'Name That Space Rock' -- describes the difference between those flying rocks from space. Credit and copyright: Tim Lilis. Used by permission.
With all the various space rocks flying by and into Earth last Friday, perhaps you’ve been wondering about the correct terminology, since a rock from space has different names depending on what it is made of and where it is.
Infographics artist Tim Lillis has put together a primer of sorts, in the form of an infographic, describing the different between a comet, asteroid, meteoroid, meteor and meteorite.
Asteroids are generally larger chunks of rock that come from the asteroid belt located between the orbits of Mars and Jupiter. Sometimes their orbits get perturbed or altered and some asteroids end up coming closer to the Sun, and therefore closer to Earth.
Comets are much like asteroids, but might have a more ice, methane, ammonia, and other compounds that develop a fuzzy, cloud-like shell called a coma – as well as a tail — when it gets closer to the Sun. Comets are thought to originate from two different sources: Long-period comets (those which take more than 200 years to complete an orbit around the Sun) originate from the Oort Cloud. Short-period comets (those which take less than 200 years to complete an orbit around the Sun) originate from the Kuiper Belt.
Space debris smaller than an asteroid are called meteoroids. A meteoroid is a piece of interplanetary matter that is smaller than a kilometer and frequently only millimeters in size. Most meteoroids that enter the Earth’s atmosphere are so small that they vaporize completely and never reach the planet’s surface. And when they do enter Earth’s atmosphere, they gain a different name:
Meteors. Another name commonly used for a meteor is a shooting star. A meteor is the flash of light that we see in the night sky when a small chunk of interplanetary debris burns up as it passes through our atmosphere. “Meteor” refers to the flash of light caused by the debris, not the debris itself.
If any part of a meteoroid survives the fall through the atmosphere and lands on Earth, it is called a meteorite. Although the vast majority of meteorites are very small, their size can range from about a fraction of a gram (the size of a pebble) to 100 kilograms (220 lbs) or more (the size of a huge, life-destroying boulder).
Thanks again to Tim Lillis for sharing his infographic with Universe Today. For more info about Tim’s work, see his Behance page, Flickr site, Twitter, or his website.
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. Image credit: NASA/JPL-Caltech
The Jet Propulsion Laboratory has released an initial view of radar observations of asteroid 2012 DA14 generated from data obtained by NASA’s Goldstone Solar System Radar, taken on Feb. 15-16, 2013 as the asteroid headed away from Earth. While these first radar data aren’t very picturesque, they do reveal one obvious thing: this asteroid is tumbler.
The movie is comprised of 73 radar “images” looped nine times. JPL said that during the observations, the space rock’s distance increased from 120,000 to 314,000 km (74,000 to 195,000 miles) from Earth. The resolution here is 4 meters per pixel.
The images span close to eight hours and clearly show an elongated object undergoing roughly one full rotation. JPL said the images suggest that the asteroid has a long axis of about 40 meters (130 feet). The radar observations were led by scientists Lance Benner and Marina Brozovic of JPL. Additional Goldstone radar observations were taken as the asteroid continued to move away from Earth, on February 18, 19, with more observations scheduled on the 20th.
Radar is one of the best techniques for studying an asteroid’s size, shape, rotation state, surface features and surface roughness, and for improving calculations of its orbit. Radar measurements of asteroid distances and velocities often enable computation of asteroid orbits much further into the future than if radar observations weren’t available.
A photo of Asteroid 2012 DA 14 as seen from the suburbs of Paris on February 15, 2013. Credit and copyright: Thierry Legault.
Yesterday a 50 meter (160 foot) rock passed just over 27,000 kilometers (17,000 miles) from the Earth’s surface. This big space rock, named 2012 DA14, dodged us while another smaller and unrelated asteroid gave us an extraterrestrial punch over Russia (read more about that here). Telescopes around the world — both big professional ones and smaller amateur ones — focused on the fast-moving 2012 DA14, whizzing along at 28,100 kilometers per hour (17,450 miles per hour), or 7.82 kilometers per second (4.8 miles per second) relative to Earth.
Here are some of the images from around the world of 2012 DA14. Noted French astrophotographer Thierry Legault sent Universe Today a note that he “easily spotted it visually through the 4″ refractor. It was running very fast amongst the stars!” he said.
In a really nice piece of astrophotography, François Colas from the Pic du Midi observatory in southern France captured the fast moving asteroid with just the right combination of exposure, allowing him to get the asteroid as a point and not a line. He used a Pentax K5 – 6400 ASA – 85mm f/1.4. Field of view 15°
Richard Fleet from Wiltshire, England also got a good capture of the asteroid. “Clouds were a problem most of the evening but I did manage to catch it going past the Coma Berenices cluster,” he said via email. “I saw the asteroid several times in 15×75 binoculars and the motion was obvious in seconds when it was near a star, though it took a bit longer to be sure in the more barren areas.”
He used a used a 200mm lens on a Canon 5D for the very nice sequence as it ‘ran among the stars’:
Image taken remotely from Spain on February 15, 2013 at 22:31UT, 3 hours after the close approach. Credit: Ernesto Guido and Nick Howes/Remanzacco Observatory.
The Remanzacco Observatory team has been following 2012 DA14 for a few days (click on the image above for their animation if it not ‘animating’.) See their website for several different shots from various remote telescopes around the world.
This image shows asteroid 2012 DA14 and the Eta Carinae Nebula, with the white box highlighting the asteroid’s path. The image was taken using a 3″ refractor equipped with a color CCD camera. The telescope is located at the Siding Spring Observatory in Australia and is maintained and owned by iTelescope.net. Credit: Aaron Kingery/NASA/MSFC
Gianluca Masi from the Virtual Telescope Project held a special webcast for the close approach of this asteroid. He reported they had more than 150,000 viewers from 166 countries. “Unfortunately, the clouds came, too, but at least we had some clear skies soon after the minimum distance was [reached],” he wrote. “For the occasion, the PlaneWave 17? robotic unit was used, trusting its exceptional Paramount ME robotic mount. The mount was controlled by TheSkyX Pro suite and the software was perfectly tuned to track this VERY DIFFICULT target. The results shown here speak by themselves: the asteroid was perfectly tracked, despite it was moving at 0.65 degrees per minute! All this after the scope was just slewed, without any manual adjustment! Amazing.”
2012 DA14 was about 36,500 km from Earth at the time.
Animation of 2012 DA14 created from 17 images, each with 3 second of exposures. Credit: Gianluca Masi, Virtual Telescope Project. Click on the image to animate if it is not ‘moving’ in your browser.
The Talmassons astronomy club from Udine, Italy took this imagery:
Shahrin Ahmad from Kuala Lumpur, Malaysia posted some of his images on Google+:
A 30 second exposure of Asteroid 2012 DA14 passing by Theta Crateris on Feb. 15, 2013 at 19:22 UTC, as seen from Malaysia. The Moon is added for comparison.Credit: Shahrin Ahmad
Nahum Mendez Chazarra from Spain’s Centro de Investigación y Divulgación Astronómica del Mediterráneo sent the video below. You can see more images on their Facebook page.
The Bareket Observatory in Israel had a live webcast of 2012 DA14’s close pass, and they reported they had more than 150K viewers overall. Here is a video they put together of some of the highlights of their observations:
Asteroid 2012 DA14 flies by NGC 4244 at a distance of 14 million light years. Credit and copyright: David G. Strange.
Nick Rose from San Mateo, California tracked 2012 DA14 on its way as it headed away from Earth, using a 6″ reflector with a high end Orion CCD imager on a modified Vixen Super Polaris mount, on the evening of February 15. “I inverted the image to make it easier to see the asteroid,” Nick said, “and the video consists of 100 10 second Binned 1×1 images.”
Mikko Suominen, a freelance science journalist from Finland created this 3-D animation based on the JPL’s information graphics using rendering software called Blender. “They ar not extremely precise,” Suominen said via email, “but for popular science purposes I think they are accurate enough.”
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
A meteorite flashes across the sky over Chelyabinsk, Russia, taken from a dashboard camera.
A small asteroid entered Earth’s atmosphere early Friday, February 15, 2013 over Chelyabinsk, Russia at about 9:20 am local Russian time. Initial estimates, according to Bill Cooke, lead for the Meteoroid Environments Office at NASA’s Marshall Space Flight Center, is that the asteroid was about 15 meters (50 feet) in diameter, with a weight of 7,000 metric tons. It hit the atmosphere at a shallow angle of about 20 degrees, at a speed of about 65,000 km/h (40,000 mph).
It traveled through the atmosphere for about 30 seconds before breaking apart and producing violent airburst ‘explosion’ about 20-25 km (12-15 miles) above Earth’s surface, producing an energy shockwave equivalent to a 300 kilotons explosion. That energy propagated down through the atmosphere, stuck the city below – the Chelyabinsk region has a population of about 1 million — and windows were broken, walls collapsed and there were other reports of minor damage throughout the city.
The official impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15).
Cooke said that at this time, the known damage is not due to fragments of the bolide striking the ground but only from the airburst. “There are undoubtedly fragments on the ground, but at the current time no pieces have been recovered that we can verify with any certainty,” Cooke said during a media teleconference today.
He added that the space rock appears to be “an asteroid in nature,” – likely a rocky asteroid since it broke apart in the atmosphere. It wasn’t detected by telescopes searching for asteroids because of its small size, but also because “it came out of the daylight side of our planet – was in the daylight sky and as a result was not detected by any earth based telescopes. #RussianMeteor was not detected from Earth because it came from the daylight side (i.e the Sun-facing side of Earth).
The meteor left a trail in the sky about 480 km (300 miles) long.
Cooke, along with Paul Chodas, a research scientist in the Near Earth Object Program Office at NASA’s Jet Propulsion Laboratory said that asteroids this size hit the Earth on average about once every 100 years. “These are rare events, and it was an incredible coincidence that it happened on the same day as the close flyby of Asteroid 2012 DA14,” Chodas said. “The two are not related in any way.”
The Russian meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia. Oddly enough, the Tunguska event was caused by an object about the size of 2012 DA14, the asteroid that flew by Earth today harmlessly. The meteor, which was about one-third the diameter of asteroid 2012 DA14, became brighter than the Sun, as seen in some of the videos here. Its trail was visible for about 30 seconds, so it was a grazing impact through the atmosphere.
There were certainly pieces that hit the ground, according to Jon M. Friedrich from Fordham University. “For something that created a bolide and sonic detonation of the size seen in Russia, it seems likely that fragments reached the earth,”Friedrich said in an email to Universe Today. “In fact, there are reports of a crater in a frozen lake and other locations that were in the path of the meteor. The resulting fragments are not likely large – I’d expect some of the absolute largest to be football to basketball sized, with many fragments being smaller, like marbles.”
Chodas said that defending the Earth against tiny asteroids like this is challenging issue, “something that is not currently our goal,” he said. “NASA’s goal it to find the larger asteroids. Even 2012 DA14 is on the smaller size. The tiny asteroid that hit over Russia is very difficult to detect, an in order to defend the Earth, the problem and issue there is to find these things early enough to do something about it if we wanted to divert it. While smaller asteroids are easier to divert, they are much more difficult to detect.”
“What an amazing day for near Earth objects,” Chodas said, “with two events happening on the same day.”
The lead animation courtesy of Analytical Graphics, Inc.
We interrupt your regular Weekly Space Hangout with this extra special edition to cover to the two asteroid-related events: the Russian meteor explosion and the close pass of Asteroid 2012 DA14.
We record the Weekly Space Hangout every Friday at 12 pm Pacific / 3 pm Eastern. You can watch us live on Google+, Cosmoquest or listen after as part of the Astronomy Cast podcast feed (audio only).
Asteroid 2012 DA14 as seen on February 14, 2013 at 11:00 UTC when the asteroid was at 0.018 Astronomical Unit from Earth. Images taken with Faulkes Telescope South operated by Las Cumbres Observatory Global Telescope Network by E.Gomez. Animation by Remanzacco Observatory
Our friends Ernesto Guido and Nick Howes from the Remanzacco Observatory — along with Edward Gomez from the Faulkes Telescope — have nabbed a look at asteroid 2012 DA14 as it was approaching Earth on Feb. 14, 2013 at around 11:06UT. Guido and Howes said the asteroid was about 748,000 kilometers (465,000 miles) from Earth, and was only about magnitude 17 in brightness. The animation was created from 3 images taken by Faulkes Telescope South through a 2.0-m f/10.0 Ritchey-Chretien telescope with a CCD. (You may have to click on the image for the animation, depending on your browser.)
See their website for some unique animations and detailed info about tomorrow’s (Feb. 15, 2013) close flyby of this 50 meter- (164 feet-) wide space rock.
The orbital path of asteroid 2012 DA14 as seen face on (top) & near edge on (bottom). (Credit: JPL Small Body Database Browser).
Want to keep tabs on asteroid 2012 DA14 as it whizzes past Earth tomorrow (Feb. 15)? NASA TV and several online astronomy outlets will be tracking this asteroid as it makes its record-setting close shave. This marks the first time there has been an asteroid of this size passing this close that we’ve known a year beforehand. No, there’s no chance it will hit us, but it will come within 27,630 kilometers (17,168 miles) from the surface of the Earth, inside the ring of geosynchronous satellites girdling our planet Earth. It will closest to Earth at 2:25 p.m. EST (19:25 UTC).
Find out how you can watch on TV or online as this 50 meter- (164 feet-) wide space rock goes by:
NASA Television will provide commentary starting at 2 p.m. EST (11 a.m. PST, 19:00 UTC) on Friday, Feb. 15. This flyby will provide a unique opportunity for researchers to study a near-Earth object up close. You can either watch the feed below, or on your own television if you get NASA TV, or online here.
The half-hour broadcast from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., will incorporate real-time animation to show the location of the asteroid in relation to Earth, along with live or near real-time views of the asteroid from observatories in Australia, weather permitting.
Astronomer Gianluca Masi from the Virtual Telescope Project will provide live views of asteroid 2012 DA14 from Ceccano, Italy, beginning at 5 p.m. EST (2200 GMT). You can watch at this link.
Bareket Observatory, Israel
The Bareket Observatory in Israel will have a free live webcast of the 2012 DA14 asteroid flyby on Friday from at 2 p.m. to 3:30 p.m. EST (19:00 to 20:39 UTC).
“The observatory will offer a special live view of the close approach, using a remote telescope coupled with a cooled CCD camera, accessible via the Internet,” said the observatory team.
Slooh Space Camera, Africa and Arizona
The Slooh Space Camera webcast will provide views of the asteroid from observatories in the Canary Islands (off the west coast of Africa) and in Arizona. They will also be viewable on iOS and Android mobile devices. Just go to the Slooh website on your device.
Slooh’s webcast will begin on the 15th at 6 p.m. PST / 9 p.m. EST / 02:00 UTC (2/16). The webcasts will feature real-time commentary by Slooh Space Camera’s Paul Cox, astronomer Bob Berman of Astronomy Magazine, and Matt Francis, the manager of Prescott Observatory at Embry-Riddle University in Arizona.
If you haven’t heard yet, this Friday, February 15, 2013 will be a close flyby of an asteroid named 2012 DA14. It’s turning out to be a highly anticipated event, as it will pass just 27,630 kilometers (17,168 miles) from the surface of the Earth, well within the range of many Earth-orbiting satellites. If you could watch the action from the vantage point of space, what would this flyby look like? Analytical Graphics, Inc., a company that creates modeling and analysis software for space, defense and other areas, has put together an animation which includes the asteroid’s trajectory as it approaches Earth, a closeup of the asteroid during its closest approach, a highlighted portion of Earth orbit that it is expected to pass through, and other interesting data.
The video above also provides a view of the asteroid’s pass by Earth below the geosynchronous orbit belt, how it will crossing the equatorial plane from South to North, a size comparison, and how the Earth/Moon will perturbs the asteroid’s orbit.
This asteroid is about 50 meters (164 feet) in size. Asteroid experts, including NASA’s Don Yeomans has , said there is no possibility of this asteroid hitting Earth, and they have also effectively ruled out the chance of any satellites getting hit.
The asteroid will not be bright enough to be visible with the unaided eye, but will be visible to backyard astronomers with good telescopes. The timing of the pass will allow viewers in eastern Europe, Africa, Australia and New Zealand to have the best chance of seeing this asteroid.
This asteroid must be stirring the imaginations of many; already renowned and award-winning space artist David A. Hardy has created a painting of his impression of 2012 DA14’s approach to Earth:
Thanks to Hardy for allowing us to post his lovely artwork. You can see more at his website, and he did an interview with us last year, which you can read here.
Asteroid 2012 DA14 Zooms just 17,200 miles above Earth on Feb. 13 in this artist’s concept. Credit; NASA
Our home planet is due for a record setting space encounter on Friday (Feb. 15) of this week, when a space rock roughly half a football field wide skirts very close by Earth at break neck speed and well inside the plethora of hugely expensive communications and weather satellites that ring around us in geosynchronous orbit.
“There is no possibility of an Earth impact” by the Near Earth Asteroid (NEO) known as 2012 DA 14, said Don Yeomans, NASA’s foremost asteroid expert at a media briefing. Well that’s good news for us – but a little late for the dinosaurs.
At its closest approach in less than 4 days, the 45 meter (150 feet) wide Asteroid 2012 DA14 will zoom by within an altitude of 27,700 kilometers (17,200 miles). That is some 8000 km (5000 miles) inside the ring of geosynchronous satellites, but far above most Earth orbiting satellites, including the 6 person crew currently working aboard the International Space Station.
Although the likelihood of a satellite collision is extremely remote, NASA is actively working with satellite providers to inform them of the space rocks path.
The razor thin close shave takes place at about 2:24 p.m. EST (11:24 a.m. PST and 1924 UTC) as the asteroid passes swiftly by at a speed of about 7.8 kilometers per second (17,400 MPH)- or about 8 times the speed of a rifle bullet. For some perspective, it will be only about 1/13th of the distance to the moon at its closest.
“Asteroid 2012 DA14 will make a very close Earth approach, traveling rapidly from South to North and be moving at about two full moons per minute,” said Yeomans, who manages NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “That’s very fast for a celestial object.”
Diagram depicting the passage of asteroid 2012 DA14 through the Earth-moon system on Feb. 15, 2013. Credit: NASA/JPL-Caltech
No known asteroid has ever passed so near to Earth.
“This is a record predicted close approach for a known object this size,” stated Yeomans. “Such close flybys happen every 40 years on average. An actual Earth collision would happen about every 1200 years.”
Yeomans said that if an asteroid the size of 2012 DA14 fell to Earth, the impact effect would be similar to the 1908 Tunguska event in Siberia. That was an air blast event that leveled trees over an area greater than about 800 square miles.
So the local effect on human cities for example of a 50 meter wide asteroid impact would be deadly and utterly devastating. But it would not be catastrophic to all life on Earth. Nevertheless, at this moment, Earth has no defenses against asteroids other than talk.
By comparison, the K-T event that caused the mass extinction of the dinosaurs some 65 million years ago was caused by an asteroid about 10 km (6 mi) in diameter. About 2/3 of all species went extinct. If 2012 DA14 impacted Earth the force would be equivalent to about 2.4 megatons of energy (2.4 million tons of TNT), said Yeomans.
Artists concept of meteoroide impact event
There is no danger to the ISS crew and apparently they won’t have any chance to observe it.
“The ISS is not positioned right for observations,” Lindley Johnson, program executive, Near Earth Object Observations Program, NASA Headquarters, Washington, told Universe Today.
“No NASA space-based assets will be making measurements,” Lindley told me. “The asteroid is moving to fast.”
However, radar astronomers do plan to take images around eight hours after the flyby using the Goldstone antenna in California’s Mojave Desert, which is part of NASA’s Deep Space Network.
Some skilful and knowledgeable Earthlings might have a chance to see the asteroid hurtling by with binoculars or a small telescope.
“The asteroid will be observable in the dark sky in Eastern Europe, Asia and Australia, achieving about 7.5 magnitude, somewhat fainter than naked eye visibility,” explained Yeomans. “Closest approach will be over Indonesia.”
Astronomers at the La Sagra Sky Survey program in southern Spain discovered the asteroid in February 2012 just after its last Earth flyby, at a fairly distant 7 Earth-Moon distances. They reported the finding to the Minor Planet Center.
NASA’s NEO group and collaborators in Pisa, Italy then use such data to predict future flight paths and look into past trajectories as well.
Yeomans said that the Feb 15 flyby will be the closest for the next 100 years and its orbit will be perturbed so that it comes back less frequently – changing its orbital class from Apollo to Aten.
Due to its small size and recent discovery, not much is known about the composition of 2012 DA14. It might be silicate rock.
Small space rocks hit Earth on a daily basis amounting to about 100 tons. Car sized rocks hit weekly.
