Posted on

NASA Unveils Thrilling First Full Frame Images of Vesta from Dawn

[/caption]

NASA has just released the first full frame images of Vesta– and they are thrilling! The new images unveil Vesta as a real world with extraordinarily varied surface details and in crispy clear high resolution for the first time in human history.

Vesta appears totally alien and completely unique. “It is one of the last major uncharted worlds in our solar system,” says Dr. Marc Rayman, Dawn’s chief engineer and mission manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Now that we are in orbit we can see that it’s a unique and fascinating place.”

“We have been calling Vesta the smallest terrestrial planet,” said Chris Russell, Dawn’s principal investigator at the UCLA. “The latest imagery provides much justification for our expectations. They show that a variety of processes were once at work on the surface of Vesta and provide extensive evidence for Vesta’s planetary aspirations.”

Dawn launch on September 27, 2007 by a Delta II Heavy rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

The newly published image (shown above) was taken at a distance of 3,200 miles (5,200 kilometers) by Dawn’s framing camera as the probe continues spiraling down to her initial science survey orbit of some 1,700 miles (2,700 km) altitude. The new images show the entire globe all the way since the giant asteroid turns on its axis once every five hours and 20 minutes.

Vesta and its new moon – Dawn – are approximately 114 million miles (184 million kilometers) distant away from Earth.

“The new observations of Vesta are an inspirational reminder of the wonders unveiled through ongoing exploration of our solar system,” said Jim Green, planetary division director at NASA Headquarters in Washington.

The Dark Side of Vesta Captured by Dawn
NASA's Dawn spacecraft obtained this image over the northern hemisphere with its framing camera on July 23, 2011. It was taken from a distance of about 3,200 miles (5,200 kilometers) away from the giant asteroid Vesta. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn was launched atop a Delta II Heavy booster rocket in September 2007, took a gravity assist as it flew past Mars and has been thrusting with exotic ion propulsion for about 70 percent of the time ever since.

Dawn will spend 1 year collecting science data in orbit around Vesta before heading off to the Dwarf Planet Ceres.

The science team has just completed their press briefing. Watch for my more detailed report upcoming soon.

And don’t forget JUNO launches on Aug 5 – It’s an exciting week for NASA Space Science and I’ll be reporting on the Jupiter orbiter’s blastoff and more – as Opportunity closes in on Spirit Point !

NASA’s groundbreaking interplanetary science is all inter connected – because Vesta and Ceres failed to form into full-fledged planets thanks to the disruptive influence of Jupiter.

Read my prior features about Dawn
Dawn Spirals Down Closer to Vesta’s South Pole Impact Basin
First Ever Vesta Vistas from Orbit – in 2D and 3D
Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Dawn Begins Approach to Asteroid Vesta and Snaps First Images
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on

JUNO Orbiter Mated to Mightiest Atlas rocket for Aug. 5 Blastoff to Jupiter

[/caption]

In less than one week’s time, NASA’s $1.1 Billion Juno probe will blast off on the most powerful Atlas V rocket ever built and embark on a five year cruise to Jupiter where it will seek to elucidate the mysteries of the birth and evolution of our solar system’s largest planet and how that knowledge applies to the remaining planets.

The stage was set for Juno’s liftoff on August 5 at 11:34 a.m. after the solar-powered spacecraft was mated atop the Atlas V rocket at Space Launch Complex 41 at Cape Canaveral and firmly bolted in place at 10:42 a.m. EDT on July 27.

“We’re about to start our journey to Jupiter to unlock the secrets of the early solar system,” said Scott Bolton, the mission’s principal investigator from the Southwest Research Institute in San Antonio. “After eight years of development, the spacecraft is ready for its important mission.”

Inside the Vertical Integration Facility at Space Launch Complex 41, the Juno spacecraft, enclosed in an Atlas payload fairing, is in position on top of its Atlas launch vehicle. The spacecraft was prepared for launch in the Astrotech Space Operations' payload processing facility in Titusville, Fla. Credit: NASA/Cory Huston

The launch window for Juno extends from Aug. 5 through Aug. 26. The launch time on Aug. 5 opens at 11:34 a.m. EDT and closes at 12:43 p.m. EDT. Juno is the second mission in NASA’s New Frontiers program.

JUNO’s three giant solar panels will unfurl about five minutes after payload separation following the launch, said Jan Chodas, Juno’s project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

The probe will cartwheel through space during its five year trek to Jupiter.

Upon arrival in July 2016, JUNO will fire its braking rockets and go into polar orbit and circle Jupiter 33 times over about one year. The goal is to find out more about the planet’s origins, interior structure and atmosphere, observe the aurora, map the intense magnetic field and investigate the existence of a solid planetary core.

Hoisting Juno inside the payload fairing at Space Launch Complex 41. Credit: NASA/Cory Huston

“Juno will become the first polar orbiting spacecraft at Jupiter. Not only are we over the poles, but we’re getting closer to Jupiter in our orbit than any other spacecraft has gone,” Bolton elaborated at a briefing for reporters at the Kennedy Space Center. “We’re only 5,000 kilometers above the cloud tops and so we’re skimming right over those cloud tops and we’re actually dipping down beneath the radiation belts, which is a very important thing for us. Because those radiation belts at Jupiter are the most hazardous region in the entire solar system other than going right to the sun itself.”

“Jupiter probably formed first. It’s the largest of all the planets and in fact it’s got more material in it than all the rest of the solar system combined. If I took everything in the solar system except the sun, it could all fit inside Jupiter. So we want to know the recipe.”

Watch for my continuing updates and on-site launch coverage of Juno, only the 2nd probe from Earth to ever orbit Jupiter. Galileo was the first.

Posted on

Worlds Apart: Planet and Moon Align

Here’s a cool animation showing Mars’ little moon Phobos passing in front of distant Jupiter from the viewpoint of ESA’s Mars Express orbiter:

The conjunction event occurred on June 1.

[/caption]

Only 21 km (13 miles) across at the widest, the irregularly-shaped Phobos may have been created by a large impact on Mars in its distant past, a chunk of the planet’s crust thrown into orbit. Mars Express most recently performed a close flyby of Phobos back on January 9, passing it at a distance of only 100 km (62 miles).

What’s really amazing to think about is the distances between these two worlds – about 529 million km! But those kinds of distances are no hindrance to vision out in space, especially when the farther object is a giant planet like Jupiter.

The images were taken with Mars Express’ High Resolution Stereo Camera (HRSC), which was kept centered on Jupiter during the conjunction. A total of 104 images were taken over a span of 68 seconds to create the animation.

“By knowing the exact moment when Jupiter passed behind Phobos, the observation will help to verify and even improve our knowledge of the orbital position of the martian moon.”

– ESA

Read the news release on the ESA Space Science site here.

All images shown here were processed at the Department of Planetary Sciences and Remote Sensing at the Institute of Geological Sciences of the Freie Universität Berlin. Credit: ESA/DLR/FU Berlin (G. Neukum)

Posted on

New Movie Revives Old Voyager Data of Jupiter’s Clouds

I remember, some time after Voyager 1 flew past Jupiter, of seeing a television show that played a movie of Jupiter’s bands of rolling clouds. I was mesmerized. Now, UnmannedSpaceflight.com member Bjorn Jonsson has re-mastered that data into a crisp, clear video. I find it just as mesmerizing! In his description, Jonsson says, “The movie is based on 58 orange-green-blue color composites obtained on every Jovian rotation from January 6 to January 29, 1979. Over this period Voyager 1’s distance from Jupiter dropped from 58 to 36 million km so the resolution and sharpness of the frames increases from start to finish. The 58 frames were tweened, increasing the number of frames by a factor of 8 (that is, 7 synthetic frames are inserted between each real frame).”

You can see more of Jonsson’s work at his website.

Credit: NASA/JPL/Processed by Bjorn Jonsson

Posted on

Guest Post: Drifting on Alien Winds: Exploring the Skies and Weather of Other Worlds

[/caption]

Editor’s note: We all want to explore other worlds in our solar system, but perhaps you haven’t considered the bizarre weather you’d encounter — from the blistering hurricane-force winds of Venus to the gentle methane rain showers of Saturn’s giant moon Titan. Science journalist Michael Carroll has written a guest post for Universe Today which provides peek at the subject matter for his new book, “Drifting on Alien Winds: Exploring the Skies and Weather of Other Worlds.”

It’s been a dramatic year for weather on Earth. Blizzards have blanketed the east coast, crippling traffic and power grids. Cyclone Tasha drenched Queensland, Australia as rainfall swelled the mighty Mississippi, flooding the southern US. Eastern Europe and Asia broke high temperature records. But despite these meteorological theatrics, the Earth’s conditions are a calm echo of the weather on other worlds in our solar system.


Take our nearest planetary neighbor, Venus. Nearly a twin of Earth in size, Venus displays truly alien weather. The hurricane-force Venusian winds are ruled not by water (as on Earth), but by battery acid. Sunlight tears carbon dioxide molecules (CO2) apart in a process called photodissociation. Leftover bits of molecules frantically try to combine with sulfur and water to become chemically stable, resulting acid hazes. Temperatures soar to 900ºF at the surface, where air is as dense as the Earthly oceans at a depth of X feet.

Venus is the poster child of comparative planetology, the study of other planets to help us understand our own. Earth’s simmering sibling has taught us about greenhouse gases, and gave us an even more immediate cautionary tale in 1978. The Pioneer Venus orbiter discovered that Venus naturally generates chlorofluorocarbons (CFCs) in its atmosphere. These CFCs were tearing holes in the planet’s ozone. At the same time, a wide variety of industries were preparing to use CFCs in insecticides, spray paints, and other aerosol products. Venus presented us with a warning that may have averted a planet-wide crisis.

In the same way, Mars has provided insights into long-term climate change. Its weather is a simplified version of our own. Locked within its rocks and polar caps lie records of changing climate over eons.

Jupiter’s Great Red Spot is a cyclone larger than two Earths. (photomontage ©Michael Carroll)

But fans of really extreme weather must venture further out, to the outer planets. Jupiter and Saturn are giant balls of gas with no solid surface, and are known as the “gas giants.” They are truly gigantic: over a thousand Earths could fit within Jupiter itself.

The skies of Jupiter and Saturn are dominated by hydrogen and helium, the ancient building blocks of the solar system. Ammonia mixes in to produce a rich brew of complex chemistry, painting the clouds of Jupiter and Saturn in tans and grays. Lightning bolts sizzle through the clouds, powerful enough to electrify a small city for weeks. Ammonia forms rain and snow in the frigid skies. Jupiter’s Great Red Spot is a centuries-old cyclone large enough to swallow three Earths. Saturn has its own bizarre storms: a vast hexagon-shaped trough of clouds races across the northern hemisphere. Over the south pole, a vast whirlpool gazes from concentric clouds like a Cyclops.

Clouds tower into a twilight sky on Saturn. The planet’s glowing rings seem to bend at the horizon because of the dense air. (painting ©Michael Carroll)

Beyond Jupiter and Saturn lie the “ice giants”, Uranus and Neptune. These behemoths host atmospheres of poisonous brews chilled to cryogenic temperatures. Methane tints Uranus and Neptune blue. Neptune’s clear air reveals a teal cloud deck. Hydrocarbon hazes tinge Uranus to a paler shade of blue-green. Neptune’s clear air is somewhat of a mystery to scientists. This may be because cloud-forming particles can’t stay airborne long enough to become visible clouds. Some scientists propose that Neptune’s abundant methane rains may condense so rapidly that within a few seconds tiny methane raindrops swell to something the size of a beachball. There are no clouds adrift, because methane rains out of the atmosphere too quickly.

One of the strangest cases of bizarre weather comes to us from Neptune’s moon Triton. Triton’s meager nitrogen air is tied to the freezing and thawing of polar ices, also composed of nitrogen. Triton’s entire atmosphere collapses twice a year, when it’s winter on one of the poles. At that time of year, all of Triton’s air migrates to the winter pole, where it freezes to the ground. The moon only has “weather” during the spring and fall; its atmosphere exists only during those seasons.

So, the next time you contemplate complaining about the heat, think of Venus. And if it’s blizzards you worry about, find comfort in Triton: at least our atmosphere doesn’t disappear in winter!

For more on the subject, see Michael Carroll’s newest book, Drifting on Alien Winds: Exploring the Skies and Weather of Other Worlds from Springer.

Posted on

Solar Powered Jupiter bound JUNO lands at Kennedy Space Center for blastoff

[/caption]

Juno, NASA’s next big mission bound for the outer planets, has arrived at the Kennedy Space Center to kick off the final leg of launch preparations in anticipation of blastoff for Jupiter this summer.

The huge solar-powered Juno spacecraft will skim to within 4800 kilometers (3000 miles) of the cloud tops of Jupiter to study the origin and evolution of our solar system’s largest planet. Understanding the mechanism of how Jupiter formed will lead to a better understanding of the origin of planetary systems around other stars throughout our galaxy.

Juno will be spinning like a windmill as it fly’s in a highly elliptical polar orbit and investigates the gas giant’s origins, structure, atmosphere and magnetosphere with a suite of nine science instruments.

Technicians at Astrotech's payload processing facility in Titusville, Fla. secure NASA's Juno spacecraft to the rotation stand for testing. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins. Credit: NASA/Jack Pfaller

During the five year cruise to Jupiter, the 3,600 kilogram probe will fly by Earth once in 2013 to pick up speed and accelerate Juno past the asteroid belt on its long journey to the Jovian system where it arrives in July 2016.

Juno will orbit Jupiter 33 times and search for the existence of a solid planetary core, map Jupiter’s intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet’s auroras.

The mission will provide the first detailed glimpse of Jupiter’s poles and is set to last approximately one year. The elliptical orbit will allow Juno to avoid most of Jupiter’s harsh radiation regions that can severely damage the spacecraft systems.

Juno was designed and built by Lockheed Martin Space Systems, Denver, and air shipped in a protective shipping container inside the belly of a U.S. Air Force C-17 Globemaster cargo jet to the Astrotech payload processing facility in Titusville, Fla.

Juno undergoes acoustics testing at Lockheed Martin in Denver where the spacecraft was built. Credit: NASA/JPL-Caltech/Lockheed Martin

This week the spacecraft begins about four months of final functional testing and integration inside the climate controlled clean room and undergoes a thorough verification that all its systems are healthy. Other processing work before launch includes attachment of the long magnetometer boom and solar arrays which arrived earlier.

Juno is the first solar powered probe to be launched to the outer planets and operate at such a great distance from the sun. Since Jupiter receives 25 times less sunlight than Earth, Juno will carry three giant solar panels, each spanning more than 20 meters (66 feet) in length. They will remain continuously in sunlight from the time they are unfurled after launch through the end of the mission.

“The Juno spacecraft and the team have come a long way since this project was first conceived in 2003,” said Scott Bolton, Juno’s principal investigator, based at Southwest Research Institute in San Antonio, in a statement. “We’re only a few months away from a mission of discovery that could very well rewrite the books on not only how Jupiter was born, but how our solar system came into being.”

Juno is slated to launch aboard the most powerful version of the Atlas V rocket – augmented by 5 solid rocket boosters – from Cape Canaveral, Fla. on August 5. The launch window extends through August 26. Juno is the second mission in NASA’s New Frontiers program.

NASA’s Mars Curiosity Rover will follow Juno to the Atlas launch pad, and is scheduled to liftoff in late November 2011. Read my stories about Curiosity here and here.

Because of cuts to NASA’s budget by politicians in Washington, the long hoped for mission to investigate the Jovian moon Europa may be axed, along with other high priority science missions. Europa may harbor subsurface oceans of liquid water and is a prime target in NASA’s search for life beyond Earth.

Technicians inside the clean room at Astrotech in Titusville, Fla. guide NASA's Juno spacecraft, as it is lowered by overhead crane, onto the rotation stand for testing. Credit: NASA/Jack Pfaller
Technicians at Astrotech unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Credit: NASA
Juno's interplanetary trajectory to Jupiter. Juno will launch in August 2011 and fly by Earth once in October 2013 during its 5 year cruise to Jupiter. Click to enlarge. Credit: NASA/JPL
Posted on

How Jupiter is Getting Its Belt Back

[/caption]

Earlier this year, one of Jupiter’s stripes went missing. The Southern Equatorial Band started to get lighter and paler, and eventually disappeared. Now, follow-up images from both professional and amateur astronomers are showing some activity in the area of the SEB, and scientists now believe the vanished dark stripe is making a comeback. They say these new observations will help our understanding of the interaction between Jupiter’s winds and cloud chemistry.

“The reason Jupiter seemed to ‘lose’ this band – camouflaging itself among the surrounding white bands – is that the usual downwelling winds that are dry and keep the region clear of clouds died down,” said Glenn Orton, a research scientist at JPL. “One of the things we were looking for in the infrared was evidence that the darker material emerging to the west of the bright spot was actually the start of clearing in the cloud deck, and that is precisely what we saw.”

This image of Jupiter is a composite of three color images taken on Nov. 16, 2010, by NASA's Infrared Telescope Facility. The particles lofted by the initial outbreak are easily identified in green as high altitude particles at the upper right, with a second outbreak to the lower left. Image credit: NASA/JPL-Caltech/IRTF

This white cloud deck is made up of white ammonia ice. When the white clouds float at a higher altitude, they obscure the missing brown material, which floats at a lower altitude. Every few decades or so, the South Equatorial Belt turns completely white for perhaps one to three years, an event that has puzzled scientists for decades. This extreme change in appearance has only been seen with the South Equatorial Belt, making it unique to Jupiter and the entire solar system.

The white band wasn’t the only change on the big, gaseous planet. At the same time, Jupiter’s Great Red Spot became a darker red color. Orton said the color of the spot – a giant storm on Jupiter that is three times the size of Earth and a century or more old – will likely brighten a bit again as the South Equatorial Belt makes its comeback.

A false-color composite image of Jupiter and its South Equatorial Belt shows an unusually bright spot, or outbreak, where winds are lofting particles to high altitudes in this image made from data obtained by the W.M. Keck telescope on Nov. 11, 2010. Image credit: NASA/JPL-Caltech/W. M. Keck Observatory

The South Equatorial Belt underwent a slight brightening, known as a “fade,” just as NASA’s New Horizons spacecraft was flying by on its way to Pluto in 2007. Then there was a rapid “revival” of its usual dark color three to four months later. The last full fade and revival was a double-header event, starting with a fade in 1989, revival in 1990, then another fade and revival in 1993. Similar fades and revivals have been captured visually and photographically back to the early 20th century, and they are likely to be a long-term phenomenon in Jupiter’s atmosphere.

Scientists are particularly interested in observing this latest event because it’s the first time they’ve been able to use modern instruments to determine the details of the chemical and dynamical changes of this phenomenon. Observing this event carefully may help to refine the scientific questions to be posed by NASA’s Juno spacecraft, due to arrive at Jupiter in 2016, and a larger, proposed mission to orbit Jupiter and explore its satellite Europa after 2020.

Observations by amateur astronomers Christopher Go of Cebu City, Philippines and Anthony Wesley of Australia have helped, and scientists have used the “big guns” in Hawaii — NASA’s Infrared Telescope Facility, the W.M. Keck Observatory and the Gemini Observatory telescope.

Go imaged an outburst that piqued the interest of other astronomers. “I was fortunate to catch the outburst,” said Christopher Go, referring to the first signs that the band was coming back. “I had a meeting that evening and it went late. I caught the outburst just in time as it was rising. Had I imaged earlier, I would not have caught it,” he said.

Source: JPL

Posted on

Follow-up Studies on June 3rd Jupiter Impact

[/caption]

Poor Jupiter just can’t seem to catch a break. Ever since 1994, when our largest planet was hit by Comet Shoemaker-Levy, detections of impacts on Jupiter have occurred with increasing regularity. Most recently, an impact was witnessed on August 20. On June 3rd of 2010, (coincidentally the same day pictures from Hubble were released from a 2009 impact) Jupiter was hit yet again. Shortly after the June 3rd impact, several other telescopes joined the observing.

A paper to appear in the October issue of The Astrophysical Journal Letters discusses the science that has been gained from these observations.

The June 3rd impact was novel in several respects. It was the first unexpected impact that was reported from two independent locations simultaneously. Both discoverers were observing Jupiter with aims of engaging in a bit of astrophotography. Their cameras were both set to take a series of quick images, each lasting a fifth to a tenth of a second. This short time duration is the first time astronomers have had the ability to recreate the light curve for the meteor. Additionally, both observers were using different filters (one red and one blue) allowing for exploration of the color distribution.

Analysis of the light curve revealed that the flash lasted nearly two seconds and was not symmetric; The decay in brightness occurred faster than the increase at onset. Additionally, the curve showed several distinct “bumps” which indicated a flickering that is commonly seen on meteors on Earth.

The light released in the burning up of the object was used to estimate the total energy-released and in turn the mass of the object.  The total energy released was estimated to be between roughly (1.0–4.0) × 1015 Joules (or 250–1000 kilotons).

Follow-up observations from Hubble three days later revealed no scars from the impact. In the July 2009 impact, a hole punched in the clouds remained for several days. This indicated the object in the June 3 impact was considerably smaller and burned up before it was able to reach the visible cloud decks.

Observations intended to find debris came up empty. Infrared observations showed that no thermal signature was left even as little as 18 hours following the discovery.

Assuming that the object was an asteroid with a relative speed of ~60 km/sec and a density of ~2 g/cm3, the team estimated the size of the object to be between 8 and 13 meters, similar to the size of the two asteroids that recently passed Earth. This represents the smallest meteor yet observed on Jupiter. An object of similar size was estimated to be responsible for the impact on Earth in 1994 near the Marshall Islands. Estimates “predict objects of this size to collide with our planet every 6–15 years” with significantly higher rates on Jupiter ranging from one to one hundred such events annually.

Clearly, amateur observations led to some fantastic science. Modest telescopes, “in the range 15–20 cm in diameter equipped with webcams and video recorders” can easily allow for excellent coverage of Jupiter and continued observation could help in determining the impact rate and lead to a better understanding of the population of such small bodies in the outer solar system.

Posted on

Jupiter Gets Smacked Yet Again?

It looks like once again, Jupiter has taken a hit! And once again an amateur astronomer spotted and captured the event. Masayuki Tachikawa was observing Jupiter on at 18:22 Universal Time on August 20th (early on August 21 in Japan) and his video camera captured a 1-second-long flash on the planet’s disk, along the northern edge of the gas giant’s North Equatorial Belt. The event was reported by astronomer Junichi Watanabe from the National Astronomical Observatory of Japan, on his blog.
Continue reading “Jupiter Gets Smacked Yet Again?”

Posted on

Hubble Delves into Two Recent Jupiter Mysteries

[/caption]

Jupiter has a few mysteries these days. Between an equatorial belt that has gone missing and an impact that didn’t leave a mark, astronomers decided they needed to put the Hubble Space Telescope on the case. New and detailed observations from the venerable space telescope have provided some insights into these two recent puzzling events.

At 22:31 (CEST) on June 3, 2010 Australian amateur astronomer Anthony Wesley saw a two-second-long flash of light on the disc of Jupiter, captured from a live video feed from his telescope. In the Philippines, amateur astronomer Chris Go confirmed that he had simultaneously recorded the transitory event on video. Wesley was also the discoverer of the now world-famous July 2009 impact.

Astronomers around the world suspected that something significant must have hit the giant planet to unleash a flash of energy bright enough to be seen here on Earth, about 770 million kilometers away. But they didn’t know how just how big it was or how deeply it had penetrated into the atmosphere. Over the past two weeks there have been ongoing searches for the “black-eye” pattern of a deep direct hit like those left by former impactors.

Astronomers turned Hubble’s Wide Field Camera 3 aboard the NASA/ESA Hubble Space Telescope on June 7, and found no sign of debris above Jupiter’s cloud tops. This means that the object didn’t descend beneath the clouds and explode as a fireball. If it had, then dark sooty blast debris would have been ejected and would have rained down onto the clouds.

Instead the flash is thought to have come from a giant meteor burning up high above Jupiter’s cloud tops, which did not plunge deep enough into the atmosphere to explode and leave behind any telltale cloud of debris, as seen in previous Jupiter collisions.

“The cloud tops and the impact site would have appeared dark in the ultraviolet and visible images due to debris from an explosion,” said team member Heidi Hammel of the Space Science Institute in Boulder, Colorado. “We can see no feature that has those distinguishing characteristics in the known vicinity of the impact, suggesting there was no major explosion and no ‘fireball’.”

Dark smudges marred Jupiter’s atmosphere when a series of fragments of Comet Shoemaker-Levy 9 hit Jupiter in July 1994, and a similar dark area formed in July 2009 when a suspected asteroid slammed into Jupiter. The latest intruder is estimated to be only a fraction of the size of these previous impactors and is thought to have been a meteor.

So, Wesley and Go were fortunate to have spotted the flash.

“Observations of these impacts provide a window on the past — onto the processes that shaped our Solar System in its early history,” said team member Leigh Fletcher of the University of Oxford, UK. “Comparing the two collisions — from 2009 and 2010 — will hopefully yield insights into the types of impact processes in the outer Solar System, and the physical and chemical response of Jupiter’s atmosphere to these amazing events.”

These Hubble images of Jupiter taken 11 months apart show the Southern Equatorial Belt has disappeared. Credit: NASA, ESA, M. H. Wong (University of California, Berkeley, USA), H. B. Hammel (Space Science Institute, Boulder, Colorado, USA), A. A. Simon-Miller (Goddard Space Flight Center, Greenbelt, Maryland, USA) and the Jupiter Impact Science Team.

Since Hubble was now trained on Jupiter, astronomers used the opportunity to get a close-up look at changes in Jupiter’s atmosphere following the disappearance of the dark cloud feature known as the Southern Equatorial Belt several months ago.

In the Hubble view, a slightly higher altitude layer of white ammonia ice crystal clouds appears to obscure the deeper, darker belt clouds. “Weather forecast for Jupiter’s Southern Equatorial Belt: cloudy with a chance of ammonia,” Hammel said.

The team predicts that these ammonia clouds should clear out in a few months, as they have done in the past. The clearing of the ammonia cloud layer should begin with a number of dark spots like those seen by Hubble along the boundary of the south tropical zone.

“The Hubble images tell us these spots are holes resulting from localized downdrafts. We often see these types of holes when a change is about to occur,” said Amy Simon-Miller from Goddard Space Flight Center. .

“The Southern Equatorial Belt last faded in the early 1970s. We haven’t been able to study this phenomenon at this level of detail before,” Simon-Miller added. “The changes of the last few years are adding to an extraordinary database on dramatic cloud changes on Jupiter.”

Source: ESA’s Hubble website