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).
The January 2013 occultation of Jupiter by the Moon as seen from South America. (Image courtesy of Luis Argerich & Nightscape Photography; used with permission.
The movement of the Moon makes a fascinating study of celestial mechanics. Despite the light pollution it brings to the nighttime sky, we’re fortunate as a species to have a large solitary satellite to give us lessons in “Celestial Mechanics 101″
This weekend, we’ll get to follow that motion as the Moon crosses into the constellation Taurus for a near-pass of the planet Jupiter, and for a very few citizens of our fair world, occults it.
The Moon versus Jupiter during the previous occultation of the planet last month. (Image courtesy of Luis Argerich at Nightscape Photography; used with permission).
In astronomy, the term “occultation” simply means that one astronomical body passes in front of another. The term has its hoary roots in astronomy’s ancient past; just like the modern day science of chemistry sprung from the pseudo-science of alchemy, astronomy was once intertwined with the arcane practice of astrology, although the two have long since parted ways. When I use the term “occultation” around my non-space geek friends, (I do have a few!) I never fail to get a funny look, as if I just confirmed every wacky suspicion that they ever had about us backyard astronomers…
But those of us who follow lunar occultations never miss a chance to observe one. You’ll actually get to see the motion of the Moon as it moves against the background planet or star, covering it up abruptly. The Moon actually moves about 12° degrees across the sky per 24 hour period.
The position of the Moon & Jupiter as seen from Tampa (Feb 18th, 7PM EST), Perth, (Feb 18th 11:30UT) & London (Feb 18th at 19UT). Created by the author using Stellarium.
On the evening of Monday, February 18th, the 56% illuminated waxing gibbous Moon will occult Jupiter for Tasmania and southern Australia around 12:00 Universal Time (UT). Folks along the same longitude as Australia (i.e., eastern Asia) will see a close pass of the pair. For North America, we’ll see the Moon approach Jupiter and Aldebaran of February 17th (the night of the Virtual Star Party) and the Moon appear past the pair after dusk on the 18th.
Orientation of Jupiter, the Moon & Vesta on the evening of February 18th for North America. (Created by the author in Starry Night).
But fret not; you may still be able to spot Jupiter near the Moon on the 18th… in the daytime. Daytime planet-spotting is a fun feat of visual athletics, and the daytime Moon always serves as a fine guide. Jupiter is juuuuuust bright enough to see near the Moon with the unaided eye if you know exactly where to look;
Jupiter captured during a close 2012 pass in the daytime! (Photo by author).
To see a planet in the daytime, you’ll need a clear, blue sky. One trick we’ve used is to take an empty paper towel tube and employ it as a “1x finder” to help find our target… binoculars may also help! To date, we’ve seen Venus, Jupiter, Sirius & Mars near favorable opposition all in the daylight… Mercury and Vega should also be possible under rare and favorable conditions.
This week’s occultation of Jupiter is the 3rd and final in a series that started in December of last year. The Moon won’t occult a planet again until an occultation of Venus on September 8th later this year, and won’t occult Jupiter again until July 9th, 2016. We’re also in the midst of a long series of occultations of the bright star Spica (Alpha Virginis) in 2013, as the Moon occults it once every lunation from somewhere in the world. Four major stars brighter than +1st magnitude lie along the Moon’s path near the ecliptic; Spica, Aldebaran, Regulus, and Antares which we caught an occultation of in 2009;
Also of note: we’re approaching a “plane-crossing” of the Jovian moons next year. This means that we’ll start seeing Callisto casting shadows on the Jovian cloud tops this summer on July 20th, and it will continue until July 21st, 2016. The orbits of the Jovian moons appear edge-on to us about every five years, and never really deviate a large amount. Callisto is the only moon that can “miss” casting a shadow on the disk of Jupiter in its passage. The actual plane crossing as seen from the Earth occurs in November 2014. Jupiter reaches solar conjunction this year on June 19th and doesn’t come back into opposition until early next year on January 5th. 2013 is an “opposition-less” year for Jupiter, which occurs on average once per every 11-12 years. (One Jovian orbit equals 11.8 Earth years).
The Moon plus Jupiter during last month’s close conjunction. (Photo by author).
But wait, there’s more… the Moon will also occult +7.7th magnitude 4 Vesta on February 18th at~21:00 UT. This occultation occurs across South America and the southern Atlantic Ocean. It would be fun to catch its ingress behind the dark limb of the Moon, and we bet that a precisely timed video might just show evidence for Vesta’s tiny angular diameter as it winks out. For North American observers, Vesta will sit just off the northern limb of the Moon… if you have never seen it, now is a great time to try!
Finally, we realized that also in the field with 4 Vesta is an explorer that just departed its environs, NASA’s Dawn spacecraft. Although unobservable from Earth, we thought that it would be an interesting exercise to see if it gets occulted by the Moon as well this week, and in fact it does, for a very tiny slice of the planet;
The occultation of the Dawn spacecraft as seen from Earth. Created by the author using Occult 4.0.
Hey, calculating astronomical oddities is what we do for fun… be sure to post those pics of Jupiter, the Moon and more up to our Universe Today Flickr page & enjoy the celestial show worldwide!
DE-STAR, a proposal to blow up asteroids as they bear down on Earth. Credit: Philip M. Lubin
The uncanny — but unrelated — combination of today’s close flyby of Asteroid 2012 DA14 and the meteor that created an airburst event over Russia has many wondering how we could deal with future potential threats to Earth from space. A group of researchers are hoping to aim a laser-blasting vaporizer in its direction and blow it away.
Dubbed DE-STAR, or Directed Energy Solar Targeting of Asteroids and exploRation, the theoretical orbital system is designed to convert the sun’s energy into laser blasts that would annihilate any cosmic intruders bearing down on Earth.
Although the system sounds like a plot from a science fiction movie, the researchers — led by scientists at two California universities — maintain that it is built on sound principles.
“This system is not some far-out idea from Star Trek,” stated Gary Hughes, a researcher and professor from California Polytechnic State University, San Luis Obispo, in a press release.
“All the components of this system pretty much exist today. Maybe not quite at the scale that we’d need – scaling up would be the challenge – but the basic elements are all there and ready to go. We just need to put them into a larger system to be effective, and once the system is there, it can do so many things.”
Construction details were not clear in a press release advertising DE-STAR, but the researchers describe astonishing results from even a modest-sized version of the system.
DE-STAR was modeled at several different sizes. At 328 feet (100 meters) in diameter, which is double the International Space Station’s size, it could “start nudging comets or asteroids out of their orbits,” Hughes stated.
A 6.2 mile (10-kilometer) DE-STAR version could send 1.4 megatons of energy daily to the marauding asteroid, providing enough juice every year to kill a space rock as big as 1,640 feet (500 meters) across. (That’s more than 10 times the size of 2012 DA14, which came within 17,200 miles of Earth Feb. 15.)
“Our proposal assumes a combination of baseline technology –– where we are today –– and where we almost certainly will be in the future, without asking for any miracles,” added Philip Lubin, who is with the University of California, Santa Barbara.
Besides asteroid annihilation, DE-STAR could give a fuel boost to long-distance space travellers.
A proposed DE-STAR 6 (size not disclosed) is advertised as able to push “a 10-ton spacecraft at near the speed of light, allowing interstellar exploration to become a reality without waiting for science fiction technology such as ‘warp drive’ to come along.”
The press release did not reveal a budget for any version of the DE-STAR, how it would be constructed, or how quickly the system could begin fencing with asteroids.
Researchers emphasized, however, that system proposals such as theirs must be taken seriously to ward off incoming space rocks.
“We have to come to grips with discussing these issues in a logical and rational way,” stated Lubin.
“We need to be proactive rather than reactive in dealing with threats. Duck and cover is not an option. We can actually do something about it and it’s credible to do something. So let’s begin along this path. Let’s start small and work our way up. There is no need to break the bank to start.”
In a wave of media releases, the latest studies performed by NASA’s Fermi Gamma-ray Space Telescope are lighting up the world of particle astrophysics with the news of how supernovae could be the progenitor of cosmic rays. These subatomic particles are mainly protons, cruising along through space at nearly the speed of light. The rest are electrons and atomic nuclei. When they meet up with a magnetic field, their paths change like a bumper car in an amusement park – but there’s nothing amusing about not knowing their origins. Now, four years of hard work done by scientists at the Kavli Institute for Particle Astrophysics and Cosmology at the Department of Energy’s (DOE) SLAC National Accelerator Laboratory has paid off. There is evidence of how cosmic rays are born.
“The energies of these protons are far beyond what the most powerful particle colliders on Earth can produce,” said Stefan Funk, astrophysicist with the Kavli Institute and Stanford University, who led the analysis. “In the last century we’ve learned a lot about cosmic rays as they arrive here. We’ve even had strong suspicions about the source of their acceleration, but we haven’t had unambiguous evidence to back them up until recently.”
Until now, scientists weren’t clear on some particulars – such as what atomic particles could be responsible for the emissions from interstellar gas. To aid their research, they took a very close look at a pair of gamma ray emitting supernova remnants – known as IC 443 and W44. Why the discrepancy? In this case gamma rays share similar energies with cosmic ray protons and electrons. To set them apart, researchers have uncovered the neutral pion, the product of cosmic ray protons impacting normal protons. When this happens, the pion rapidly decays into a set of gamma rays, leaving a signature decline – one which provides proof in the form of protons. Created in a process known as Fermi Acceleration, the protons remain captive in the rapidly moving shock front of the supernova and aren’t affected by magnetic fields. Thanks to this property, the astronomers were able to trace them back directly to their source.
“The discovery is the smoking gun that these two supernova remnants are producing accelerated protons,” said lead researcher Stefan Funk, an astrophysicist with the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in California. “Now we can work to better understand how they manage this feat and determine if the process is common to all remnants where we see gamma-ray emission.”
Are they little speedsters? You betcha. Every time the particle passes across the shock front, it gains about 1% more speed – eventually enough to break free as cosmic ray. “Astronauts have documented that they actually see flashes of light associated with cosmic rays,” Funk noted. “It’s one of the reasons I admire their bravery – the environment out there is really quite tough.” The next step in this research, Funk added, is to understand the exact details of the acceleration mechanism and also the maximum energies to which supernova remnants can accelerate protons.
However, the studies don’t end there. More new evidence of supernovae remnants acting like particle accelerators emerged during careful observational analysis by the Serbian astronomer Sladjana Nikolic (Max Planck Institute for Astronomy). They took a look at the composition of the light. Nikolic explains: “This is the first time we were able to take a detailed look at the microphysics in and around the shock region. We found evidence for a precursor region directly in front of the shock, which is thought to be a prerequisite of cosmic ray production. Also, the precursor region is being heated in just the way one would expect if there were protons carrying away energy from the region directly behind the shock.”
Nikolic and her colleagues employed the spectrograph VIMOS at the European Southern Observatory’s Very Large Telescope in Chile to observe and document a short section of the shock front of the supernova SN 1006. This new technique is known as integral field spectroscopy – a first-time process which allows astronomers to thoroughly examine the composition of the light from the supernova remnant. Kevin Heng of the University of Bern, one of the supervisors of Nikolic’s doctoral work, says: “We are particularly proud of the fact that we managed to use integral field spectroscopy in a rather unorthodox way, since it is usually used for the study of high-redshift galaxies. In doing so, we achieved a level of precision that far exceeds all previous studies.”
It really is an intriguing time to be taking closer looks at supernovae remnants – especially in respect to cosmic rays. As Nikolic explains: “This was a pilot project. The emissions we observed from the supernova remnant are very, very faint compared to the usual target objects for this type of instrument. Now that we know what’s possible, it’s really exciting to think about follow-up projects.” Glenn van de Ven of the Max Planck Institute for Astronomy, Nikolic’s other co-supervisor and an expert in integral field spectroscopy, adds: “This kind of novel observational approach could well be the key to solving the puzzle of how cosmic rays are produced in supernova remnants.”
Kavli Institute Director Roger Blandford, who participated in the Fermi analysis, said, “It’s fitting that such a clear demonstration showing supernova remnants accelerate cosmic rays came as we celebrated the 100th anniversary of their discovery. It brings home how quickly our capabilities for discovery are advancing.”
A meteorite flashes across the sky over Chelyabinsk, Russia, taken from a dashboard camera.
The meteor that streaked over the skies of Russia — creating a shockwave that shattered windows, injuring upwards of 1,000 people — is not related to the asteroid that will whiz past Earth later today, (Feb.15), NASA has confirmed.
As many of our readers have noted in comments on our previous story on the Russian meteor, the trajectory of the Russian meteorite was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object.
“Information is still being collected about the Russian meteorite and analysis is preliminary at this point,” NASA said in a statement. “In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14’s trajectory is in the opposite direction, from south to north.”
Images and video of the Russian bolide taken from satellites in Earth orbit confirm the trajectory:
An image from the SEVIRI instrument aboard the Meteosat-10 geostationary satellite. The vapor trail left by the meteor that was seen near Chelyabinsk in Russia on 15th February 2013 is visible in the center of the image. Original data Copyright EUMETSAT 2013
Reports are still coming in, but perhaps more than 1,000 people were injured, according to a statement from the Russian Emergency Ministry, primarily by glass cuts when windows were shattered from the shockwave blast. The vapor trail of the meteor was visible before the blast, so many people were standing in front of windows, looking at the trail visible across the sky.
The meteor appeared in the skies at around 09:25 a.m. local time in the Chelyabinsk region, near the southern Ural Mountains. It disintegrated and ‘exploded’ about 30-50 kilometers above Earth’s surface. The fireball blinded drivers and a subsequent explosion blew out windows. Reports of damaged buildings are being checked.
Initial estimates for the Russian Meteor are that it was a 1.5 meter-wide object weighing about 10 tons, traveling at 15 km/s.
Meteosat-10 image of Meteoroid trail aligned border with Kazakhstan in Google Maps. Credit: Paul Attivissimo
Nature News is reporting that this morning was the largest recorded object to strike the Earth in more than a century. “Infrasound data collected by a network designed to watch for nuclear weapons testing suggests that today’s blast released hundreds of kilotonnes of energy. That would make it far more powerful than the nuclear weapon tested by North Korea just days ago and the largest rock crashing on the planet since a meteor broke up over Siberia’s Tunguska river in 1908<" Nature News said.
[caption id="attachment_100015" align="aligncenter" width="580"] Satellite images from the European MET-7 weather satellite. Credit: EUMETSAT. [/caption]
We’ll continue to provide updates on this story as they become available.
A bright meteor witnessed over Russia on Feb. 15, 2013 (RussiaToday)
This just in: reports of bright meteors and loud explosions have been coming from Russia, with the incredible video above showing what appears to be a meteor exploding in the atmosphere on the morning of Friday, Feb. 15.
According to Reuters the objects were seen in the skies over the Chelyabinsk and Sverdlovsk regions.
“Preliminary indications are that it was a meteorite rain,” an emergency official told RIA-Novosti. “We have information about a blast at 10,000-meter (32,800-foot) altitude. It is being verified.” UPDATE: The Russian Academy of Sciences has estimated that the single 10-ton meteor entered the atmosphere at around 54,000 kph (33,000 mph) and disintegrated 30-50 kilometers (18-32 miles) up. Nearly 500 people have been injured, most by broken glass — at least 3 in serious condition. (AP)
Chelyabinsk is 930 miles (1,500 km) east of Moscow, in Russia’s Ural Mountains.
Preliminary reports on RT.com state that the meteorite “crashed into a wall near a zinc factory, disrupting the city’s internet and mobile service.” 150 minor injuries have also been reported from broken glass and debris created by the explosion’s shockwave.
ADDED: More videos below:
Contrails and explosions can be heard here, with breaking glass:
Over a city commercial district:
And yet another dash cam:
Watch the garage door get blown in at the 30-second mark:
Here’s a great summary from Russia Today
This event occurs on the same day that Earth is to be passed at a distance of 27,000 km by the 45-meter-wide asteroid 2012 DA14. Coincidence? Most likely. But – more info as it comes!
Illustration of gas cloud G2 approaching Sgr A* . Our central supermassive black hole periodically snacks on clouds and other material like this. That gives off X-rays and other emissions. (ESO/MPE/M.Schartmann/J.Major)
The heart of our Milky Way galaxy is an exotic place. It’s swarming with gigantic stars, showered by lethal blasts of high-energy radiation and a veritable cul-de-sac for the most enigmatic stellar corpses known to science: black holes. And at the center of the whole mélange is the granddaddy of all the black holes in the galaxy — Sagittarius A*, a supermassive monster with 4 million times more mass than the Sun packed into an area smaller than the orbit of Mercury.
Sgr A* dominates the core of the Milky Way with its powerful gravity, trapping giant stars into breakneck orbits and actively feeding on anything that comes close enough. Recently astronomers have been watching the movement of a large cloud of gas that’s caught in the pull of Sgr A* — they’re eager to see what exactly will happen once the cloud (designated G2) enters the black hole’s dining room… it will, in essence, be the first time anyone watches a black hole eat.
But before the dinner bell rings — estimated to be sometime this September — the cloud still has to cover a lot of space. Some scientists are now suggesting that G2’s trip through the crowded galactic nucleus could highlight the locations of other smaller black holes in the area, revealing their hiding places as it passes.
In a new paper titled “G2 can Illuminate the Black Hole Population near the Galactic Center” researchers from Columbia University in New York City and the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts propose that G2, a cloud of cool ionized gas over three times more massive than Earth, will likely encounter both neutron stars and other black holes on its way around (and/or into) SMBH Sgr A*.
Estimated number of stellar-mass black holes to be encountered by G2 along its trajectory (Bartos et al.)
The team notes that there are estimated to be around 20,000 stellar-mass black holes and about as many neutron stars in the central parsec of the galaxy. (A parsec is equal to 3.26 light-years, or 30.9 trillion km. In astronomical scale it’s just over 3/4 the way to the nearest star from the Sun.) In addition there may also be an unknown number of intermediate-mass black holes lurking within the same area.
These ultra-dense stellar remains are drawn to the center region of the galaxy due to the effects of dynamical friction — drag, if you will — as they move through the interstellar material.
Of course, unless black holes are feeding and actively throwing out excess gobs of hot energy and matter due to their sloppy eating habits, they are very nearly impossible to find. But as G2 is observed moving along its elliptical path toward Sgr A*, it could very well encounter a small number of stellar- and intermediate-mass black holes and neutron stars. According to the research team, such interactions may be visible with X-ray spotting spacecraft like NASA’s Chandra and NuSTAR.
NuSTAR X-ray image of a flare emitted by Sgr A* in July 2012 (NASA/JPL-Caltech)
The chances of G2 encountering black holes and interacting with them in such a way as to produce bright enough x-ray flares that can be detected depends upon a lot of variables, like the angles of interaction, the relative velocities of the gas cloud and black holes, the resulting accretion rates of in-falling cloud matter, and the temperature of the accretion material. In addition, any observations must be made at the right time and for long enough a duration to capture an interaction (or possibly multiple interactions simultaneously) yet also be able to discern them from any background X-ray sources.
Still, according to the researchers such observations would be important as they could provide valuable information on galactic evolution, and shed further insight into the behavior of black holes.
Read the full report here, and watch an ESO news video about the anticipated behavior of the G2 gas cloud around the SMBH Sgr A* below:
This research was conducted by Imre Bartos, Zoltán Haiman, and Bence Kocsis of Columbia University and Szabolcs Márka of the Harvard-Smithsonian Center for Astrophysics.
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.
