Asteroids Archives

September 30, 2017September 30, 2017 by Matt Williams

Mission to Metal World Takes a Big Step Forward with Thruster Test

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

As NASA sets its sight on the next generation of space exploration, one area of focus is on missions that can teach us more about our Solar System. This was a major priority during the thirteenth round of NASA’s Discovery Program, which put out the call for proposals back in February of 2014. One of the proposals to make the cut was the Psyche mission, which will send an orbiter to the asteroid of the same name in 2o22.

This mission is unique in that it will entail visiting an asteroid that is entirely composed of metal, which scientists believe is the remnant core of an early planet. For the sake of the mission, NASA’s Glenn Research Center has been working hard to develop a cutting-edge, next-generation thruster that balances power with fuel efficiency. This thruster was recently subjected to tests designed to simulate its journey through space.

Originally discovered in 1852, the object known as 16 Psyche has been a source of fascination ever since astronomers were able to determine its composition. Unlike other asteroids that are largely carbonaceous (C-type), silicate (S-type), or composed of rock and metal (M-type), Psyche is the only asteroid to date that has been found to have an exposed nickel-iron surface.

Because of its unique nature, scientists have theorized that the metal asteroid is actually the core of a Mars-sized planet that formed during the early Solar System. This planet, they theorize, lost its outer layers after experiencing a massive collision, thus leaving an exposed core behind. The study of this asteroid is therefore expected to reveal a great deal about the interior of terrestrial planets and what powers their magnetic fields.

As David Oh, the mission’s lead project systems engineer, said in a recent NASA press release:

“Psyche is a unique body because it is, by far, the largest metal asteroid out there; it’s about the size of Massachusetts. By exploring Psyche, we’ll learn about the formation of the planets, how planetary cores are formed and, just as important, we’ll be exploring a new type of world. We’ve looked at worlds made of rock, ice and of gas, but we’ve never had an opportunity to look at a metal world, so this is brand new exploration in the classic style of NASA.”

The Psyche missions brings together researchers from Arizona State University and experts from NASA’s Jet Propulsion Laboratory. For the sake of designing the engine that would send their spacecraft to its destination, the joint Arizona-JPL team turned to NASA’s Glenn Research Center, which has been conducting research into Solar Electric Propulsion (SEP) for years.

SEP thrusters are essentially ion-engines that rely on electrically-charged inert gases (like xenon) to provide thrust. Like all Hall Effect ion-engines, this allows the thruster to provide a gentle, non-stop stream of thrust that gradually pushes a spacecraft up to greater and greater speeds. Such a system is ideal for deep-space missions where fuel-efficiency is a must.

As Carol Tolbert, the project manager for Psyche thruster testing at NASA Glenn, explained:

“For deep space missions, the type and amount of fuel required to propel a spacecraft is an important factor for mission planners. A SEP system, like the one used for this mission, operates more efficiently than a conventional chemical propulsion system, which would be impractical for this type of mission.”

The Psyche mission, which will be built jointly by JPL and Space Systems Loral (SSL), will use a SPT-140 Hall effect thruster that relies on solar power to provide electrical charges. The reduced fuel mass of this thruster will allow the mission to enter orbit around the metal asteroid while also providing additional space for the mission’s suite of scientific instruments.

These include a multispectral imager, a magnetometer, and a gamma-ray spectrometer, all of which will help the science team to obtain vital information on the asteroid’s origin, composition and history. The SEP also provides flexibility and robustness in the mission flight plan, since it will allow Psyche to get to its destination with greater speed and efficiency than conventional propulsion would allow for.

To test how the thruster performs during low-power operations, engineers at NASA Glenn placed the thruster into a space environment chamber designed to generate the low-pressures and temperatures it will encounter in space. As Carol explained:

“This mission will be the first to use a Hall effect thruster system beyond lunar orbit, so the tests here at Glenn, which had never been conducted before, were needed to ensure the thruster could perform and operate as expected in the deep space environment.”

*Artist’s impression of the surface of 16 Psyche. Credit: Arizona State University / NASA*

For decades, the Glenn center has used its compliment of chambers to simulate the conditions missions will encounter in space. However, this test is the first time that engineers have sought to determine how an SEP Hall-Effect thruster would fare. As Oh explained, this test is very important since it will simulate precisely how the spacecraft will fly, and the results have been encouraging so far:

“Glenn has a world-class facility that allowed us to go to very low pressures to simulate the environment the spacecraft will operate in and better understand how our thrusters will perform around Psyche. At first glance, the results confirm our predictions regarding how the thruster will perform, and it looks like everything is working as expected. But, we will continue to refine our models by doing more analysis.”

As the team works towards the mission’s proposed launch – which is scheduled for August 2022 – they will use the data collected at NASA Glenn to update their thruster modeling and incorporate it into mission trajectories. Once the spacecraft reaches its destination – the planned arrival will take place by 2026 – it is expected to reveal a great deal about this unique asteroid.

This data is also likely to teach us much about the history of the Asteroid Belt and the Solar System. If indeed 16 Psyche is the remnant of a Mars-sized planet that formed in the Main Belt, it could cause astronomers to rethink their notions of how the Solar System formed and evolved.

Further Reading: NASA

September 28, 2017September 29, 2017 by Ken Kremer

NASA’s OSIRIS-REx Captures Lovely Blue Marble during Gravity Assist Swing-by to Asteroid Bennu

A color composite image of Earth taken on Sept. 22, 2017 by the MapCam camera on NASA’s OSIRIS-REx spacecraft just hours after the spacecraft completed its Earth Gravity Assist at a range of approximately 106,000 miles (170,000 kilometers). Credit: NASA/Goddard/University of Arizona

KENNEDY SPACE CENTER, FL – NASA’s OSIRIS-REx asteroid mission captured a lovely ‘Blue Marble’ image of our Home Planet during last Fridays (Sept. 22) successful gravity assist swing-by sending the probe hurtling towards asteroid Bennu for a rendezvous next August on a round trip journey to snatch pristine soil samples.

The newly released color composite image of Earth was taken on Sept. 22 by the spacecrafts MapCam camera.

It was taken at a range of approximately 106,000 miles (170,000 kilometers), just a few hours after OSIRIS-REx completed its critical Earth Gravity Assist (EGA) maneuver.

“NASA’s asteroid sample return spacecraft successfully used Earth’s gravity on Friday, Sept. 22 to slingshot itself on a path toward the asteroid Bennu, for a rendezvous next August,” the agency confirmed after receiving the eagerly awaited telemetry.

OSIRIS-Rex, which stands for Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer, is NASA’s first ever asteroid sample return mission.

As it swung by Earth at 12:52 p.m. EDT on Sept. 22, OSIRIS-REx passed only 10,711 miles (17,237 km) above Antarctica, just south of Cape Horn, Chile.

The probe departed Earth by following a flight path that continued north over the Pacific Ocean and has already travelled 600 million miles (1 billion kilometers) since launching on Sept. 8, 2016.

OSIRIS-REx flight path over Earth’s surface during the Sept. 22, 2017 slingshot over Antarctica at 12:52 a.m. EDT targeting the probe to Asteroid Bennu in August 2018. Credits: NASA’s Goddard Space Flight Center/University of Arizona

The preplanned EGA maneuver provided the absolutely essential gravity assisted speed boost required for OSIRIS-Rex to gain enough velocity to complete its journey to the carbon rich asteroid Bennu and back.

The mission was only made possible by the slingshot which provided a velocity change to the spacecraft of 8,451 miles per hour (3.778 kilometers per second).

“The encounter with Earth is fundamental to our rendezvous with Bennu,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

“The total velocity change from Earth’s gravity far exceeds the total fuel load of the OSIRIS-REx propulsion system, so we are really leveraging our Earth flyby to make a massive change to the OSIRIS-REx trajectory, specifically changing the tilt of the orbit to match Bennu.”

The spacecraft conducted a post flyby science campaign by collecting images and science observations of Earth and the Moon that began four hours after closest approach in order to test and calibrate its onboard suite of five science instruments and help prepare them for OSIRIS-REx’s arrival at Bennu in late 2018.

NASA’s OSIRIS-REx spacecraft OTES spectrometer captured these infrared spectral curves during Earth Gravity Assist on Sept. 22 2017, hours after the spacecraft’s closest approach. Credit: NASA/Goddard/University of Arizona/Arizona State University

The MapCam camera Blue Marble image is the first one to be released by NASA and the science team.

The image is centered on the Pacific Ocean and shows several familiar landmasses, including Australia in the lower left, and Baja California and the southwestern United States in the upper right.

“The dark vertical streaks at the top of the image are caused by short exposure times (less than three milliseconds),” said the team.

“Short exposure times are required for imaging an object as bright as Earth, but are not anticipated for an object as dark as the asteroid Bennu, which the camera was designed to image.”

The instrument will gather additional data and measurements scanning the Earth and the Moon for three more days over the next two weeks.

“The opportunity to collect science data over the next two weeks provides the OSIRIS-REx mission team with an excellent opportunity to practice for operations at Bennu,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

“During the Earth flyby, the science and operations teams are co-located, performing daily activities together as they will during the asteroid encounter.”

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

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.

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

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

NASA’s OSIRIS-REx spacecraft OVIRS spectrometer captured this visible and infrared spectral curve, which shows the amount of sunlight reflected from the Earth, after the spacecraft’s Earth Gravity Assist on Sept. 22, 2017. Credit: NASA/Goddard/University of Arizona

September 24, 2017September 24, 2017 by Matt Williams

Hubble Spots Unique Object in the Main Asteroid Belt

Artist’s impression shows the binary asteroid 288P, located in the Main Asteroid Belt between the planets Mars and Jupiter. Credit: ESA/Hubble, L. Calçada.

In 1990, the NASA/ESA Hubble Space Telescope was deployed into Low Earth Orbit (LEO). As one of NASA’s Great Observatories – along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope – this instrument remains one of NASA’s larger and more versatile missions. Even after twenty-seven years of service, Hubble continues to make intriguing discoveries, both within our Solar System and beyond.

The latest discovery was made by a team of international astronomers led by the Max Planck Institute for Solar System Research. Using Hubble, they spotted a unique object in the Main Asteroid Belt – a binary asteroid known as 288P – which also behaves like a comet. According to the team’s study, this binary asteroid experiences sublimation as it nears the Sun, which causes comet-like tails to form.

The study, titled “A Binary Main-Belt Comet“, recently appeared in the scientific journal Nature. The team was led by Jessica Agarwal of the Max Planck Institute for Solar System Research, and included members from the Space Telescope Science Institute, the Lunar and Planetary Laboratory at the University of Arizona, the Johns Hopkins University Applied Physics Laboratory (JHUAPL), and the University of California at Los Angeles.

Using the Hubble telescope, the team first observed 288P in September 2016, when it was making its closest approach to Earth. The images they took revealed that this object was not a single asteroid, but two asteroids of similar size and mass that orbit each other at a distance of about 100 km. Beyond that, the team also noted some ongoing activity in the binary system that was unexpected.

As Jessica Agarwal explained in a Hubble press statement, this makes 288P the first known binary asteroid that is also classified as a main-belt comet. “We detected strong indications of the sublimation of water ice due to the increased solar heating – similar to how the tail of a comet is created,” she said. In addition to being a pleasant surprise, these findings are also highly significant when it comes to the study of the Solar System.

Since only a few objects of this type are known, 288P is an extremely important target for future asteroid studies. The various features of 288P also make it unique among the few known wide asteroid binaries in the Solar System. Basically, other binary asteroids that have been observed orbited closer together, were different in size and mass, had less eccentric orbits, and did not form comet-like tails.

The observed activity of 288P also revealed a great deal about the binary asteroids past. From their observations, the team concluded that 288P has existed as a binary system for the past 5000 years and must have accumulated ice since the earliest periods of the Solar System. As Agarwal explained:

“Surface ice cannot survive in the asteroid belt for the age of the Solar System but can be protected for billions of years by a refractory dust mantle, only a few meters thick… The most probable formation scenario of 288P is a breakup due to fast rotation. After that, the two fragments may have been moved further apart by sublimation torques.”

*Image depicting the two areas where most of the asteroids in the Solar System are found: the Main Asteroid Belt and the Trojans. Credit: ESA/Hubble, M. Kornmesser*

Naturally, there are many unresolved questions about 288P, most of which stem from its unique behavior. Given that it is so different from other binary asteroids, scientists are forced to wonder if it merely coincidental that it presents such unique properties. And given that it was found largely by chance, it is unlikely that any other binaries that have similar properties will be found anytime soon.

“We need more theoretical and observational work, as well as more objects similar to 288P, to find an answer to this question,” said Agarwal. In the meantime, this unique binary asteroid is sure to provide astronomers with many interesting opportunities to study the origin and evolution of asteroids orbiting between Mars and Jupiter.

In particular, the study of those asteroids that show comet-like activity (aka. main-belt comets) is crucial to our understanding of how the Solar System formed and evolved. According to contrasting theories of its formation, the Asteroid Belt is either populated by planetesimals that failed to become a planet, or began empty and gradually filled with planetesimals over time.

In either case, studying its current population can tell us much about how the planets formed billions of years ago, and how water was distributed throughout the Solar System afterwards. This, in turn, is crucial to determining how and where life began to emerge on Earth, and perhaps elsewhere!

Be sure to check out this animation of the 288P binary asteroid too, courtesy of the ESA and Hubble:

Further Reading: Hubble, Nature

September 22, 2017September 22, 2017 by Matt Williams

Scientists Urge Europe to Stick With “Armageddon”-style Asteroid Mission

A computer generated handout image released by the European Space Agency shows the impact of the DART (Double Asteroid Redirection Test) projectile on the binary asteroid system (65803) Didymos. Credit: ESA/AFP

For decades, scientists have known that in near-Earth space there are thousands of comets and asteroids that periodically cross Earth’s orbit. These Near-Earth Objects (NEOs) are routinely tracked by NASA’s Center for Near Earth Object Studies (CNEOS) to make sure that none pose a risk of collision with our planet. Various programs and missions have also been proposed to divert or destroy any asteroids that might pass too closely to Earth in the future.

One such mission is the Asteroid Impact & Deflection Assessment (AIDA), a collaborative effort between NASA and the European Space Agency (ESA). Recently, the ESA announced that it would be withdrawing from this mission due to budget constraints. But this past Wednesday (Sept. 20th), during the European Planetary Science Conference in Riga, a group of international scientists urged them to reconsider.

In addition to NASA and the ESA, AIDA was designed with assistance from the Observatoire de la Côte d´Azur (OCA), and the Johns Hopkins University Applied Physics Laboratory (JHUAPL). To test possible asteroid deflection techniques, the mission intends to send a spacecraft to crash into the tiny moon of the distant asteroid named Didymos (nicknamed “Didymoon”) by 2022 to alter its trajectory.

*Artist’s impression of the path DART will take to reach the asteroid Didymos. Credit: NASA*

This mission would be a first for scientists, and would test the capabilities of space agencies to divert rocks away from Earth’s orbit. NASA’s contribution to this mission is known as the Double Asteroid Redirection Test (DART), the spacecraft which would be responsible for crashing into Didymoon. Plans for this spacecraft recently entered Phase B, having met with approval, but still in need of further development.

The plan was to mount DART on an already planned commercial or military launch, and would then be placed in geosynchronous orbit between December 2020 and May 2021. It would then rely on a NEXT-C ion engine to push itself beyond the Moon and reach an escape point to depart the Earth-Moon system, eventually making its way to Didymos and Didymoon.

Europe’s contribution to the mission was known as the Asteroid Impact Mission (AIM), which would involve sending a small craft close to Didymos to observe the crash and conduct research on the asteroid’s moon. Unfortunately, this aspect of the mission suffered a setback when space ministers from the ESA’s 22 member states rejected a €250 million ($300 million USD) request for funding last December.

However, during the European Planetary Science Congress – which will be taking place from September 17th to 22nd in the Latvian capital of Riga – scientists took the opportunity to advise the mission’s European partners to get back on board. As they emphasized, this mission – which is a dry-run for future asteroid redirect missions – is crucial if space agencies hope to develop the capacity to protect Earth from hazardous NEOs.

ESA’s Asteroid Impact Mission, a candidate mission due for launch in 2020, will map the smaller body of the Didymos binary asteroid system down to 1 m resolution following its arrival in 2022. Credit: ESA

Andrew Cheng from JHUAPL is the project scientist for the DART mission. As he told the AFP at the European Planetary Science Congress, “This is the kind of disaster that could be a tremendous catastrophe.” He also stressed that unlike other natural disasters, an asteroid strike “is something that the world is able to defend. We can do something.”

But before that can happen, the methods need to be further developed, tested and refined. Hence why Didymoon was selected as the target for the AIDA mission. Whereas the meteor that exploded over the Russian town of Chelyabinsk in 2013 was just 20 meters across (65 feet), but still injured 1600 people, Didymoon measures about 160 meters (525 feet) in diameter.

It is estimated that if this asteroid struck Earth, the resulting impact would be as powerful as a 400 megatonne blast. To put that in perspective, the most powerful thermonuclear device ever built – the Soviet Tsar Bomba – had a yield of 50 megatonnes. Hence, the smaller companion of this binary asteroid, if it struck Earth, would have an impact 80 times greater than the most powerful bomb ever built by humans.

In addition to advocating that the ESA remain committed to the mission, European scientists at the conference also proposed an altered, more cost-effective alternative for AIM. This alternative called for a miniaturized version of the AIM craft that would be equipped with just a camera, forgoing a lander and radars designed to probe Didymoon’s internal structure.

*Simulated image of the Didymos system, derived from photometric lightcurve and radar data. Credits: Naidu et al./AIDA Workshop (2016)*

According to Patrick Michel, the science lead for the AIM mission, this revised mission would cost about €210 million ($250 million USD). But as he also noted, this would require that the AIM part of the mission be delayed. While it would still conduct crucial measurements of Didymoon, it would not be part of the AIDA mission if NASA decides to stick with its original timeline.

“The main point of the mission was to measure the mass of the object, because this is how you really measure the deflection,” he said. “Two or three years (after impact), these things won’t change. Of course it’s better… that we have the two at the same time. But we found something I think that still works and allows to relax the very tight schedule.”

In the meantime, Jan Woerner – the head of the European Space Agency – indicated that the ESA would be moving forward with the new proposal when the next ministerial meeting takes place in 2019. As he told the AFP via email:

“It is important for humanity, as a species we have the means today to deflect an asteroid. We know it will happen, one day sooner or later. It’s not a question of if, but when. We have never tested asteroid deflection and there is no way we can test in (the) laboratory. We need to know if our models are correct, (whether) our simulations work as expected.”

In the end, it remains to be seen if the AIDA mission will see one or two missions traveling to Didymoon by 2022. Obviously, it would be better if both mission happened simultaneously, as the AIM mission will be capable of obtaining information DART will not. Much of that information has to do with with studying the effects of the collision up close and as they happen.

But regardless of how this mission unfolds, it is clear that space agencies from around the world are dedicated to developing techniques for protecting Earth from asteroids that pose a collision hazard. Between NASA, the ESA, and their many institutional partners and private contractors, multiple methods are being developed to divert or destroy oncoming space rocks before they hit us.

However, I’m pretty sure not one of them involves sending a bunch of miners with minimal training into space to plant a nuke inside an asteroid. That would just be silly on its face!

And be sure to check out this video that details the AIDA and Asteroid Impact Mission, courtesy of ESA:

Further Reading: AFP

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

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

“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.