Jupiter Archives - Page 30 of 33

June 3, 2010December 24, 2015

New Hubble Images Zoom In on Asteroid Impact on Jupiter

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When amateur astronomer Anthony Wesley from Australia saw a dark spot the size of the Pacific Ocean appear on Jupiter through his telescope on July 19, 2009, this started a flurry of astronomic activity, with other telescopes quickly slewing to take a look. It didn’t take long for other astronomers to confirm Jupiter had been hit by an object, either an asteroid or a comet. Of course, the world’s most famous telescope, Hubble, zeroed in on this unexpected activity on Jupiter, and luckily, the telescope had been recently updated with a new Wide Field Camera 3 and newly repaired Advanced Camera for Surveys. Astronomers have now released a series of images from Hubble which may show for the first time the immediate aftermath of an asteroid striking another planet.

Astronomers have witnessed this kind of cosmic event before, but from a comet. Similar scars had been left behind during the course of a week in July 1994, when more than 20 pieces of Comet P/Shoemaker-Levy 9 (SL9) plunged into Jupiter’s atmosphere. The 2009 impact occurred during the same week, 15 years later.

But comparing Hubble images of both collisions, astronomers say the culprit was likely an asteroid about 1,600 feet (500 meters) wide.

Source: Hubblesite.org

“This solitary event caught us by surprise, and we can only see the aftermath of the impact, but fortunately we do have the 1994 Hubble observations that captured the full range of impact phenomena, including the nature of the objects from pre-impact observations” says astronomer Heidi Hammel of the Space Science Institute in Boulder, Colo., leader of the Jupiter impact study.

The analysis revealed key differences between the two collisions (in 1994 and 2009), providing clues to the 2009 event. Astronomers saw a distinct halo around the 1994 impact sites in Hubble ultraviolet (UV) images, evidence of fine dust arising from a comet-fragment strike. The UV images also showed a strong contrast between impact-generated debris and Jupiter’s clouds.

Hubble ultraviolet images of the 2009 impact showed no halo and also revealed that the site’s contrast faded rapidly. Both clues suggest a lack of lightweight particles, providing circumstantial evidence for an impact by a solid asteroid rather than a dusty comet.

The elongated shape of the recent asteroid impact site also differs from the 1994 strike, indicating that the 2009 object descended from a shallower angle than the SL9 fragments. The 2009 body also came from a different direction than the SL9 pieces.

Source: Hubblesite.org

Team member Agustin Sanchez-Lavega of the University of the Basque Country in Bilbao, Spain, and colleagues performed an analysis of possible orbits that the 2009 impacting body could have taken to collide with Jupiter. Their work indicates the object probably came from the Hilda family of bodies, a secondary asteroid belt consisting of more than 1,100 asteroids orbiting near Jupiter.

The 2009 strike was equal to a few thousand standard nuclear bombs exploding, comparable to the blasts from the medium-sized fragments of SL9. The largest of those fragments created explosions that were many times more powerful than the world’s entire nuclear arsenal blowing up at once.

The recent impact underscores the important work performed by amateur astronomers. “This event beautifully illustrates how amateur and professional astronomers can work together,” said Hammel.

The Jupiter bombardments reveal that the solar system is a rambunctious place, where unpredictable events may occur more frequently than first thought. Jupiter impacts were expected to occur every few hundred to few thousand years. Although there are surveys to catalogue asteroids, many small bodies may still go unnoticed and show up anytime to wreak havoc.

The study by Hammel’s team appeared in the June 1 issue of The Astrophysical Journal Letters.

Science Paper by: Hammel et al. (PDF document)

Source: HubbleSite

May 28, 2010September 23, 2016

How Many Earths Can Fit in Jupiter?

Jupiter is known as the “King of the Planets”, and for good reason. For one, it is the largest planet in the Solar System, and is actually more massive than all the other planets combined. Fittingly, it is named after the king of the Roman pantheon, the latinized version of Zeus (the king of the Olympian gods).

Compare that to Earth, which is the largest of the terrestrial planets, but a tiny marble when compared to the Jovian giant. Because their disparity in size, people often wonder many times over Earth could be squeezed in Jupiter’s massive frame. As it turns out, you could it do many, many times over!

Size and Mass Comparison:

To break the whole size discrepancy down, Jupiter has a mean radius of 69,911 ± 6 km (60217.7 ± 3.7 mi). As already noted, this is roughly 2.5 times the mass of all the planets in the Solar System combined. Compared this to Earth’s mean radius of 6,371.0 km (3,958.8 mi), and you could say that Earth fits into Jupiter almost 11 times over (10.97 to be exact).

*Rough visual comparison of Jupiter, Earth, and the Great Red Spot. Approximate scale is 44 km/px. Credit: NASA/Brian0918/ Wikipedia Commons*

And as already noted, Jupiter is more massive than all the other planets in our Solar System – 2.5 times as massive, that is. In fact, Jupiter weighs in at a hefty 1.8986 × 10²⁷ kg (~4.1857 x 10²⁷ lbs), or 1898.6 billion trillion metric tons (2.092 billion trillion US tons).

Compare that to Earth, which has a mass of 5.97 × 10²⁴ kg (13.1668 × 10²⁴ lb) – 5.97 billion trillion metric tons, or 6.5834 billion trillion US tons. Doing the math, we then come to the conclusion that Jupiter is approximately 317.8 times as massive as Earth.

Volume Comparison:

However, figuring for radius is only useful is you are planning on stacking the Earths end to end across the middle of the gas giant. And comparing their masses doesn’t give you a sense of size, seeing as how the planets are widely different in terms of their density.

*Jupiter/Earth comparison. Credit: NASA/SDO/Goddard/Tdadamemd*

To know how many Earth’s could truly fit inside in three-dimensions, you have to consider total volume, which you can calculate using the simple formula of 4/3 x Pi x radius².

Doing the math, we find that Jupiter has a volume of 1.43 x 10¹⁵ km³ (1,430 trillion cubic km; 343 trillion cubic mi) while Earth has a volume of 1.08 trillion km³(259 million mi). Divide the one by the other, and you get a value of 1299, meaning you could fit almost 1300 Earth’s inside Jupiter.

In short, the king of the planets is much, much, MUCH bigger than the planet we call home. Someday, if we ever hope to live around Jupiter (i.e. colonize its moons), we will be able to appreciate just how big it is up close. Until then, these impressive figures will have to suffice!

We’ve written many articles about Jupiter for Universe Today. Here’s Ten Interesting Facts About Jupiter, Jupiter Compared to Earth, What is the Diameter of Jupiter?, and How Much Bigger is Jupiter than Earth?

If you’d like more information on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.

Sources:

May 13, 2010December 24, 2015

Jupiter, It Is A-Changing

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Jupiter’s appearance has changed dramatically since the end of 2009, when it moved too close to the Sun from our vantage point on Earth to be observed. New looks at the planet after it emerged from the Sun’s glare reveals that one of the bands of clouds, the South Equatorial Belt, has gone missing. This image from amateur astronomer Anthony Wesley (the same astronomer who captured an impact spot on Jupiter last year) taken on May 9, 2010, shows a rather undressed Jupiter without its usually prominent southern band. See a comparison of earlier images below.

Dramatic changes in Jupiter from less than a year ago. The South Equatorial Belt (SEB) has faded away leaving just the north belt (NEB) viewable in small telescopes. Credit: Anthony Wesley, caption via Bob King

What caused the disappearance of the band? Astronomers aren’t sure, but this isn’t the first time this has happened. Back in 1973 when the Pioneer 10 spacecraft flew by and took the first close-up images of the planet, the southern band was missing, and it also disappeared in the early 1990s. Also, in 2007 cloud bands around its equator that had been light-colored for the past 15 years or so were noticeably darker.

Emily at the Planetary Society has written about this, and so has amateur astronomer Bob King, a.k.a “Astro Bob,” who explains:

“Every 3-15 years, the belt, which is normally dark reddish-brown in color and typically divided in two by the south equatorial belt zone, fades from view. After some weeks or months a brilliant white spot forms within that zone and begins spouting dark blobs of material which get stretched into filaments and ovals by Jupiter’s fierce winds into a new SEB. Within a few weeks (or longer) the belt is back and Jupiter presents its familiar dual “tire track” appearance through a telescope.”

Check out Anthony Wesley’s gallery of Jupiter images, and watch for new images over the next days and months to monitor the changes. Surely, Hubble and other observatories will be making new observations, as well.

Thanks to Anthony Wesley for sharing his images.

March 16, 2010January 22, 2016

New Images Unlock Secrets of Jupiter’s Red Spot

New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot. Image credit: NASA/JPL/ESO and NASA/ESA/GSFC

It’s difficult enough to track the weather on Earth, but with new thermal images of Jupiter’s Great Red Spot, scientists now have the first detailed interior weather map of a giant storm system on another planet. “This is our first detailed look inside the biggest storm of the solar system,” said Glenn Orton, a senior research scientist at NASA’s Jet Propulsion Laboratory. “We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated.”
Continue reading “New Images Unlock Secrets of Jupiter’s Red Spot”

January 25, 2010December 24, 2015

One of Jupiter’s Moons is Melted!

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Jupiter’s two moons Ganymede and Callisto could be considered fraternal twins. They have a similar composition and size, but visually, they are different. Also, data from the Galileo and Voyager spacecraft reveal the two moons’ interiors are very dissimilar, as well. The reasons for the differences have eluded scientists for 30 years, but a new study provides an explanation. During the Late Heavy Bombardment, Callisto escaped relatively unscathed, while Ganymede was a battered child; so much so that the later moon melted. “Impacts during this period melted Ganymede so thoroughly and deeply that the heat could not be quickly removed,” said Dr. Amy Barr of the Southwest Research Institute. “All of Ganymede’s rock sank to its center the same way that all the chocolate chips sink to the bottom of a melted carton of ice cream. Callisto received fewer impacts at lower velocities and avoided complete melting.”

Barr and and Dr. Robin Canup created a model showing how Jupiter’s strong gravity focused cometary impactors onto Ganymede and Callisto 3.8 billion years ago, during the LHB period. Each impact onto Ganymede or Callisto’s mixed ice and rock surface creates a pool of liquid water, allowing rock in the melt pool to sink to the moon’s center.

But Ganymede is closer to Jupiter and therefore was hit by twice as many icy impactors as Callisto. Additionally, the impactors hitting Ganymede had a higher average velocity. Modeling by Barr and Canup shows that core formation begun during the late heavy bombardment becomes energetically self-sustaining in Ganymede but not Callisto.

Interior density structures created by an outer solar system late heavy bombardment onto Ganymede (top row) and Callisto (bottom row). Credit: SwRI

Watch a movie that shows the effect of an outer solar system late heavy bombardment on the interior structure of Callisto (top model in the movie) and Ganymede (bottom).

“Similar to Earth and Venus, Ganymede and Callisto are twins, and understanding how they were born the same and grew up to be so different is of tremendous interest to planetary scientists,” explains Barr. “Our study shows that Ganymede and Callisto record the fingerprints of the early evolution of the solar system, which is very exciting and not at all expected.”

The “Ganymede-Callisto dichotomy,” has been a classical problem in comparative planetology, a field of study that seeks to explain why some solar system objects with similar bulk characteristics have radically different appearances. The study by Barr and Canup also links the evolution of Jupiter’s moons to the orbital migration of the outer planets and the bombardment history of Earth’s moon.

Their article, “Origin of the Ganymede-Callisto dichotomy by impacts during the late heavy bombardment,” by Barr and Canup, appears online in Nature Geoscience on Jan. 24, 2010.

Source: SwRI

December 18, 2009December 24, 2015

How Hot is Jupiter?

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Given how far Jupiter is from the Sun, you might think that “how cold is Jupiter?” would be a more relevant question and you would be partially right. “How hot is Jupiter?” becomes more relevant the deeper into the planet’s atmosphere and core that you travel. Near the very center of the planet, scientists believe that temperatures can reach 35,500 C.

The outer edges of Jupiter’s atmosphere are much cooler than the core region. Temperatures in the atmosphere are thought to be as cold as -145 degrees C. The intense atmospheric pressure on Jupiter contributes to temperature increases as you descend. Not far into the atmosphere the pressure can be ten times what it is here on Earth and scientists speculate that the temperature is 20 degrees C(average room temperature on Earth). A few hundred km deeper into the planet and hydrogen becomes hot enough to turn into a liquid. The temperature at this point is believed to be over 9,700 C. The layer of dense molten hydrogen metal extends to the 78th percentile of the planet’s radius. Between the cold clouds and the molten lower regions is an interior atmosphere of hydrogen. The hydrogen in this region is at a temperature where there are no distinct liquid and gas phases, so the hydrogen is said to be in a supercritical fluid state.

The molten inner regions of the planet serve to heat the rest of the planet through convection, so Jupiter gives off more heat than it receives from the Sun. This heating prevents it from being an ice giant instead of a gas giant, but wreaks havoc in the atmosphere. Storms and high winds are generated by cool air and warm air mixing here on Earth. Scientist think that the same holds true on Jupiter. The Galileo spacecraft observed winds in excess of 600 kph. One difference is that the jet streams that drive storms and winds on Earth are caused by the Sun heating the atmosphere. On Jupiter it seems that the jet streams are driven by the planets’ own heat. Storms on Jupiter are as out-sized as the planet. The Great Red Spot is a single storm that has been raging for hundreds of years. Other storms have been observed to grow to more than 2,000 km in diameter in a single day.

“How hot is Jupiter?” is more relevant than you may have thought. The planet’s inner heat seems to be the basis for its identity as a stormy world. The actual temperatures of the different areas of the planet may not be a mystery much longer. Hopefully, the recently launched JUNO space mission will clear up many of the Jovian theories that scientists currently have.

We’ve written many articles about the temperature of planets for Universe Today. Here’s an article about how hot Mercury is, and here’s an article about how hot Venus is.

If you’d like more information on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.

Sources:
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter
http://www.nasa.gov/mission_pages/juno/main/index.html

December 18, 2009December 24, 2015

Jupiter’s Core

Jupiter probably does not have a solid core. Jupiter’s core contains some rock and hydrogen metals. Scientists can not be 100 percent certain if deep within the planet there is a solid core or not, but based on gravitational measurements compared with Earth’s, the best educated guesses possible based on those measurements say there is no solid core. Those measurements make them think that the core is a thick, super hot soup.

Jupiter’s composition is more of a mystery than anything else. The accepted theory holds that it consists of a dense core made of a mixture of elements, the core is thought to be surrounded by a layer of liquid metallic hydrogen and helium, then the outer layer is to be dominated by molecular hydrogen. The core is often speculated to be rocky. It wasn’t until 1997 that the existence of the core was even theorized. Gravitational measurements were taken, indicating a mass in the neighborhood of 12 to 45 times the Earth’s mass, so the proposed core accounts for about 3–15% of the total mass of the planet. The presence of a planetary core follows accepted knowledge of planetary formation. According to this knowledge base, Jupiter would have had to form a rocky or icy core with enough mass in order to capture such a high percentage of gasses from the early solar nebula. Scientists admit that the planet may lack a core at this time due to the high heat and as hot liquid metallic hydrogen mixed with the molten core, carrying it to higher levels of the planet’s interior.

The layer of dense molten hydrogen metal extends to the 78th percentile of the planet’s radius. Just above the layer of metallic hydrogen is an interior atmosphere of hydrogen. The hydrogen at this point is at a temperature where there are no distinct liquid and gas phases, so the hydrogen is in a supercritical fluid state. The temperature and pressure increase steadily toward the core. In the region where hydrogen becomes metallic, the temperatures are thought to be up to 10,000 K and the pressure is 200GPa. The temperature at the core boundary is estimated to be 36,000 K and the pressure is believed to be 3,000 to 4,500 Gpa.

Since very little is known about the composition of Jupiter’s core or even if it still exists, the JUNO space mission was launched on August of 2011. It should arrive in orbit around Jupiter in 2016. The purpose of the mission is to orbit the poles and clear up some of the mysteries surrounding the planet and the entire Jovian system.

We’ve written several articles about planetary cores for Universe Today. Here’s an article about the Earth’s core, and here’s an article about the core of Mercury.

If you’d like more information on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast all about Jupiter. Listen here, Episode 56: Jupiter.

Source: NASA

December 18, 2009December 24, 2015

Weight on Jupiter

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If you are worried about your weight, do not go to Jupiter. The Jovian gravity is much more intense than Earth’s. 2.528 times more intense to be exact. That means if you weigh 100 kg on Earth, your weight on Jupiter would be 252.8 kg.

Of course, you can not stand on the surface of Jupiter. Jupiter is composed of about 90% hydrogen and 9.99% helium. The gaseous nature of the planet makes a solid surface impossible. Scientists have devised a way to define the surface of Jupiter, though. The surface of the planet is defined as the point where the pressure of the atmosphere is 1 bar, which is equal to the atmospheric pressure at Earth’s surface. That point is at the tops of Jupiter’s clouds.

Now that we have defined your weight on Jupiter, let’s move to on some other interesting facts about the planet. To start off, even though it is the largest planet in our Solar System, it is not the largest planet that we know of. While there are several planets larger than Jupiter, the largest known to man is TrES-4. TrES-4 is 70% larger than Jupiter, but is quite a bit less massive. Scientists think that it has a structure similar to cotton candy for lack of a better analogy.

Since Jupiter’s gravity is so intense, it has trapped quite a few moons. The are 63 acknowledged Jovian moons and there are a few others being studied, so that number could go up at any time.

Jupiter has a system of rings. Many people are surprised to find out that Saturn is not the only ringed planet in our Solar System. In addition to Saturn; Jupiter, Uranus, and Neptune have rings. Rings are generally formed by dust and debris left orbiting after a meteorite impact on a moon. With so many moons, you would think that Jupiter would have a bunch of rings. It only has four defined rings, though.

A day on Jupiter is just under 10 Earth hours long, but a single years lasts 11.86 Earth years.

Some scientists think that Jupiter’s gravity is intense enough to affect the Sun. They believe that when Jupiter is at its closest approach to the Sun, solar flare activity increases. Others believe that Jupiter’s gravity may eventually push Mercury our of our Solar System.

Now that you know what your weight on Jupiter would be, we hope that you will want to research more Jovian facts.

We’ve written several articles about your weight on other planets. Here’s an article about your weight on the Moon, and here’s a link about your weight on Mercury.

If you’d like more information on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.

Source: NASA

December 10, 2009May 4, 2017

What is the Surface of Jupiter Like?

Have you ever wondered what it might feel like to stand on Jupiter’s surface? Well, there’s a problem. Jupiter is made up almost entirely of hydrogen and helium, with some other trace gases. There is no firm surface on Jupiter, so if you tried to stand on the planet, you sink down and be crushed by the intense pressure inside the planet.

When we look at Jupiter, we’re actually seeing the outermost layer of its clouds. Jupiter upper atmosphere is made of up to 90% hydrogen, with 10% helium, and then other gases like ammonia. The bands and storms that we can see on the planet are all generated in the upper atmosphere. The cloud layer we can see is made of ammonia, and only extends down for about 50 km or so. The large storms like the Great Red Spot occur within this layer; although it’s thought they may dredge up material from deeper down inside the planet.

If you could stand on the surface of Jupiter, you would experience intense gravity. The gravity at Jupiter’s surface is 2.5 times the gravity on Earth. If you weighed 100 pounds on Jupiter, you’d weigh 250 pounds on Jupiter. Of course, there’s no actual surface, so you’d just sink into the planet if you tried to stand on it.

We’ve written many articles about Jupiter for Universe Today. Here’s an article about how Jupiter might have captured a comet as a temporary moon, and does Jupiter have a solid core?

If you’d like more info on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an entire episode of Astronomy Cast all about Jupiter. Listen here, Episode 56: Jupiter.

December 10, 2009December 24, 2015

Planet Jupiter

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Jupiter is the 5th planet in the Solar System, and by far the largest, containing 2.5 times the mass of the rest of the planets in the Solar System. Everything about planet Jupiter is big. It has the most moons in the Solar System, including the largest moon, Ganymede. It has the largest storm: the Great Red Spot; the most extreme gravity, and the biggest temperature extremes.

Because you can see Jupiter with the unaided eye, it’s impossible to say who actually discovered Jupiter. But it was Galileo Galilei who first turned his rudimentary telescope on Jupiter in 1610. Even with its dim optics, Galileo was able to make out the fact that Jupiter had 4 bright moons and bands across the planet. Since astronomers believed that everything orbited around the Earth, finding moons orbiting Jupiter threw the Earth-centered theory of the Universe into doubt. Even the smallest telescope will show you what Galileo saw.

Planet Jupiter orbits the Sun at an average distance of 779 million km (484 million miles), and it takes 4,333 Earth days to complete one orbit around the Sun; that’s almost 12 years. But Jupiter rotates once on its axis every 9 hours and 56 minutes. This high rotation speed has flattened out the planet, so that its equator is much further from the center of Jupiter than the poles. Jupiter’s also the largest plane in the Solar System, with an equatorial diameter of 142,984 kilometers (88,846 miles) – 11 times the diameter of Earth.

Jupiter has 318 times more mass than Earth, but it has a relatively low density; only 1/4 the density of Earth. It has such a low density because Jupiter is made up almost entirely of hydrogen with a little bit of helium. The upper atmosphere has tiny amounts of ammonia and other chemicals, which create the bands and clouds we see in photographs. The most familiar feature in Jupiter’s atmosphere is the planet’s Great Red Spot. This is a long-lived storm large enough to swallow up three planets the size of Earth.

It also has the largest number of moons in the Solar System: 63 at last count. The 4 largest moons are the Galilean moons, named after Galileo who discovered them. Ganymede measures 3,273 km across, and it’s the largest moon in the Solar System. Io orbits the closest of these moons and its undergoing almost constant volcanic activity because of tidal flexing being so close to Jupiter. Europa and Callisto probably have oceans of liquid water underneath thick shells of ice, and could be the home to exotic forms of life. Jupiter also has its own set of rings.

Seven spacecraft from Earth have made the journey to Jupiter: Pioneer 10, Pioneer-Saturn, Voyager 1, Voyager 2, Ulysses, Galileo, and New Horizons. Pioneer 10 was the first to reach the planet, making its flyby in 1972. The Galileo spacecraft actually went into orbit around Jupiter, to study the planet and its moons in great detail.

We’ve written many articles about Jupiter for Universe Today. Here’s an article about how Jupiter might protect us in the Solar System, and here’s an article about how you can see Jupiter in a telescope.

If you’d like more info on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.

Reference:
NASA