Asteroids Archives

September 21, 2017September 22, 2017 by Ken Kremer

NASA’s OSIRIS-REx Asteroid Sampler Slingshots Around Earth Friday, Sept. 22 – Catch It If You Can!

Artist's concept shows the OSIRIS-REx spacecraft passing by Earth on Sept. 22, 2017. Credits: NASA's Goddard Space Flight Center/University of Arizona

KENNEDY SPACE CENTER, FL – Barely a year after NASA’s OSIRIS-REx robotic asteroid sampler launched on a trailblazing mission to snatch a soil sample from a pristine asteroid and return it to Earth for research analysis, the probe is speeding back home for a swift slingshot around our home planet on Friday Sept. 22 to gain a gravity assist speed boost required to complete its journey to the carbon rich asteroid Bennu and back.

As it swings by Earth NASA’s first ever asteroid sample return mission, OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer), will pass only 11,000 miles (17,000 kilometers) above Earth just before 12:52 p.m. EDT on Friday.

And NASA is asking the public to try and ‘Catch It If You Can’ – by waving hello and/or taking snapshots during and after the probes high speed flyby.

Plus you can watch NASA Facebook Live event at Noon Friday: https://www.facebook.com/NASAGoddard/

OSIRIS-REx will be approaching Earth at a velocity of about 19,000 mph on Friday as it begins flying over Australia during the Earth Gravity Assist (EGA) maneuver.

Since blastoff from the Florida Space Coast on Sept. 8, 2016 the probe has already racked up almost 600 million miles on its round trip journey from Earth and back to set up Friday’s critical gravity assist maneuver to Bennu and back.

As OSIRIS-REx continues along its flight path the spacecraft will reach its closest point to Earth over Antarctica, just south of Cape Horn, Chile. It will gain a velocity boost of about 8400 mph.

The spacecraft will also conduct a post flyby science campaign by collecting images and science observations of Earth and the Moon four hours after closest approach to calibrate its five science instruments.

NASA’s OSIRIS-REx asteroid sampling spacecraft, return capsule and payload fairings inside the Payloads Hazardous Servicing Facility high bay at NASA’s Kennedy Space Center is being processed for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral, FL. Credit: Ken Kremer/kenkremer.com

The allure of Bennu is that it is a carbon rich asteroid – thus OSIRIS-REx could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.

“We are interested in that material because it is a time capsule from the earliest stages of solar system formation,” OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview with the spacecraft in the cleanroom at NASA’s Kennedy Space Center.

The do or die gravity assist plunge is absolutely essential to set OSIRIS-REx on course to match the asteroid’s path and speed when it reaches the vicinity of asteroid Bennu a year from now in October 2018.

“The Earth Gravity Assist is a clever way to move the spacecraft onto Bennu’s orbital plane using Earth’s own gravity instead of expending fuel,” says Lauretta, of the University of Arizona, Tucson.

Just how close to Earth will OSIRIS-REx be during its flyby on Friday? The spacecraft will come within 11,000 miles (17,000 km) of the Earth’s surface as it passes over Antarctica at 12:52 a.m. EDT. on Sept. 22, 2017. Credits: NASA’s Goddard Space Flight Center/University of Arizona

Bennu’s orbit around the Sun is tilted at a six-degree inclination with respect to Earth’s orbital plane.

The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.

Numerous NASA spacecraft – including NASA’s just completed Cassini mission to Saturn – utilize gravity assists around a variety of celestial bodies to gain speed and change course to save vast amounts of propellant and time in order to accomplish science missions and visit additional target objects that would otherwise be impossible.

The flyby will be a nail-biting time for NASA and the science team because right afterwards the refrigerator sized probe will be out of contact with engineers – unable to receive telemetry for about an hour.

“For about an hour, NASA will be out of contact with the spacecraft as it passes over Antarctica,” said Mike Moreau, the flight dynamics system lead at Goddard, in a statement.

“OSIRIS-REx uses the Deep Space Network to communicate with Earth, and the spacecraft will be too low relative to the southern horizon to be in view with either the Deep Space tracking station at Canberra, Australia, or Goldstone, California.”

NASA says the team will regain communication with OSIRIS-REx roughly 50 minutes after closest approach over Antarctica at about 1:40 p.m. EDT.

The post flyby science campaign is set to begin at 4:52 p.m. EDT, Friday, Sept. 22.

United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. Liftoff was at 7:05 p.m. EDT on September 8, 2016 in this remote camera view taken from inside the launch pad perimeter. Note the newly install crew access arm and white room for astronaut flights atop Atlas starting in early 2018. Credit: Ken Kremer/kenkremer.com

The OSIRIS-Rex spacecraft originally departed Earth atop a United Launch Alliance Atlas V rocket under crystal clear skies on September 8, 2016 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida.

Everything with the launch went exactly according to plan for the daring mission boldly seeking to gather rocks and soil from carbon rich Bennu.

View of science instrument suite and TAGSAM robotic sample return arm on NASA’s OSIRIS-REx asteroid sampling spacecraft inside the Payloads Hazardous Servicing Facility at NASA’s Kennedy Space Center. Probe is slated for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Ken Kremer/kenkremer.com

OSIRIS-Rex is equipped with an ingenious robotic arm named TAGSAM designed to collect at least a 60-gram (2.1-ounce) sample and bring it back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.

“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu,” OSIRIS-Rex Principal Investigator Dante Lauretta told me in the prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final launch preparations.

“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”

“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”

NASA and the mission team is also inviting the public to get engaged by participating in the Wave to OSIRIS-REx social media campaign.

“Individuals and groups from anywhere in the world are encouraged to take photos of themselves waving to OSIRIS-REx, share them using the hashtag #HelloOSIRISREx and tag the mission account in their posts on Twitter (@OSIRISREx) or Instagram (@OSIRIS_REx).

Participants may begin taking and sharing photos at any time—or wait until the OSIRIS-REx spacecraft makes its closest approach to Earth at 12:52p.m. EDT on Friday, Sept. 22.”

The probe’s flight path during the flyby will pass through the ring of numerous satellites orbiting in geosynchronous orbit, but none are expected to be within close range.

Members of the OSIRIS-REx mission team celebrate the successful spacecraft launch on Sept. 8, 2016 atop ULA Atlas V at the post-launch briefing at the Kennedy Space Center, FL. Principal Investigator Dante Lauretta is 4th from right, NASA Planetary Science Director Jim Green is center, 5th from left. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s continuing onsite NASA mission and launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

September 20, 2017September 21, 2017 by Matt Williams

New Study Says Primordial Asteroid Belt was Empty

Artist concept of the asteroid belt. Credit: NASA

Between the orbits of Mars and Jupiter lies a disk of rocks, small bodies and planetoids known as the Main Asteroid Belt. The existence of this Belt was first theorized in the 18th century, based on observations that indicated a regular pattern in the orbits of Solar planets. By the following century, regular discoveries began to be made in the space between Mars and Jupiter, prompting astronomers to theorize where the Belt came from.

For a long time, scientists debated whether the Belt was the remains of a planet that broke up, or remnants left over from the early system that failed to become a planet. But a new study by a pair of astronomers from the University of Bordeaux has offered a different take. According to their theory, the Asteroid Belt began as an empty space which was gradually filled by rocks and debris over time.

For the sake of their study – which recently appeared in the journal Science Advances under the title “The Empty Primordial Asteroid Belt” – astronomers Sean N. Raymond and Andre Izidoro of the University of Bordeaux considered the current scientific consensus, which is that the Main Belt was once much more densely packed and became depleted of mass over time.

*Artist’s impression of how the Asteroid Belt could have become filled with C-type and S-type asteroids over time. Credit: Sean Raymond/planetplanet.net*

As Dr. Raymond explained to Universe Today via email:

“The standard picture is that the building blocks of the Solar System — what we call planetesimals, generally thought of as 10-100 km-scale bodies — started off in a smooth distribution across the Sun’s planet-forming disk. The problem is, that puts a couple of times Earth’s mass in the asteroid belt, where there is now less than a thousandth of an Earth mass. The challenge in this picture is therefore to understand how the belt lost 99.9% of its mass (but not 100%).”

To this, Dr. Raymond and Dr. Izodoro considered the alternate possibility that perhaps the primordial belt started as an empty space. In accordance with this theory, there were no planetesimals – i.e. Ceres, Vesta, Palla, and Hygeia – orbiting between Mars and Jupiter as there are today. This began as a thought experiment which, as Dr. Raymond admits, sounded a bit crazy at first.

However, he and Dr. Izodoro soon realized that several protoplanetary disks like the one they were envisioning had already been discovered in other star systems. For example, in 2014, the Atacama Large Millimeter/submillimeter Array in Chile photographed a planet-forming disk of dust and gas (aka, a protoplanetary disk) in the HL Tauri system, a very young star located about 450 light years away in the Taurus constellation.

As the image (shown below) revealed, the dust in this disk is not smooth, but consists of several broad regions and less dense regions. “The exact explanation for the structure in this disk is still debated but pretty much all models invoke drifting dust,” said Raymond. “And planetesimals form when drifting dust piles up into sufficiently-dense rings. So, dust rings should (we think) produce rings of planetesimals.”

*Image of the HL Tau planet-forming disk taken with the Atacama Large Millimeter Array. Credit: ALMA (ESO/NAOJ/NRAO)*

To test this hypothesis, they constructed a model of the early Solar System which included an empty Main Belt region. As they moved the simulation forward, they found that the formation of the disk was related to the formation of the rocky planets, and would gradually become what we see today. As Raymond indicated:

“What we found is that the growth of the rocky planets is not 100% efficient. A fraction of planetesimals is gravitationally kicked outward and stranded in the asteroid belt. The orbits of captured bodies matches closely those of S-type asteroids. The efficiency of implanting S-types in the belt is quite low, only about 1 in 1000. However, recall that the belt is almost empty. There is a total of about 4 hundred-thousandths of an Earth-mass in S-types in the present-day belt. Our simulations typically implanted a few times that amount. Given that some are lost during later evolution of the Solar System, this matches both the distribution and amount of S-type asteroids in the belt.

They then combined this model with previous work which looked at the growth of Jupiter and Saturn and how this would effect the Solar System. In this study, they showed the C-type asteroids would be deposited in the Belt over time, and that these asteroids would also be responsible for delivering water to Earth. When they combined the distribution of implanted C-type and S-type asteroids with their current work, they found that it matched the present-day distribution of asteroids.

Interestingly enough, this is not the first theory Raymond and Izodoro have come up with to address the Asteroid Belt’s missing mass. Back in 2011, Raymond was a co-author on the study that proposed the Grand Tack model, in which he and his colleagues proposed that Jupiter migrated from its original orbit after it formed. At first, the planet moved closer to Mars’ current orbit, then back out towards where it is today.

*Diagram comparing two possible explanations for how the Asteroid Belt formed. Credit: Sean Raymond/planetplanet.net*

In the process, the asteroid belt would have been cleared, and Mars would have been deprived of mass, thus leading to its diminutive size – relative to Earth and Venus. This resolved a key problem with classical theories of Asteroid Belt formation, which was known as the “small Mars problem”. In short, all previous simulations of Solar planet formation tended to produce Mars analogs that were far more massive than Mars is today.

However, the Grand Tack hypothesis still contained theoretical uncertainties, which prompted Raymond and Izodoro to consider the the Empty Primordial Belt theory. “Our new result lends credence to an alternate model in which planetesimals never formed in the asteroid belt at all,” he said. “Different pieces of this new alternative model have been developed in recent years, and I think they add up to make a solid alternative to the Grand Tack model.”

Looking ahead, Raymond says that he and Izodoro hope to conduct further studies and simulations to see if either theory can be confirmed or falsified. “That’s the next step,” he said. “Until the next (seemingly-)crazy idea!”

Further Reading: Science Advances, PlanetPlanet

September 20, 2017September 20, 2017 by Matt Williams

Dawn Probe Finds Evidence of Subsurface Ice on Vesta

Artist's concept of the Dawn spacecraft arriving at Vesta. Image credit: NASA/JPL-Caltech

In 2011, NASA’s Dawn spacecraft established orbit around the large asteroid (aka. planetoid) known as Vesta. Over the course of the next 14 months, the probe conducted detailed studies of Vesta’s surface with its suite of scientific instruments. These findings revealed much about the planetoid’s history, its surface features, and its structure – which is believed to be differentiated, like the rocky planets.

In addition, the probe collected vital information on Vesta’s ice content. After spending the past three years sifting through the probe’s data, a team of scientists has produced a new study that indicates the possibility of subsurface ice. These findings could have implications when it comes to our understanding of how Solar bodies formed and how water was historically transported throughout the Solar System.

Their study, titled “Orbital Bistatic Radar Observations of Asteroid Vesta by the Dawn Mission“, was recently published in the scientific journal Nature Communications. Led by Elizabeth Palmer, a graduate student from Western Michigan University, the team relied on data obtained by the communications antenna aboard the Dawn spacecraft to conduct the first orbital bistatic radar (BSR) observation of Vesta.

*Artist rendition of Dawn spacecraft orbiting Vesta. Credit: NASA/JPL-Caltech*

This antenna – the High-Gain telecommunications Antenna (HGA) – transmitted X-band radio waves during its orbit of Vesta to the Deep Space Network (DSN) antenna on Earth. During the majority of the mission, Dawn’s orbit was designed to ensure that the HGA was in the line of sight with ground stations on Earth. However, during occultations – when the probe passed behind Vesta for 5 to 33 minutes at a time – the probe was out of this line of sight.

Nevertheless, the antenna was continuously transmitting telemetry data, which caused the HGA-transmitted radar waves to be reflected off of Vesta’s surface. This technique, known as bistatic radar (BSR) observations has been used in the past to study the surfaces of terrestrial bodies like Mercury, Venus, the Moon, Mars, Saturn’s moon Titan, and the comet 67P/CG.

But as Palmer explained, using this technique to study a body like Vesta was a first for astronomers:

“This is the first time that a bistatic radar experiment was conducted in orbit around a small body, so this brought several unique challenges compared to the same experiment being done at large bodies like the Moon or Mars. For example, because the gravity field around Vesta is much weaker than Mars, the Dawn spacecraft does not have to orbit at a very high speed to maintain its distance from the surface. The orbital speed of the spacecraft becomes important, though, because the faster the orbit, the more the frequency of the ‘surface echo’ gets changed (Doppler shifted) compared to the frequency of the ‘direct signal’ (which is the unimpeded radio signal that travels directly from Dawn’s HGA to Earth’s Deep Space Network antennas without grazing Vesta’s surface). Researchers can tell the difference between a ‘surface echo’ and the ‘direct signal’ by their difference in frequency—so with Dawn’s slower orbital speed around Vesta, this frequency difference was very small, and required more time for us to process the BSR data and isolate the ‘surface echoes’ to measure their strength.”

*This high-res geological map of Vesta is derived from Dawn spacecraft data. Brown colors represent the oldest, most heavily cratered surface. Credit: NASA/JPL-Caltech/ASU*

By studying the reflected BSR waves, Palmer and her team were able to gain valuable information from Vesta’s surface. From this, they observed significant differences in surface radar reflectivity. But unlike the Moon, these variations in surface roughness could not be explained by cratering alone and was likely due to the existence of ground-ice. As Palmer explained:

“We found that this was the result of differences in the roughness of the surface at the scale of a few inches. Stronger surface echoes indicate smoother surfaces, while weaker surface echoes have bounced off of rougher surfaces. When we compared our surface roughness map of Vesta with a map of subsurface hydrogen concentrations—which was measured by Dawn scientists using the Gamma Ray and Neutron Detector (GRaND) on the spacecraft—we found that extensive smoother areas overlapped areas that also had heightened hydrogen concentrations!”

In the end, Palmer and her colleagues concluded that the presence of buried ice (past and/or present) on Vesta was responsible for parts of the surface being smoother than others. Basically, whenever an impact happened on the surface, it transferred a great deal of energy to the subsurface. If buried ice was present there, it would be melted by the impact event, flow to the surface along impact-generated fractures, and then freeze in place.

Much in the same way that moon’s like Europa, Ganymede and Titania experience surface renewal because of the way cryovolcanism causes liquid water to reach the surface (where it refreezes), the presence of subsurface ice would cause parts of Vesta’ surface to be smoothed out over time. This would ultimately lead to the kinds of uneven terrain that Palmer and her colleagues witnessed.

*The planetoid Vesta, which was studied by the Dawn probe between July 2011 and September 2012. Credit: NASA*

This theory is supported by the large concentrations of hydrogen that were detected over smoother terrains that measure hundreds of square kilometers. It is also consistent with geomorphological evidence obtained from the Dawn Framing Camera images, which showed signs of of transient water flow over Vesta’s surface. This study also contradicted some previously-held assumptions about Vesta.

As Palmer noted, this could also have implications as far as our understanding of the history and evolution of the Solar System is concerned:

“Asteroid Vesta was expected to have depleted any water content long ago through global melting, differentiation, and extensive regolith gardening by impacts from smaller bodies. However, our findings support the idea that buried ice may have existed on Vesta, which is an exciting prospect since Vesta is a protoplanet that represents an early stage in the formation of a planet. The more we learn about where water-ice exists throughout the Solar System, the better we will understand how water was delivered to Earth, and how much was intrinsic to Earth’s interior during the early stages of its formation.”

This work was sponsored by NASA’s Planetary Geology and Geophysics program, a JPL-based effort that focuses on fostering the research of terrestrial-like planets and major satellites in the Solar System. The work was also conducted with the assistance of the USC’s Viterbi School of Engineering as part of an ongoing effort to improve radar and microwave imaging to locate subsurface sources of water on planets and other bodies.

Further Reading: USC, Nature Communications

August 29, 2017August 29, 2017 by David Dickinson

Watch Asteroid 3122 Florence Zip Past Earth This Weekend

An artist's conception of an NEO asteroid 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 +10^th 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 1^st at 12:06 Universal Time (UT)/ 8:06 AM Eastern Daylight Saving Time (EDT).

Universe Today ran 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.

Florence orbit — 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 1^st, at 12:06 UT as the asteroid crosses the along the border of the constellations Equuleus and Delphinus at closest approach, reaching +9^th 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.

Path of Florence — 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 29^th and also crosses the celestial equator on September 1^st

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 9^th.

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.

Earth view — 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 31^st/September 1^st, 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 31^st 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!

August 18, 2017August 18, 2017 by Matt Williams

Large Near-Earth Asteroid Will Pass Earth by This September

Artist's impression of a Near-Earth Asteroid passing by Earth. Credit: ESA

Within Earth’s orbit, there are literally thousands of what are known as Near-Earth Objects (NEOs), more than fourteen thousands of which are asteroids that periodically pass close to Earth. Since the 1980s, these objects have become a growing source of interest to astronomers, due to the threat they sometimes represent. But as ongoing studies and decades of tracking the larger asteroids has shown, they usually just pass Earth by.

More importantly, it is only on very rare occasions (i.e. over the course of millions of years) that a larger asteroid will come close to colliding with Earth. For example, this September 1st, the Near-Earth Asteroid (NEA) known as 3122 Florence, will pass by Earth, but poses no danger of hitting us. Good thing too, since this Near-Earth Asteroid is one of the largest yet to be discovered, measuring about 4.4 km (2.7 mi) in diameter!

To put that in perspective, the asteroid which is thought to have killed the dinosaurs roughly 65 million years ago (aka. the Cretaceous–Paleogene extinction event) is believed to have measured 10 km (6 mi) in diameter. This impact also destroyed three-quarters of the plant and animal species on Earth, hence why organizations like NASA’s Center for Near-Earth Object Studies (CNEOS) is in he habit of tracking the larger NEAs.

Asteroid Florence, a large near-Earth asteroid, will pass safely by Earth on Sept. 1, 2017, at a distance of about 7 million km (4.4 million mi). Credits: NASA/JPL-Caltech

Once again, NASA has determined that this particular asteroid will sail harmlessly by, passing Earth at a minimum distance of over 7 million km (4.4 million mi), or about 18 times the distance between the Earth and the Moon. As Paul Chodas – NASA’s manager of CNEOS at the Jet Propulsion Laboratory in Pasadena, California – said in a NASA press statement:

“While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller. Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began.”

Rather than being a threat, the flyby of this asteroid will be an opportunity for scientists to study it up close. NASA is planning on conducting radar studies of Florence using the Goldstone Solar System Radar in California, and the National Science Foundation’s (NSF) Arecibo Observatory in Peurto Rico. These studies are expected to yield more accurate data on its size, and reveal surface details at resolutions of up to 10 m (30 feet).

This asteroid was originally discovered on March 2nd, 1981, by American astronomer Schelte Bus at the Siding Spring Observatory in southwestern Australia. It was named in honor of Florence Nightingale (1820-1910) the founder of modern nursing. Measurements obtained by NASA’s Spitzer Space Telescope and the NEOWISE mission are what led to the current estimates on its size – about 4.4 km (2.7 mi) in diameter.

Artist’s rendition of how far Florence will pass by Earth. Credits: NASA/JPL-Caltech

The upcoming flyby will be the closest this asteroid has passed to Earth since August 31st, 1890, where it passed at a distance of 6.7 million km (4.16 million mi). Between now and then, it also flew by Earth on August 29th, 1930, passing Earth at a distance of about 7.8 million km (4.87 million mi). While it will pass Earth another seven times over the course of the next 500 years, it will not be as close as it will be this September until after 2500.

For those interesting into doing a little sky watching, Florence will be brightening substantially by late August and early September. During this time, it will be visible to those using small telescopes for several nights as it moves through the constellations of Piscis Austrinus, Capricornus, Aquarius and Delphinus.

Be sure to check out these animations of Florence’s orbit and its close flyby to Earth:

https://echo.jpl.nasa.gov/asteroids/Florence/Florence_orbit.mov

https://echo.jpl.nasa.gov/asteroids/Florence/Florence_Earth_flyby.mov

Further Reading: NASA

June 29, 2017June 29, 2017 by Nancy Atkinson

Watch Live 24-Hour Webcast for International Asteroid Day

Picture of the asteroid that exploded over Cherlyabinsk on Feb 15, 2013. Credit: Tuvix/Youtube

Every day, Earth is hit by 60 to 300 metric tons of space dust and smaller meteoroids. But sometimes, larger and more dangerous space rocks plummet to Earth, such as on June 30, 1908 when an estimated 40 meter-wide meteoroid exploded over the Tunguska, Siberia region in Russia, devastating 2000 sq. kilometers (770 square miles) of forest. As the 2013 Chelyabinsk meteor event attests, the likelihood of a similar event happening again is not an “if” but a “when.”

To raise public awareness about asteroid impact hazards and to urge political leaders to work together to be prepared, the United Nations proclaimed June 30 as International Asteroid Day.

A first-ever 24-hour Asteroid Day program will be feature nearly 1,000 events around the world. It starts at 9 p.m. EDT on June 29 (1 a.m. June 30 GMT), streaming online at the Asteroid Day webcast.

The events start in Tucson, Arizona with an event hosted by our friend, Meteorite Man and Action Scientist Geoff Notkin speaking with Dante Lauretta and Heather Enos from the OSIRIS-REx mission to asteroid Bennu, Eric Christensen, director, Catalina Sky Survey for Near-Earth Objects and many more.

Other events around the world feature Brian Cox, Neil deGrasse Tyson, Brian May, Peter Gabriel, as well as dozens of expert scientists, technologists and researchers in planetary science, NASA astronauts Rusty Schweickart, Ed Lu and Nicole Stott, ESA astronauts Michel Tognini, Jean-François Clervoy; and Romanian astronaut Dorin Prunariu.

NASA and ESA are both hosting events as well. You can see the entire lineup of events here (Google document) and find additional information at the Asteroid Day Live website.

In addition, the Discovery Channel, has produced two specials about asteroids and Asteroid Day to air June 30 around the world: “How to Survive an Asteroid Impact” and a three-minute Virtual Reality video that re-enacts the Tunguska event, provides viewers with an insight into the risks of asteroids, how scientists are trying to protect our planet, and what viewers should do if an asteroid is about to impact their city.

There is also a seven-part series called “Scientists Rock” that introduces you to the people working to protect us from Asteroids.

According to a press release from Asteroid Day, central to Asteroid Day is the 100x Declaration, calling for the 100-fold increase in the detection and monitoring of asteroids. Signed to date by more than 60,000 people around the world, the Declaration resolves to “solve humanity’s greatest challenges to safeguard our families and quality of life on Earth in the future. The Declaration is available online for the signature of anyone concerned about advancing asteroid research and technology.

May 25, 2017 by Bob King

NASA Moves Up Mission to Metal Asteroid Psyche

This illustration depicts the spacecraft of NASA’s Psyche mission orbiting the metal asteroid Psyche (pronounced SY-kee). Solar power with electric propulsion will be used to propel the spacecraft to Psyche. The asteroid’s average distance from the sun is about three times the Earth’s distance or 280 million miles. Credit: SSL/ASU/P. Rubin/NASA/JPL-Caltech

I’m getting psyched for Psyche, which is both the name of an asteroid orbiting the sun between Mars and Jupiter and NASA’s mission to the asteroid. Part of the reason for this excitement comes from learning today that NASA has moved up the launch one year to 2022, with a planned arrival in the asteroid belt in 2026 — four years earlier than the original timeline.

The mission team calculated a new trajectory to Psyche, one eliminating the need for an Earth gravity assist, that would get the probe there about twice as fast and reduce costs.

Fly over Psyche in this cool animation

“We challenged the mission design team to explore if an earlier launch date could provide a more efficient trajectory to the asteroid Psyche, and they came through in a big way,” said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. “This will enable us to fulfill our science objectives sooner and at a reduced cost.”

Campo del Cielo meteorites are heavy, metallic and dimpled with regmaglypts or “thumbprints” where softer materials melted away during the meteorite’s fall through the air. This small fragment was once part of a different planetary core similar to Psyche. Credit: Bob King

With a diameter of over 120 miles (200 km), Psyche is one of the ten most massive asteroids in the main asteroid belt. Like certain meteorites found on Earth, it’s made almost entirely of nickel-iron metal. Metal is usually found as pepper-like flecks in stony meteorites, which represent the crust of an asteroid. Heat released during the formation of a large asteroid or planet causes the rock to melt, releasing heavier elements like iron and nickel which trickle downward under the force of gravity to form a metallic core. Radioactivity can also play a role in heating the rock.

A 3-D model of the asteroid Psyche based on its light curve, ie. variations in brightness as it rotates. Credit: Astronomical Institute of the Charles University: Josef ?urech, Vojt?ch Sidorin / CC BY 4.0

That’s why Psyche’s kind of weird. How do you get a 120-mile-wide body of exposed metal floating around space? Astronomers think it was the core of a developing planet — a protoplanet — and probably covered once upon a time by a mantle of rock. Through collisions with other asteroids, that rock layer was eventually blasted away, exposing the metal core. As such, it offers a unique look into the violent collisions that created Earth and the terrestrial planets.

Planets start as small planetesimals (10-100 kilometers across) and grow by gathering up material from new impacts until becoming large enough to serve as embryos for planets. Psyche may have started down the road of planethood only to be chopped down to size by hit-and-run impacts that broke away at its rocky envelope. Credit: Arizona State University

After a 4.6 year cruise that includes a Mars gravity assist flyby, the spacecraft will arrive at Psyche and spend 20 months in orbit mapping and studying the asteroid’s properties. The scientific goals of the mission are to understand the building blocks of planet formation and explore a new type of asteroid never seen up close before. The mission team will seek to find out whether Psyche is the core of an early planet, how old it is, what its surface is like and whether it formed in similar ways to Earth’s core.

Who knows, maybe we’ll learn it was once large enough to be considered a planet just like our own. You can stay in touch with mission developments on their Twitter site.

May 18, 2017 by Evan Gough

Dinosaur Killing Asteroid Hit in Exactly the Wrong Place

When an asteroid struck the Yucatan region about 66 million years ago, it triggered the extinction of the dinosaurs. ESA's Hera mission is visiting the smallest spacerock ever as part of our effort to not get creamed by an asteroid. Credit: NASA/Don Davis

The asteroid that struck Earth about 66 million years ago and led to the mass extinction of dinosaurs may have hit one of the worst places possible as far as life on Earth was concerned. When it struck, the resulting cataclysm choked the atmosphere with sulphur, which blocked out the Sun. Without the Sun, the food chain collapsed, and it was bye-bye dinosaurs, and bye-bye most of the other life on Earth, too.

But, as it turns out, if it had struck a few moments earlier or later, it would not have hit the Yucatan, and things may have turned out differently. Why? Because of the concentration of the mineral gypsum in that area.

The place where the asteroid hit Earth is called the Chicxulub Crater, and scientists have been studying that area to try to learn more about the impact event that altered the course of life on Earth. An upcoming BBC documentary called “The Day The Dinosaurs Died,” focuses on what happened when the asteroid struck. Drill-core samples from the Yucatan area help explain the events that followed the impact.

The drilling rig off the coast of the Yucatan. The rig was there in the Spring of 2016 obtaining samples from the seafloor. Image: BBC/Barcroft Productions.

The core samples, which are from as deep as 1300 m beneath the Gulf of Mexico, are from a feature called the peak ring.

When the asteroid struck Earth, it excavated a crater 100 km across and 30 km deep. This crater collapsed into a wider but shallower crater 200 km across and a few km deep. Then the center of the crater rebounded, and collapsed again, leaving the peak ring feature. The Chicxulub crater is now partly under water, and that’s where a drilling rig was set up to take samples.

The peak ring is at the center of the crater, offshore of the Yucatan Peninsula. Image: NASA/BBC

The core samples revealed rock that has been heavily fractured and altered by immense pressures. The same impact that altered those rocks would have generated an enormous amount of heat, and that heat created an enormous cloud of sulphur from the vaporized gypsum. That cloud persisted, which led to a global winter. Temperatures dropped, plant growth came to a standstill, and the course of events on Earth were altered forever.

“Had the asteroid struck a few moments earlier or later, rather than hitting shallow coastal waters it might have hit deep ocean,” documentary co-presenter Ben Garrod told the BBC.

“This is where we get to the great irony of the story – because in the end it wasn’t the size of the asteroid, the scale of blast, or even its global reach that made dinosaurs extinct – it was where the impact happened,” said Ben Garrod, who presents “The Day The Dinosaurs Died” with Alice Roberts.

“An impact in the nearby Atlantic or Pacific oceans would have meant much less vaporised rock – including the deadly gypsum. The cloud would have been less dense and sunlight could still have reached the planet’s surface, meaning what happened next might have been avoided,” said Garrod.

In the documentary, host Alice Roberts will also visit a quarry in New Jersey, where fossil evidence shows a massive die-off in a very short period of time. In fact, these creatures could have died on the very day that the asteroid struck.

The core samples from the drilling rig show rocks that were subjected to immense heat and pressure at the time of the impact. Image: Barcroft Productions/BBC

“All these fossils occur in a layer no more than 10cm thick,” palaeontologist Ken Lacovara tells Alice. “They died suddenly and were buried quickly. It tells us this is a moment in geological time. That’s days, weeks, maybe months. But this is not thousands of years; it’s not hundreds of thousands of years. This is essentially an instantaneous event.”

There’s lots of evidence showing that an asteroid struck Earth about 66 million years ago, causing widespread extinction. NASA satellite images clearly show crater features, now obscured by 66 million years of geological activity, but still visible.

There’s also what’s called the K-T Boundary, or Cretaceous-Tertiary Boundary. It’s a geological signature dating to 66 million years ago, which marks the end of the Cretaceous Period. In that boundary is a layer of iridium at very high concentrations, much higher than is normally present in the Earth’s crust. Since iridium is much more abundant in asteroids, the conclusion is that it was probably deposited by an asteroid.

But this is the first evidence that shows how critical the actual location of the event may have been. If it had not struck where it had, dinosaurs may never have gone extinct, you and I would not be here, and things on Earth could look much different.

It might sound like the stuff of science fiction, but who knows? Maybe a race of intelligent lizards might already have mastered interstellar travel.

April 19, 2017April 19, 2017 by Bob King

2014 JO25 Flies By Earth — See It Tonight

This composite of 30 images of asteroid 2014 JO25 was generated with radar data collected using NASA’s Goldstone Solar System Radar in California’s Mojave Desert on Tuesday April 18. Credit: NASA/JPL-Caltech/GSSR

Asteroid 2014 JO25, discovered in 2014 by the Catalina Sky Survey in Arizona, was in the spotlight today (April 19) when it flew by Earth at just four times the distance of the Moon. Today’s encounter is the closest the object has come to the Earth in 400 years and will be its closest approach for at least the next 500 years.

Lots of asteroids zip by our planet, and new ones are discovered every week. What makes 2014 JO25 different it’s one of nearly 1,800 PHAs (Potentially Hazardous Asteroids) that are big enough and occasionally pass close enough to Earth to be of concern. PHAs have diameters of at least 100-150 meters (330-490 feet) and pass less than 0.05 a.u (7.5 million km / 4.6 million miles) from our planet. Good thing for earthlings, no known PHA is predicted to impact Earth for at least the next 100 years.

Most of these Earth-approachers are on the small side, only a few to a few dozen meters (yards) across. 2014 JO25 was originally estimated at ~2,000 feet wide, but thanks to radar observations made the past couple days, we now know it’s nearly twice that size. Radar images of asteroid were made early this morning with NASA’s 230-foot (70-meter) radio antenna at Goldstone Deep Space Communications Complex in California. They reveal a peanut-shaped asteroid that rotates about once every 5 hours and show details as small as 25 feet.

NASA radar images and animation of asteroid 2015 JO25

The larger of the two lobes is about 2,000 feet (620 meters) across, making the total length closer to 4,000 feet. That’s similar in size (though not as long) as the Rock of Gibraltar that stands at the southwestern tip of Europe at the tip of the Iberian Peninsula.

“The asteroid has a contact binary structure — two lobes connected by a neck-like region,” said Shantanu Naidu, a scientist from NASA’s Jet Propulsion Laboratory in Pasadena, California, who led the Goldstone observations. “The images show flat facets, concavities and angular topography.” Contact binaries form when two separate asteroids come close enough together to touch and meld as one.

The Goldstone dish dish, based in the Mojave Desert near Barstow, Cal. is used for radar mapping of planets, comets, asteroids and the Moon. Credit: NASA

Radar observations of the asteroid have also been underway at the National Science Foundation’s Arecibo Observatory in Puerto Rico with more observations coming today through the 21st which may show even finer details. The technique of pinging asteroids with radio waves and eking out information based on the returning echoes has been used to observe hundreds of asteroids.

When these relics from the early solar system pass relatively close to Earth, astronomers can glean their sizes, shapes, rotation, surface features, and roughness, as well as determine their orbits with precision.

Because of 2014 JO25’s relatively large size and proximity, it’s bright enough to spot in a small telescope this evening. It will shine around magnitude +10.9 from North America tonight as it travels south-southwest across the dim constellation Coma Berenices behind the tail of Leo the Lion. A good map and 3-inch or larger telescope should show it.

Use the maps at this link to help you find and track the asteroid tonight. The key to spotting it is to allow time to identify and get familiar with the star field the asteroid will pass through 10 to 15 minutes in advance — then lay in wait for the moving object. Don’t be surprised if 2014 JO25 deviates a little from the predicted path depending on your location and late changes to its orbit, so keep watch not only on the path but around it, too. Good luck!

March 3, 2017 by Matt Williams

This Asteroid Broke In Half, and Then Both Halves Grew Tails Like Comets

Images from the Hubble Space Telescope of activated asteroid P/2013P5 where the dust tail can be seen. Source: NASA/ESA.

In the 18th and 19th centuries, astronomers made some profound discoveries about asteroids and comets within our Solar System. From discerning the true nature of their orbits to detecting countless small objects in the Main Asteroid Belt, these discoveries would inform much of our modern understanding of these bodies.

A general rule about comets and asteroids is that whereas the former develop comas or tails as they undergo temperature changes, the latter do not. However, a recent discovery by an international group of researchers has presented another exception to this rule. After viewing a parent asteroid in the Main Belt that split into a pair, they noted that both fragments formed tails of their own.

The reason asteroids do not do behave like comets has a lot to do with where they are situated. Located predominantly in the Main Belt, these bodies have relatively circular orbits around the Sun and do not experience much in the way of temperature changes. As a result, they do not form tails (or halos), which are created when volatile compounds (i.e. nitrogen, hydrogen, carbon dioxide, methane, etc.) sublimate and form clouds of gas.

*Images of the P/2016 J1 asteroid pair taken on May 15th, 2016. They show a central region, the asteroid, and a diffuse blot corresponding to the dust tail. Credit: IAA*

As astronomical phenomena go, asteroid pairs are quite common. They are created when an asteroid breaks in two, which can be the result of excess rotational speed, impact with another body, or because of the destabilization of binary systems (i.e. asteroid that orbit each other). Once this happens, these two bodies will orbit the Sun rather than being gravitational bound to each other, and progressively drift farther apart.

However, when monitoring the asteroid P/2016 J1, an international team from the Institute of Astrophysics in Andalusia (IAA-CSIC) noticed something interesting. Apparently, both fragments in the pair had become “activated” – that is to say, they had formed tails. As Fernando Moreno, a researcher at IAA-CSIC who led the project, said in an Institute press release:

“Both fragments are activated, i.e., they display dust structures similar to comets. This is the first time we observe an asteroid pair with simultaneous activity… In all likelihood, the dust emission is due to the sublimation of ice that was left exposed after the fragmentation.”

While this is not the first instance where asteroids proved to be an exception to the rule and began forming clouds of sublimated gas around them, this is the first time it was observed happening with an asteroid pair. And it seems that the formation of this tail was in response to the breakup, which is believed to have happened six years ago, during the previous orbit of the asteroid.

*An artist’s conception of two tidally locked objects orbiting the Sun from afar (2010 WG9). Credit: zmescience*

In 2016, the research team used the Great Telescope of the Canary Islands (GTC) on the island of La Palma and the Canada-France-Hawaii Telescope (CFHT) at Mauna Kea to confirm that the asteroid had formed a pair. Further analysis revealed that the asteroids were activated between the end of 2015 and the beginning of 2016, when they reached the closest point in their orbit with the Sun (perihelion).

This analysis also revealed that the fragmentation of the asteroid and the bout of activity were unrelated. In other words, the sublimation has happened since the breakup and was not the cause of it. Because of this, these objects are quite unique as far as Solar System bodies go.

Not only are they two more exceptions to the rule governing comets and asteroids (there are only about twenty known cases of asteroids forming tales), the timing of their breakup also means that they are the youngest asteroid pair in the Solar System to date. Not bad for a bunch of rocks!

Further Reading: IAA