Sky and Telescope has prepared four detailed charts to help observers locate 3122 Florence this week. Two of these show the asteroid’s general motion northward among the constellations. Two more show small areas of sky, plotting all stars brighter than magnitude 9.5, for North American observers on the evenings of August 29-31 and September 1-3. Note that the detailed charts are labeled for Universal Time (GMT), and you’ll have to apply a time-zone correction for your location (for example, 0h UT on August 31st corresponds to 8 pm EDT on August 30th).
During its visit, Florence will be traveling roughly south to north, crossing through the constellations Capricornus, Aquarius, Delphinus, Vulpecula, and Cygnus. An especially good opportunity occurs at about 8 pm Eastern Daylight Time on Saturday evening, September 2nd, when the asteroid crosses the quartet of 4th-magnitude stars that mark the head of Delphinus, the Dolphin. It will be gliding northward by a little less than the full Moon’s diameter each hour, motion that should be obvious by watching the asteroid’s starlike pinpoint through a telescope for just a few minutes.
Florence appears this bright, despite being far away, both because it’s among the largest near-Earth asteroids (2.7 miles across) and it has a fairly bright surface that reflects more than 20% of the sunlight that strikes it. (For comparison, the Moon’s average reflectivity is just 12%.) Although it rotates in just 2.4 hours, this asteroid must be nearly spherical because its brightness varies by no more than about 11% – too small a change to pick up by eye.
A house-sized asteroid will shave past our planet on October 12, far inside the Moon’s orbit but without posing any threat, astronomers said Thursday. The space rock will zoom by harmlessly at a distance of about 44,000 kilometres (27,300 miles) — an eighth of the distance from the Earth to the Moon, according to the European Space Agency. This is just far enough to miss our geostationary satellites orbiting at about 36,000 kilometres.
“We know for sure that there is no possibility for this object to hit the Earth,” Detlef Koschny of ESA’s “Near Earth Objects” research team told AFP. There is no danger whatsoever.”
The asteroid, dubbed 2012 TC4, first flitted past our planet in October 2012 — at about double the distance — before disappearing from view. It is about 15-30 metres (49-98 feet) long, and was travelling at a speed of some 14 kilometres (nine miles) per second when spotted. Scientists expected the asteroid to return for a near-Earth rendezvous this year, but did not know how close it would get. Now, the Very Large Telescope of the European Southern Observatory (ESO) in Chile has managed to track the rock down, some 56 million kilometres away, and determine its trajectory.
“It’s damn close,” said Rolf Densing, who heads the European Space Operations Centre in Darmstadt, Germany. “The farthest satellites are 36,000 kilometres out, so this is indeed a close miss,” he told AFP.
For researchers, the near miss will provide a rare chance to test Earth’s “planetary defence” systems — which at this point are focused on early warning rather than active asteroid deflection.
Observing TC4’s movements “is an excellent opportunity to test the international ability to detect and track near-Earth objects and assess our ability to respond together to a real asteroid threat,” said an ESA statement. Asteroids are rocky bodies left over from the formation of our solar system some 4.5 billion years ago. There are thought to be millions of them, most of them in a “belt” between the orbits of Mars and Jupiter.
A space rock slightly bigger than TC4, at 40 metres, caused the largest Earth impact in recent history when it exploded over Tunguska, Siberia, in 1908.
In 2013, a meteoroid of about 20 metres exploded in the atmosphere over the city of Chelyabinsk in central Russia with the kinetic energy of about 30 Hiroshima atom bombs.
The resulting shockwave blew out the windows of nearly 5,000 buildings and injured more than 1,200 people. It caught everyone unawares.
If an object the size of TC4 were to enter Earth’s atmosphere, “it would have a similar effect to the Chelyabinsk event,” said the ESA.
But Earth’s atmosphere stretches only a few hundred kilometres far, and TC4 will comfortably miss it. Also, it would likely behave very differently to the Chelyabinsk object.
“The Chelyabinsk meteoroid was a piece of comet and they are usually made of icy material,” said Densing. “Due to the icy nature it probably dissipated in the atmosphere… When we’re talking about asteroids, this is solid material. They are mostly made up of iron, so will not so easily dissipate their energy in the atmosphere.”
TC4 is unlikely to shed any debris into the atmosphere.
Even if it did, no evacuation would be required for an object this size, said Koschny, merely a warning for people to stay away from windows that could shatter from the shockwave.
Densing, who has previously warned that humanity is not ready to defend itself against an Earth-bound object, said he would not lose any sleep, not over this one. “However, it makes you wonder what will happen next time,” he said. “I would have felt a bit more comfortable if we… had a longer pre-warning time.”
The British Columbia Meteor Network and its associate members are dedicated volunteers who have worked together to advance knowledge of meteor science. Some of our members are professionals although most are devoted amateurs.
The network is comprised of a video detection component as well as a radio detection component. We share our data with multinational governments and astronomy groups.
Data collection is only one goal of the the network. We also hope to promote a strong educational program in open cooperation with the school districts and community colleges of British Columbia.
Feel free to browse our site. Likewise, feel free to contact us if you have any questions or would like to know more.
On 19 April an asteroid will pass close by. At its closest it will be less than five times the distance of the Moon. The asteroid, named 2014 JO25, is about 600 metres across. It will scoot across our northern sky in a few hours, moving at 33.5 km/s. It will be closest to us at 08:24 EDT, 05:24 PDT. However, to see it you’ll need a telescope.
If it were made of basalt, like the Moon, it would have a mass of some 300 million tonnes. This is the biggest object in about 13 years to pass this close. A rough estimate suggests on average we could be hit by something that size every million years or so. Such an event would certainly be a disaster, but it would not be likely to endanger our existence. Smaller objects pass within that distance every week and on average one of them could hit us every 80 years.
The Moon is peppered with craters due to impacts. The Earth has been hit at least as often, but weathering and the continuous recycling of the Earth’s surface due to subduction and the emergence of new land surface have erased most of them. However, there are still conspicuous craters on the Earth’s surface. These cosmic collisions are not unusual; they are just part of the ongoing process of planet building.
The Earth itself was formed through impacts, as dust and progressively larger lumps of material smashed together some 4.6 billion years ago. Some of that material contained ice, which brought us the water to make our oceans. Fortunately most of that primordial “building material” has been used, but there are still pieces of it orbiting the Sun. A piece of this material some 12km across smashed down in the Sudbury area in Ontario about 1.8 billion years ago. The geological disturbance brought a wealth of minerals closer to the surface and concentrated them.
One of the most well-known and dramatic impacts occurred about 64 million years ago. After 180 million years of stability, environmental change and habitat loss was putting many species, such as the dinosaurs and ammonites into a steady decline. Then a 10km diameter asteroid hit the Earth, leading to such a rapid environmental change that 75% of species became extinct, including the dinosaurs and ammonites. In 1908 something entered the atmosphere and exploded over Tunguska, Siberia. Over 2000 square kilometres were flattened, and glasses rattled on shelves in Paris, France. A tiny difference in arrival time could have put that impact in Europe.
Today, our species dominates the Earth. Feeding ourselves and providing for our other needs involves heavily exploiting our planet’s resources. That means we are becoming increasingly vulnerable to any sort of environmental disaster. Can we do anything to reduce the impact risk? This involves two problems: detecting impact threats and then somehow mitigating them.
Small, dark objects on a dark background are hard to see. We usually detect them just in time to watch them sail past. Current radar methods are no better. In principle we can use our observations to assess the possibilities of future collisions. This is rendered difficult by all our data being obtained over a tiny part of the orbit, and the perturbation of that orbit by little tugs by the other planets. This means that unless we can give threatening asteroids a really big “shove”, changing the orbit by more than the uncertainties in our calculations, we might turn a miss into a hit. Unfortunately, as yet we don’t know how to give objects with masses of millions of tonnes a big shove. Blowing them up, as in the movies, would just turn one threat into many. However, the detection and mitigation of cosmic impact threats are getting a lot of attention.
Ken Tapping is an astronomer at the Dominion Radio Astrophysical Observatory, Penticton, BC.
April 4 and the 22nd had some excellent Aurora Borealis, and Saturday the 22nd was also the Lyrid meteor shower. The skies were clear for a brief time, so I saw a few Lyrid meteors.
Jerry Mason’s photo above shows green auroral glow and blue streaks. Taken from College Way above Vernon at 10:30pm. I suspect the curved streak at right is a lens reflection from the streetlight at lower left.
Something new, have you heard about auroral proton arcs actually being a new high velocity 300km high, high temperature gas stream called “STEVE” acronym: Strong Thermal Emission Velocity Enhancement?
STEVE was assumed by aurora photographers to be a “proton arc”. (Protons can hit the upper atmospheric gases also and while the electrons they bump loose can cause a glowing light, it’s a broad, diffuse and dim glow unlike the structure of STEVE that is a narrow streamer with rotation and other motion.
Photo Credit: Karina & Amir, Vanexus Photography, Vancouver BC. Taken at Porteau Cove provincial Park in August 2016. “While it started as a thin white line, it transformed into vibrant greens and purples before fading away.”
Basics about STEVE, from NASA’s Aurorasaurus blog: source: http://blog.aurorasaurus.org/?p=449
1.STEVE appears ~10-20° (in latitude) closer to the equator (south in the Northern hemisphere) than where the normal green aurora is overhead. This means it could be overhead at latitudes similar to Calgary, Canada.
2.STEVE is a very narrow arc aligned East-West and extending for hundreds or thousands of miles.
3.STEVE emits light in mostly purplish colors. It is quite faint but is usually photographed with 5-10 second exposures.
4.Sometimes, it is accompanied by a rapidly evolving green short-lived picket fence structure.
5.STEVE can last 20 minutes or even longer.
6.STEVE appears to have a season. For instance, it has not been observed by citizen scientists from October 2016 to February 2017.
7.This phenomena has been reported from the UK, Canada, Alaska, northern US states, and even New Zealand.
“Ordinary auroras we see from the ground and space are caused by electrons precipitating down into the atmosphere,” Dennis Gallagher of the Nasa Marshall Space Flight Centre said last year. “Protons can cause auroras, too, but they are different. For one thing, proton auroras are brightest in the UV part of the spectrum, invisible to the human eye.”
There is some visible light from proton auroras, but these are broad and spread out, not tight and filamentary like the streaks seen in the photographs.
Eric Donovan, a professor of Physics and Astronomy from the University of Calgary:
With data gathered by Alberta’s network of aurora watchers, Eric Donovan found it coincided with a flyby from one of the three satellites from the European Space Agency’s Swarm magnetic field mission.
“As the satellite flew straight through Steve, data from the electric field instrument showed very clear changes. The temperature 300 km above Earth’s surface jumped by 3000°C and the data revealed a 25 km-wide ribbon of gas flowing westwards at about 6 km/s compared to a speed of about 10 m/s either side of the ribbon,” explained U of C astronomer Eric Donovan in an ESA blog post.
“It turns out that STEVE is actually remarkably common, but we hadn’t noticed it before. It’s thanks to ground-based observations, satellites, today’s explosion of access to data and an army of citizen scientists joining forces to document it.
“Swarm allows us to measure it and I’m sure will continue to help resolve some unanswered questions.”
Roger Haagmans, Swarm’s mission scientist added that there is still a lot we need to learn about Steve. For example, it is not created by the interaction of solar particles with the Earth’s magnetic field, meaning it is not classified as an Aurora and requires further investigation.
So, instead of an aurora caused by solar particles slamming into air molecules, this turned out to be a super-heated ribbon of gases, where the air molecules were emitting light simply due to the heat, like the filament of an incandescent light bulb.
According to NASA’s Aurorasaurus blog, there were more than 50 observed sightings of Steve (which has since been hammered into the acronym Strong Thermal Emission Velocity Enhancement) last year and they’re hoping to gather more data in 2017.
(Email from Cattle Point Dark Sky Urban Star Park volunteer William Smith)
Dear Gerhard Drolshagen : On the Orbit of WT1190F (aka Snoopy)
Does object get captured weeks before and go into earth’s orbit, slowly losing speed and descending? OR does it come shooting directly into the earth’s atmosphere – almost perpendicular to a tangent ie pointing at the earth’s centre? This is important because if it orbits the earth one or two times as it slows down, then we might see it in the dark of the late evening where we are on West Coast of North America..
If you look at the ISS paths then focus in on the one which crosses southern India, this might indicate that SNOOPY (coming also NW-> SE) would pass over Panana, Bahamas, Northern Spain , Mediterranean and then IRAN . No luck for west coast of USA/Canada where I am.
Gerhard Drolshagen forwarded your message to me. Here is some of the info we have on WT1190F.
The object has been in Earth’s orbit at least since 2009. It has been moving in an elongated orbit with apogee at about twice the distance of the Moon, and perigee getting closer and closer to the Earth, until the upcoming re-entry. Since 2009, it has completed dozens of orbits around the Earth, and each orbit is about a month long.
The impact trajectory is not very vertical, but still much steeper than the typical re-entry of a low-orbiting satellite. It will come in with an angle of about 20° from the horizontal (=70° from vertical).
Given the fact that the orbit is so long, the geometry is totally different from a pass of the ISS. The latter orbits the Earth in about 90 minutes, while WT1190F takes weeks. So the current pass is actually the last part of the last orbit for this object.
Anyway, from a geometry point of view, it will definitely be observable from north America in the morning hours of November 12. However, it will be very faint, magnitude 19 or so, invisible by eye even with a large telescope. A CCD camera and at least a moderate-size telescope will be needed to get an image of it at that time.
Even for Europe and Northern Africa, which are the countries best-placed to observe it just hours before impact, it will only reach magnitude 15 or so, too faint for anything but images with a good telescope.
If you want to get an ephemeris for a specific site, I suggest you use this page from the Minor Planet Center: http://www.minorplanetcenter.net/iau/artsats/artsats.html. Just select WT1190F, enter the required information, and you will get your specific ephemeris based on the latest data.
Let us know if you need any additional info, and thanks for contacting us.
For the past few weeks you may have noticed meteors shooting across the sky. There is the Geminid meteor shower and three other smaller meteor showers in progress. Although with the bright moon, the dimmer meteors aren’t as easily seen.
The Geminids started Dec 4 and end Dec 17. On Sat Dec 14, at their peak they can give 120 meteors per hour. Fairly slow for meteors, they are travelling at a speed of 35 km/s. (That’s still pretty fast. For comparison, the International space station orbits at 8km/s, and goes around the Earth in 90 minutes.)
There are three smaller showers in progress: The sigma-Hydrids from Dec 03-Dec 15, peaked on Thurs Dec 12 with 3 meteors/hour, at speeds of 58km/s. The Comae Berenicids from Dec 12-Jan 23 peaked on Monday Dec 16 with 3 meteors/hour, at speeds of 65km/s And the December Leo Minorids from Dec 05-Feb 04 peak on Thurs Dec 19 with 5 meteors/hour at 64km/s
Don’t forget Comet Lovejoy in the early morning around 7am, before sunrise, a small fuzzy blob visible between Hercules and Corona Borealis above the eastern horizon. The bright moon drowns it out currently, so you’ll need binoculars or a telescope to see it and its slight tail.
2015-11-13 : 10:21 PST. Splashdown was last night at 22:19 PST in SRI LANKA off coast of Matara. Was late evening on USA Westcoast Thursday. Please enjoy my Blog. This is a conversation between young post-grad scientist Subath Amaradasa of the “Near Earth Objects” Team at the University of Ruhuna, who is on ground with French scientists from European Space Agency and William Smith who is the Hoyle-Shield coordinator at Cattle Point DARK SKY Urban Star Park, Victoria, Canada.
PS There will be a post script to the Snoopy event. Snoopy is almost certainly the Apollo 10 lunar lander – aka Snoopy. Its orbit which reaches way past the moon, makes this almost certain. No wonder it burned out. Very high speed entering the upper atmosphere. Ten times the speed of the fastest bullet on earth. Being small and with no shielding, no wonder it quickly burned out. Thanks to Rick Nowell for inspiring Subath Amaradasa and his “Near Earth Object” team at the University of Ruhuna in Matara, Sri Lanka.
A Meteor fireball fell over Central Washington State, and broke up over the Colville Reservation north of Yakima. The bright fireball was seen by many people from Vancouver Island , Vancouver, Seattle, and as far East as Spokane, Washington. The American Meteor Society received 116 reports of “a fireball” over Washington, B.C., Idaho and Oregon.
Vancouver time that was Thursday March 16, 2017 at 9:39pm. People described a green tail turning briefly yellow, followed by a quick double flash at it broke up.
Kathy M. wrote on the AMS site: “It was so amazing and beautiful. I’ve seen small, white falling stars before but never anything like this….large bright green with a huge white tail. Very cool.” http://www.amsmeteors.org/members/imo_view/event/2017/1012
Colour VIDEO: Tammy Kwan, a Vancouver weekly newspaper Georgia Straight reporter, posted her dashcam video to YouTube she was driving on Lougheed Highway in Pitt Meadows. See https://www.youtube.com/watch?v=xfcg_GiZhqA
Many of The Meteor Network All sky cameras across BC and Washington picked it up at 17 Mar 2017 at 04:39 UTC :
Bellview Wash (just a flash through clouds) at 04:39 UTC
Victoria BC at 04:39
Cranbrook BC at 04:39;
West Kelowna BC at 04:39.
Prince George BC at 04:53. (Their clock may be out).
The Anarchist Mtn, and Richland, Wash sites weren’t online. The Courtney BC site didn’t see it.
TRIANGULATION: On these Allsky photos, North is at the top, and East is on the left. Knowing the location of the photos, and from their directions, we can triangulate where the meteor was. If you get your ruler out and draw intersecting lines on a map, it appears South of Kelowna BC, in Central Washington, over the Colville Reservation. In this case, it’s unlikely it hit the ground.
A second smaller meteor was seen to the North on 03/17/2017 at 04:53 UT, 14 minutes afterward.