juno observed at high latitudes.
Credits: NASA/JPL-Caltech/SwRI/JHUAPL
この画像はジュノーが検出した木星を取り囲む新しい放射線エリアを示したもので、赤津近くから大気上空へ拡がっています。また木星の高緯度で検出された高エネルギーの重イオン領域も示しています。

画像クリックで拡大表示します

This figure gives a look down into Jupiter’s Great Red Spot, using data from the microwave radiometer instrument onboard NASA’s Juno spacecraft. Each of the instrument’s six channels is sensitive to microwaves from different depths beneath the clouds
Credits: NASA/JPL-Caltech/SwRI
この画像はNASAのジュノー探査機搭載のマイクロ波放射計からのデータを使用して、木星の大赤斑の内部構造を表しものです。観測機の6つのチャンネルのそれぞれのマイクロ波は、雲の下の異なる深さでの状態を観測できます。

記事本文

Data collected by NASA’s Juno spacecraft during its first pass over Jupiter’s Great Red Spot in July 2017 indicate that this iconic feature penetrates well below the clouds. Other revelations from the mission include that Jupiter has two previously uncharted radiation zones. The findings were announced Monday at the annual American Geophysical Union meeting in New Orleans.
NASAのジュノー探査機が2017年7月に木星の大赤斑を初めて観測した際に収集されたデータです。今回の観測から木星には未知の2つの放射ゾーンがあることがわかりました。このデータは、ニューオーリンズで開かれた米国地球物理学連合(AMSA)の月曜日の会合で発表されました。

“One of the most basic questions about Jupiter’s Great Red Spot is: how deep are the roots?” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “Juno data indicate that the solar system’s most famous storm is almost one-and-a-half Earths wide, and has roots that penetrate about 200 miles (300 kilometers) into the planet’s atmosphere.”

The science instrument responsible for this in-depth revelation was Juno’s Microwave Radiometer (MWR). “Juno’s Microwave Radiometer has the unique capability to peer deep below Jupiter’s clouds,” said Michael Janssen, Juno co-investigator from NASA’s Jet Propulsion Laboratory in Pasadena, California. “It is proving to be an excellent instrument to help us get to the bottom of what makes the Great Red Spot so great.”

Jupiter’s Great Red Spot is a giant oval of crimson-colored clouds in Jupiter’s southern hemisphere that race counterclockwise around the oval’s perimeter with wind speeds greater than any storm on Earth. Measuring 10,000 miles (16,000 kilometers) in width as of April 3, 2017, the Great Red Spot is 1.3 times as wide as Earth.

“Juno found that the Great Red Spot’s roots go 50 to 100 times deeper than Earth’s oceans and are warmer at the base than they are at the top,” said Andy Ingersoll, professor of planetary science at Caltech and a Juno co-investigator. “Winds are associated with differences in temperature, and the warmth of the spot’s base explains the ferocious winds we see at the top of the atmosphere.”

The future of the Great Red Spot is still very much up for debate. While the storm has been monitored since 1830, it has possibly existed for more than 350 years. In the 19th century, the Great Red Spot was well over two Earths wide. But in modern times, the Great Red Spot appears to be diminishing in size, as measured by Earth-based telescopes and spacecraft. At the time NASA’s Voyagers 1 and 2 sped by Jupiter on their way to Saturn and beyond, in 1979, the Great Red Spot was twice Earth’s diameter. Today, measurements by Earth-based telescopes indicate the oval that Juno flew over has diminished in width by one-third and height by one-eighth since Voyager times.

Juno also has detected a new radiation zone, just above the gas giant’s atmosphere, near the equator. The zone includes energetic hydrogen, oxygen and sulfur ions moving at almost light speed.

“The closer you get to Jupiter, the weirder it gets,” said Heidi Becker, Juno’s radiation monitoring investigation lead at JPL. “We knew the radiation would probably surprise us, but we didn’t think we’d find a new radiation zone that close to the planet. We only found it because Juno’s unique orbit around Jupiter allows it to get really close to the cloud tops during science collection flybys, and we literally flew through it.”

The new zone was identified by the Jupiter Energetic Particle Detector Instrument (JEDI) investigation. The particles are believed to be derived from energetic neutral atoms (fast-moving ions with no electric charge) created in the gas around the Jupiter moons Io and Europa. The neutral atoms then become ions as their electrons are stripped away by interaction with the upper atmosphere of Jupiter.

Juno also found signatures of a high-energy heavy ion population within the inner edges of Jupiter’s relativistic electron radiation belt — a region dominated by electrons moving close to the speed of light. The signatures are observed during Juno’s high-latitude encounters with the electron belt, in regions never explored by prior spacecraft. The origin and exact species of these particles is not yet understood. Juno’s Stellar Reference Unit (SRU-1) star camera detects the signatures of this population as extremely high noise signatures in images collected by the mission’s radiation monitoring investigation.

To date, Juno has completed eight science passes over Jupiter. Juno’s ninth science pass will be on Dec. 16.

Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida, and arrived in orbit around Jupiter on July 4, 2016. During its mission of exploration, Juno soars low over the planet’s cloud tops — as close as about 2,100 miles (3,400 kilometers). During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of Caltech in Pasadena, California.

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov

Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington
202-358-1726 / 202-358-1077
dwayne.c.brown@nasa.gov / laura.l.cantillo@nasa.gov

Last Updated: Dec. 12, 2017
Editor: Tony Greicius

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