Planets

Jupiter Got Smashed by a Speeding Space Rock

The gas giant appears to have experienced a pretty significant impact event and the flash of the extraterrestrial meteor was caught by amateur astronomers who just happened to be videoing Jupiter and its moons.

Jupiter just took one for the team.

The gas giant appears to have experienced a pretty significant impact event and the flash of the extraterrestrial meteor was caught by amateur astronomers who just happened to be videoing Jupiter and its moons.

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As the biggest and most massive planet in the solar system, the gas giant king isn't unfamiliar with being hit by errant space rocks - Jupiter's gravitational field is an interplanetary vacuum of sorts and is often viewed as the inner solar system's protector. (Or is Jupiter a little more evil than that? We're not entirely sure.) Any asteroid or comet that strays too close will be ripped to shreds and pulled into Jupiter's unforgiving thick atmosphere at high speed.

According to Bad Astronomer Phil Plait, this latest Jupiter impact was reported by two amateur astronomers located in Austria and Ireland who saw the suspect flash on Jupiter's limb at approximately the same time. It is unknown whether the flash was caused by an asteroid or a comet.

ANALYSIS: Confirmed! Jupiter was Shot with an Asteroid

Having just one observer see the meteor would be interesting, but that would leave some ambiguity as to whether the flash was caused by a physical impact or a glitch in the observer's camera CCD or some optical aberration in the telescope lens. But to have two observers seeing the event at the same time in the same place of Jupiter's atmosphere is more than just chance. With more than one observer, the likelihood is pretty high that an asteroid or comet slammed into Jupiter on March 17.

See for yourself:

click to play video

This footage was captured by "Gerrit" who is located in Mödling, Austria. The amateur astronomer only realized they had captured the flash after reviewing the video 10 days later. At the same time, John Mckeon, who was observing Jupiter from near Dublin, Ireland, also reported seeing the bright flash:

click to play video

Videoing Jupiter isn't an uncommon astronomical technique. Although on any given night you wouldn't expect to see much action from the massive planet, the individual frames of a video are processed by astronomical imaging software and the individual frames are stacked to produce a high-resolution final image. This technique is used to remove the haze and turbulence caused by atmospheric effects. But very occasionally, these videos can capture the odd transient event, like a meteor flash.

ANALYSIS: Impact Observed in Jupiter's Atmosphere

Although seeing a bright flash across millions of miles of interplanetary space may give the impression that Jupiter was hit by something pretty big, as Plait mentions in his blog, the impactor wasn't likely more than a few tens of meters wide. As Jupiter has a more powerful gravitational field than Earth, objects will hit the Jovian atmosphere around five-times faster than they hit Earth's atmosphere. Greater velocity means more energy, so (from the kinetic energy equation E=1/2mv2) we'd expect an object hitting Jupiter to be carrying 25 times more energy than a comparable object hitting Earth's atmosphere. This means 25 times more energy will be released on impact, producing a way bigger flash.

If you're experiencing a little deja vu right now, you're right, this certainly isn't the first time amateur astronomers have witnessed Jupiter flashing.

In 2009, a significant impact was witnessed by amateur astronomer Anthony Wesley in Australia that, after some detective work, was found to be an asteroid impact. Then in 2010, Wesley was again looking in the right place at the right time to spot another large impact and confirmed by Philippines-based amateur astronomer Christopher Go.

ANALYSIS: Why Did Jupiter Flash?

But the biggest cometary carnage event in recorded history was chronicled by the Hubble Space Telescope when Comet Shoemaker-Levy 9 fought with Jupiter's gravity in July 1994, but ultimately got shredded, peppering the Jovian atmosphere with huge chunks of icy debris.

These impact events are critical for planetary scientists to understand just how often planets get hit by asteroids and comets, particularly Jupiter. Some theories suggest that Jupiter is Earth's protector in some ways; its gravitational well prevents potential Earth-impacting asteroids or comets from causing mayhem. But other theories hint that Jupiter's gravity may actually redirect some near-Earth object orbits into Earth's path.

In this case it seems that Jupiter was being our defender, and amateur astronomers - once again - were key to this impact event's discovery.

Source: Bad Astronomy

This observation of Jupiter and moons was captured during the Voyager 1 flyby in 1979.

As NASA's Juno mission speeds towards a July 2016 date with Jupiter, the spacecraft is already racking up milestones in space. Just this month it became the furthest-flying solar spacecraft ever, even surpassing the feat of the Rosetta spacecraft that is still operating well at Comet 67P/Churyumov–Gerasimenko. As a preview of this amazing mission to the solar system's biggest planet, explore some of the science and engineering tasks Juno will focus on during its mission.

PHOTO: Juno Looks Back, Photographs Earth-Moon System

We often speak about the water on the icy moons in the outer solar system, such as Jupiter's Europa. But what is not is well-known is Jupiter itself has quite a bit of water in it. The upper atmosphere is actually seeded with water from the Shoemaker-Levy 9 comet impact of 1994. The water was discovered in 2013 after the Herschel Space Observatory found water concentrated in areas close to where the comet fragments

slammed into the atmosphere

. Water in other parts of the atmosphere may have come about during Jupiter's formation, when icy planetesimals were abundant in the solar system. Looking at water and other elements within Jupiter will give us a sense of what the solar system used to look like, because Jupiter -- unlike our own planet -- is very close in composition to what it was when it was formed. (Earth gained a new atmosphere through plants and volcanic eruptions, among other factors.

ANALYSIS: LEGO Figures Hitch a Ride with NASA's Juno Mission

Image: Jupiter's water distribution in the stratosphere, mapped by the Herschel Space Observatory. White and cyan show high concentrations, and blue is lower concentrations. The map is overlaid on a visible-image picture of Jupiter taken by the Hubble Space Telescope.

Jupiter has an enormous and powerful magnetosphere, which is greatly apparent in the strength of its auroras. (This 2007 outburst is an example). The challenge is there are few long-term observations of faraway planets, which is where Juno will have an advantage over observatories such as the Hubble Space Telescope that can only check in from time to time. The key to Jupiter's strong auroras is hydrogen gas getting crushed in the planet's intense gravity. It becomes metallic hydrogen and this fluid is very conductive. Juno will look at Jupiter's charged particles and magnetic fields from up close, with the aim of making projections for other big planets in our solar system and other locations.

ANALYSIS: Is Jupiter a Soggy Planet?

Image: A 2007 X-ray view of auroras on Jupiter taken by the Chandra X-Ray Telescope (purple). The optical picture is from the Hubble Space Telescope.

Jupiter's immense gravity is a boon when we try to send spacecraft far out in the solar system. We've used the giant planet as a speed boost for missions such as Voyager and New Horizons. The bonus is during these maneuvers, investigators usually turn on the cameras and at least some instruments to add to our scientific knowledge of Jupiter. Juno's role will be to look at the gravity field in detail, to find out about any changes and how they may be caused. Fluctuations in gravity could point to changes in the planet's interior structure.

VIDEO: Juno's Epic Flyby View of the Earth and Moon

Image: A massive plume is visible on Io (foreground) in this montage picture of Jupiter based on New Horizons data obtained in 2007.

One of the atmospheric mysteries of Jupiter is why the Great Red Spot is shrinking. This feature has been a part of Jupiter for at least 400 years (as long as we have had telescopes), but it's getting smaller for reasons that are poorly understood. The rate of shrinking also changes from year to year. The Hubble image you see here also shows a rare wave structure that was only seen once before, in pictures from 1977 taken by the Voyager 2 mission. For its part, Juno will map how deep these colorful features in the atmosphere penetrate, and also track the motions of fluids below the cloud tops for the first time.

NEWS: Spacecraft Sets Sail For Jupiter

Image: A 2015 map of Jupiter taken by the Hubble Space Telescope, including the Great Red Spot (lower right).

While Juno is focused on the science, the spacecraft itself will also be a useful point of study to plan future long-term missions. Juno is actually the furthest-operating spacecraft to use solar power, a milestone it just passed this month. Improvements in energy efficiency for the instruments and spacecraft, as well as better solar-cell performance, made this possible. As with all missions, scientists will be looking at how well the spacecraft does over time. When something breaks (as it inevitably will), the team will try to figure out a way to fix it. They will also try to design the next generation of that part better so that it doesn't break on the next spacecraft.

PHOTO: Smile, Earthlings: Jupiter Mission Captures Flyby Portrait