Each of the individual images in this movie required about five minutes of data collection by the Goldstone radar. The moon has an elongated appearance.
Using 55 images made with the 270-foot (70-m) wide Goldstone radar dish scientists have released a new movie clip showing the newly discovered moon orbiting asteroid 1998 QE2. This widely publicized asteroid passed 3.6 million miles (5.8 million km) from Earth on May 31.
A slightly older animation of thirteen images captured by the Goldstone radio telescope on May 30, 2013. 1998 QE2 spins once every 5 hours Credit: NASA
The not-yet-named moon is a little more than one-third of a mile wide (2,000 feet or 600 m) and like our own moon orbits with one side always facing 1998 QE2. Astronomers call this synchronous rotation – the moon spins on its axis at the same rate as it revolves around the asteroid. While our moon takes nearly a month to loop around the Earth, the asteroid’s moon completes an orbit every 32 hours only 4 miles (6.4 km) out from its parent.
Interestingly, QE2′s moon is 20% as big as the 1.9 mile (3 km) wide asteroid, while our moon is proportionately only a little larger at 27% Earth’s diameter.
1998 QE2 is still out in the night sky traveling through the summertime constellation Ophiuchus. Shining at magnitude 12.5 tonight and 13th magnitude tomorrow night, you’ll need at least a 6-inch telescope to find it.
The red-boxed figures are JPL Horizons positions in R.A. (right ascension) and Dec. (declination) for asteroid 1998 QE2 tonight through June 22 at 0 hours Greenwich time (7 p.m. CDT). The purple box highlights the asteroid’s magnitude or brightness the next two nights. Credit: NASA
One of my favorite and guaranteed ways to find an asteroid is to hand-plot its position on a chart made with sky mapping software programs like Stellarium, Megastar or SkyMap. I create an ephemeris (table of locations during a span of time) using JPL’s Horizons site for the time I want to view an object. I then locate those positions on the chart and mark them with a pencil. Old-fashioned but it never fails.
This illustration shows the path of the small asteroid 2013 LR6, which will safely pass within 65,000 miles (105,000 kilometers) of Earth tonight June 7. Credit: NASA/JPL-Caltech
2013 LR6, a 30-foot-wide (10-m) rock from the asteroid belt, will cruise just 65,000 miles (105,000 km) above the Southern Ocean, south of Tasmania, at 11:42 p.m. Central Daylight Time tonight. No need to panic. The asteroid will not be sucked into the Earth. anymore than any previous close flyby; it’s moving too fast for that to happen. On the other hand, Earth’s dominant gravity will almost certainly change the shape of its orbit.
2013 LR6 was discovered by the NASA-sponsored Catalina Sky Survey on June 6. If it were larger, small telescopes might get to see this one during the time of closest approach, but its small size means it will be faint – only 15th magnitude at best. To see it, you’d need a good map and large amateur telescope.
We welcome this new space rock. It’s one more asteroid that’s moved from the realm of unknown to that of the known. One more potential hazard to watch to better understand its travel plans in the years ahead.
Radar images made on May 29, when 1998 QE2 was about 3.75 million miles from Earth, show a brand new moonlet circling its papa. Click image to see a video and read more about the discovery. Credit: NASA
So we got this hefty asteroid approaching Earth tomorrow. 1998 QE2will pass a safe 3.6 million miles (5.8 million km) or 15 times the distance of the moon at 3:59 p.m. Central time tomorrow afternoon. The 1.7 (2.7 km) mile wide space rock was discovered in August 1998 and while it still has no formal name, we’ll become closely acquainted via optical and radio telescope over the next several nights.
Many asteroid approach Earth much more closely but QE2 is exceptional because it’s larger than your average Earth-approacher and is making its closest pass for at least the next two centuries.
Many separate telescopic images were combined to create this animation of asteroid 1998 QE2 moving through a star field earlier this month. Credit: Ernesto Guido and Nick Howes
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., will show live images of the asteroid on NASA TV and host a discussion with NASA Administrator Charles Bolden and experts from JPL and the Goldstone Deep Space Communications Complex from 12:3-1:30 p.m. CDT today May 30. Scientists at Goldstone will be using radar to track and image the asteroid. You can watch it on NASA TV or Ustream.
The orbit of asteroid 1998 QE2. Its closest point to the sun is similar to Earth’s; when farthest it’s 353 million miles from the sun in the asteroid belt between Mars and Jupiter. Credit: NASA/JPL-Caltech
Be aware that the live images will show 1998 QE2 as a slowly moving “star”. It’s much too small and far away to show any detail in optical telescopes. Pictures created using the 230-foot Goldstone radio dish to ping the asteroid with radio waves will show details as small as 12 feet (3.75m), but these won’t be available in real time. They require time for processing.
Asteroid 1998 QE2 slices across Libra over the coming nights. Sky watchers with 4-inch or larger telescopes can use the detailed charts (below) to spot it. Click for hi-res version of map. Created with Chris Marriott’s SkyMap program
From 7-9 p.m. CDT tonight Bill Cooke of the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Ala., will host an onlinechaton 1998 QE2. Click the link a few minutes before 7 p.m., log in to the chat module that appears on the page and ask away. You can also watch it live during closest approach on SLOOH starting at 4 p.m. CDT tomorrow May 31.
If you’re game, you can even see the asteroid for yourself. You’ll need at least a 4-inch telescope and reasonably dark skies. Unfortunately it’s not visible with the naked eye or standard binoculars. For the next few nights 1998 QE2 will shine around 10.5 – 11 magnitude as it exits the constellation of Hydra and moves through the zodiac constellation Libra.
This map shows 1998 QE2′s position every hour starting this evening at 10:30 p.m. CDT. Remember to convert that time to your own time zone. North is up and east to the left; stars are shown to about 11th magnitude. The star patterns I’ve drawn will help you find the asteroid – especially tonight – since it won’t be near any obvious bright stars. Click to enlarge. Created with Chris Marriott’s SkyMap program
Libra’s well up in the south-southeast for much of the northern and southern hemisphere as soon as the sky gets dark. No setting the alarm for some ungodly hour. The farther south you are, the higher in the sky the asteroid will be.
The wide-view map shows the asteroid’s position at 10:30 p.m. CDT now through early June. At closest approach tomorrow, 1998 QE2 will move about one degree (two full moons side by side) every 3 hours, a motion you easily detect in just a few minutes using low power in your scope. You’ll be looking for a faint “star” that won’t stay put but slowly moves to the east as the seconds and minutes tick by.
Map of the asteroid’s travels tomorrow and Saturday nights. Once again, north is up and east to the left. Friday night you can see that QE2 passes near several brighter stars plotted on the wide angle map (above) making it easier to find. Click to enlarge. Created with Chris Marriott’s SkyMap software
I usually “lay a trap” and find a relatively bright star or stars the asteroid will pass through some minutes ahead of time. Then I stare into the eyepiece and wait for the asteroid to enter the field of view. The maps should work for most locations on the planet, but don’t be surprised if 1998 QE2 arrives a bit early (or late) and tracks a bit north or south of the plotted path. Look around a little instead of staring at the exact spot you’re expecting to see it.
Once you find it, hold on tight for the ride. Don’t let go – at least for a few minutes. It’s fun to jump on an asteroid and go for a cruise across the star fields. You may even see its light vary as tiny world rotates on its axis, presenting first one side and then another to your eyes. My favorite moments are when an asteroid passes really close to a star, making its motion obvious in seconds. Zoom!
To get hi-res versions of all three maps that you can print out and use at the telescope, just click each image. That’ll take you to my Flickr site. Right-click each map and select “Original” and then make a print out. If you have your own night sky program, go HERE to grab 1998 QE2′s orbital elements and create your own charts.
Olivine and spinel have been found in the central peaks of the 58-mile-wide lunar crater Copernicus. See closeup photo below. Credit: Paolo R. Lazzarotti
Minerals seen in some of the moon’s craters may not belong to the moon at all but instead were likely delivered by asteroids or possibly even the Earth. Unusual minerals like spinel (ruby-like red gemstone) and olivine (olivine-green gemstone) have been found on the floors and especially in the central peaks of several larger lunar craters including the familiar Tycho, Copernicus and Theophilus using instruments like NASA’s Moon Mineralogy Mapper. Scientists assumed they were seeing material excavated from deep below the moon’s surface.
A bird’s eye view of some of the Copernican mountain peaks photographed by the Lunar Reconnaissance Orbiter. Peaks form during rebound of the crater’s floor after impact. Copernicus is about 900 million years old. Click to enlarge. Credit: NASA
Maybe not. These very same minerals are also common in meteorites. A recently published study in the journal Nature Geoscience by a team of scientists from the U.S. and China used computer models to fling simulated asteroids and meteorites at the moon with speeds under 26,820 mph (43,160 kph). Some 30% of asteroidal debris striking the moon travels below that speed according to the study.
Tycho, one of the most prominent craters on the moon, is 51 miles (82 km) across and formed when a small asteroid struck the moon relatively recently – only 110 million years ago. Like Copernicus, olivine has been found atop its central peak. Credit: William Wiethoff
When these slower-moving space rocks slam into the moon, the researchers found that fragments survived the impact. If the newly formed crater was 12 miles (20 km) wide or larger, asteroid material sent flying outward toward the crater’s rim would later fall back through gravity into the crater’s central peak. Peaks form in big craters when material that’s crushed and compacted by the incoming asteroid rebounds or rises back up in the crater’s center after impact.
An LRO photograph of Tycho’s 1.2-mile-high (2 km) central peak. The mountain complex measures 9.3 miles (15 km) from side to side. Resting near the summit is a large boulder 400 feet (120 m) wide. Click to enlarge. Credit: NASA Goddard/Arizona State University
“This observation may explain recent observations of exotic Mg-rich spinels and olivine in the central peaks of craters too small to have excavated the deep crust or mantle of the Moon,” they wrote. By extension, the team suggests that crater peaks on Mars and Vesta may also preserve remnants of exotic minerals delivered by asteroids.
A tighter view of the boulder in the photo above. The scene is 3/4 mile (1.2 km) wide. How such a large object ended up intact atop a mountain isn’t know for certain, but it probably rolled out of the impact debris forming the rising summit. Click to enlarge. Credit: NASA Goddard/Arizona State University
It’s generally assumed meteorites vaporize upon impact and leave only tiny fragments in crater floors, but if the impactor moves below a critical speed, the results of the study show it can leave bigger pieces. That means scientists must be cautious when deciding if the rock in the moon’s peaks really do represent samples excavated from deep down in the moon’s mantle or whether they’re alien rocks left by potshot asteroids.
Steps in the formation of a crater’s central peak. Small impact make simple, bowl-shaped craters; larger ones have peaks. Credit: JAXA
More intriguing is the possibility that some of those olivines and other exotic minerals came from Earth. Our planet got whacked as much or more than the moon several billion years back. More than 170 named lunar meteorites have been found on Earth, and studies have shown that delivery of “Earth meteorites” to the moon via impact is easily accomplished. You never know – there may even be the hardened, glassy remains of stromatolites, one of the planet’s earliest life forms dating from as early as 3.5 billion years ago, sparkling atop some lunar mountain. In simulations, materials leaving Earth would have melted on the outside but remained intact within.
Many separate telescopic images were combined to create this animation of asteroid 1998 QE2 moving through a star field this past week. Credit: Ernesto Guido and Nick Howes
An asteroid it would take an hour to walk across will speed past Earth on May 31 and provide radio astronomers a perfect opportunity to nab closeup views of its surface. 1998 QE2, discovered in 1998 by the Massachusetts Institute of Technology Lincoln Near Earth Asteroid Research (LINEAR) program, will miss our planet by a healthy 3.6 million miles (5.8 million km) or 15 times the distance of the moon. Closest approach occurs at 3:59 p.m. Central time.
The asteroid’s large size combined with its relatively close approach makes it a great target for both the 230-foot (70-m) Goldstone radio dish and 1,000-foot (305-m) Arecibo dish in Puerto Rico. Lance Benner, the principal investigator for the Goldstone radar observations from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., will have all hands on deck for the flyby. By sending bursts of radio waves at 1998 QE2 and measuring the retured radar echoes, Benner expects the dishes to resolve surface features as small as 12 feet (3.75m) across on the 1.7-mile-long asteroid (2.7 km).
The orbit of asteroid 1998 QE2. Its May 31 flyby will be the closest it comes to Earth for at least the next 200 years. Its closest point to the sun is similar to Earth’s; when farthest it’s 353 million miles from the sun in the asteroid belt between Mars and Jupiter. Credit: NASA/JPL-Caltech
Through an ordinary optical telescope, even a large one, 1998 QE2 will appear as a point of light. Radar observations reveal far more including shape, size, rotation and a wide variety of surface features. Goldstone observations are scheduled from May 30 – June 9; those at Arecibo for several days around June 5.
Already optical telescopes in the southern hemisphere have this monster rock in their crosshairs. By measuring repeating highs and lows in the asteroid’s brightness as it spins on its axis, astronomers can determine its rotation rate. 1998 QE2′s composition is gleaned by how it reflects sunlight. Reflected sunbeams streaming back to Earth carry the imprint of particular minerals that absorb and reflect portions of the sun’s light in unique ways that nail down their identities.
“It is tremendously exciting to see detailed images of this asteroid for the first time,” said Benner. “With radar we can transform an object from a point of light into a small world with its own unique set of characteristics. In a real sense, radar imaging of near-Earth asteroids is a fundamental form of exploring a whole class of solar system objects.”
1998 QE2 looks like a point of light in this time exposure taken remotely with a telescope in Australia by the team of Ernesto Guido and Nick Howes. The asteroid is currently very faint and only visible in the southern hemisphere. Click for more on the asteroid in their blog.
I’m excited about the asteroid because it will be bright enough to be visible in small telescopes across both northern and southern hemispheres for several nights around the time of closest approach. Between May 30 and June 5 it will shine at 10.5-11.0 magnitude while chugging through the constellations Libra and Ophiuchus, both conveniently placed at nightfall. Its steady movement across the sky – 2/3 of a full moon diameter an hour – will be obvious through the telescope. Come the end of the month, I’ll create a map to help you find it.
Read more about 1998 QE2 HERE. Amateur astronomers needing orbital elements and ephemerides can check out the Goldstone planner.
A trove of Chelyabinsk meteorites collected or purchased by Arizona meteorite hunter Michael Farmer. Many are rounded as their outer skins were melted during flight through the atmosphere. Credit: Michael Farmer
It’s official. February’s Russian fireball finally has a birth certificate with a name. The Meteoritical Society, the organization responsible for naming and maintaining the official tally of meteorite finds and falls, has named it Chelyabinsk (pronounced chel-YAH-binsk) after the largest city in the region of the fall.
Meteorite hunter Evgenij Suhanov smiles as he holds a fresh specimen found in the countryside near Chelyabinsk. Credit: Evgenij Suhanov
According to the rules of the Society’s Nomenclature Committee, acceptable names for meteorites include terrain-based features like rivers, mountains, lakes, bays, capes, and islands; political features such as towns, counties, states, and provinces, and sites of human activity such as parks, mines, historical sitesand railroad stations. Sites connected to recent human activity like buildings, shops and businesses, schools, bridges, roads, and golf courses are generally not acceptable. Sorry, there won’t be a Target meteorite anytime soon.
A beautiful Chelyabinsk “button” showing flight orientation. The left photo shows the nosecone side that sped downward through the atmosphere. The back side has a melted, frothy texture. Credit: Evgenij Suhanov
Official names are required to publish studies about this or that meteorite in some scientific journals. A meteorite gets a name after it’s been analyzed and classified in the lab. Until that time it’s one of a multitude of “unclassified” meteorites with no official status.
95.6% of meteorites found or seen to fall like Chelyabinsk are classed as ordinary chondrites, rocks containing rounded mineral grains called chondrules and peppered with flakes of metallic iron-nickel. Chondrites (KON-drites) derive from the outer crust of their parent asteroids and get a free trip to Earth after being blasted loose from long-ago impacts by other asteroids.
Ordinary chondrites are further subdivided into H, L and LL varieties. H stands for high metal (12-21% iron-nickel metal in the rock), L for low metal (5-10%) and LL (about 2%).
Chondrules and iron-nickel metal grains on a sawn face of an unnamed chondrite from northern Chile. It’s probably an H5 – high metal and altered minerals from heating. Credit: Randy Korotov
Rocks that ultimately came to Earth as meteorites were heated to varying degrees by the decay of radioactive elements in the asteroid’s crust altering their mineral structure. Those least affected by heat and which most resemble the first solid materials to form in the solar system are petrographic type 3; those most affected are type 6. So for example, an L3 meteorite has low metal and was little affected by heating, while an H6 has lots of metal and got baked.
A cut-open Chelyabinsk specimen shows a light texture with darker patches of shocked or impact-melted minerals. When meteorite minerals like olivine are shocked by impact, chemical changes occur that make them darken. Credit: Evgenij Suhanov
I apologize for the “tech talk” but it will help us better understand the nature of the Russian meteorite. Chelyabinsk is classified as an LL5 chondrite – low metal and a good amount of mineral alteration from early heating. Further, about a third of the stones found consist of a dark impact melt containing mineral and chondrule fragments. Like the name suggests, the melted rock probably came from the impact that sent chunks of the original asteroid on their earthward course.
You might wonder how long it took for the Chelyabinsk meteoroid (the name given a meteor or meteorite before it enters Earth’s atmosphere). Called its cosmic ray exposure age, the average time for an LL5 chondrite to arrive after getting blown off its asteroid is around 31 million years. That is a long, long time yet only a fraction – about 0.7% – of the meteorite’s true age of 4.6 billion years. Kind of makes you stop and reflect, doesn’t it?
Early samples from the perimeter of the hole in the ice of Lake Chebarkul. Credit: AP / The Urals Federal University Press Service, Alexander Khlopotov
I’ve been checking Chelyabinsk meteorites for sale on eBay and the few private sales I’ve been aware of. Prices range from around $35-150 per gram. As of March 21 there are 115 meteorites advertised on eBay as Chelyabinsk by everyone from first-time sellers to well-established meteorite folks. Surprisingly, most of the specimens appear to be the real thing. Chelyabinsk meteorites have either black or brown fusion crust – the dark, melted outer crust from heating during atmospheric entry - smooth or bumpy surfaces and are generally small. Undoubtedly the force of the explosion when the meteorite came down shattered the original meteoroid to bits.
Another fine fusion-crusted Chelyabinsk meteorite, this one weighing 43 grams. Credit: Evgenij Suhanov
Only a few larger pieces have been recovered. The largest weighs about 4 lbs. (1.8 kg). The total amount of material collected by locals and scientists is at least 220 lbs (100 kg) and perhaps more than 1,100 lbs. (500 kg). As for that 26 foot (8 m) hole in the ice in Lake Chebarkul likely punched out by a falling space rock, divers have yet to retrieve the culprit. They did however just discover a 10-foot (3 m) underwater crateroffset about 32 feet from the hole.
For more details on the Chelyabinsk meteorite, click HERE.
Short movie of the asteroid 2013 ET tracking across the sky made over a half-hour on March 4, 2013
Like cars on a freeway, they come out of nowhere, blow by and disappear in the distance. Asteroid 2013 EB passed within a moon’s distance of Earth on Feb. 28, while 2013 EC did the same four days later. Both spanned between 40-50 feet across or slightly smaller than the object that lit up Russian skies three weeks ago.
Radar image of the 230-foot-wide asteroid 2005 YU55 obtained during a flyby of Earth on November 7, 2011. 2013 ET is a tad larger. Both are rocky bodies orbiting the sun in Earth’s vicinity. Credit: NASA / JPL-Caltech
Next up is the heftier 2013 ET which cruises by Earth Saturday morning (6:09 a.m. CST) at a distance of 600,000 miles. That’s about 2 1/2 times the distance of the moon. Astronomers estimate ET’s diameter at 328 feet (100 meters).
None of the earlier flybys posed a threat to Earth and neither will 2013 ET as it diligently follows its path around the sun. You can keep your eyes on the asteroid courtesy of astrophysicist Gianluca Masi and his robotic telescope setup in Italy starting at 1 p.m. (CST) tomorrow March 8. Masi will broadcast the live photos of 2013 ET on WebTV and provide commentary.
Diagram showing the difference in the orbits of typical near-Earth asteroids (in blue) and the smaller subset of potentially hazardous asteroids (PHAs). PHA’s come within 5 million miles of Earth and have the potential, if they survive their flight through the atmosphere, to cause regional or larger-scale damage. Credit: NASA
All three building-sized rocks were discovered very recently. 2013 ET was spotted on March 3 by the Catalina Sky Survey based in the Catalina Mountains north of Tucson, Arizona. Discoveries like these are almost a daily occurrence and highlight the fact that of the estimated one million small near-Earth asteroids out there, we’ve discovered and tracked only 9,754 as of March 4, 2013. That’s less than 1%.
Of these, 861 have diameters of 1 kilometer (0.6 mile) or larger and 1,379 are classified as potentially hazardous, meaning their orbits take them threatening close to our planet. This doesn’t necessarily mean we’ll be hit, just that the potential exists.
Artist’s rendering of the gravity anomaly map of the Chicxulub Crater area. Red and yellow are gravity highs; green and blue are gravity lows. White areas indicate multiple sinkholes. The shaded area is the Yucatán Peninsula. Variations in the density of the rock were used to discover the crater which is buried under several thousand feet of limestone. Credit: Milan Studio
But there’s a silver lining. We’ve already discovered over 90% of the big, kilometer-plus-sized asteroids, greatly reducing the uncertainty of “what’s out there” when it comes to the worst potential impacts. The last really big smack-down of which we’re aware was the impact of a 6-mile-wide asteroid that triggered the mass extinction that wiped out the dinosaurs 65 million years ago. The 110-mile-diameter Chicxulub Crater in the Yucutan Peninsula remains as a testament to this Earth-altering event.
This collage of 72 individual radar-generated images of asteroid 2012 DA14 was created using data from NASA’s 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif. The observations were made on the night of Feb. 15-16, 2013 Click for large image. Credit: NASA/JPL-Caltech
NASA released the first radar images of 2012 DA14 made with the Deep Space Network’s 230-foot radio antenna at Goldstone during last Friday’s flyby. Astronomers used the dish to beam radio waves at the asteroid and “listened” to the echoes to create pictures of its shape and surface features. Bats use the sonic equivalent by bouncing sound waves off of objects to “see” their environment and hunt for food.
The pictures were made over 7.8 hours about 8 hours after closest approach on the night of Feb. 15-16, 2013. Like a child in a portrait session, 2012 DA14 refused to sit still. As the antenna did its magic, the asteroid’s distance from Earth increased from 74,000 to 195,000 miles. Additional radar observations are planned through Wednesday Feb. 20 to further refine its orbit.
Watch 2012 DA14 rotate in this animation of 73 frames made with the Goldstone antenna. The video is a loop – you’ll see it 9 rotations.
Watching the video, you can easily see at least two interesting features of the 150-foot-long asteroid. First, it’s elongated like an Idaho spud. Second, it appears to be spinning about its long axis in a counterclockwise direction. Astronomers were fortunate to catch nearly one complete ~8 hour rotation of the asteroid during the observing window.
The NASA press release indicated these pictures are “the initial sequence”. It’s hoped more and higher quality images will become available soon. More information and another image HERE.
Fragments said to be from the Russian meteorite fall ring the hole in Chebarkul Lake. Credit: Reuters: Chelyabinsk region Interior Ministry
Asteroid 2012 DA14 has moved on, and the Russians are busy cleaning up the mess from yesterday’s fireball. Hopefully a few people are also busy looking for meteorites from the fall. The only meteorite-maybes I’ve seen photos of are the small, black rocks found around the perimeter of the hole in Chebarkul Lake, west of Chelybinsk.
A Tagish Lake meteorite fragment. Credit: Michael Holly, Creative Services, University of Alberta.
If these are indeed meteorites from the bolide, they remind me of the black, carbonaceous debris dropped by the Tagish Lake fall over the Tagish Lake area in British Columbia on January 18, 2000. Carbonaceous chondrites are fragile, carbon-rich meteorites that easily shatter into dust and small bits during a fall. If that’s what we’re dealing with here, meteorite hunters better get cracking – this type erodes quickly. Divers found no trace of any meteorites in the lake at the bottom of the hole today.
It is odd though that two days have gone by without a single significant fragment found. Meteorites, which develop a black fusion crust on atmospheric entry, would show up beautifully against the snowy Russian landscape. So what gives? How long will see purported Chelyabinsk “meteorites”pop up on eBay before the real item finally shows? Only hours after the fall, the first dubious specimens appeared on the auction site. Not a one of them looks like a fresh fall and some are clearly not meteorites. Buyer beware!
These MET-7 satellite photos clearly show the Russian fireball traveling from east to west. North is at top. Asteroid DA14′s trajectory was south to north or nearly perpendicular to the fireball’s. Click for more information and a short video. Credit and copyright: EUMETSAT
As for the Russian fireball being related in any way to the asteroid flyby, it is not. I’ve been in touch with folks who orbits and it’s becoming even clearer that we’re dealing with two very different asteroids. Not only were their orbits nearly perpendicular to each other from the perspective of the Earth, but it’s not possible for a cloud of DA14 fragments to even reach the city of Chelyabinsk at 55 degrees north latitude in Russia.
Since the fragments would approach Earth from due south nearly parallel to the planet’s axis, if they hit the planet, they’d strike the southern hemisphere. From the fragments’ very-close-to-Earth perspective, Chelyabinsk, Russia is on the far or opposite side of the globe and totally out of sight. Amateur asteroid discoverer Dr. Marco Langbroekuses this analogy and I paraphrase slightly:
“Compare it with a car. A bird flying toward your car will always hit the front of the car – it cannot hit the back of the car. Chelyabinsk at 55 North latitude is “the back of the car” in this comparison, given the approach direction of 2012 DA 14 and any fragments of it.”
We place a lot of faith in coincidence because, well, if you drop a plate, it breaks. The two are related. So if two close meteors or asteroids appear around the same time, many of us make the assumption they’re related too. It totally makes sense to wonder about a connection between the two events, but once the data is in, we need to take another look at our surmise. Speaking of data, we’re still waiting on radar images from the Goldstone antenna. As soon as they’re available, you’ll see them here.
Animation of DA14 made from images taken this morning from New Mexico. Credit: Ernesto Guido and Nick Howes
I’m curious if any of you got to see the asteroid flyby either through binoculars or telescope. If so, we’d love to hear your story. Clouds were cruel here in Duluth, Minn., but I stood at the telescope and waited. And waited. Finally, a few thin openings passed the asteroid’s location just above the bowl of the Little Dipper about 7:15 p.m. (CST). There was just enough time to identify DA14 and watch it scoot north. One minute of joy followed by hours of clouds.
Cosmic debris rains down through the atmosphere nearly every day, accumulating at a rate of 37,000 to 78,000 tons per year. While that may sound like a lot, much of it is dust or passes unseen over the oceans.
At least a half-dozen times a year, however, a fireball burns up over a populated area and drops meteorites. Their fall is pinpointed by careful analysis of the angle of entry based on eyewitness reports, Doppler weather radar, security cameras or even dashboard cams, as we saw in Russia on Friday. Once the word is out, everyone from those closest to the areas of impact to meteorite hunters from across the planet are eager to find a piece of otherworldly treasure. The Chelyabinsk region has been pretty much off-limits to foreigners until recently, so it should be interesting to see who gets in and out without being arrested.
What they’re looking for are leftover fragments from collisions of bodies in the asteroid belt between Mars and Jupiter. Over the eons, Jupiter’s gravity nudges the shattered rocks out of the belt, sending them toward the inner solar system. Millions of years later, those fragments may hurl toward Earth. As the space rocks plummet through the atmosphere, the heat and pressure become so intense that even a fairly large object, say 13 to 50 feet across, will more often than not burst into harmless pieces that fall to the ground as meteorites.
The famous Peekskill fireball of October 9, 1992 that dropped a meteorite that smashed the rear end of a Chevy Malibu
A 13-footer hits our planet about once a year. One the size of Friday’s fall in Russia — about 50 feet across and weighing about 7,000 tons — strikes Earth about once every 50-60 years. The bigger they are, the less frequently they fall but the greater the consequences.
Yesterday’s flyby asteroid 2012 DA14, a rock about 150 feet across, would have caused regional devastation had it struck in one piece. One that size only rings our bell every thousand years. An asteroid of about 0.9 miles across could cause planet-wide devastation and climate change. The good news is such an event happens only once in half a million years.
While most of the 0.9-mile and larger near-Earth asteroids have been discovered, there are something like a million others as big as the one that zoomed by harmlessly yesterday. Sky surveys have ferreted out many of them, but many more remain to be found — before they find us. While there are many great ideas about how we might deflect an asteroid headed toward Earth, there are presently no programs underway to accomplish that goal.
2012 DA14 earlier this morning seen from Australia. The negative or reversed image is a 4-minute time exposure. The fast-moving asteroid created a trail of light during that time. Credit: Dave Herald
After this morning’s Russian fireball, we’re all sitting on the edge of our seats, but the fireball and 2012 DA14 are unrelated asteroid fragments on very different paths. One made a beeline directly to Earth, the other will safely pass 17,150 miles away around 1:24 p.m. (CST) today. The latest estimates on the Russian meteoroid’s size before it broke it up in the atmosphere put it around 50 feet across with a weight upwards of 7,000 tons. Today’s asteroid in contrast is about 150 feet end-to-end and tips the scales at 209,000 tons.
Amateur astronomer Dave Herald of Australia has been busy taking pictures of 2012 DA14 through his telescope overnight. His photograph shows the asteroid as a trail against the starry backdrop as it moved northward during the 4-minute time exposure. Herald will be providing an online feed with his observations and photos for NASA later today.
Simulated image of 2012 DA14 approaching Earth this morning around 9:15 a.m. CST. Antarctica shows up nicely as the asteroid closes in. Click to see the latest image.
If you’d like to hear commentary and see real-time pictures of the flyby (from Dave and others), check out NASA TV’s live stream beginning at 11 a.m. Central Time and continuing through the afternoon. Undoubtedly you’ll learn more about the Russian fireball there, too. When pictures are shown, the asteroid will look exactly like a star, because you’re looking at a small object many thousands of miles away.
A Ustream feed of the flyby from a telescope at NASA’s Marshall Space Flight Center in Huntsville, Ala., will be streamed for three hours starting at 8 p.m. CST this evening when the asteroid is visible in a dark sky over the U.S. You can view the feed and ask researchers questions about the flyby via Twitter HERE.
And don’t forget to take a virtual ride-along with the asteroid available HERE. Images are updated every 2 minutes. Enjoy the show!
