Viewing Alert: Jupiter May Have Been Impacted by a Fireball

An apparent object impact captured about 6:35 am on Sept. 10, 2012 from Dallas, Texas USA. Credit: George Hall.

UPDATE: Yes, there was an impact! An amateur astronomer in Dallas Texas, George Hall captured the impact flash in his webcam — click here to see his website and image — at about 6:30 am on Sept. 10, 2012.

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From astronomer Heidi Hammel of the Space Science Institute comes news about a potential new impact on Jupiter. She reports there has been a visual sighting of an apparent fireball on Jupiter earlier today (about 10 hours ago, as of this posting) so the impact site should be visible again over the next few hours. According to amateur astronomers discussing this on G+, the impact area on Jupiter won’t be visible again until about 05:00 UTC, (01:00 EDT). The amateur who observed the flash was Dan Petersen, from Oregon, who made the observation at approximately 11:35 UTC on September 10. Petersen reported it to Richard Schmude of the Association of Lunar and Planetary Observers (ALPO). Hammel says the report sounds realistic, but obviously it needs confirmation if possible: a) by looking for any ‘impact scar’ tonight or over the next few days; b) by searching any webcam video that any observers might have been recording at the time. From the time and position given, the flash was on the North Equatorial Belt at approximately L1=335, L2=219, L3=257. “Let’s hope someone has a record of it!” Hammel says.

If it was the impact was sizable enough, it might have left an impact scar like those seen after the Shoemaker-Levy/9 impacts and this one in 2010:

Color image of impact on Jupiter on June 3, 2010. Credit: Anthony Wesley

Anthony Wesley from Australia captured the flash of an impact in June 3, 2010. There was also a similar impact and flash in later in 2010 and a big one in 2009.

On the Cloudy Nights astronomy forum, Petersen described his sighting:

This morning (9/10/2012) at 11:35:30 UT, I observed a bright white two second long explosion just inside Jupiter’s eastern limb, located at about Longitude 1 = 335, and Latitude = + 12 degrees north, inside the southern edge of the NEB. This flash appeared to be about 100 miles in diameter. I used my Meade 12″ LX200 GPS telescope and a binoviewer working at 400X for the observation, seeing was very good at the time. I was thinking about imaging Jupiter this morning but decided to observe it instead, had I been imaging I’m sure I would have missed it between adjusting webcam settings and focusing each avi. We’ll have to wait and see if a dark spot develops inside the southern regions of the NEB over the next day or two. Good luck imaging this. My best guess is that it was a small undetected comet that is now history, hopefully it will sign its name on Jupiter’s cloud tops.

If you make any observations or find you have webcam footage that may show such an impact, please send us an email.

Simulated view showing where impact may have occurred (Lat +1... on Twitpic

Via astronomer Pete Lawrence (@Avertedvision on Twitter) is a simulated view showing where impact may have occurred (X marks the spot).

We’ll provide more updates as they become available.

Rivers of Rock

The Moon may not have ever had liquid water on its surface — despite the use of the term mare, Latin for “sea” and moniker for the large regions of darker material visible from Earth — but liquid did indeed flow on the Moon in ages past… liquid rock, briefly set loose by the impacts that formed its ubiquitous craters.

When large meteorites impacted the Moon, crust at the site would melt and get flung outwards, flowing downhill as rivers of rock and creating streams and pools of melted material before cooling and solidifying. There the rivers would remain, a permanently-hardened testament to the event that made them.

The image above, part of a NAC scan acquired by NASA’s Lunar Reconnaissance Orbiter on March 9, shows a solidified melt flow dating back to the creation of Tycho crater approximately 108 million years ago –which may sound like a long time but it’s actually very recent for large-scale lunar features.

The flow is interrupted by a younger, 400-meter-wide crater that impacted the lunar surface along its length. Since it punches through the melt flow as well as the local surface, it would be a great place for future astronaut geologists to explore!

Taken under slightly different lighting conditions, the image below shows a large melt pond that the flow above terminates in. The pond is about 4500 meters long by 2100 meters across (2.8 x 1.3 miles).

Such images wouldn’t be possible without the awesome Lunar Reconnaissance Orbiter. Launched on June 18, 2009, LRO explores the lunar surface from an altitude of only 50 km (31 miles). Read more on the LRO site here.

Image credits: NASA/GSFC/Arizona State University

A New Look at Apollo Samples Supports Ancient Impact Theory

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New investigations of lunar samples collected during the Apollo missions have revealed origins from beyond the Earth-Moon system, supporting a hypothesis of ancient cataclysmic bombardment for both worlds.

Samples of Apollo 16 breccia that contain chondritic material (JSC)

Using scanning electron microscopes, researchers at the Lunar-Planetary Institute and Johnson Space Center have re-examined breccia regolith samples returned from the Moon, chemically mapping the lunar rocks to discern more compositional detail than ever before.

What they discovered was that many of the rocks contain bits of material that is chondritic in origin — that is, it came from asteroids, and not from elsewhere on the Moon or Earth.

Chondrites are meteorites that originate from the oldest asteroids, formed during the development of the Solar System. They are composed of the initial material that made up the stellar disk, compressed into spherical chondrules. Chondrites are some of the rarest types of meteorites found on Earth today but it’s thought that at one time they rained down onto our planet… as well as our moon.

The Lunar Cataclysm Hypothesis suggests that there was a period of extremely active bombardment of the Moon’s surface by meteorite impacts around 3.9 billion years ago. Because very few large impact events — based on melt rock samples — seem to have taken place more than 3.85 billion years ago, scientists suspect such an event heated the Moon’s surface enough prior to that period to eradicate any older impact features — a literal resurfacing of the young Moon.

There’s also evidence that there was a common source for the impactors, based on composition of the chondrites. What event took place in the Solar System that sent so much material hurtling our way? Was there a massive collision between asteroids? Did a slew of comets come streaking into the inner solar system? Were we paid a brief, gravitationally-disruptive visit by some other rogue interstellar object? Whatever it was that occurred, it changed the face of our Moon forever.

Curiously enough, it was at just about that time that we find the first fossil evidence of life on Earth. If there’s indeed a correlation, then whatever happened to wipe out the Moon’s oldest craters may also have cleared the slate for life here — either by removing any initial biological development that may have occurred or by delivering organic materials necessary for life in large amounts… or perhaps a combination of both.

Timeline for the Lunar Cataclysm Hypothesis (LPI)

The new findings from the Apollo samples provide unambiguous evidence that a large-scale impact event was taking place during this period  on the Moon — and most likely on Earth too. Since the Moon lacks atmospheric weathering or water erosion processes it serves as a sort of “time capsule”, recording the evidence of cosmic events that take place around the Earth-Moon neighborhood. While evidence for any such impacts would have long been erased from Earth’s surface, on the Moon it’s just a matter of locating it.

In fact, due to the difference in surface area, Earth may have received up to ten times more impacts than the Moon during such a cosmic cataclysm. With over 1,700 craters over 20 km identified on the Moon dating to a period around 3.9 billion years ago, Earth should have  17,000 craters over 20 km… with some ranging over 1,000 km! Of course, that’s if the craters could had survived 3.9 billion years of erosion and tectonic activity, which they didn’t. Still, it would have been a major event for our planet and anything that may have managed to start eking out an existence on it. We might never know if life had gained a foothold on Earth prior to such a cataclysmic bombardment, but thanks to the Moon (and the Apollo missions!) we do have some evidence of the events that took place.

Sample of lunar impact melt breccia, showing exterior and chondrule-filled interior. (Click for sample report.) Source: JSC

The LPI-JSC team’s paper was submitted to the journal Science and accepted for publication on May 2. See the abstract here, and read more on the Lunar Science Institute’s website here.

And if you want to browse through the Apollo lunar samples you can do so in depth on the JSC Lunar Sample Compendum site.

What’s the Moon Made Of? Earth, Most Likely.

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Recent research on lunar samples has shown that the Moon may be made of more Earth than green cheese — if by “green cheese” you mean the protoplanet impactor that was instrumental in its creation.

It’s an accepted hypothesis that Earth’s moon was created during an ancient, violet collision between our infant planet and a Mars-sized world called Theia, an event that destroyed Theia and sent part of Earth’s crust and upper mantle into orbit as a brief-lived ring of molten material. This material eventually coalesced to form the Moon, and over the next 4.5 billion years it cooled, became tidally locked with Earth, accumulated countless craters and gradually drifted out to the respectable distance at which we see it today.

Theia’s remains were once assumed to have been a major contributor to the material that eventually formed the Moon.   Lunar samples, however, showed that the ratio of oxygen isotopes on the Moon compared to Earth were too similar to account for such a formation. Now, further research by a team led by scientists from The University of Chicago shows that titanium isotopes — an element much more refractive than oxygen — are surprisingly similar between the Moon and Earth, further indicating a common origin.

“After correcting for secondary effects associated with cosmic-ray exposure at the lunar surface using samarium and gadolinium isotope systematics, we find that the 50Ti/47Ti ratio of the Moon is identical to that of the Earth within about four parts per million, which is only 1/150 of the isotopic range documented in meteorites,” wrote University of Chicago geophysicist Junjun Zhang, lead author of the paper published in the journal Nature Geoscience on March 25.

If the Moon is more Earth than Theia, then what happened to the original impacting body? Perhaps it was made of heavier stuff that sunk deeper into the Moon, or was assimilated into Earth’s mantle, or got lost to space… only more research will tell.

But for now, you can be fairly sure that when you’re looking up at the Moon you’re seeing a piece of Earth, the cratered remnants of a collision that took place billions of years ago.

See the team’s paper here.

Image credit: NASA / JPL-Caltech

Mexican Lake Bears Witness To Ancient Impact

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Exotic sediments found beneath the floor of Lake Cuitzeo in central Mexico support theories of a major cosmic impact event 12,900 years ago, report a 16-member international research team. The impact may have caused widespread environmental changes and contributed to the extinctions of many large animal species.

Images of single and twinned nanodiamonds show the atomic lattice framework of the nanodiamonds. Each dot represents a single atom. (Source: UCSB release.)

The team found a 13,000-year-old  layer of sediment that contains materials associated with impact events, such as soot, impact spherules and atomic-scale structures known as nanodiamonds. The nanodiamonds found at Lake Cuitzeo are of a variety known as lonsdaleite, even harder than “regular” diamond and only found naturally as the result of impact events.

The thin layer of sediment below Cuitzeo corresponds to layers of similar age found throughout North America, Greenland and Western Europe.

It’s thought that a large several-hundred-meter-wide asteroid or comet entered Earth’s atmosphere at a shallow angle 12,900 years ago, melting rocks, burning biomass and, in general, causing widespread chaos and destruction. This hypothesized event would have occurred just before a period of unusually cold climate known as the Younger Dryas.

The Younger Dryas has been associated with the extinction of large North American animals such as mammoths, saber-tooth cats and dire wolves.

“The timing of the impact event coincided with the most extraordinary biotic and environmental changes over Mexico and Central America during the last approximately 20,000 years, as recorded by others in several regional lake deposits,” said James Kennett, professor of earth science at UC Santa Barbara and member of the research team. “These changes were large, abrupt, and unprecedented, and had been recorded and identified by earlier investigators as a ‘time of crisis.’ ”

The exotic materials found in the sediment beneath Cuitzeo could not have been created by any volcanic, terrestrial or man-made process. “These materials form only through cosmic impact,” Kennett said.

The only other widespread sedimentary layer ever found to contain such an abundance of nanodiamonds and soot is found at the K-T boundary, 65 million years ago. This, of course, corresponds to the impact event that led to the extinction of the dinosaurs.

The researchers’ findings appeared March 5 in the Proceedings of the National Academy of Sciences. Read the news release from UC Santa Barbara here.

Asteroid 2005 YU55 Gets Closer to Earth; “No Chance of an Impact”

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Yes, it’s coming. Yes, it’s big. Yes, it will be even closer than the Moon. And yes… we’re completely safe.

The 400-meter-wide asteroid 2005 YU55 is currently zipping through the inner Solar System at over 13 km (8 miles) a second. On Tuesday, November 8, at 6:28 p.m. EST, it will pass Earth, coming within 325,000 km (202,000 miles). This is indeed within the Moon’s orbit (although YU55’s trajectory puts it a bit above the exact plane of the Earth-Moon alignment.) Still, it is the closest pass by such a large object since 1976… yet, NASA scientists aren’t concerned. Why?

Because its orbit has been well studied, there’s nothing in its way, and frankly there’s simply nothing it will do to affect Earth.

Animation of 2005 YU55's trajectory on Nov. 8. (NASA/JPL) Click to play.

Period.

2005 YU55’s miniscule gravity will not cause earthquakes. It has no magnetic field. It will not strike another object, or the Moon, or the Earth. It will not come into contact with cometary debris, Elenin, a black dwarf, Planet X, or Nibiru. (Not that those last three even exist.) No, YU55 will do exactly what it’s doing right now: passing through the Solar System. It will come, it will go, and hopefully NASA scientists – as well as many amateur astronomers worldwide – will have a chance to get a good look at it as it passes.

Scientists with NASA’s Near-Earth Objects Observation Program will begin tracking YU55 on Friday, November 4 using the 70-meter radar telescope at the Deep Space Network in Goldstone, California , as well as with the Arecibo Planetary Radar Facility in Puerto Rico beginning November 8. These facilities will continue to track it until the 10th.

This close pass will offer a great opportunity to get detailed radar imaging of YU55, an ancient C-type asteroid literally darker than coal. Since these objects can be difficult to observe using visible light, radar mapping can better reveal details about their surface and composition.

To help inform the public about YU55 NASA’s Jet Propulsion Laboratory in Pasadena recently hosted a live Q&A session on Ustream featuring specialists Marina Brozovic, a Goldstone Radar Team scientist, and Don Yeomans, manager of NASA’s Near-Earth Object Program. They fielded questions sent in via chat and Twitter… a recording of the event in its entirety can be seen below:



Video streaming by Ustream

Undoubtedly there will still be those who continue to spread misinformation about 2005 YU55. After all, they did the same with the now-disintegrated comet Elenin. But the truth is out there… and the truth is that there’s no danger, no cover-ups, no “plots”, and simply no cause for concern.

“It’s completely safe… no chance of an impact.”

– Don Yeomans, JPL

Read more about YU55 on our previous post or  on NASA’s Near-Earth Object Program site.

UPDATE: JPL has released a brief video about YU55 featuring research scientist Lance Benner, who specializes in radar imaging of near-Earth objects:

Although classified as a potentially hazardous object, 2005 YU55 poses no threat of an Earth collision over at least the next 100 years. However, this will be the closest approach to date by an object this large that we know about in advance and an event of this type will not happen again until 2028 when asteroid (153814) 2001 WN5 will pass to within 0.6 lunar distances. – Near-Earth Object Program, JPL

1-in-75 Chance Of Tunguska-Size Impact On Mars

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A 164-foot (50 meter) wide asteroid will be crossing the orbit of Mars at the end of January 2008. Currently, there is a 1-in-75 chance of the “Mars Crosser” hitting the Red Planet, and if it does, the 30,000 mile per hour speeding mass would generate a three megaton explosion (approximately the size of the terrestrial Tunguska impact over Siberia in 1908) and create a crater half-a-mile wide somewhere north of Meridiani Planum. So, the Mars Rover Opportunity will get a ringside seat should this once-in-a-thousand-year event occur…

NASA’s Near-Earth Object Office at the Jet Propulsion Laboratory (JPL) in Pasadena, California reported this month that a known Near Earth Asteroid (NEO) will be crossing the path of Mars on January 30, 2008. This puts asteroid “2007 WD5” in a special group of asteroids: “Mars Crossers“. NASA’s Near Earth Object Observation Program (or “Spaceguard” program) is intended to track asteroids that come close to the orbit of Earth, but also provides data for any asteroids tracked near our planetary neighbors.

Scientists are both excited and concerned by the possibility of an impact on Mars. Whilst this is a once in a lifetime opportunity to observe an impact of this size on Mars (remember the excitement at Shoemaker-Levy hitting Jupiter in 1994?), this event would eject millions of tons of dust into the Mars atmosphere, interfering with the Mars Expedition Rovers, and hindering orbital imaging of the planet. The Phoenix mission (currently en-route) will undoubtedly be affected. Looking far into the future, this event could have serious consequences for manned exploration.

“Right now asteroid 2007 WD5 is about half-way between the Earth and Mars and closing the distance at a speed of about 27,900 miles per hour […] Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid’s trajectory,” – Don Yeomans, manager of the NEO Office at JPL.

Although the odds are low, and the asteroid is expected to miss Mars by 30,000 km, asteroid hunters will be keeping a close eye on the progress of 2007 WD5 as it barrels closer and closer to the Red Planet and our robotic explorers.

Source: Near Earth Object Program