This week’s apparition of asteroid 1994 PC1 offers observers a chance to see a space rock moving in real time.
In a slow moving universe, asteroids give us a rare chance to see things moving in real time. We have such a chance coming right up on the evening of Tuesday, January 18th, when 1.1-kilometer asteroid (7482) 1994 PC1 passes 1.23 million miles (1.98 million kilometers) from the Earth. This is about five times the distance from the Earth to the Moon, and just a shade over the distance to the anti-sunward Earth-Sun Lagrange 2 point, soon to be the home of the James Webb Space Telescope.
An artist's conception of an NEO asteroid orbiting the Sun. Credit: NASA/JPL.
An artist’s conception of an NEO asteroid similar to 3122 Florence orbiting the Sun. Credit: NASA/JPL.
Ready to hunt for low-flying space rocks? We’ve got an interesting pass of a Near Earth Asteroid (NEA) this upcoming U.S. Labor Day weekend, one that just slides over the +10th magnitude line into binocular range.
We’re talking about asteroid 3122 Florence, which passes 4.4 million miles from our fair planet (that’s 7 million kilometers, about 18 times the distance from Earth to the Moon) this Friday on September 1st at 12:06 Universal Time (UT)/ 8:06 AM Eastern Daylight Saving Time (EDT).
Universe Todayran an article on the close pass about a week ago. Now, we’d like to show you how to see this asteroid as it glides by.
Ordinarily, a four million mile pass (about 4.7% of an astronomical unit, just under the criterion to make 3122 Florence a Near Earth Object) isn’t enough to grab our attention. Lots of asteroids pass closer weekly, and 3122 Florence is certainly no danger to the Earth this or any week in the near future. What makes this asteroid an attractive target is its size: NASA’s NEOWISE and Spitzer infrared telescope missions estimate that 3122 Florence is about 2.7 miles (4.4 kilometers) in diameter, a pretty good-sized chunk of rock as near Earth asteroids go.
The inclined orbit of 3122 Florence. Credit: NASA/JPL.
The last large asteroid with a similar close approach was 4179 Toutatis, which passed just under four lunar distances (a little under a million miles) from the Earth on September 29th, 2004.
Asteroid 3122 Florence (1981 ET3) was discovered by prolific asteroid hunter Schelte J. Bus from Siding Spring observatory in Australia on the night of March 2nd, 1981. Named after social reformer and founder of modern nursing Florence Nightingale, this weekend’s pass is the closest 3122 Florence gets to Earth over a 600 year plus span, running from 1890 (well before its discovery) out past 2500 AD.
Plans are afoot to ping 3122 Florence using Goldstone and Arecibo radars as it passes by the weekend. we might just see if it has a any attending moonlets or a strange bifurcated shape like comets 67/P Churyumov-Gerasimenko or Comet 45/P Honda-Mrkos-Pajdušáková very soon.
Asteroid 2014 JO25 imaged by Arecibo earlier this year… are contact binary ‘rubber-duck’ shaped asteroids and comets a thing? Credit: NASA/Arecibo/NSF.
3122 Florence has an inclined orbit, tilted 22 degrees in respect to the ecliptic plane. Orbiting the Sun once every 859 days, 3122 Florence travels from around 1 to 2.5 AUs from the Sun, making it an Amor class asteroid which journeys beyond the orbit of Mars and approaches but doesn’t pass interior to the orbit of the Earth.
This week’s pass sees 3122 Florence rapidly vaulting up from the southern to northern hemisphere.
This apparition culminates on Friday, September 1st, at 12:06 UT as the asteroid crosses the along the border of the constellations Equuleus and Delphinus at closest approach, reaching +9th magnitude. 3122 Florence will be moving at 20′ per hour (that’s about 2/3rds the diameter of the Full Moon) at closest approach, fast enough that you’ll notice its motion against the background stars in a low power field of view after about 10 minutes or so.
The path of 3122 Florence through the sky this week, times for the tick marks are in EDT (UT-4 hours). Credit: Starry Night Education software.
3122 Florence crosses through the constellations Piscis Austrinus, Capricornus, Aquarius, Equuleus and Delphinus this week. Keep in mind, the Moon is headed towards Full next week on September 6th, making the next few evenings a good time to track this fleeting space rock down.
3122 Florence from August 28th, about 8 million kilometers from the Earth. The asteroid is the center dot, while the streak to the left is the geostationary satellite AMC-14. Credit: the Virtual Telescope Project.
Finding 3122 Florence
3122 Florence races across the ecliptic northward on the night of August 29th and also crosses the celestial equator on September 1st
Tonight is also a good time to track down 3122 Florence, as it passes just 16′ from +3.8 magnitude star Zeta Capricorni. It also threads its way through the tiny the diamond-shaped asterism of Delphinus the Dolphin just over week after its closest pass on the evening of Saturday, September 9th.
Currently, 3122 Florence is 45 degrees above the southern horizon around local midnight for observers based along 30 degrees north latitude. The best view during Friday’s pass is from the Pacific Rim, including Australia, New Zealand and surrounding regions at closest approach.
The orientation of the Earth as seen from asteroid 3122 Florence during Friday’s closest approach. Credit: Starry Night Education software.
North American viewers will get a good view at local midnight just about eight hours prior to closest approach on the night of August 31st/September 1st, about 60 degrees above the southern horizon. The next good views occur the following evening about 16 hours after closest approach, as the asteroid is receding but 10 degrees higher above the southern horizon.
The 24 hour celestial path of of 3122 Florence through the night sky, centered on the September 1st closest approach. Tick mark times are in EDT (UT-4 hours). Created using Starry Night Education software.
A series short wide field exposures over about an hour revealing stars down to +10 magnitude should reveal the motion of 3122 Florence against the starry background. A good visual alternative is to sketch the suspect star field about 10 minutes apart, carefully looking for a ‘star’ that has moved during the intervening time.
JPL Horizons is a good place to generate accurate right ascension and declination coordinates for 3122 Florence to aid you in your quest. This one is distant enough to simple geocentric coordinates should suffice, and observer parallax shouldn’t shift the position of the asteroid significantly.
Clouded out? The good folks over at the Virtual Telescope Project will be featuring 3122 Florence during a live webcast starting on Thursday, August 31st at 19:30 UT/3:30 PM EDT.
We can be thankful that 3122 Florence isn’t headed Earthward, as it’s perhaps about half the size of the 10-15 kilometer diameter Chicxulub impactor that hit the Yucatan 65 million years ago, causing a very bad day for the dinosaurs. Plus, it would just be weird if an asteroid named after humanitarian Florence Nightingale caused the extinction of humanity…
And this is a great pre-show for a smaller and closer anticipated asteroid pass coming up in a few short weeks, as 2012 TC4 buzzes the Earth on October 12th, 2017.
Good luck in your quest to find 3122 Florence… let us know what you see!
Artist's concept of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.
Missed us… a concept image of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.
It’s a shooting gallery out there. The spattered face of Earth’s Moon and large impact sites such as Meteor Crater outside of Flagstaff, Arizona remind us that we still inhabit a dangerous neck of the solar neighborhood. But despite the inevitable cries proclaiming the “End of the World of the Week” this coming weekend, humanity can breathe a collective sigh of relief next Wednesday on April 19th, when asteroid 2014 JO25 passes safely by the Earth.
To be sure, lots of smaller space rocks pass by the Earth closer than the Moon (that’s an average of 240,000 miles distant) on a monthly basis. Take for example 4-meter asteroid 2017 GM, which passed just 16,000 kilometers distant on April 4th. What makes 2014 JO25 special is its size: measurements from NASA’s NEOWISE mission suggest that 2014 JO25 is about 2,000 feet (650 meters) along its longest axis, about twice the length of a Nimitz-class aircraft carrier. 2014 JO25 is passing 1.1 million miles (1.8 million kilometers) or 4.6 times the Earth-Moon distance on Wednesday, the closest large asteroid pass since 5-km Toutatis in September, 2004. The next predicted large asteroid pass near Earth is 1999 AN10, set to pass 1 LD (lunar distance) from the Earth in 2027.
4179 Toutatis as seen from China’s Chang’e 2 spacecraft. Credit: CNSA
This is also the closest passage of 2014 JO25 near the Earth for a 900 year span.
Discovered on May 5th, 2014 by the Catalina Sky survey, asteroid 2014 JO25 orbits the Sun once every three years, taking it from a perihelion of 0.237 AU (interior to Mercury’s orbit) out to an aphelion of 3.9 distant in the asteroid belt, interior to Jupiter’s orbit.
The orbit of NEO asteroid 2014 JO25. Credit: NASA/JPL.
Finding 2014 JO25 at its Closest Approach
With an estimated albedo (surface brightness) about twice that the lunar surface, 2014 JO25 will reach magnitude +10 to +11 on closest approach on Wednesday. Currently low in the dawn sky in the Square of Pegasus asterism, asteroid 2014 JO25 passed perihelion sunward as seen from the Earth at 1.015 Astronomical Units (AU) distant on March 11th. At its closest to the Earth on April 19th at 12:24 Universal Time (UT)/6:24 AM EDT, asteroid 2014 JO25 will skim the jagged Draco-Ursa Minor border below the bowl of the Little Dipper, moving at a whopping three degrees per hour. Sitting just 25 degrees from the north celestial pole on closest approach, catching sight of 2014 JO25 at favors western North America and northeastern Asia, though the eastern half of North America and Europe have a shot at the asteroid a few hours prior to closest approach in the early morning hours of April 19th. North American viewers get another shot at catching the fleeting asteroid later the same evening 13 hours after closest approach as the asteroid sails through the galaxy-rich constellation Coma Berenices.
The 24 hour path of asteroid 2014 JO25 from midnight UT April 18th through April 19th. (note: hourly time hacks are in Eastern Daylight Saving Time EDT UT-4). Credit: Starry Night Education software.
At +11th magnitude, you’ll need a telescope of at least 6” aperture or larger and a good star chart to nab 2014 JO25 as it glides against the starry background. Fellow Universe Today contributor Bob King has some great star charts of the pass over at Sky & Telescope. The Moon will be at Last Quarter phase on the morning of the 19th, providing moderate light pollution.
Plans are also afoot for NASA to ping asteroid 2014 JO25 using Arecibo and Goldstone radar… expect stunning animations to follow next week.
And if you’re out hunting for asteroids on the coming mornings, there are currently two bright binocular comets in the dawn sky to keep you company: Comet C/2017 E4 Lovejoy in the constellation Andromeda and Comet C/2015 ER61 PanSTARRS in Aquarius. Both are currently performing above expectations at about magnitude +7.
A busy neighborhood: Known asteroids as of April 1st, 2016. Credit: NASA/JPL.
“What if” an asteroid the size of 2014 JO25 hit the Earth? Well, the Chelyabinsk meteor was an estimated 20 meters in size; the impactor that formed Meteor Crater in Arizona was about 50 meters in diameter. The Chicxulub event off the Yucatan peninsula 66 million years ago was an estimated 10 kilometer-sized impactor well over ten orders of magnitude bigger than 2014 JO25. While the impact of a 600 meter asteroid would be a noteworthy event and a bad day locally, it would pale in comparison to an extinction level event.
All something to consider, as you watch the faint dot of asteroid 2014 JO25 pass harmlessly by the Earth and through the news cycle for the coming week.
The launch of Chan'ge-2 with 3rd stage (arrowed) now known as 2010 Q (Credit CALT).
Can’t find asteroid 2010 QW1 in the Minor Planet Database? No, the “Men in Black” didn’t secretly remove this Earth-orbiting asteroid from the listing… but recent top-notch detective work by astronomers did.
The mystery of this object all started back on August 23rd of this year, when the PanSTARRS sky survey based on the summit of Haleakala on the island of Maui in Hawai’i spotted an asteroid that was given the provisional designation of 2013 QW1.
The object was in a wide-ranging orbit around the Earth, leading astronomers to wonder if it was a naturally captured asteroid or perhaps space debris from a previous launch. Either solution to the dilemma would be fascinating. Our large Moon keeps the Earth pretty well swept clear of debris, though a “second Moon,” however small, would be an interesting find. And if 2013 QW1 were to prove artificial, it just might be a piece of history.
The European Space Agency’s NEO Coordination Centre decided to take up the challenge. A call went out to track and observe the 2013 QW1, and a team led by Elisabetta Dotto of INAF-Observatorio di Roma & Maria Barucci & Davide Perna of the Observatoire de Paris managed to get time on the Italian Telescopio Nazaionale Galileo based at La Palma to obtain a spectrum of the object.
“It was a bit of a challenge, because the object was moving fast with respect to a typical NEO,” said Dr. Perna in a recent ESA press release.
The team used an instrument known as DOLORES to make the crucial measurements. DOLORES stands for the Device Optimized for LOw RESolution. The spectrum obtained in the early morning hours of August 25th shows something much brighter than your typical asteroid, but is characteristic of a painted metallic object.
The launch of Chan’ge-2 with 3rd stage (arrowed) now known as 2013 QW1 (Credit: CALT).
And thus, 2013 QW1 was removed from the ledger of NEO asteroids maintained by the IAU Minor Planet Center (MPEC). And the leading suspect? The third stage booster of a Chinese Long March 3C rocket that launched the Chang’e 2 spacecraft from Xichang, China on October 1st, 2010.
Chang’e-2 entered lunar orbit 8 days after launch, and departed on June 8th of the following year after studying and mapping the Moon. Chang’e-2 then went on to become the first spacecraft to directly reach the L2 Lagrange point 1.5 million kilometres beyond Earth from lunar orbit. The spacecraft also made the first flyby of NEO asteroid 4179 Toutatis on December 13th of last year. The probe is estimated to continue functioning into 2014, and will be used to hone China’s ability to track objects in deep space.
The NORAD tracking identification assigned to the 3rd stage booster that launched Chan’ge-2 is 2010-50B.
This sort of discovery is not without precedent.
The launch of Apollo 12, with the 3rd stage (arrowed) would one day be “asteroid Joo2E3”. (Credit: NASA).
On September 3rd, 2002, amateur astronomer Bill Yeung discovered an asteroid tentatively designated J002E3. Subsequent studies revealed that the asteroid had a spectrum consistent with that of titanium oxide paint, a decidedly unasteroid-like coating for a space rock to sport. This was, however, a common veneer in use during the Apollo era, and it is now known that J002E3 is the S-IVB third stage booster that launched the second mission to land men on the Moon on November 14th, 1969. Unlike other boosters, such as the one that launched Apollo 14, the Apollo 12 3rd stage did not impact the Moon as part of seismic experiments. After a brief period as a “pseudo-moon” of the Earth, J002E3 was kicked out into solar orbit in June 2003 and may return to our neighborhood once again in the 2040s.
NASA’s Lunar Reconnaissance Orbiter has documented the lunar crash sites of these historic boosters. It’s of note that the Apollo 10 Lunar Module Snoopy remains discarded out in solar orbit as well, having been used as a dress rehearsal for the historic Apollo 11 landing. Apollo 10 never landed on the Moon. Efforts have been made by UK astronomer Nick Howes to recover it as well.
And there are more relics of the Space Age awaiting discovery. One of the first things we always check in the case of a pass by a newly discovered NEO closer than the Moon to the Earth is its history, to see if it matches up with any launches headed out beyond Earth orbit in the past.
And the upcoming Mars launches of MAVEN and India’s Mars Orbiter Mission in October & November will be the first to depart Earth orbit since 2011. These will give future generations of asteroid hunters new human-made space hardware to ponder.
The B612 Foundation’s asteroid-hunting Sentinel Space Telescope will also “up the game,” scouting for asteroids from a vantage point interior to the Earth’s orbit. Sentinel is slated for launch in 2016 atop a SpaceX Falcon 9 rocket.
And no, the fabled “Black Knight” satellite of UFO conspiracy buffs’ dreams is nowhere to be found.
What other fascinating relics of the Space Age lie are out there in the solar system, waiting to tell their tale?
This week offers a fine chance to catch sight of a unique asteroid.
324 Bamberga reaches opposition this week in the constellation Pisces on (friggatriskaidekaphobics take note) Friday the 13th at 7AM EDT/11:00 Universal Time.
About 230 kilometres in size, 324 Bamberga reaches 0.81 astronomical units from the Earth this week. No other asteroid so large gets so close.
Discovered on February 25th, 1892 by Johann Palisa, 324 Bamberga only reaches a favorable opposition once every 22 years.
Shining at magnitude +8.1, 324 Bamberga is also one of the highest numbered asteroids visible with binoculars. Earth-crossing asteroids 433 Eros, which made a close pass last year, and 4179 Toutatis are two of the very few asteroids that possess a larger number designations that can regularly reach +10th magnitude.
Look east in mid-September about an hour after sunset. The inset covers the region that 324 Bamberga is currently traversing in the introductory graphic. (Created by the author using Stellarium).
So, why did it take so long for 324 Bamberga to be uncovered? One factor is its high orbital eccentricity of 0.34. This means that most of the oppositions of the asteroid aren’t favorable. 324 Bamberga orbits the Sun once every 4.395 years and only comes around to an opposition that lands near perihelion once every 22 Earth years. Perihelion this year occurs only 45 days after opposition on October 27th.
The resonance between 324 Bamberga and Earth is nearly five Earth orbits for every one circuit of the Sun for the asteroid and is offset by only 9 days, meaning that the 22 year window to see the asteroid will actually become less favorable in centuries to come. 324 Bamberga made its last favorable appearance on September 15th, 1991 and won’t surpass +10th magnitude again until September 2035.
Observing asteroids requires patience and the ability to pick out a slowly moving object amidst the starry background. 324 Bamberga spends September west of the circlet of Pisces, drifting two degrees a week, or just over 17’ a day, to cross over into the constellation Pegasus in early October.
324 Bamberga will be moving too slow to pick up any motion in real time, but you can spy it by either sketching the field on successive nights or photographing the region and noting if the asteroid can be seen changing position against the background of fixed stars. Start hunting for 324 Bamberga tonight, as the Full Harvest Moon will be visiting Pisces later next week on the 19th.
A closeup of the path of 324 Bamberga for the week of September 10-17th. Decimal points for comparison stars are omitted. (Created by the author using Starry Night Education software).
324 Bamberga is also unique as the brightest C-type asteroid that is ever visible from Earth. The runner up in this category is asteroid 10 Hygiea, which can shine a full magnitude fainter at opposition.
It’s also remarkable that Palisa actually managed to discover 324 Bamberga while it was at 12th magnitude! Palisa was one of the most prolific visual hunters of asteroids ever, discovering 121 asteroids from 1874 to 1923. He accomplished this feat first with the use of a 6” refractor while based at the Austrian Naval Observatory in Pola (now the Croatian town of Pula) and later using the Vienna observatory’s 27” inch refractor.
The Great Refractor of the University of Vienna used to discover asteroid 324 Bamberga. (Credit: Prof. Franz Kerschbaum, Wikimedia Commons image under an Attribution-Share Alike 3.0 Unported license).
324 Bamberga itself takes its name from the town of Bamberg in Bavaria, the site of the 1896 meeting of the Astronomische Gesellschraft.
An occultation of a star by 324 Bamberga on December 8th, 1987 allowed astronomers to pin down its approximate size. Searches have also been carried out during occultations for any possible moons of this asteroid, though thus far, none have been discovered.
It’s interesting to note that 324 Bamberga will also actually occult the star 2UCAC 3361042 tonight in the early morning hours at 8:59-9:10 UT for observers spanning a path from Florida to Oregon. The magnitude drop will, however, be very slight, as the star is actually 3 full magnitudes fainter than the asteroid itself. Dave Gee caught a fine occultation of a 7.4 magnitude star in the constellation Corvus by 324 Bamberga in 2007.
There’s also something special about this time of year and the region that 324 Bamberga is crossing. More visual discoveries of asteroids have been historically made in the month of September than any other calendar month. In fact, 344 of the first 1,940 numbered asteroids were found in September, more than twice the average. Palisa’s own track record bears this out, though 324 Bamberga was discovered in February.
One of the primary reasons for a September surge in discoveries is viewing direction. Astronomers of yore typically hunted for asteroids approaching opposition in the anti-sunward direction, which in September lies in the relatively star poor fields of Pisces. In December and June —the months with the lowest numbers of visual discoveries at only 75 and 65 for the “first 1,940” respectively —the anti-sunward point lies in the star-rich regions of Sagittarius and Gemini. And by the way, the meteor that exploded over the city of Chelyabinsk on February 15th was sneaking up on the Earth from the sunward direction.
Be sure to catch a glimpse of this unique asteroid through either binoculars or a telescope over the coming weeks. The next chance to observe 324 Bamberga won’t roll around again until September 2035… it’ll be great to compare notes of the 2013 apparition on that far off date!
