Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.
Looking at the power of the Chelyabinsk meteor (which struck a year ago and is visible starting around 1:15 in the video above) is still terrifying all these months later. Happily for those of on Earth worried about these big space rocks, the world’s space agencies are taking the threat seriously and are starting to implement new tracking systems to look out for more threatening space rocks.
“It was a pretty nasty event. Luckily, no one was killed but it just shows the sort of force that these things have,” said Alan Harris, senior scientist of the DLR Institute of Planetary Research in Berlin, in this new European Space Agency video.
An asteroid that is only about 100 meters (328 feet) in diameter, for example, “could actually completely destroy an urban area in the worst case. So those are the things we’re really looking out for and trying to find ways to tackle.”
Check out the video for some examples of how the Europeans are talking about dealing with this problem, including a fun comparison to cosmic billiards and a more serious discussion on how to shove these rocks aside if they were on a collision course with our planet.
Illustration from Parker et al, 2008, of the decomposition of the main-belt asteroid population into families and background
objects in proper a vs. sin(i) (left panels) and proper a vs. e (right panels). The top panels show all
(background and family) objects in the data subset. The two middle panels show objects from 37 identi?ed
families, and the bottom two panels show the background population. Credit: Parker et al, 2008.
Who knew asteroids could be so beautiful and mesmerizing? In 2008, a group of astronomers led by Alex Parker did a study of the size distribution of asteroid families using data from the Sloan Digital Sky Survey. Asteroid families often have distinctive optical colors, the team said, and they were able to offer an improved way to separate out the family members into their colors. This resultant animation put together just this week by Parker shows the orbital motions of over 100,000 asteroids, with colors illustrating the compositional diversity and relative sizes of the asteroids.
“The compositional gradient of the asteroid belt is clearly visible,” says Parker, “with green Vesta-family members in the inner belt fading through the blue C-class asteroids in the outer belt, and the deep red Trojan swarms beyond that.”
All main-belt asteroids and Trojan asteroids with orbits known to high precision are shown in the video and the animation is rendered with a timestep of 3 days. Via Twitter, Parker said this animation took — from start to finish — 20 hours to render on 8 CPUs.
For reference, the average orbital distances of Mercury, Venus, Earth, Mars, and Jupiter are illustrated with rings.
Artist's impression of an asteroid breaking up. Credit: NASA/JPL-Caltech
When you throw a bunch of rock and debris at a rapidly spinning star, what happens? A new study suggests that so-called pulsar stars change their dizzying spin rate as asteroids fall into the gaseous mass. This conclusion comes from observations of one pulsar (PSR J0738-4042) that is being “pounded” with debris from rocks, researchers said.
Lying 37,000 light-years from our planet in the southern constellation Puppis, this supernova remnant’s environment is swarming with rocks, radiation and “winds of particles”. One of those rocks likely was more than a billion metric tonnes in mass, which is nowhere near the mass of Earth (5.9 sextillion tonnes), but is still substantial.
“If a large rocky object can form here, planets could form around any star. That’s exciting,” stated Ryan Shannon, a researcher with the Commonwealth Scientific and Industrial Research Organisation who participated in the study.
Pulsars are sometimes called the clocks of the universe because their spins, fast as they are, precisely emit radio beams with each revolution — a beam that can be seen from Earth if our planet and the star are aligned in the right way. A 2008 study by Shannon and others predicted the spin could be altered by debris falling into the pulsar, which this new research appears to confirm.
Artist’s conception of stellar rubble around pulsar 4U 0142+61. Credit: NASA/JPL-Caltech
“We think the pulsar’s radio beam zaps the asteroid, vaporizing it. But the vaporized particles are electrically charged and they slightly alter the process that creates the pulsar’s beam,” Shannon said.
As stars explode, the researchers further suggest that not only do they leave behind a pulsar star remnant, but they also throw out debris that could then fall back towards the pulsar and create a debris disc. Another pulsar, J0146+61, appears to display this kind of disc. As with other protoplanetary systems, it’s possible the small bits of matter could gradually clump together to form bigger rocks.
You can read the study in Astrophysical Journal Letters or in preprint version on Arxiv. The study was led by Paul Brook, a Ph.D. student co-supervised by the University of Oxford and CSIRO. Observations were performed with the Hartebeesthoek Radio Astronomy Observatory in South Africa, and CSIRO’s Parkes radio telescope.
Somewhere in this image there should be a static point of light that is the asteroid 2000 EM26. Based on orbital data from NASA/JPL, this is where it should have been. Credit: Slooh
Yesterday evening you may have dropped by to watch Slooh’s live coverage of asteroid 2000 EM26 as it passed just 8.8 lunar distances of Earth. Surprise – the space rock never showed up! Slooh’s robotic telescope attempted to recover the asteroid and share its speedy travels with the world but failed to capture an image at the predicted position.
Now nicknamed Moby Dick after the elusive whale in Herman Melville’s novel of the same name, the asteroid’s gone missing in the deep sea of space. Earthlings need fear no peril; it’s not headed in our direction anytime soon. Either the asteroid’s predicted path was in error or the object was much fainter than expected. More likely the former.
Last night’s coverage attempt of 2000 E26’s close flyby of Earth
2000 EM26’s predicted brightness at the time was around magnitude 15.4, not bright but well within range of the telescope. Rather than throwing their hands up in the air, the folks at Slooh are calling upon amateur astronomers make a photographic search for the errant space rock in the next few nights.
Since the asteroid was last observed 14 years ago for only 9 days, it isn’t too surprising that uncertainties in its position could add up over time, shifting the asteroid’s position and path to a different part of the sky by 2014. According to Daniel Fischer, German amateur astronomer and astronomy writer, the positions were off by 100 degrees! As Paul Cox, Slooh’s Observatory Director, points out:
“Discovering these Near Earth Objects isn’t enough. As we’ve seen with 2000 EM26, all the effort that went into its discovery is worthless unless followup observations are made to accurately determine their orbits for the future. And that’s exactly what Slooh members are doing, using the robotic telescopes at our world-class observatory site to accurately measure the precise positions of these asteroids and comets.”
If a determined, modern-day Ahab doesn’t find this asteroidal Moby Dick, one of the large scale robotic telescope surveys probably will. Here’s a link to the NASA/JPL particulars including brightness, coordinates and distance for 2000 EM26.
Similar sized asteroids, including ones passing even closer to Earth, zip by every month. 2000 EM26 received a lot of coverage yesterday likely because it arrived near the time of the anniversary of the Chelyabinsk meteorite fall over Russia. Though it remains scarce for now, eyes are on the sky to find the asteroid again and refine its orbit. Hopefully the beast won’t get away next time.
Looking for something off of the beaten celestial path to observe? The coming weeks will offer telescope users a rare chance to catch a well known asteroid, as it puts on its best show for over two decades.
Over the coming weeks, 2 Pallas, one of the “big four” asteroids – or do you say minor/dwarf planet/planetoid? – reaches a favorable observing point known as opposition. Gliding northward through the constellations of Hydra and Sextans through February and March 2014, 2 Pallas presents a favorable binocular challenge for both northern and southern hemisphere observers as it rises to the east opposite to the setting Sun and transits the local meridian around midnight.
And although 2 Pallas reaches opposition roughly every 16 months as seen from our Earthly vantage point, 2014 provides a chance to catch it under exceptional circumstances. And to top it off, the other “Big 4” asteroids – 1 Ceres, 3 Juno and 4 Vesta – are all currently visible as well and reach opposition in the January through April time frame.
2 Pallas as imaged by the Hubble Space Telescope. Credit: NASA
Pallas and its brethren also have a checkered history though the course of 19th century astronomy. The second minor planet to be discovered, Heinrich Wilhelm Olbers spied 2 Pallas near opposition on the night of March 28th, 1802. Olbers made this discovery observing from his home rooftop observatory in Bremen, Germany using a five foot – telescopes were often measured in focal length rather than aperture in those days – Dollond refractor.
Olbers discovered 2 Pallas on the border of the astronomical constellations of Virgo and Coma Berenices shining at magnitude +7.5.
A simulation of the orbit of 2 Pallas near opposition this month. Credit: NASA/JPL Horizons.
If the name Olbers sounds familiar, it’s because he also lent it to the paradox that now bears his name. Obler’s paradox was one of the first true questions in cosmology posed in a scientific framework that asked: if the universe is actually infinite in time and space, then why isn’t the sky infinitely bright? And, on a curious side note, it was American horror author Edgar Allan Poe that delivered the answer.
But now back to our solar system. Olbers also discovered 4 Vesta just five years after Pallas.
He was definitely on a roll. The discoveries of these space rocks also grabbed the attention of Olbers contemporary, Johann Bode. Bode had formulated a law now known as the Titus-Bode Law that seemed to put the spacing of then known bodies of the solar system in tidy order. In fact, the Titus-Bode law seemed to predict that a body should lie between Mars and Jupiter, and for a brief time in the 18th century — and again in 2006 when the International Astronomical Union let Eris and Pluto in the door before kicking them back out — Ceres, Pallas, Juno and Vesta were all considered planets.
A size comparison of the first ten asteroids discovered compared to Earth’s moon. Wikimedia Commons graphic in the Public Domain.
Today, we now know that 2 Pallas is a tiny world about 575 kilometres in diameter. 2 Pallas orbits the Sun once every 4.62 years and has a relatively high inclination of 34.8 degrees relative to the ecliptic. Pallas has no confirmed satellites, though one was once hinted at during a May 29th, 1979 stellar occultation. And though we’ve yet to send a mission to examine Pallas up close, there were early planning considerations to send NASA’s Dawn spacecraft there after its visit to 1 Ceres.
The path of 2 Pallas from February 16th though March 21st. Created by the author using Stellarium.
This month, look for 2 Pallas as a +7th magnitude wandering star at dusk. Mid-February finds 2 Pallas in the constellation Hydra, and it crosses briefly into Sextans starting on March 22nd until it passes just three degrees east of the 2nd magnitude Alphard (Alpha Hydrae) on March 1st, making a good guidepost to find it at its brightest.
2 Pallas last broke +7th magnitude visibility as seen from Earth in 1991 and won’t do so again til 2028. This is because 18.5 Earth years very nearly equals four orbits of Pallas around the Sun, bringing the two worlds back “into sync.” According to calculations by Belgian astronomer Jean Meeus, the 2014 opposition season offers the closest passage to Earth for Pallas from 1980-2060. Pallas can appear at a maximum brightness of magnitude +6.5 — just on the threshold of naked eye visibility — as seen from Earth.
A narrow field finder chart for 2 Pallas with sample comparison magnitudes, decimal points omitted. Created by the author using Stellarium.
Opposition for Pallas occurs on February 22nd, 2014, when the asteroid is 1.23 AUs distant from our fair planet. Watch for 2 Pallas near opposition this year moving at just under half a degree a day — about the diameter of the Full Moon — headed northward at closest approach.
Hunting asteroids at the eyepiece can be a challenge, as they visually resemble pinpoint stars and show no apparent disks even at high magnification. Sketching or photographing the field of view on successive nights is a fun and easy way to cross this object off of your life list. For those who own scopes with digital setting circles, Heavens-Above is a great quick look source for current coordinates.
2 Pallas just passed perihelion at 2.13 Astronomical Units from the Sun on December 6th, 2013, and passes closest to Earth on February 24th at 1.2 A.U.s distant.
Don’t miss the chance to spy this fascinating an enigmatic worldlet coming to a sky near you this season!
-Got pics of 2 Pallas and friends? Be sure to send ‘em in to Universe Today!
Itokawa, a peanut-shaped asteroid that has different densities in its small body. Credit: ESO/JAXA
From directly inferring the inside of an asteroid for the first time, astronomers have discovered these space rocks can have strange variations in density. The observations of Itokawa — which you may remember from the Japanese Hayabusa mission that landed on the asteroid in 2005 — not only teach us more about how asteroids came to be, but could help protect Earth against stray space rocks in the future, the researchers said.
“This is the first time we have ever been able to to determine what it is like inside an asteroid,” stated Stephen Lowry, a University of Kent scientist who led the research. “We can see that Itokawa has a highly varied structure; this finding is a significant step forward in our understanding of rocky bodies in the solar system.”
It’s not clear why Itokawa has such different densities at opposite sides of its peanut shape; perhaps it was two asteroids that rubbed up against each other and merged. At just shy of six American football fields long, the space rock has density varying from 1.75 to 2.85 grams per cubic centimetre. This precise measurement came courtesy of the European Southern Observatory’s New Technology Telescope in Chile.
The telescope calculated the speed and speed changes of Itokawa’s spin and combined that information with data on how sunlight can affect the spin rate. Asteroids are generally tiny and irregularly shaped sorts of bodies, which means the effect of heat on the body is not evenly distributed. That small difference makes the asteroid’s spin rate change.
This heat effect (more properly called the Yarkovsky-O’Keefe-Radzievskii-Paddack effect) is slowly making Itokawa’s spin rate go faster, at a rate of 0.045 seconds every Earth year. This change, previously unexpected by scientists, is only possible if the peanut bulges have different densities, the scientists said.
“Finding that asteroids don’t have homogeneous interiors has far-reaching implications, particularly for models of binary asteroid formation,” added Lowry. “It could also help with work on reducing the danger of asteroid collisions with Earth, or with plans for future trips to these rocky bodies.”
Artist's conception of asteroids and a gas giant planet. Credit: Harvard-Smithsonian Center for Astrophysics
We at Universe Today have snow on our minds these days with all this Polar Vortex talk. From out the window, the snowflakes all look the same, but peer at flakes under a microscope and you can see all these different designs pop up. Turns out that our asteroid belt between Mars and Jupiter is also much more diverse than previously believed, all because astronomers took the time to do a detailed survey.
Here’s the interesting thing: the diversity, the team says, implies that Earth-like planets would be hard to find, which could be a blow for astronomers seeking an Earth 2.0 somewhere out in the universe if other research agrees.
To jump back a couple of steps, there’s a debate about how water arose on Earth. One theory is that back billions of years ago when the solar system was settling into its current state — a time when planetesimals were crashing into each other constantly and the larger planets possibly migrated between different orbits — comets and asteroids bearing water crashed into a proto-Earth.
Artist’s conception of asteroids or comets bearing water to a proto-Earth. Credit: Harvard-Smithsonian Center for Astrophysics
“If true, the stirring provided by migrating planets may have been essential to bringing those asteroids,” the astronomers stated in a press release. “This raises the question of whether an Earth-like exoplanet would also require a rain of asteroids to bring water and make it habitable. If so, then Earth-like worlds might be rarer than we thought.”
To take this example further, the researchers found that the asteroid belt comes from a mix of locations around the solar system. Well, a model the astronomers cite shows that Jupiter once migrated much closer to the sun, basically at the same distance as where Mars is now.
When Jupiter migrated, it disturbed everything in its wake and possibly removed as much as 99.9 per cent of the original asteroid population. And other planet migrations in general threw in rocks from everywhere into the asteroid belt. This means the origin of water in the belt could be more complicated than previously believed.
You can read more details of the survey in the journal Nature. Data was gathered from the Sloan Digital Sky Survey and the research was led by Francesca DeMeo, a Hubble postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics.
Dots (circled) in this image show the first asteroid spotted by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) after the mission came out of hibernation. Credit: NASA
If anything, NASA’s asteroid-hunting spacecraft seems to be refreshed after going into forced hibernation for 2.5 years. In the first 25 days since it started seeking small solar system bodies in earnest again, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) found three new objects and detected an additional 854, NASA said Thursday (Jan. 23).
Luckily for people interested in this field, Amy Mainzer (the principal investigator for this mission) has been tweeting out discoveries as they come — and other observations besides. “Just passed our @WISE_Mission post-restart review. I believe the technical term is “Yee haw!!” she wrote Jan. 21. Below are a couple of illustrated examples of discoveries from her Twitter feed. Click on the pictures for larger versions.
In a release, NASA added that NEOWISE is “observing and characterizing” one NEO a day, which means not only looking at the object, but probing its size and composition. Astronomers know of about 10,500 NEOs, but of those only 10% (or about 1,500) have physical measurements cataloged as well. NEOWISE investigators aim to make hundreds of more of these measurements.
The mission (originally called WISE) launched in December 2009 to examine the universe in infrared light. After completely mapping the sky, it ran out of coolant it needed to do this work in 2010. It then shifted to examining comets and asteroids before being put into hibernation in February 2011. Read more about its mission history in this past Universe Today article.
With the Dawn spacecraft now heading towards the dwarf planet/asteroid Ceres, the mission has suddenly gotten even more intriguing. The Herschel space observatory has discovered water vapor around Ceres, and the vapor could be emanating from water plumes — much like those that are on Saturn’s moon Enceladus – or it could be from cryovolcanism from geysers or icy volcano.
“This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,” said Michael Küppers of ESA in Spain, lead author of a paper in the journal Nature.
Ceres might be considered to have a bit of an identity crisis, and this new discovery might complicate things even more. When it was discovered in 1801, astronomers thought it was a planet orbiting between Mars and Jupiter. Later, other bodies with similar orbits were found, marking the discovery of our Solar System’s main belt of asteroids.
Ceres laid claim as the largest asteroid in our Solar System, but in 2006, the International Astronomical Union reclassified Ceres as a dwarf planet because of its large size.
But now, could Ceres also have comet-like attributes? Herschel scientists say the most straightforward explanation of the water vapor production is through sublimation, where ice is warmed and transformed directly into gas, dragging the surface dust with it, and exposing fresh ice underneath to sustain the process. This is how comets work.
Ceres is roughly 950 kilometers (590 miles) in diameter. The best guess on Ceres composition is that it is layered, perhaps with a rocky core and an icy outer mantle. Ice had been theorized to exist on Ceres but had not been detected conclusively, until now.
This graph shows variability in the intensity of the water absorption signal detected at Ceres by the Herschel space observatory on March 6, 2013. Credit: ESA.
Herschel used its far-infrared vision with the HIFI instrument to see a clear spectral signature of the water vapor. But, interestingly, Herschel did not see water vapor every time it looked. There were variations in the water signal during the dwarf planet’s 9-hour rotation period. The telescope spied water vapor four different times, on one occasion there was no signature. The astronomers deduced that almost all of the water vapor was seen to be coming from just two spots on the surface.
Although Herschel was not able to make a resolved image of Ceres, the team was able to derive the distribution of water sources on the surface.
“We estimate that approximately 6 kg of water vapour is being produced per second, requiring only a tiny fraction of Ceres to be covered by water ice, which links nicely to the two localised surface features we have observed,” says Laurence O’Rourke, Principal Investigator for the Herschel asteroid and comet observation programme called MACH-11, and second author on the paper.
The two emitting regions are about 5% darker than the average on Ceres. Since darker regions are able to absorb more sunlight, they are then likely the warmest regions, resulting in a more efficient sublimation of small reservoirs of water ice, the team said.
They added that this new finding could have significant implications for our understanding of the evolution of the Solar System.
“Herschel’s discovery of water vapour outgassing from Ceres gives us new information on how water is distributed in the Solar System,” said Göran Pilbratt, ESA’s Herschel Project Scientist. “Since Ceres constitutes about one fifth of the total mass of asteroid belt, this finding is important not only for the study of small Solar System bodies in general, but also for learning more about the origin of water on Earth.”
Dawn is scheduled to arrive at Ceres in the spring of 2015 after spending more than a year orbiting the large asteroid Vesta. Dawn will give us the closest look ever at Ceres surface and provide more insight into this latest finding.
“We’ve got a spacecraft on the way to Ceres, so we don’t have to wait long before getting more context on this intriguing result, right from the source itself,” said Carol Raymond, the deputy principal investigator for Dawn. “Dawn will map the geology and chemistry of the surface in high resolution, revealing the processes that drive the outgassing activity.”
This is an artist's concept of NASA's OSIRIS-REx spacecraft preparing to take a sample from asteroid Bennu. Credit:
NASA/Goddard/Chris Meaney
NASA and the Planetary Society are teaming up to give everyone the opportunity tag along on the next mission to an asteroid … well, your name can go along on the trip, anyway! You can submit your name to be added on to a microchip that will be aboard the Origins-Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) spacecraft, which will launch to the asteroid Bennu in 2016 and arrive in 2018.
“We’re thrilled to be able to share the OSIRIS-REx adventure with people across the Earth, to Bennu and back,” said Dante Lauretta, principal investigator of the OSIRIS-REx mission from the University of Arizona in Tucson. “It’s a great opportunity for people to get engaged with the mission early and join us as we prepare for launch.”
The spacecraft will spend more than two years at the 1,760-foot (500-meter)-wide asteroid. The spacecraft will collect a sample of Bennu’s surface and return it to Earth in 2023 in a sample return capsule.
The “Messages to Bennu!” microchip will travel to the asteroid on the spacecraft, and once the sample return capsule deploys, the spacecraft will be placed into a long-term solar orbit around the Sun, along with the microchip and every name on it.
You can submit your name at this website. The deadline is September 30, 2014.
After you submit your name, you can download and print a certificate.
“You’ll be part of humankind’s exploration of the solar system — How cool is that?” said Bill Nye, chief executive officer of The Planetary Society.
Participants who “follow” or “like” the mission on Facebook will receive updates on the location of their name in space from launch time until the asteroid samples return to Earth. Facebook fans also will be kept apprised of mission progress and late-breaking news through regular status updates.
The OSIRIS-REx mission goal is to address basic questions about the composition of the very early solar system, the source of organic materials and water that made life possible on Earth, and to better predict the orbits of asteroids that represent collision threats to the Earth. It will collect a minimum of 2 ounces (60 grams) of surface material.
